WO2025053948A1 - Functional pickering emulsions and methods for making and using the same - Google Patents

Abstract

Embodiments relate to polysaccharides such as amphiphilic hairy cellulose nanocrystals and methods of making and using thereof. The amphiphilic hairy cellulose nanocrystals may dually function as a versatile Pickering stabilizer and as an antiscalant. The amphiphilic hairy cellulose nanocrystals may include hydrophobic alkyl chains and hydrophilic carboxylate groups anchored onto protruding disordered cellulose chains of cellulose bodies. Other groups, such as cationic and/or electrically neutral groups, can be anchored onto protruding disordered chains to impart additional functionality.

Description

FUNCTIONAL PICKERING EMULSIONS AND METHODS FOR MAKING AND USING THE SAME

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims priority to U.S. Provisional Patent Application No. 63/581,087, filed on September 7, 2023. The entirety of this provisional patent application is incorporated by reference herein.

FIELD

[0002] Embodiments relate to compositions and methods for emulsion stabilization and scale inhibition. In particular, embodiments relate to polysaccharides such as amphiphilic hairy cellulose nanocrystals bearing hydrophilic and hydrophobic chemical groups configured to dually function as an emulsion stabilizer and antiscalant and methods for making and using thereof.

BACKGROUND

[0003] Emulsions play a pivotal role in a diverse range of consumer and industrial applications, from cosmetics and foods to oil and gas processes. However, conventional emulsion stabilizers, like surfactants and emulsifiers, pose environmental and health challenges, and their functionalities can be restrictive. Moreover, nucleation and growth of sparingly soluble salts, referred to as scaling, has posed substantial challenges in industrial processes that deal with multiphase flows, including enhanced oil recovery (EOR). During crude oil extraction/recovery, seawater is injected into oil reservoirs and yields water-in-oil (W/O) emulsions that may undergo calcium carbonate (CaCO3) scaling. However, existing antiscaling macromolecules and nanoparticles often have adverse environmental impacts and/or are limited to functioning only in single-phase aqueous media.

[0004] It remains challenging to simultaneously stabilize emulsions and prevent scaling because scale formation may sequester surfactants and destabilize emulsions. There is an unmet need to develop an environmentally friendly emulsion stabilizer that overcomes current functionality restrictions and inhibits scale formation in multiphase media.

SUMMARY

[0005] Designing a bio-based, environmentally safe stabilizer without the use of traditional surfactants is critical for the future of emulsion stabilization. Similarly, developing scale- resistant W/O emulsions is integral for environmental and economic advancement in the oil industry. Design criteria for such a material may include (i) preferential residence at the oil and water interface to function as a stabilizer, and (ii) simultaneous interaction with Ca²⁺ to act as an antiscalant.

[0006] We have found that hairy cellulose nanocrystals (HCNCs) are promising candidates for a stabilizer because of their disordered cellulose chains accommodating a high content of varying functional groups (i.e., one order of magnitude higher than conventional cellulose nanocrystals). Accordingly, we have developed innovative amphiphilic hairy cellulose nanocrystals (AmHCNCs) as a dual functioning Pickering emulsion stabilizer and scale inhibitor in order to address the above-identified needs. The AmHCNCs may feature densely packed hydrophilic and hydrophobic chemical groups anchored onto protruding disordered cellulose chains of hairy cellulose nanocrystals. [0007] Notably, the AmHCNCs may facilitate the creation of exceptionally stable water-in-oil (W/O), water-in-organic solvent, oil-in-water (O/W), and/or organic solvent-in-water Pickering emulsions. The AmHCNCs can also be used to stabilize droplets of polymers dissolved by organic solvents in water to reduce the amount of solvent required for processing water-insoluble polymers and materials, which enables the formation of particles, coatings, and/or bulk materials using non-water-soluble polymers in aqueous environments.

[0008] Additionally, with regard to scale inhibition in multiphase systems, a prevalent type of scale is calcium carbonate (CaCO₃), which emerges due to the interaction of calcium ions with dissolved carbon dioxide, yielding carbonate ions. If the concentration of these ions exceeds a certain limit, various forms of calcium carbonate can precipitate. We have found that the hydrophobic chemical groups anchored onto protruding disordered cellulose chains of hairy cellulose nanocrystals may stabilize organic-aqueous interfaces, and may further work alongside hydrophilic groups to prevent CaCO₃ scaling.

[0009] In an exemplary embodiment, a method of producing an emulsion stabilizer comprises providing polysaccharide bodies, such as cellulose bodies; oxidizing the polysaccharide bodies to provide dialdehyde modified polysaccharide bodies; oxidizing the dialdehyde modified polysaccharide bodies to provide polysaccharide bodies bearing aldehyde and hydrophilic anionic groups; and subjecting the polysaccharide bodies bearing aldehyde and hydrophilic anionic groups to provide polysaccharide bodies bearing hydrophobic alkyl chains and hydrophilic anionic groups. [0010] In some embodiments, the hydrophobic alkyl chains comprise compounds with 8-22 carbons.

[0011] In some embodiments, the hydrophilic anionic groups comprise dicarboxylate.

[0012] In some embodiments, the polysaccharide bodies are cellulose bodies.

[0013] In some embodiments, the cellulose bodies are oxidized with periodic acid or salts thereof.

[0014] In some embodiments, the dialdehyde modified polysaccharide bodies are oxidized with chlorite ions.

[0015] In some embodiments, the method further comprises heating the polysaccharide bodies bearing hydrophobic alkyl chains and hydrophilic anionic groups; sonicating the polysaccharide bodies bearing hydrophobic alkyl chains and hydrophilic anionic groups; and centrifuging the polysaccharide bodies bearing hydrophobic alkyl chains and hydrophilic anionic groups.

[0016] In some embodiments, the content of hydrophobic alkyl chains is between 0.5 and 7 mmol g^-1, and the content of hydrophilic anionic groups is between 0.5 and 7 mmol g^-1.

[0017] In some embodiments, the content of hydrophobic alkyl chains is between 3.2-3.4 mmol g^-1, and the content of hydrophilic anionic groups is between 3.0-3.2 mmol g^-1.

[0018] In some embodiments, the content of hydrophobic alkyl chains and the content of hydrophilic anionic groups are the same.

[0019] In some embodiments, the hydrophilic anionic groups are configured to provide the emulsion stabilizer with antiscaling properties. [0020] In an exemplary embodiment, an emulsion stabilizer is made by a method comprising the steps of providing cellulose bodies; oxidizing the cellulose bodies to provide dialdehyde modified cellulose bodies; oxidizing the dialdehyde modified cellulose bodies to provide cellulose bodies bearing aldehyde and hydrophilic anionic groups; and subjecting the cellulose bodies bearing aldehyde and hydrophilic anionic groups to provide cellulose bodies bearing hydrophobic alkyl chains and hydrophilic anionic groups.

[0021] In some embodiments, the hydrophilic anionic groups and the hydrophobic alkyl chains are attached to cellulose chains protruding from the cellulose bodies.

[0022] In some embodiments, the cellulose bodies are plant-based.

[0023] In some embodiments, the cellulose bodies have a rod-like shape.

[0024] In some embodiments, the cellulose bodies have a length between 10 and 1000 nanometers.

[0025] In some embodiments, the cellulose bodies have a length between 77 and 125 nanometers.

[0026] In some embodiments, the cellulose bodies have a width between 1.5 and 10 nanometers. [0027] In some embodiments, the emulsion stabilizer is configured to create a stable water-in-oil emulsion, a stable water-in-organic solvent emulsion, a stable oil-in-water emulsion, or a stable organic solvent-in-water emulsion.

[0028] In some embodiments, the emulsion stabilizer is configured to maintain stability at concentrations up to 2.0 wt.%. [0029] In an exemplary embodiment, an emulsion stabilizer comprises cellulose bodies comprising cellulose chains protruding from the cellulose bodies; hydrophobic alkyl chains attached to a first portion of the cellulose chains; and hydrophilic alkyl groups attached to a second portion of the cellulose chains.

[0030] Further features, aspects, objects, advantages, and possible applications of the present invention will become apparent from a study of the exemplary embodiments and examples described below, in combination with the Figures, and the appended claims.

BRIEF DESCRIPTION OF THE FIGURES

[0031] The above and other objects, aspects, features, advantages, and possible applications of the present invention will be more apparent from the following more particular description thereof, presented in conjunction with the following drawings. It should be understood that like reference numbers used in the drawings may identify like components.

[0032] FIG. 1 shows an exemplary method of producing the AmHCNCs configured as a dual functioning Pickering emulsion stabilizer and scale inhibitor.

[0033] FIG. 2 shows a schematic illustration of exemplary AmHCNCs configured as a dual functioning Pickering emulsion stabilizer and scale inhibitor.

[0034] FIG. 3 shows a schematic illustration of an exemplary method of synthesizing AmHCNC from a source of cellulose fibrils and/or crystals via consecutive and controlled periodate oxidation (yielding DAMC), partial chlorite oxidation (yielding bifunctional fibrils bearing aldehyde and carboxylate groups), and Schiff base reaction (yielding AmHCNC after heating). [0035] FIG. 4 shows a schematic illustration of an exemplary method of synthesizing S-CNC and AHCNC from a source of cellulose fibrils and/or crystals using H₂SO₄ (65 wt.%) or consecutive periodate oxidation reactions, respectively.

[0036] FIG. 5 is a graph showing representative pH titration of DAMC fibrils to obtain the aldehyde content.

[0037] FIG. 6 is a graph showing representative pH titration of bifunctional cellulose fibrils and/or crystals for the aldehyde content measurement.

[0038] FIG. 7 shows a schematic illustration of alkylation chemistry involving a Schiff base reaction between primary amine groups of octylamine and aldehyde groups of bifunctional cellulose fibrils and/or crystals. The imine bond enables hydrophobic alkyl chain grafting to carboxylate -bearing cellulose fibrils and/or crystals.

[0039] FIG. 8 is a graph showing charge (carboxylate) content of AHCNC and AmHCNC measured via conductometric titration.

[0040] FIG. 9 is a graph showing a representative conductometric titration curve of AHCNC to measure carboxylate content.

[0041] FIG. 10 is a graph showing a representative conductometric titration of AmHCNC to measure the carboxylate content.

[0042] FIG. 11 is an image showing water contact angles for S-CNC, AHCNC, and AmHCNC films, measured at room temperature after 1 s equilibrium. The dashed lines and arrows show the film surface and tangent line of the water droplet, respectively, within the designated region for water contact angle (0) determination. [0043] FIG. 12 shows a schematic illustration of exemplary antiscaling Pickering emulsion enabled by the dual function of AmHCNC: the anionic groups may impair CaCO₃ scaling, and the alkyl groups may contribute to the emulsion stabilization.

[0044] FIG. 13 is a graph showing ζ-potential values of S-CNC, AHCNC, and AmHCNC at pH ~ 8.

[0045] FIG. 14 is a graph showing hydrodynamic equivalent size of S-CNC, AHCNC, and AmHCNC at pH ~ 8.

[0046] FIG. 15 shows an Attenuated Total Reflection-Fourier Transform Infrared (ATR-FT1R) spectra of S-CNC, AHCNC, and AmHCNC. The peaks at 2924 cm"¹ and 2855 cm^-1, correlated to C-H stretching vibrations, confirm the alkyl groups on the AmHCNC.

[0047] FIG. 16 shows representative atomic force microscopy (AFM) images of S-CNC, AHCNC, and AmHCNC. All three nanocelluloses may have a needle-like morphology. The inset presents a magnified view of end-to-end assembled AmHCNC.

[0048] FIG. 17 is a graph showing violin plots for crystal length distribution of S-CNC, AHCNC, and AmHCNC, acquired by analyzing AFM images using ImageJ software. Solid and dashed lines represent median and quartiles, respectively.

[0049] FIG. 18 is a graph showing violin plots for shows crystal width distribution of S-CNC, AHCNC, and AmHCNC obtained by analyzing AFM images of greater than 50 particles using Gwyddion software. Solid and dashed lines represent median and quartiles, respectively.

[0050] FIG. 19 shows x-ray diffraction (XRD) diffractograms of S-CNC, AHCNC, and

AmHCNC. [0051] FIG. 20 is a graph showing CI values of S-CNC, AHCNC, and AmHCNC, assessed by the XRD spectroscopy.

[0052] FIG. 21 shows a schematic illustration of AmHCNC-stabilized W/O Pickering emulsions generated using a flow focusing microfluidic device.

[0053] FIG. 22 shows optical microscopy images of W/O Pickering emulsions, containing varying AmHCNC concentrations at varying incubation times. The most stable emulsion was formed at an AmHCNC concentration of 1.00 wt. %. Scale bars are 100 μm.

[0054] FIG. 23 is a graph showing ζ-potentials (pH ~ 8) at varying initial AmHCNC concentrations.

[0055] FIG. 24 is a graph showing hydrodynamic sizes of AmHCNC at varying initial AmHCNC concentrations.

[0056] FIG. 25 is a graph showing interfacial tension of aqueous and oil phases in W/O emulsions stabilized by varying AmHCNC concentrations. The most stable W/O emulsions were stabilized by 1.0 wt.% of AmHCNC, which is associated with the surface coverage of ~51% and the lowest interfacial tension.

[0057] FIG. 26 shows pendant droplet images of varying AmHCNC concetrations (0.25, 0.5, 1.0, and 2.0 wt.%).

[0058] FIG. 27 shows optical microscopy images of W/O emulsions, stabilized by AmHCNC (1.0 wt.%) at varying Ca²⁺ concentrations and incubation times, showing a Ca²⁺ concentration higher than 1 mM destabilizes the emulsions. Scale bars are 100 pm. [0059] FIG. 28 is a graph showing electrophoretic mobility of AmHCNC at varying Ca²⁺ concentrations.

[0060] FIG. 29 is a graph showing hydrodynamic equivalent size of AmHCNC at varying Ca²⁺ concentrations.

[0061] FIG. 30 shows a schematic illustration of a destabilization process of W/O emulsions stabilized by AmHCNC containing 10 mM Ca²⁺.

[0062] FIG. 31 shows optical microscopy images of Span 80-stabilized W/O emulsions, containing varying Ca²⁺ concentrations in aqueous phase, versus incubation time (Span 80 concentration = 1.0 wt.%, scale bars are 100 pm).

[0063] FIG. 32 shows optical microscopy images of CaCO₃ scales in W/O emulsions, stabilized by Span 80 or AmHCNC at varying S Scale bars are 100 pm.

[0064] FIG. 33 shows photographs of AmHCNC (1.00 wt.%) -stabilized W/O Pickering emulsions without (5=0) and with (S ~ 143) at 5 minutes and 24 hours of preparation.

[0065] FIG. 34 is a graph showing mass of CaCO₃ scales formed in W/O emulsions, stabilized by Span 80 or AmHCNC at varying 5.

[0066] FIG. 35 shows pendant drop images of AmHCNC (1.0 wt.%) dispersion containing varying Ca²⁺ concentrations (0-24.9 mM) with or without CO₃ ^2- (4.5 mM) injected in hexadecane, and a pendant drop image of Milli-Q water in Span 80 (1.0 wt.%)-containing hexadecane.

[0067] FIG. 36 is a graph showing the effect of Ca²⁺ concentration on the water-oil interfacial tension, without or with CO₃ ^2- (4.5 mM) in the AmHCNC-containing aqueous phase. The dashed line shows the interfacial tension (4.0 ± 0.1 mM m^-1) of aqueous and oil phases in Span 80- stabilized emulsions. Note that the concentration of Span 80 or AmHCNC = 1.0 wt.%.

[0068] FIG. 37 shows time to break AmHCNC-stabilized W/O Pickering emulsions containing varying Ca²⁺ concentrations with and without CO₃ ^2-. (AmHCNC concentration = 1.0 wt.%).

[0069] FIG. 38 shows scanning electron microscope (SEM) images of CaCO₃ scale formation in Span 80-stabilized W/O emulsions.

[0070] FIG. 39 shows SEM images of CaCO₃ scale formation in AmHCNC -containing aqueous solutions.

[0071] FIG. 40 shows SEM images of CaCO₃ scale formation in AmHCNC-stabilized W/O emulsions.

[0072] FIG. 41 shows XRD spectra of CaCO₃ polymorphs in Span 80-stabilizcd emulsions.

[0073] FIG. 42 shows XRD spectra of CaCO₃ polymorphs in AmHCNC -containing aqueous solution.

[0074] FIG. 43 shows XRD spectra of CaCO₃ polymorphs in AmHCNC-stabilized emulsions.

DETAILED DESCRIPTION OF THE INVENTION

[0075] The following description is of an embodiment presently contemplated for carrying out the present invention. This description is not to be taken in a limiting sense but is made merely for the purpose of describing the general principles and features of the present invention. The scope of the present invention should be determined with reference to the claims. [0076] In the present description, the term “emulsion” is used to describe a macroscopically homogeneous but microscopically heterogeneous mixture of two or more immiscible phases. [0077] In the present description, the term “Pickering emulsion” is used to describe an emulsion that is stabilized by particles in colloidal suspension located at a water/oil interface. Such particles may be referred to herein as “Pickering stabilizers.”

[0078] In the present description, the term “scale” is used to describe a crystalline mineral salt deposited onto a surface. Accordingly, the term “scale inhibitor” or “antiscalant” is used to describe a material configured to hinder or prevent the formation of a crystalline mineral salt. [0079] As seen in FIG. 2, embodiments generally relate to compositions and methods for emulsion stabilization and scale inhibition. Exemplary compositions may comprise polysaccharides, such as amphiphilic hairy cellulose nanocrystals (AmHCNCs) bearing hydrophilic and hydrophobic chemical groups and configured to dually function as an emulsion stabilizer and antiscalant and methods for making and using thereof.

[0080] The AmHCNCs may comprise cellulose (polysaccharide) bodies, such as cellulose fibrils and/or crystals. In some embodiments, the cellulose bodies may nanoscale (e.g., less than 100 nanometers in size) bodies. For example, the cellulose bodies may be nanofibrils and/or nanocrystals. It is contemplated that the cellulose bodies may be derived from any suitable source. In preferred embodiments, the cellulose bodies may be biosourced (e.g., derived from biomass). For example, the cellulose bodies may be plant-based, such as derived from wood pulp, cotton, algae, or any other suitable plant-base source. It is further contemplated that the cellulose bodies may be non-toxic and and/or biodegradable. [0081] The cellulose bodies may have a plurality of cellulose chains (also referred to as “hairs”) protruding from their ends. The cellulose chains may be configured to be functionalized with one or more chemical groups. The cellulose chains may be disordered such that they are configured to accommodate a high content of chemical groups.

[0082] In an exemplary embodiment, a portion of the cellulose chains may be functionalized with hydrophobic alkyl chains. The hydrophobic alkyl chains may include any alkyl chain with 8-22 carbon atoms. It is contemplated that the hydrophobic alkyl chains may all have the same number of carbon atoms, or the hydrophobic alkyl chains may have any different numbers of carbon atoms. The hydrophobic alkyl chains may be attached to any functional groups, such as amines (-NH₂), carboxylates (-COO"), etc., to facilitate functionalization of the cellulose chains. It is contemplated that the hydrophobicity of the alkyl chains may impart wettability properties to the AmHCNCs, thus enabling the AmHCNCs to form Pickering emulsions by residing at the water-oil interface. Moreover, it is contemplated that AmHCNCs may serve as versatile Pickering stabilizers and facilitate the creation of stable water-in-oil (W/O), water-in-organic solvent, oil-in-water (O/W), and/or organic solvent-in-water Pickering emulsions. In an exemplary embodiment, the hydrophobic alkyl chains may be functionalized to the cellulose chains via a Schiff base reaction.

[0083] In an exemplary embodiment, a portion of the cellulose chains may be functionalized with hydrophilic anionic groups. The hydrophilic anionic groups may be selected from the group consisting of carboxylates, dicarboxylates, sulfates, or any other suitable anionic group. It is contemplated that the hydrophilic anionic groups may impart antiscaling properties to the AmHCNCs, thus enabling the AmHCNC to be used as scale inhibitors. In exemplary embodiments, the hydrophilic anionic groups may be functionalized to the cellulose chains via a chlorite oxidation reaction.

[0084] As can be appreciated from the above, one portion of the cellulose chains may be functionalized with hydrophobic alkyl chains and another portion of the cellulose chains may be functionalized with hydrophilic anionic groups, such the AmHCNCs may have functionality as both a Pickering stabilizer and an antiscalant. In such embodiments, the concentrations of the hydrophobic alkyl chains and hydrophilic anionic groups functionalized on the cellulose chains may be the same or approximately the same. It is contemplated that the concentration of the alkyl chains functionalized on the cellulose chains may be 0.5-7 mmol g^-1, preferably approximately 3.2-3.4 mmol g^-1, and the concentration of the anionic groups functionalized on the cellulose chains may be 0.5-7 mmol g’¹, preferably approximately 3.0-3.2 mmol g^-1.

[0085] In other embodiments, a portion of the cellulose chains may be functionalized with additional chemical groups, such as cationic and/or electrically neutral groups, to impart additional functionality to the AmHCNCs.

[0086] The AmHCNCs may be any shape and/or size, though it is contemplated that the AmHCNCs may be rod-like or needle-like structures with lengths in the range of 10-1000 nm, preferably 77-125 nm, and widths (e.g., diameters) in the range of 1.5-10 nm. Advantageously, the cellulose bodies are elongated in shape; that is, having a length/width ratio higher than 1. [0087] It is contemplated that the AmHCNCs may have improved wettability properties in comparison to other nanocelluloses. The AmHCNCs may have a contact angle between 51.4 and 72.4 degrees.

[0088] It is contemplated that the AmHCNCs may remain stable at weight percentages up to 2.0 wt.%, preferably up to 1.0 wt.%. For example, the AmHCNCs may remain stable for at least 120 min. at a weight percentage of 1.0 wt.%.

[0089] It is contemplated that the AmHCNCs have a hydrodynamic equivalent size ranging from 269-281 nm.

[0090] Methods of preparing the AmHCNCs may generally comprise at least a periodate oxidation step, a chlorite oxidation step, and an alkyl amination (i.e., Schiff base reaction) step. [0091] As seen in FIG. 1, exemplary embodiments, the method may comprise providing cellulose bodies, such as cellulose fibrils and/or crystals. As mentioned above, the cellulose bodies may be derived from any suitable source.

[0092] The method may further comprise oxidizing the cellulose bodies (e.g., with periodic acid or its salts) to synthesize dialdehyde modified cellulose (DAMC). It is contemplated that the cellulose bodies may have vicinal diols (adj acent hydroxyl groups) in their structures, and this oxidation step may cleave the carbon-carbon bond between the diols, resulting in the formation of aldehydes. This step may be used to selectively oxidize the diols without affecting other functional groups present in the molecule. It is therefore contemplated that the DAMC may comprise reactive aldehyde groups that may be subject to further processing. [0093] In exemplary embodiments, the method may further comprise oxidizing the DAMC (e.g., with chlorite ions) to synthesize DAMC modified with anionic groups. It is contemplated that this step may be carried out in acidic conditions and may result in the formation of chlorate ions as the primary oxidation product. In preferred embodiments, this step may be carried out such that half or approximately half of the reactive aldehyde groups of the DAMC are converted to anionic groups. As described above, it is contemplated that anionic groups may impart antiscaling properties to the molecules, thus enabling the resulting AmHCNCs to be used as scale inhibitors. This chlorite oxidation step may therefore be critical in achieving the antiscaling properties of the AmHCNCs.

[0094] In some embodiments, as seen in FIG. 3, the chlorite oxidation step may comprise adding DAMC to a solution comprising NaCIO₂, and H₂O₂ may then be added (dropwise) to form DAMC modified with a desired amount of anionic groups.

[0095] In exemplary embodiments, the method may further comprise subjecting the remaining reactive aldehyde groups to alkyl amination, thus yielding cellulose bodies bearing both anionic groups and alkyl chains. It is contemplated that alkyl amination may involve introducing an alkyl group to the molecule by replacing a hydrogen atom with the alkyl group, thus resulting in the formation of an alkylamine. As described above, it is contemplated that alkyl chains may impart stabilizing properties to the molecules, thus enabling the resulting AmHCNCs to be used as Pickering stabilizers. This alkyl amination step may therefore be critical in achieving the antiscaling properties of the AmHCNCs. In some embodiments, the alkyl amination step may comprise subjecting the remaining reactive aldehyde groups of the cellulose bodies to a Schiff base rection (see FIG. 7). In preferred embodiments, half or approximately half of the reactive aldehyde groups of the DAMC are converted to anionic groups, and half or approximately half of the reactive aldehyde groups of the DAMC are converted to alkyl chains.

[0096] In some embodiments, as seen in FIG. 3, this step may comprise suspending the modified DAMC in DI water, adding alkyl chains, and stirring the resulting mixture. The product may be collected and dialyzed. The product may then be heated, sonicated (e.g., using a probe sonicator) in an ice bath, and centrifuged to remove un-fibrillated fibrils. An AmHCNC- containing supernatant may then be finally separated from the mixture.

[0097] In some embodiments, the method may further comprise functionalizing a portion of the reactive aldehyde groups with additional chemical groups, such as cationic and/or electrically neutral groups, to impart additional functionality to the AmHCNCs.

[0098] Exemplary methods of using the above-described AmHCNCs may include using the AmHCNCs in oil and gas operations. For example, it is contemplated that the AmHCNCs comprises dual-functionality and may (i) form Pickering emulsions via residing at the water-oil interface (enabled by the alkyl chains) while also (ii) impairing scaling in the aqueous phase (enabled by decarboxylated hairs). Exemplary methods of using the above-described AmHCNCs may further include using the AmHCNCs in cosmetic applications. It is contemplated that the AmHCNCs may effectively stabilize emulsions, resulting in cosmetic products with a smoother (e.g., less gritty) appearance and feel. Exemplary methods of using the above-described AmHCNCs may further include using the AmHCNCs in food applications. However, it should be understood that the above are only exemplary uses for the described AmHCNCs, and uses of the AmHCNCs are not limited to these listed examples.

EXAMPLES

[0099] Below are examples of specific embodiments for carrying out the present application.

The examples are offered for illustrative purposes only, and are not intended to limit the scope of the present application in any way. Efforts have been made to ensure accuracy with respect to numbers used (e.g., amounts, temperatures, etc.), but some experimental error and deviation should, of course, be allowed for.

[00100] T o assess the simultaneous Pickering stabilization and scale inhibition capability of nanocelluloses, AHCNC and AmHCNC were synthesized, and S-CNC was purchased.

[00101] FIG. 4 presents common synthesis pathways for S-CNC or AHCNC involving the strong acid hydrolysis or sequential oxidation of cellulose fibrils, respectively. Sulfuric acid ( H₂SO₄, 65 wt %)-mediated hydrolysis of cellulose fibrils at 45°C for 45 minutes removes the disordered regions and yields negatively charged S-CNC, bearing sulfate half-ester groups, as shown in FIG. 4. HCNC synthesis involves the conversion of cellulose fibrils to dialdehyde modified cellulose (DAMC) fibrils via NalO₄-mediated oxidation. DAMC fibrils undergo further oxidation using NaCIO₂ to functionalize disordered cellulose regions with dicarboxylate groups and partially solubilize them, yielding AHCNC and DCC chains, which are then separated from each other via EtOH-mediated precipitation, as presented in FIG. 4. A representative pH titration curve of DAMC fibrils is shown in FIG. 5, indicating the amount of NaOH required to neutralize the HC1 released from the hydroxylamine-aldehyde reaction. Accordingly, the DAMC aldehyde content was 6.3 ± 0.1 mmol g^-1.

[00102] FIG. 3 presents the 3-step synthesis pathway of AmHCNC, including consecutive periodate oxidation, chlorite oxidation, and Schiff base reaction. To synthesize AmHCNC, half of the DAMC aldehyde groups (i.e., ~ 3 mmol g^-1) were subjected to chlorite oxidation, yielding bifunctional cellulose fibrils and/or crystals, bearing both aldehyde and dicarboxylate groups. The aldehyde content of bifunctional cellulose fibrils was ~3.3 ± 0.3 mmol g^-1, measured via pH titration, as shown in FIG. 6 for a representative sample. The aldehyde groups on bifunctional cellulose fibrils were then reacted with the primary amine group of octylamine via a Schiff base reaction to form amphiphilic cellulose fibrils, as shown in FIG. 7. The charge content of AHCNC and AmHCNC is shown in FIG. 8, indicating that the carboxylate group content of AmHCNC is lower than the AHCNC as the DAMC aldehyde groups were partially converted to carboxylate groups during 4AmHCNC synthesis. FIGS. 9 and 10 show representative curves for the conductometric titration of AHCNC and AmHCNC, respectively. The carboxylate group content was calculated from the NaOH volume required to neutralize the carboxylic acid (i.e., weak acid), resulting in 5.3 ± 0.1 mmol g^-1 for AHCNC and 3.1 ± 0.1 mmol g^-1 for AmHCNC. Almost 90% of DAMC aldehyde groups were converted to carboxylate groups to form AHCNC.

However, in AmHCNC synthesis, only ~50% of DAMC aldehyde groups were converted to carboxylate groups. The content of alkyl groups (~3.3 mmol g^-1) was then estimated by subtracting the remaining aldehyde groups on AmHCNC (FIG. 6) from the remaining aldehyde groups on bifunctional cellulose fibrils. [00103] To examine the wettability of nanocelluloses bearing hydrophilic and/or hydrophobic functional groups, FIG. 11 presents the water contact angle on S-CNC, AHCNC, or AmHCNC films in air. The AmHCNC had a higher contact angle (61.9 ± 10.5°) compared with S-CNC (24.3 ± 0.3°) and AHCNC (29.8 ± 0.6°), showing that the grafted alkyl chains increased the film hydrophobicity. FIG. 12 schematically shows the dual-functionality of AmHCNC, forming Pickering emulsions via adsorbing to the water-oil interface, mediated by the alkyl chains, while impairing CaCO₃ scaling in the aqueous phase, enabled by the dicarboxylate- modified cellulose chains (hairs).

[00104] T o compare the colloidal behavior of hairy and non-hairy nanocelluloses, the ζ,- potential and hydrodynamic equivalent size were measured in Milli-Q water (pH ~ 8, adjusted using NaOH), as presented in FIGS. 13 and 14. AHCNC had the highest ζ-potential (-51 ± 2 mV) compared with S-CNC (-35 ± 2 mV) and AmHCNC (-36 ± 2 mV) as it bears the highest content of charged groups (5.9 ± 0.1 mmol of carboxylate g^-1). The ζ-potential of AHCNC agreed with the values reported for AHCNC with a carboxylate content of ~5~6 mmol g^-1, i.e., up to -70 mV. AmHCNC had the largest hydrodynamic equivalent size (275 ± 6 nm) compared with S-CNC (126 ± 5 nm) and AHCNC (131 ± 6 nm) likely because of the grafted, long alkyl chains on the protruding hairs, which facilitate supramolecular hydrophobic interactions.

[00105] To identify the characteristic functional groups of nanocelluloses, ATR-FTIR spectra were obtained. FIG. 15 presents the ATR-FTIR spectra of S-CNC, AHCNC, and AmHCNC. In the spectra of all three nanocelluloses, characteristic peaks of cellulose at ~3300 and ~2900 cm^-1 were observed, corresponding to O-H and C-H stretching vibrations, respectively. In addition, the peaks at ~ 1410, ~ 1300, and —1000 cm^-1 in the spectra of all nanocelluloses were assigned to CH₂ scissor bending, O-H bending, and CH2-O-CH2 stretching vibrations in the cellulose structure, respectively. The S-CNC spectrum had a peak at 868 cm^-1, which corresponds to the symmetrical C-O-S vibrations of sulfate half-ester groups introduced during H2SO4 hydrolysis. In the spectra of both AHCNC and AmHCNC, a peak was observed at ~1600 cm^-1 representing the C=O stretching vibrations of carboxylate groups. This confirmed the successful introduction of dicarboxylate groups via chlorite oxidation. For AmHCNC, the grafting of eight-carbon alkyl chains was reflected in the strong peaks at 2924 and 2855 cm^-1, corresponded to asymmetric and symmetric-CH2- stretching vibrations, respectively. Together, the FTIR spectra show that the aliphatic chains were successfully grafted to AmHCNC, which also bear dicarboxylate groups.

[00106] The morphology and dimensions of nanocelluloses were examined using AFM imaging. FIG. 16 shows the representative AFM images of S-CNC, AHCNC, and AmHCNC. All three nanocellulose had a rod- or needle-like morphology, which was consistent with the reported nano-celluloses isolated via oxidation or acid hydrolysis reactions. Notably, AFM images of AmHCNC show some end-to-end assembled particles, which may be a result of interparticle hydrophobic interactions, induced by grafted alkyl chains on the hairs. FIG. 17 presents the length of nanocellulose crystalline body, obtained via analyzing the AFM images of >50 particles using the ImageJ software (Version 1.53t 24). The average crystal lengths of S-

CNC, AHCNC, or AmHCNC were 108 ± 32, 84 ± 25, or 104 ± 27 nm, respectively. Note that

AFM imaging captures the crystalline body of nano-celluloses, and visualizing protruding, disordered chains is not trivial. Indirect evidence of amorphous chains (hairs) is discussed in our previous publications. The width of nanocellulose crystalline body, determined by AFM imaging (FIG. 18), is 8 ± 4 nm for S-CNC, 3 ± 1 nm for AHCNC, and 2.5 ± 1.0 nm for AmHCNC. The higher width of S-CNC may be a result of colloidal aggregation originating from low charge density.

[00107] To investigate the crystallinity of hairy and non-hairy nanocelluloses, XRD patterns were acquired, and the corresponding crystallinity index (CI) values were calculated. FIG. 19 shows the X-ray diffractograms of S-CNC, AHCNC, and AmHCNC. The diffractograms of all nanocelluloses included the cellulose I_β characteristic peaks, i.e., the (110), (110), and (200) crystalline planes. This confirms that the crystalline regions of cellulose fibrils were preserved following oxidation or acid hydrolysis reactions. FIG. 20 presents the CI of S-CNC, AHCNC, and AmHCNC, which was —90% for all three nanocelluloses without any significant differences. The CI of softwood kraft pulp used for the synthesis of cellulose micro- and nanoparticles was ~79%. The higher CI values for the nanocelluloses may be associated with the partial removal of disordered regions. The CI values agreed with those previously reported for S- CNC (-90%) and AHCNC (-91%).

[00108] Assessing AmHCNC as a Pickering Stabilizer: To generate stable W/O Pickering emulsions, an aqueous phase containing S-CNC, AHCNC, or AmHCNC (concentration = 0.25-2.00 wt %) was used. FIG. 21 presents a schematic of W/O emulsion preparation using a three-dimensional (3D) printed flow focusing microfluidic device. Droplets with a diameter of 115 ± 5 pm were formed via pinching the aqueous phase with an oil phase (hexadecane). Neither the S-CNC nor AHCNC were able to form stable W/O emulsions likely because of their highly hydrophilic surface. The crystalline part of S-CNC or AHCNC may be adsorbed at the water-oil interface; however, the sulfate half-ester groups of CNC or dicarboxylate groups of AHCNC favor the nanoparticles to stay in the aqueous phase, hindering their adsorption at the interface. Note that the wettability of intact nanocellulose (i.e., crystalline body) corresponds to the (200)|3/(220)a hydrophobic edge plane. CNC-stabilized Pickering emulsions reported in the literature have been prepared by intensive homogenization or sonication techniques in which the size of droplets was much smaller (~ 1 pm) than the emulsion droplets generated by the flow focusing device here (~ 115 pm). The reduced size of dispersed droplets leads to a higher curvature and thus higher Laplace pressure, which is defined as the pressure difference between the inside and outside of a droplet. Indeed, for the small, highly curved droplets in the emulsification process, additional energy is needed to overcome the pressure in the droplets. Hence, the large droplets, i.e., those generated in this example, with lower Laplace pressure, are easier to break and more likely to become unstable. Grafting hydrophobic alkyl chains increases the AmHCNC wettability by oil phase, as supported by an increase in contact angle (~62°) compared with AHCNC (~30°). Hydrophobic emulsifiers (e.g., Span 80, hydrophile-lipophile balance HLB = 4.3) or Pickering stabilizers (e.g., hydrophobic silica particles) prevent the coalescence of water droplets in W/O emulsions. FIG. 22 shows the optical microscopy images of W/O Pickering emulsions, stabilized using varying AmHCNC concentrations over time. By increasing the AmHCNC concentration from 0.50 to 1.00 wt %, the emulsions remained stable from ~5 min up to ~ 120 min, whereas using 2.00 wt % of AmHCNC, the emulsions were destabilized in ~10 min. The W/O emulsions were unstable when the initial AmHCNC concentration was below 1.00 wt % because of insufficient/low surface coverage of water droplets by the nanoparticles. The surface coverage (C) was calculated from the ratio of theoretical maximum surface of AmHCNC in the emulsion to the total surface of dispersed water droplets, using Equation (1):

[00109] where m_p denotes the AmHCNC mass (0.0025, 0.0050, 0.0100, and 0.0200 g for 0.25, 0.50, 1.00, and 2.00 wt % of AmHCNC, respectively), D denotes the average droplet diameter (115 pm), h denotes the AmHCNC thickness (2.5 nm, obtained from AFM height images), p denotes the AmHCNC density (1.5 g cm^-3), and V denotes the volume of water droplets dispersed in the W/O emulsion (1 cm³). The surface coverage for emulsions stabilized by 0.25, 0.50, 1.00, and 2.00 wt % of AmHCNC were 13%, 26%, 51%, or —100%, respectively. The 51% surface coverage achieved for 1.00 wt % of AmHCNC, resulting in the most stable emulsions, was close to the minimum value of ~ 60% reported in previous literature for stabilizing Pickering emulsions. At AmHCNC concentration higher than 1.00 wt.% (e.g., 2.00 wt %), an excessive number of grafted alkyl chains may trigger colloidal aggregations in droplets via hydrophobic interactions, causing droplet coalescence.

[00110] To investigate the colloidal stability of AmHCNC at concentrations corresponding to those used in generating the Pickering emulsions, FIGS. 23 and 24 present the

(ζ-potential and the hydrodynamic equivalent size of AmHCNC at concentrations ranging from 0.25 to 2.00 wt %, respectively. The AmHCNC ^-potential was - 36 mV (pH = 8, ionic strength ~3 mM), which remained almost unchanged at varying AmHCNC concentrations, and the hydrodynamic size increased from ~250 to ~470 nm by increasing AmHCNC concentration from 0.25 to 1.00 wt %. Precipitates were formed when the AmHCNC concentration reached 2.00 wt %. The increase in the hydrodynamic size may be a result of AmHCNC aggregation, induced by the hydrophobic interactions among alkyl groups. This is in accordance with the lack of Pickering stability at an AmHCNC concentration of 2.00 wt %.

[00111] To assess the surface wettability of AmHCNC by oil and water, FIGS. 25 and 26 present the interfacial tension between the aqueous and oil phases at varying AmHCNC concentrations and representative images of pendant droplets, respectively. Note that the interfacial tension of water and hexadecane is 52 mM m^-1. By increasing the AmHCNC concentration from 0.25 to 1.00 wt %, the interfacial tension decreased from 41 ± 2 to 29 ± 4 mN m^-1, followed by an increase to 37 ± 2 mN m^-1 at 2.00 wt % of AmHCNC. The lowest interfacial tension was obtained at 1 .00 wt % of AmHCNC corresponding to the most stable emulsions, as shown in FIG. 22. The alkyl chains grafted to AmHCNC increased the oil wettability of nanoparticles, likely reducing the interfacial tension. While interfacial tension reduction by AmHCNC plays a role in emulsion stabilization, steric stabilization originated from the AmHCNC crystalline body and the cellulose hairs as well as electrostatic stabilization as a result of anionic functional groups of hairs may significantly contribute to the Pickering stabilization. Accordingly, AmHCNC may also enable Pickering emulsions via the electrosteric stabilization of water droplets, dispersed in the oil phase. [00112] CaCO₃ Scale Mitigation in the AmHCNC-Stabilized Pickering Emulsions: To understand how CaCO₃ scale interacts with AmHCNC in W/O emulsions, we first study the stability of AmHCNC -generated Pickering W/O emulsions at varying Ca²⁺ concentrations without scaling. FIG. 27 presents the optical microscopy images of W/O Pickering emulsions, stabilized by AmHCNC (1.00 wt %) at Ca²⁺ concentrations ranging from 0 to 62.2 mM over 1 week (168 h). As observed in the figure, the emulsions became significantly less stable by increasing the Ca²⁺ concentration. To investigate the colloidal interactions between Ca²⁺ and AmHCNC, FIGS. 28 and 29 present the electrophoretic mobility and the hydrodynamic equivalent size of AmHCNC at varying Ca²⁺ concentrations (pH = 8), respectively. The electrophoretic mobility changed from a negative value to ~0, and the size of predominant, nonprecipitated particles increased from 275 ± 6 nm to >5 μm by increasing the Ca²⁺ concentration from 0 mM to 124.4 mM. This implies that the Ca²⁺ neutralizes the negative charges on AmHCNC, resulting in nanoparticle bridging and aggregation. FIG. 30 schematically presents the evolution of a W/O Pickering emulsion, containing AmHCNC and Ca²⁺, over time. Ca²⁺ bridges AmHCNC, leading to colloidal aggregation and emulsion destabilization. Droplet coalescence was observed at day 3, and phase separation was observed after 7 days. As a control group, FIG. 31 presents the electrically neutral Span 80-stabilized W/O emulsions at varying Ca²⁺ concentrations, demonstrating stable emulsions without undergoing coalescence for at least 1 week.

[00113] To investigate the antiscaling properties of AmHCNC-stabilized W/O Pickering emulsions, CaCO₃ scaling was initiated by mixing CaCH and NaHCO₃ solutions in the aqueous phase of W/0 emulsions. FIG. 32 presents the optical microscopy images of aqueous droplets stabilized by Span 80 or AmHCNC in the oil, undergoing CaCO₃ scaling at varying S over time. As can be seen in this figure, there were less scale particles formed in the emulsions stabilized by AmHCNC than Span 80 at S ~ 101, and the AmHCNC-enabled Pickering emulsions were stable at all experimented S ~ 101, 124, or 143 for up to 24 h. In FIG. 33, photos of AmHCNC- stabilized W/O emulsions without or with scales (S ~ 143) 5 min and 24 h after preparation were shown as representatives. FIG. 34 presents the mass of CaCOi formed in the W/O emulsions stabilized by Span 80 (at S ~ 101) or by AmHCNC (at S ~ 101, 124, or 143) after 4 h and 1 day of incubation at room temperature. The CaCO₃ mass after 4 h was almost the same as that after 1 day in all samples, indicating that 4 h of incubation was sufficient to reach the maximum CaCO₃ crystal formation at the selected initial ion concentrations. Stoichiometrically, the initial Ca²⁺ (12.4 mM) and CO3 2- (4.5 niM) result in 454 mg L-1 CaCO₃ (4.5 mmol L^-1 x MW of CaCO₃ = 100 mg mmoL^-1), assuming the complete dissociation of HCO3- to CO₃ ^2- and that CO₃ ^2- is the limiting species. In this work, 140 mL of the aqueous solution was collected, theoretically yielding 64 mg of CaCO₃, which is close to the CaCO₃ mass in the control group i.e., Span 80- stabilizcd emulsion (57 ± 6 mg). The introduction of AmHCNC reduced the CaCO₃ mass by a factor of 5 compared with Span 80 at S ~ 101, showing the significant antiscaling efficacy of AmHCNC. Notably, the CaCO₃ mass in AmHCNC-stabilized W/O Pickering emulsions at S ~ 143 remained significantly lower (by a factor of 2) than that in the Span 80-stabilized scaling emulsion with a lower S' (S ~ 101), showing the remarkable antiscaling performance of AmHCNC without compromising Pickering stabilization. The antiscaling mechanism is associated with AmHCNC role as a threshold inhibitor, which at the ppm level interferes with the nucleation and growth of early stage CaCO₃ crystals via the electrostatic interactions between the anionic carboxylate groups on its hairs and Ca²⁺ in CaCO₃.

[00114] The wettability of AmHCNC by oil and water in the presence of scale-forming ions was also examined. FIGS. 35 and 36 present the interfacial tension of aqueous phase-oil phase, used in the AmHCNC-stabilized W/O Pickering emulsions, as well as the corresponding pendant droplets at varying concentrations of Ca²⁺ without or with CO₃ ^2- (4.5 mM), respectively. By increasing Ca²⁺ concentration from 0 to 24.9 mM in the absence of CO₃ ^2-, the interfacial tension increased from 29 ± 4 to 43 ± 4 mN m^-1. The increase in interfacial tension may be a result of electrostatic interactions between Ca²⁺ and AmHCNC dicarboxylate groups, leading to mHCNC aggregation (as shown in FIG. 29) and partially inhibiting the individual nanoparticles from residing at the water-oil interface. However, by increasing the Ca²⁺ from 0 to 24.9 mM in the presence of CO₃ ^2- , the interfacial tension remained almost constant at 31 ± 4 mN m^-1. The coaddition of Ca²⁺ and CO₃ ^2- lowered the interfacial tension compared with the addition of Ca²⁺ only. This is possibly because of the reduction of free Ca²⁺ concentration, diminishing the AmHCNC aggregation and bridging, thus AmHCNC adsorb at the interface, resulting in more stable emulsions and a lower interfacial tension (31 ± 4 mN m^-1).

[00115] To further quantify emulsion stability, FIG. 37 presents the time to break AmHCNC-enabled W/O Pickering emulsions at varying Ca²⁺ concentrations without or with CO₃ ^2- (4.5 mM). In the non-scaling emulsions (i.e., without CO₃ ^2-), the incubation time to break the emulsions decreased from ~76 to ~42 h by increasing the Ca²⁺ concentration from 10 to 20 mM as a result of Ca²⁺'mediated AmHCNC aggregation. Notably, the time to break the emulsions remained almost unchanged (~ 150 h) in the scaling system (i.e., with both Ca²⁺ and CO₃ ^2-), implying that the coexistence of Ca²⁺ and CO₃ ^2- reduced the concentration of free Ca²⁺ that would otherwise bridge AmHCNC and compromise the emulsion stability. Together, the dual functional AmHCNC not only impaired CaCO₃ scale fomiation but also imparted Pickering stability to the emulsion.

[00116] In Table 1 , AmHCNC is compared with other previously-used nano-celluloses used to form Pickering emulsions. AmHCNC at a concentration of 1.00 wt % stabilized W/O emulsions for 1 week, which is comparable to the stability reported for other nanocelluloses. Additionally, AmHCNC is the only nanocellulose that enables scale reduction in the emulsions, performing simultaneously as a “scale inhibitor” and an “emulsion stabilizer.”

Table 1: Comparison of AmHCNC with other nanocelluloses stabilizing Pickering emulsions Emulsion Emulsification Concentration Stability Nanocellulose type technique (wt.%) period

Flow focusing

AmHCNC W/O microfluidic 1 1 week device n-butylamino-CNC O/W Homogenizers 0.5 30 min Deep eutectic solvent-treated O/W Homogenizers 0.1 6 weeks CNC S-CNC O/W Sonication 0.1 4 weeks

Quaternary

No value alkylammonium- W/O Sonication 0.4 reported CNC

Aminoguanidine-

O/W Sonication 0.5 8 weeks

CNC

Octylamine-CNC O/W Sonication 35 72 h Bacterial cellulose O/W Sonication 1 10 h

[00117] CaCOs Scale Polymorphs: The effect of AmHCNC on the polymorphs of CaCO₃ scale, formed in aqueous solutions or W/O Pickering emulsions, was investigated. FIGS. 38-40 present the SEM images of CaCO₃ scales formed in the Span 80 (1.00 wt %)-containing W/O emulsion, AmHCNC (1.00 wt %)-containing aqueous solution, and AmHCNC-stabilized W/O Pickering emulsion, respectively. The CaCO₃ scales in the Span 80-containing medium had a typical calcite structure, whereas the CaCO₃ scales in an AmHCNC -containing medium had both calcite and vaterite structures.

[00118] To assess the CaCO₃ crystal structure, FIGS. 41-43 present the XRD patterns of CaCO₃ scales formed in the Span 80 (1.00 wt %)-containing W/O emulsion, AmHCNC (1.00 wt %)-containing aqueous solution, and AmHCNC (1.00 wt %)-stabilized W/O Pickering emulsion, respectively. The calcite crystal structure was identified in the Span 80-stabilized emulsions, whereas both calcite and vaterite structures were found in the AmHCNC-containing aqueous solution or AmHCNC-stabilized Pickering emulsions. No significant interactions are expected to occur between the electrically neutral, hydrophobic surfactant Span 80 in the oil phase and CaCO-, scales in the aqueous phase, leading to the most thermodynamically stable crystal structure, calcite, at the ambient condition. As for AmHCNC, the highly negatively charged dicarboxylate groups may promote interactions with CaCO₃ prenucleation clusters and nuclei. Mediated by electrostatic interactions between the anionic groups and Ca²⁺ in CaCO₃ the protruding dicarboxylate chains of AmHCNC partially arrest CaCO₃, crystallization at the least thermodynamically stable crystalline polymorph, vaterite. The stoichiometric molar ratio of COO- (3.1 mmol g^-1, 1.00 wt % AmHCNC) to the Ca²⁺ (12.4 mM) is 2.5, far exceeding the required stoichiometric molar ratio (~0.049) for AHCNC-mediated scale inhibition, based on AHCNC used in a single-phase aqueous system.16 In the W/O Pickering emulsion, a significant portion of AmHCNC are at the water-oil interface (~51% surface coverage), stabilizing the emulsion.

[00119] Materials and Methods - Materials: Northern bleached Q90 softwood kraft sheets from Resolute Inc., Canada, were used as the starting cellulose material. Sodium (metα)- periodate (NaIO₄, > 99 wt.%), sodium chloride (NaCl, > 99.5 wt.%), sodium chlorite (NaClO₂. > 80 wt.%), hydrogen peroxide (H₂O₂, 30 wt.%), octylamine (CH₃(CH₂)₇NH₂, 99% w/v, density: 0.782 g mL^-1), ethylene glycol (Reagent plus, > 99% w/v), poly-L-lysine (PLL, 0.1% w/v in water), calcium chloride dihydrate (CaCl₂.2H₂O, > 99 wt.%), sodium hydroxide (NaOH, > 97 wt.%), sodium bicarbonate (NaHCO₃, > 99 wt.%), hydrochloric acid (HC1, 37 wt.%), hydroxylamine hydrochloride (NH2OH • HC1, Reagent plus, 99 wt.%), hexadecane (C16H34, > 99% w/v), and Span 80 (C24H44O6, > 99% w/v) were supplied from Sigma-Aldrich, USA. A concentrated dispersion of CNC with sulfate half-ester groups (S-CNC, 10.1 wt.%, sodium form) with approximately 1 wt.% sulfur content, derived from softwood kraft pulp, was obtained from the University of Maine, The Process Development Center (PDC, MN, USA). Anhydrous ethanol (EtOH, pure 200 proof) was purchased from KOPTEC, USA. Custom-built micro fluidic flow focusing devices fabricated using acrylonitrile butadiene styrene (ABS) via stereolithography three-dimensional (3D) printing were provided by Proto Labs Inc. (MN, USA). The devices, with dimensions of 24 mm (length) x 26 mm (width) x 9 mm (height), featured three l/4”-28 holes positioned equidistantly. Tygon® tubing with a 1/4” outer diameter (OD) and 1/8” inner diameter (ID) was purchased from Saint-Gobain Life Sciences (OH, USA). Unless otherwise specified, all experiments were conducted using Milli-Q water (resistivity ~ 18 MΩ cm) at room temperature.

[00120] Materials and Methods - AHCNC Synthesis: To synthesize AH CNC, delignified softwood kraft pulp sheets (5 g) were torn into thin pieces (~2 x 2 cm²) and soaked in deionized (DI) water for at least 1 day. The wet pulp was then disintegrated using a fruit blender (Cleanblend, CA) for 10 min. The resulting pulp slurry was vacuum filtered to remove excess water. Next, NaIO₄ (6.6 g) and NaCl (19 g) were dissolved in the DI water containing the wet pulp (total water volume = 325 mL, including the initially absorbed water by the pulp). The beaker was wrapped with aluminum foil to prevent light-triggered NaIO₄ deactivation. The reaction was conducted via continuous stirring at room temperature for 42 h. To terminate the oxidation reaction, ethylene glycol (5 mL) was added, quenching unreacted NaIO₄. After 10 min, the partially oxidized fibrils, referred to as dialdehyde modified cellulose (DAMC), were washed thoroughly with DI water (100 mL) five times via vacuum filtration. IThe never-dried DAMC was subjected to chlorite oxidation via reacting the DAMC with NaClO₂ (4.226 g) and H₂O₂ (4.237 mL) in DI water (total volume = 250 mL, including absorbed water by DAMC). The reaction mixture was stirred at room temperature for 12 h while maintaining the pH at 5.0 ± 0.2 via gradually adding NaOH (0.5 M) during the first 5 h. Nonfibrillated fibers in the suspension were then separated via centrifugation at 27,000g for 15 min, and AHCNC were isolated from the supernatant by ethanol addition (0.8 g per 5 g of suspension) and centrifugation at 3000g for 15 min. The gel-like AHCNC precipitate was dispersed in DI water (~250 mL) and purified via dialysis (Spectra/Por dialysis bags, 6-8 kDa cutoff) against DI water for at least 3 days.

[00121] Materials and Methods - AmHCNC Synthesis: To synthesize AmHCNC bearing carboxylate and alkyl groups, a 3 -step protocol was developed, including periodate oxidation, chlorite oxidation, and Schiff base reactions. Periodate-mediated cellulose oxidation was conducted using 5 g of the starting softwood pulp for DAMC synthesis (see above). The never-dried DAMC pulps were converted to bifunctional cellulose fibrils and/or crystals, bearing aldehyde and carboxylate groups via chlorite-mediated partial oxidation. The reaction was initiated by adding wet DAMC to a solution of NaCIO₂ (1.7 g) and NaCl (8 g) in DI water (total volume = 250 mL). Once the chemicals were fully dissolved, H₂O₂ (1.7 mL) was added dropwise within ~ 1 min. Note that only half of the aldehyde groups were converted to carboxylate groups for AmHCNC synthesis, whereas for AHCNC preparation, the majority of aldehyde groups were converted. The reaction mixture was stirred at room temperature for 12 h while maintaining the pH at 5 ± 0.2 by NaOH (0.5 M) addition. The bifunctional cellulose fibrils and/or crystals were then separated through vacuum filtration and washed using an ethanol solution (80% v/v) five times.

[00122] Bifunctional cellulose fibrils and/or crystals were then modified via a Schiff base reaction with octylamine to anchor medium-length, 8-carbon alkyl chains to the remaining aldehyde groups. Never-dried bifunctional fibrils were suspended in DI water (125 mL), followed by the gradual addition of octylamine (2.5 mL) within ~ 3 min. The mixture was stirred at ambient temperature and a mildly acidic pH, adjusted to ~ 4.5 using HC1 (0.5 M), for 48 h. The resulting brownish amphiphilic fibrils were collected and dialyzed (using Spectra/Por dialysis bags, 6-8 kDa cutoff) against DI water for two days with water exchanges every 6 h. Afterward, the suspension was heated to 60 °C for 1 h, sonicated using a probe sonicator (Qsonica Q500, CT, USA) in an ice bath for 20 min, and centrifuged at 5000 Xg for 15 min to remove the unfibrillated fibrils. The AmHCNC-containing supernatant was collected and stored in the fridge (4-7 °C).

[00123] Materials and Methods - Functional Group Content Measurements: The content of DAMC fibrils and AmHCNC aldehyde groups were measured using an oxime titration protocol. A known amount of DAMC fibrils or AmHCNC (dry mass = 50 mg) was dispersed in Milli-Q water (50 mL), and the suspension pH was adjusted to 3.5 using HC1 (0.1 M). Then, a NH2OH ■ HC1 solution (5 wt.%, 10 mL) with the same pH (i.e., 3.5 adjusted using 0.1 M NaOH) was prepared and added to the DAMC suspension. Immediately after the reaction of aldehyde groups with NH₂OH ■ HC1, the oxime reaction was initiated, leading to in situ HC1 release and subsequent pH decrease. The produced HC1 was titrated against a NaOH solution (10 mM) at a flow rate of 0.1 mL min^-1 using an automatic titrator (Mctrohm 907 Titrando, USA). The titration endpoint was obtained where the pH was stabilized at 3.5 (i.e., the initial pH). [00124] To quantify the carboxylate group content of AmHCNC, a known amount of the respective dispersion (dry mass = 20 mg) was independently added to Milli-Q water (140 mL), followed by the addition of a NaCl solution (2 mL, 20 mM). The pH was adjusted to 3 using HC1 (0.1 M). Then, the automatic titrator was used to titrate the AmHCNC mixture with NaOH (10 mM) at a rate of 0.1 mL min^-1 until pH ~ 11. The carboxylate group content was calculated from the mid-region of titration curve, corresponding to the NaOH volume consumed to neutralize the weak acid.

[00125] To estimate the AmHCNC alkyl group content, the content of remaining aldehyde groups on bifunctional cellulose fibrils and/or crystals after carboxylation and the content of remaining aldehyde groups on AmHCNC were measured. Assuming that the reduction in aldehyde contents of bifunctional cellulose fibrils and/or crystals following alkylation is a result of Schiff base reaction with octylaminc amine groups, the aldehyde content difference is counted for alkyl group content. [00126] Materials and Methods - Attenuated Total Reflection (ATR)-Fourier- transform Infrared (FTIR) Spectroscopy: The functional groups of S-CNC, AHCNC, and AmHCNC were identified by the ATR-FTIR spectroscopy following the Bouguer-Beer-Lambert law. The infrared (IR) spectra were recorded on a Bruker Vertex 70 spectrometer (Bruker, USA) outfitted with a deuterium triglycine sulfate (DTGS) detector. The measurements were conducted in the attenuated total reflection (ATR) geometry using a Harrick Diamax diamond ATR accessory. Prior to the measurements, the nanocrystals were completely dried in an oven at 37 °C overnight. The spectra were the average of 100 scans recorded at a resolution of 6 cm’¹. The bare diamond spectrum was used as a reference to obtain a baseline and normalize the sample absorbance values.

[00127] Materials and Methods - Atomic Force Microscopy (AFM): The morphology of S-CNC, AHCNC, and AmHCNC was studied using a Bruker Dimension Icon AFM (Bruker, IL). A silicon nitride probe (ScanAsyst-Air) in the PeakForce tapping mode was used for the imaging. To prepare the AFM samples, freshly cleaved mica sheets (diameter = 10 mm) were adhered to stainless steel disks using the Krazy Glue and coated with a PLL solution (0.1% w/v), followed by incubation for 15 min. Disks were then rinsed with Milli-Q water five times, and one drop of a S-CNC, AHCNC, or AmHCNC dispersion (0.1 mg mL-1) was deposited onto the mica and air-dried overnight. The disks were then rinsed with Milli-Q water five more times and air-dried overnight before imaging. The acquired images were analyzed by the NanoScope Analysis software (Version 1.80, accessed through Penn State Materials Characterization Laboratory, MCL). Dimensions of >50 particles per sample were quantified by the Gwyddion software (Version 2.49, accessed through Penn State MCL).

[00128] Materials and Methods - X-ray Scattering Diffraction (XRD) Spectroscopy:

[00129] The crystallinity of oven-dried S-CNC, AHCNC, and AmHCNC was assessed using XRD spectroscopy. XRD diffractograms were acquired on a Panalytical Empyrean instrument (Malvern, UK), equipped with PIXcel^3D detector and CuKa radiation (λ l .54 A). The instrument was operated at 45 kV and 40 mA in a Bragg angle (i.e., 2θ) range of 10-50°. The crystallinity index (Cl) of all nanocelluloses (S-CNC, AHCNC, and AmHCNC) was calculated using Equation (2).

[00130] where hoc denotes the intensity of (200) plane, and /_AM is the minimum intensity of XRD diffractogram, representing the amorphous regions, /_AM for nanocelluloses was located between 15-20°.

[00131] Materials and Methods - Dynamic Light Scattering (DLS) and

Electrophoretic Light Scattering (ELS): The hydrodynamic sizes of different nanocelluloses including S-CNC, AHCNC, and AmHCNC and the effect of Ca²⁺ on the hydrodynamic sizes of AmHCNC were determined via the dynamic light scattering (DLS) spectroscopy using a Zetasizer Nano series instrument (Malvern Instruments Ltd., UK). The measurements were performed at 25 °C and a scattering angle of 90°. Prior to DLS measurements, the nanocrystal dispersions were diluted to a final concentration of 0.1% w/v using Milli-Q water at pH = 8.0, adjusted using a NaOH solution (0.5 M). Next, 70 pL of diluted samples was pipetted into low- volume quartz cuvettes (ZEN2112, Malvern, UK). The intensity Z-average values (i.e., the cumulants mean) were reported for the hydrodynamic equivalent size of particles.

[00132] Via the ELS spectroscopy, the electrophoretic mobility of S-CNC, AHCNC, and AmHCNC as well as the effect of Ca²⁺ on the electrophoretic mobility of AmHCNC were measured to determine the ζ-potential using a Zetasizer Nano series instrument (Malvern Instruments Ltd., UK). Prior to the ζ-potential measurements, dispersions were diluted to a final concentration of 0.1% w/v with Milli-Q water and NaOH solution (0.5 M) used for the pH adjustment to 8.0. Subsequently, 900 pL of each sample was pipetted into the universal dip cell kit to carry out the measurements. To approximate the ^-potential, the Oshima’s mobility expression for charged, cylindrical particles was applied to the averaged or measured electrophoretic mobilities (p_av) using Htickel equation (e.g., Equation (3)).

[00133] where μι is the electrophoretic mobility of particles in the parallel direction to the electric field, Pi is the electrophoretic mobility of particles in the perpendicular direction to the electric field, K is the Debye-Hüickel parameter, a is the radius of the cylindrical particles (obtained from AFM images), f(Kα) is Henry’s function, ε_r is the dielectric constant of vacuum, ε₀ is the dielectric constant of water, and η is the viscosity.

[00134] At the Ca²⁺-free conditions, sodium ions (Na⁺) were the counter ions when measuring theμ μ._av. Table 2 presents the Na⁺ concentrations, Ka,f (KO) and correction factor when measuring the μ_av of S-CNC and AmHCNC. When the Kα fell within the Henry limit of < 1 (i.e. , all the μ_av was determined by the two-thirds of mobility of particles in the

parallel direction to the electric field. At varying Ca²⁺ concentrations, Table 3 presents the Ca²⁺ concentrations, kα, f (Kα) and correction factor when measuring the μ_av of AmHCNC.

Table 2: Kα,f (Kα), and correction factor for S-CNC and AmHCNC in the absence of Ca²⁺ at pH = 8

Table 3: kα,f (Kα) , and correction factor for AmHCNC at varying concentrations of Ca²⁺ at pH =

8

[00135] Materials and Methods - Determining Interfacial Tension via the Pendant

Drop Method: The interfacial tension measurements were carried by a Goniometer/Tensiometer 260 (Ramehart, USA) using the pendant drop method. The effect of AmHCNC on interfacial tension between an aqueous solution and hexadecane was investigated by varying AmHCNC concentrations from 0.25 to 2.0 wt.%. To examine the effect of scaling on interfacial tension, the Ca²⁺ concentrations varied from 0 to 20 mM with or without 4.54 mM of CO₃ ^2- while the AmHCNC concentration was maintained constant at 1.0 wt.% for all samples. A droplet of an aqueous solution (dispersed phase) was suspended from a metallic 28 Gauge needle (Fisher Scientific, USA) into hexadecane (continuous phase) at room temperature. Multiple images of an individual drop with a known volume of 5 pL were taken at 0.2 s intervals for a total of 6 s. The pendant drop procedure was repeated for each sample at least three times (n = 3). The drop radius of curvature at the apex (Ro) and the shape factor (P) were analyzed for at least 10 images to determine the interfacial tension (y) using Equation (4).

[001361 where Δp denotes the density difference between water (999 kg m^-3) and hexadecane (773 kg m^-3), and g shows the gravitational acceleration of earth (i.e., 9.8 m s^-2).

[00137] Materials and Methods - Contact Angle Measurement: To assess the wettability of nanocelluloses, a Goniometer/Tensiometer 260 (Ramehart, USA) equipped with a Basler GenlCam Source camera and an Automated Dispensing System was used to determine water contact angle of the corresponding films. The dispersions of nanocelluloses, including S- CNC, AHCNC, or AmHCNC, were casted onto glass slides and oven-dried at 37 °C overnight to obtain flat films for measurements. A droplet of DI water (5 pL) was dropped from a 250 μL plastic pipette tip on multiple spots of the films. Multiple images of each drop were acquired at 1 s intervals for 10 s. Contact angle data were calculated using the DROPImage Advanced software (Version 2.6.1) via applying the Young-Laplace equation.

[00138] Materials and Methods - Nanocellulose-stabilized W/O Pickering Emulsions:

Pickering emulsions with uniform W/O droplets were generated using a flow focusing device at fixed flow rates and room temperature. The flow rates of oil and aqueous phases for W/O emulsions were set at 480 pL min^-1 and 120 pL min^-1, respectively. To formulate nanocellulose- stabilized emulsions, varying concentrations of S-CNC, AHCNC, or AmHCNC (0.25 - 2.0 wt.% dispersed in Milli-Q water, pH adjusted to 8) were added to the aqueous phase. The oil (hexadecane) and aqueous phases were then injected into the flow focusing device using two separate syringe pumps (Harvard Apparatus PHD 2000, USA) to generate the W/O emulsions.

[00139] Materials and Methods - Surfactant-stabilized W/O Emulsions: Surfactant- stabilized W/O emulsions were prepared using ABS flow focus device at fixed flow rates (oil phase: 480 pL min^-1, aqueous phase: 120 pL min^-1) and room temperature. The oil phase was prepared via dissolving Span 80 (1.0 wt.%) in hexadecane while the aqueous phase was Milli-Q water with the pH adjusted to 8. Both oil and aqueous phases were then injected into the flow focusing device using two separate syringe pumps to generate the W/O emulsions.

[00140] Materials and Methods - CaCO₃ Scale Generation in Stable W/O Emulsions:

To induce CaCO₃ scale formation in AmHCNC-stabilized W/O Pickering emulsions, the aqueous phase was prepared via dissolving 19 mg of NaHCO3 in 50 mL of an AmHCNC dispersion (1.00 wt %, pH adjusted to 8 using 0.5 M NaOH), resulting in a HCO^3- concentration of 4.5 mM. Then, 91.5, 137.3, or 183.0 mg of CaCl_{2 2}H₂O was added to the AmHCNC/HCO^3- dispersion to obtain a Ca²⁺ concentration of ~12.4, 18.7, or 24.9 mM, respectively. The oil phase for the AmCHCNC-stabilized emulsions was hexadecane. For the Span 80-stabilized emulsions, the aqueous phase was prepared via dissolving 19 mg of NaHCO3 and 91.5 mg of CaCl₂₂H₂O in 50 mL of Milli-Q water (pH adjusted to 8 using 0.5 M NaOH), yielding a HCO^3- concentration of 4.5 mM and a Ca²⁺ concentration of 12.4 mM. The oil phase was hexadecane containing Span 80 (1.00 wt %). Assuming that HCO^3- is fully dissociated to CO3^2-, the supersaturation degree (5) was calculated using Equation (5).

[00141] where a denotes the activity of Ca²⁺ or CO₃ ^2-, and K_sp is the solubility product constant. Emulsions containing a Ca²⁺ concentration of 10, 15, or 20 mM result in S of 90, 135, or 180, respectively, with respect to calcite, which has a K_SP of 5.5 x 10^-9 at room temperature. [00142] The AmHCNC- or Span 80-stabilized aqueous droplets in the oil phase were then generated via injecting the aqueous and oil phases into the flow focusing device at fixed flow rates (oil phase: 480 pL min^-1 and aqueous phase: 120 pL min^-1) and room temperature. To collect and analyze CaCO3 scales formed in water droplets, the emulsions were incubated for 4 h or 24 h at room temperature, and subsequently centrifuged at 5000 Xg for 5 min. The supernatants consisting of water, ions, and emulsifier (AmHCNC or Span 80) was decanted, and the CaCO₃-containig precipitate was thoroughly rinsed with Milli-Q water (pH adjusted to 8) and dried in an oven at 37 °C overnight for further analyses.

[00143] Materials and Methods - Optical Microscopy: Water droplets, stabilized by the nanocelluloses or the surfactant in the oil phase, and CaCO₃ scale particles were imaged using an inverted microscope (Nikon ECLIPSE TE300, Japan) with a 10X objective lens and a total magnification of 100X.

[00144] Materials and Methods - Scanning Electron Miscopy (SEM): The morphology of CaCO₃ particles formed in AmHCNC dispersion (1.0 wt.%) or in the aqueous phase of emulsions (Span 80- or AmHCNC-stabilized W/O emulsions) was imaged by a scanning electron microscope (ThermoFisher Verios G4, USA). The CaCO3 scale samples were oven-dried at 37 °C overnight, followed by fixing to SEM pin stubs (25.4 mm x 6 mm, Ted Pella, USA) using adhesive carbon tape (Agar Scientific, UK). Afterward, the samples were coated with a 3 nm-thick layer of indium using a vacuum sputtering instrument (Leica sputter coating EM ACE 600, USA). SEM imaging was conducted using an accelerating voltage of 3 kV and a beam current of 6.3 pA with the through-the-lens detector (TLD) in the field-free mode.

[00145] Materials and Methods - Statistical Analyses: Data are reported as average of n = 3 independent samples ± SD. To determine the statistical significance, t-test or a one-way analysis of variance (ANOVA) along with the Tukey-Kramer post-hoc test was carried out for comparing three groups. The ρ -values < 0.05 were considered statistically significant. For all statistical analyses, GraphPad Prism (Version 9.4.1) was used. [00146] It should be understood that the disclosure of a range of values is a disclosure of every numerical value within that range, including the end points. It should also be appreciated that some components, features, and/or configurations may be described in connection with only one particular embodiment, but these same components, features, and/or configurations can be applied or used with many other embodiments and should be considered applicable to the other embodiments, unless stated otherwise or unless such a component, feature, and/or configuration is technically impossible to use with the other embodiment. Thus, the components, features, and/or configurations of the various embodiments can be combined together in any manner and such combinations are expressly contemplated and disclosed by this statement.

[00147] It will be apparent to those skilled in the art that numerous modifications and variations of the described examples and embodiments are possible considering the above teachings of the disclosure. The disclosed examples and embodiments are presented for purposes of illustration only. Other alternate embodiments may include some or all of the features disclosed herein. Therefore, it is the intent to cover all such modifications and alternate embodiments as may come within the true scope of this invention, which is to be given the full breadth thereof.

[00148] It should be understood that modifications to the embodiments disclosed herein can be made to meet a particular set of design criteria. Therefore, while certain exemplary embodiments of the apparatus and methods of using and making the same disclosed herein have been discussed and illustrated, it is to be distinctly understood that the invention is not limited thereto but may be otherwise variously embodied and practiced within the scope of the following claims.

Claims

WHAT IS CLAIMED IS:

1. A method of producing an emulsion stabilizer, comprising: providing polysaccharide bodies; oxidizing the polysaccharide bodies to provide dialdehyde modified polysaccharide bodies; oxidizing the dialdehyde modified polysaccharide bodies to provide polysaccharide bodies bearing aldehyde and hydrophilic anionic groups; and subjecting the polysaccharide bodies bearing aldehyde and hydrophilic anionic groups to provide polysaccharide bodies bearing hydrophobic alkyl chains and hydrophilic anionic groups.

2. The emulsion stabilizer of claim 1, wherein the hydrophobic alkyl chains comprise compounds with 8-22 carbons.

3. The emulsion stabilizer of claim 1, wherein the hydrophilic anionic groups comprise dicarboxylate.

4. The emulsion stabilizer of claim 1, wherein the polysaccharide bodies are cellulose bodies.

5. The method of claim 4, wherein the cellulose bodies are oxidized with periodic acid or salts thereof.

6. The method of claim 1, wherein the dialdehyde modified polysaccharide bodies are oxidized with chlorite ions.

7. The method of claim 1, further comprising: heating the polysaccharide bodies bearing hydrophobic alkyl chains and hydrophilic anionic groups; sonicating the polysaccharide bodies bearing hydrophobic alkyl chains and hydrophilic anionic groups; and centrifuging the polysaccharide bodies bearing hydrophobic alkyl chains and hydrophilic anionic groups.

8. The method of claim 1, wherein the content of hydrophobic alkyl chains is between 0.5 and 7 mmol g^-1, and the content of hydrophilic anionic groups is between 0.5 and 7 mmol g^-1.

9. The method of claim 8, wherein the content of hydrophobic alkyl chains is between 3.2-

3.4 mmol g^-1, and the content of hydrophilic anionic groups is between 3.0-3.2 mmol g^-1.

10. The method of claim 9, wherein the content of hydrophobic alkyl chains and the content of hydrophilic anionic groups are the same.

11. The method of claim 1 , wherein the hydrophilic anionic groups are configured to provide the emulsion stabilizer with antiscaling properties.

12. An emulsion stabilizer made by a method comprising the steps of: providing cellulose bodies; oxidizing the cellulose bodies to provide dialdehyde modified cellulose bodies; oxidizing the dialdehyde modified cellulose bodies to provide cellulose bodies bearing aldehyde and hydrophilic anionic groups; and subjecting the cellulose bodies bearing aldehyde and hydrophilic anionic groups to provide cellulose bodies bearing hydrophobic alkyl chains and hydrophilic anionic groups.

13. The emulsion stabilizer of claim 12, wherein the hydrophilic anionic groups and the hydrophobic alkyl chains are attached to cellulose chains protruding from the cellulose bodies.

14. The emulsion stabilizer of claim 12, wherein the cellulose bodies are plant-based.

15. The emulsion stabilizer of claim 12, wherein the cellulose bodies have a rod-like shape.

16. The emulsion stabilizer of claim 12, wherein the cellulose bodies have a length between 10 and 1000 nanometers.

17. The emulsion stabilizer of claim 12, wherein the cellulose bodies have a length between 77 and 125 nanometers.

18. The emulsion stabilizer of claim 12, wherein the cellulose bodies have a width between

1.5 and 10 nanometers.

19. The emulsion stabilizer of claim 12, wherein the emulsion stabilizer is configured to create a stable water-in-oil emulsion, a stable water-in-organic solvent emulsion, a stable oil-in- water emulsion, or a stable organic solvent-in-water emulsion.

20. The emulsion stabilizer of claim 12, wherein the emulsion stabilizer is configured to maintain stability at concentrations up to 2.0 wt.%.

21. An emulsion stabilizer, comprising: cellulose bodies comprising cellulose chains protruding from the cellulose bodies; hydrophobic alkyl chains attached to a first portion of the cellulose chains; and hydrophilic alkyl groups attached to a second portion of the cellulose chains.