[go: up one dir, main page]

WO2013030240A1 - Réactions par transfert de phase - Google Patents

Réactions par transfert de phase Download PDF

Info

Publication number
WO2013030240A1
WO2013030240A1 PCT/EP2012/066789 EP2012066789W WO2013030240A1 WO 2013030240 A1 WO2013030240 A1 WO 2013030240A1 EP 2012066789 W EP2012066789 W EP 2012066789W WO 2013030240 A1 WO2013030240 A1 WO 2013030240A1
Authority
WO
WIPO (PCT)
Prior art keywords
magnetically responsive
phases
magnetic
reaction
phase
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/EP2012/066789
Other languages
English (en)
Inventor
Iouri Gounko
Gemma-Louise DAVIES
Stephen Byrne
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
College of the Holy and Undivided Trinity of Queen Elizabeth near Dublin
Original Assignee
College of the Holy and Undivided Trinity of Queen Elizabeth near Dublin
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by College of the Holy and Undivided Trinity of Queen Elizabeth near Dublin filed Critical College of the Holy and Undivided Trinity of Queen Elizabeth near Dublin
Publication of WO2013030240A1 publication Critical patent/WO2013030240A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J8/00—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes
    • B01J8/08—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with moving particles
    • B01J8/082—Controlling processes
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K9/00—Medicinal preparations characterised by special physical form
    • A61K9/48—Preparations in capsules, e.g. of gelatin, of chocolate
    • A61K9/50—Microcapsules having a gas, liquid or semi-solid filling; Solid microparticles or pellets surrounded by a distinct coating layer, e.g. coated microspheres, coated drug crystals
    • A61K9/5094—Microcapsules containing magnetic carrier material, e.g. ferrite for drug targeting
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J19/08—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor
    • B01J19/087—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor employing electric or magnetic energy
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/08—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor
    • B01J2219/0873—Materials to be treated
    • B01J2219/0881—Two or more materials
    • B01J2219/0888—Liquid-liquid
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/08—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor
    • B01J2219/0873—Materials to be treated
    • B01J2219/0881—Two or more materials
    • B01J2219/089—Liquid-solid
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/08—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor
    • B01J2219/0873—Materials to be treated
    • B01J2219/0892—Materials to be treated involving catalytically active material

Definitions

  • the invention relates to new approaches in phase-transfer reactions (PTR) and phase- transfer catalysis (PTC) using magnetic particles.
  • PTR phase-transfer reactions
  • PTC phase- transfer catalysis
  • an inventive method for initiating phase transfer reactions is an inventive method for initiating phase transfer reactions.
  • the present invention provides for phase transfer reactions initiated by the application of a magnetic field.
  • an inventive method for the preparation of stable nanowire structures utilising magnetically induced phase transfer catalysis and/or condensation reactions.
  • PTC is one of the most efficient and versatile technologies, which is used in organic synthesis, both in industry and in research laboratories. PTC is widely used for the production of surfactants, polymers, flavours & fragrances, petrochemicals, agricultural chemicals, dyes, pharmaceuticals and explosives. The advantages of PTC include simple experimental operations, mild reaction conditions, use of inexpensive and environmentally friendly reagents and solvents, easy scalability.
  • Common PTC approaches involve the utilisation of quaternized ammonium or phosphonium based salts (e.g. tetramethylammonium chloride or tetrabutylphosphonium bromide) as catalysts.
  • quaternized ammonium or phosphonium based salts e.g. tetramethylammonium chloride or tetrabutylphosphonium bromide
  • a quaternary ammonium cation forms an ion pair with an anionic reactant, which equilibrates between an organic and an aqueous phase.
  • U.S. Patent No. 3992432 discloses a process for catalyzing heterogeneous ionic organic reactions in a system of multiple liquid phases in which at least two of the reactants (differing in polarity) are each located in a different phase with respect to the other.
  • U.S. Patent No. 3992432 discloses a process for catalyzing heterogeneous ionic organic reactions in a system of multiple liquid phases in which at least two of the reactants (differing in polarity) are each located in a different phase with respect to the other.
  • U.S. Patent Application Publication No. 2005/0165120 relates to a process for the extraction of nanoparticles into an aqueous phase by complexation with water soluble surfactants such as cetyltrimethyl ammonium bromide (CTAB).
  • CTLAB cetyltrimethyl ammonium bromide
  • a bi-phasic mixture is prepared in which hydrophobized nanoparticles are in an organic medium and surfactant molecules are in an aqueous phase.
  • An emulsion is formed on vigorous shaking of the bi-phasic mixture and after phase separation, metal nanoparticles transfer into the aqueous medium.
  • European Patent No. 1337219 describes phase transfer catalysis of nanoparticles from a first phase to a second phase using DMAP based phase transfer catalysts.
  • U.S. Patent Application Publication No. 2010/0215851 claims the production of core/shell composite nanoparticles by initially dispersing core particles (heat treated in advance to give them a crystal structure expressing the necessary characteristics) in an organic solvent by a first dispersant to prepare a first solution, adding a polar solvent to peel off the first dispersant from the core particles and making the nanoparticles agglomerate, allowing recovery. Next, the recovered core particles are dispersed in a second organic solvent by a second dispersant to form a second solution, and addition of a precursor of the shells to the second solution forms shells on the surfaces of the core particles.
  • the present invention utilises magnetic particles as trans-phase catalyst carriers and/or reagent carriers.
  • the application of an external magnetic field is utilised to initiate or trigger the trans-phase reaction or process because the external magnetic field causes migration of the magnetic particles within a multi-phasic system.
  • the external magnetic field can cause trans- phase migration of the magnetic particles (comprising or consisting of a catalyst or other reagent) toward the magnetic field source resulting in the initiation of a reaction in one of the phases.
  • the present invention further provides for a method of producing coated magnetic micro- and nano-structures from nanoparticles by using an external magnetic field to transfer particles from a first phase in to a second phase and coat them in-situ using a one-step magnetic trans-phase delivery technique.
  • the present invention also allows magnetically triggered reaction initiation or catalysis (e.g. polymerisation, condensation, etc.) at
  • the present invention provides for a method of promoting a reaction in a reaction system comprising at least a first phase and a second phase, wherein the first and second phases are immiscible, the method comprising:
  • the term magnetically responsive particle refers to a particle that is attracted to a magnetic field.
  • the magnetic field is provided by a magnetic field source, for example a magnet.
  • the application of a magnetic field may cause the magnetically responsive particle to migrate towards the magnetic field source.
  • particle shall not be limited to material consisting of a single particle. It also covers particulate materials comprised of a plurality of particles and particle aggregates.
  • the magnetically responsive particle may consist of or comprise a reaction promoting component. This statement shall be construed as simply meaning that the magnetically responsive particle may be entirely composed of a material that is also a reaction promoting component, or that the magnetically responsive particle may be part composed of reaction promoting material or may have a reaction promoting component attached to, or adsorbed on the particle.
  • promote a reaction therein should be construed as covering direct initiation of a reaction, indirect initiation of a reaction, or enhancement/catalysis of the rate of an already occurring reaction.
  • the magnetically responsive particle migrates from one of the first or the second phase into the other of the first or second phase it may:
  • reaction initiating species which in turn initiates the reaction
  • the reaction may comprise forming a coating on the surface of the magnetically responsive particle.
  • the coatings can be functionalised to modify the properties of the magnetic materials.
  • the coatings can be modified to include luminescent moieties (e.g. organic dyes or semiconductor quantum dots), radiolabeled moieties, a drug moiety, an electrochromic moiety and combinations thereof.
  • the method of the present invention allows for clean and uncomplicated magnetic-based initiation of phase transfer reactions and processes without the use of any complex reagents and expensive systems.
  • the present invention provides for a quick, efficient and versatile method by which phase transfer reactions can be initiated.
  • the magnetically responsive particle may be selected from the group consisting of a magnetic nanoparticle, a magnetic nanorod, a magnetic nanowire, a magnetic nanoworm, a magnetic nanotube, a magnetic nanoflake and combinations thereof.
  • the magnetically responsive particle may comprise a magnetic metal, a magnetic metal oxide, a magnetic metal alloy, a magnetic spinel, or combinations thereof.
  • the magnetically responsive particle may comprise iron, iron oxides, iron alloys, iron-based spinels, cobalt, cobalt oxides, cobalt alloys, nickel, nickel oxides, nickel alloys, chromium oxides, chromium-based spinels, and combinations thereof.
  • the magnetically responsive particle may be selected from iron metal, iron oxides, cobalt ferrite, nickel ferrite, magnetic metal alloys such as CoPt, CoNi, FePt, FeAu, FeRu, and combinations thereof.
  • the present invention extends to a reaction system in which there are a plurality of immiscible phases.
  • references to first and second phases simply refer to any two phases in said plurality of immiscible phases.
  • the reaction system may be a biphasic system, i.e. consisting of two immiscible phases.
  • both the first and second phases may be liquid.
  • the first and second liquid phases may form layers.
  • the first and second liquid phases may form an emulsion or a microemulsion.
  • one of the first and second phases is aqueous and the other of the first and second phases is organic.
  • the magnetically responsive particle may be dispersed in or held in suspension in one of the first or second phases. This may be achieved with surfactants or other dispersant molecules, or by surface modification/functionalisation of the magnetically responsive particles.
  • the magnetically responsive particle may be dissolved in solution in one of the first or second phases.
  • the application of the magnetic field may cause migration of the magnetically responsive particle into a phase in which it is not soluble, whereupon it may precipitate out of solution.
  • the reaction promoting component may be a catalyst.
  • the catalyst may cause direct initiation of a reaction, indirect initiation of a reaction, or increase of the rate of an already occurring reaction.
  • the reaction promoting component may be attached to or adsorbed on the surface of the magnetically responsive particle.
  • the reaction promoting component may be physically or chemically adsorbed on the surface of the magnetically responsive particle.
  • the present invention further provides for a container having a reaction system contained therein,
  • reaction system comprising at least a first phase and a second phase, the first and second phases being immiscible
  • At least one magnetically responsive particle is disposed in one of the first or second phases, the particle consisting of or comprising a reaction promoting component, and
  • the application of a magnetic field causes the magnetically responsive particle (and the reaction promoting component) to migrate into the other of the first or second phases such that the reaction promoting component can react with the reagent disposed in the other of the first or second phases.
  • the present invention also provides for a kit comprising:
  • the magnetic field source may be a permanent magnet.
  • the magnetic field source may be a variable strength magnet.
  • the magnetic field source may be an alternating magnetic field.
  • the magnetically responsive particle may be selected from the group consisting of a magnetic nanoparticle, a magnetic nanorod, a magnetic nanowire, a magnetic nanoworm, a magnetic nanotube, a magnetic nanoflake and combinations thereof.
  • the magnetically responsive particle may comprise a magnetic metal, a magnetic metal oxide, a magnetic metal alloy, a magnetic spinel, or combinations thereof.
  • the magnetically responsive particle may comprise iron, iron oxides, iron alloys, iron-based spinels, cobalt, cobalt oxides, cobalt alloys, nickel, nickel oxides, nickel alloys, chromium oxides, chromium-based spinels, and combinations thereof.
  • the magnetically responsive particle may be selected from iron metal, iron oxides, cobalt ferrite, nickel ferrite, magnetic metal alloys such as CoPt, CoNi, FePt, FeAu, FeRu, and combinations thereof.
  • the kit extends to a reaction system in which there are a plurality of immiscible phases.
  • references to first and second phases simply refer to any two phases in said plurality of immiscible phases.
  • the reaction system may be a biphasic system, i.e. consisting of two immiscible phases.
  • Both the first and second phases may be liquid.
  • the first and second liquid phases may form layers.
  • the first and second liquid phases may form an emulsion or a microemulsion.
  • one of the first and second phases is aqueous and the other of the first and second phases is organic.
  • the magnetically responsive particle may be dispersed in or held in suspension in one of the first or second phases. This may be achieved with surfactants or other dispersant molecules, or by surface modification/functionalisation of the magnetically responsive particles.
  • the magnetically responsive particle may be dissolved in solution in one of the first or second phases. The application of the magnetic field may cause migration of the magnetically responsive particle into a phase in which it is not soluble, whereupon it may precipitate out of solution.
  • the reaction promoting component may be a catalyst.
  • the catalyst may cause direct initiation of a reaction, indirect initiation of a reaction, or increase of the rate of an already occurring reaction.
  • the reaction promoting component may be attached to or adsorbed on the surface of the magnetically responsive particle.
  • the reaction promoting component may be physically or chemically adsorbed on the surface of the magnetically responsive particle.
  • the present invention provides for use of a magnetically responsive particle consisting of, or comprising a reaction promoting component in a reaction system comprising at least two immiscible phases, wherein the application of a magnetic field causes the magnetically responsive particle to migrate from one the phases into the other of phases so that the reaction promoting component can promote a reaction therein.
  • the invention also relates to a method of coating a magnetically responsive material, the method comprising the steps of:
  • coating promoting agent associated with the magnetically responsive material shall be construed as a coating promoting agent that is attached to or adsorbed on the surface of the magnetically responsive material and also covers the case in which the coating promoting agent and the magnetically responsive material are the same material.
  • the coating promoting agent may be:
  • the magnetically responsive material i.e., the magnetically responsive material is also the coating promoting agent
  • the coating method of the present invention offers a quick, efficient and versatile approach by which magnetic materials can be coated.
  • the coating method of the present invention can be utilised with a variety of types of magnetic micro- and nano- objects and a host of different coating materials.
  • the coating method of the present invention can provide for a wide range of coated materials, which can be further manipulated or modified after their initial preparation.
  • the coating method is a one-step, one-pot, clean procedure, which allows straight-forward preparation of coated magnetic (nano)materials.
  • the coated (nano)materials can be recovered in high yields.
  • the magnetically responsive material may be selected from the group consisting of a magnetic nanoparticle, a magnetic nanorod, a magnetic nanowire, a magnetic nanoworm, a magnetic nanotube, a magnetic nanoflake and combinations thereof.
  • the magnetically responsive material may migrate into the second phase as a linear assembly so as to provide coated linear magnetic nanostructures.
  • the magnetically responsive material may migrate into the second phase as a linear assembly so as to provide coated linear magnetic nanostructures.
  • magnetically responsive material may migrate into the second phase as a linear assembly so as to provide coated magnetic nanowires.
  • Linear nanostructures may be more desirable because they are believed to exhibit superior performance than non-linear nanostructures in biomedical applications on account of their increased aspect ratio.
  • coated linear magnetic nanowires prepared by the present invention retain their linear shape even when the magnetic field has been removed.
  • the coating keeps the linear shape.
  • coated linear magnetic nanowires prepared by the present invention are flexible and are responsive to an external magnetic field after formation, i.e. they can still be attracted by an external magnetic field.
  • the coating precursor may be selected from the group consisting of metal alkoxides, silicon alkoxides, siloxanes, C 1 -C 100 polymerisable monomers, acetylacetonates, amides, and combinations thereof.
  • the coating promoting agent may be selected from the group consisting of a basic solution, a polymerisation catalyst or a condensation catalyst.
  • the basic solution may be aqueous.
  • the basic solution may comprise a hydroxide salt.
  • the basic solution may be selected from the group consisting of aqueous NH 4 OH, aqueous NaOH, and aqueous KOH.
  • the magnetically responsive materials such as magnetic nanoparticles, magnetic nanorods, magnetic nanowires, magnetic nanoworms and magnetic nanotubes can be coated with a variety of different coating materials.
  • the coatings can be functionalised to modify the properties of the magnetic materials.
  • the coatings (or coating precursor) can be modified to include luminescent moieties (e.g. organic dyes or semiconductor quantum dots), radiolabeled moieties, a drug moiety, an electrochromic moiety and
  • the coatings may be modified to include drug molecules and the coated magnetic nanoparticle may act as a drug delivery vehicle.
  • the present invention further provides for a coated magnetically responsive material obtainable by the method of the present invention.
  • the present invention provides for a method of breaking an emulsion of immiscible liquids, the emulsion comprising a first liquid phase and a second liquid phase dispersed in the first liquid phase, the method comprising the steps of:
  • the magnetically responsive material may be held in solution or in suspension in the
  • one of the first and second phases is aqueous and the other of the first and second phases is organic.
  • the magnetically responsive material may be selected from the group consisting of a magnetic nanoparticle, a magnetic nanorod, a magnetic nanowire, a magnetic nanoworm, a magnetic nanotube, and combinations thereof.
  • Figure 1 illustrates the preparation of coated nanowires utilising the phase transfer method of the present invention
  • Figure 2 illustrates silica coated cobalt ferrite nanoparticles prepared using the phase transfer method of the present invention
  • Figure 3 illustrates titania coated cobalt ferrite nanoparticles prepared using the phase transfer method of the present invention.
  • Figure 4 provides Transmission Electron Microscopy (TEM) images of coated nanowires prepared using the phase transfer chemistry of the present invention.
  • the mechanism of formation of these nanowire structures relies on the presence of an external magnetic field to pull the magnetic nanoparticles with an interstatically-attached surface layer of aqueous ammonium hydroxide catalyst.
  • the magnet attracts the magnetic nanoparticle towards it, via the liquid interface 103 in the beaker.
  • the nanoparticles move to the interface, they begin to form into a 1 -dimensional (1 -D) array of nanoparticles 104.
  • a reaction is initiated by the catalyst at the surface of the aligned nanoparticles and causes them to be coated with a thin layer of oxide 105 (from the silica or titania precursor).
  • oxide 105 from the silica or titania precursor
  • a control experiment was carried out in the absence of a magnetic field, where there was no movement of nanoparticles towards the interface; therefore no coating reaction occurred and no nanowire structures were formed. Nanowires are only formed due to the presence of the magnetic field and the formation of an oxide coating at the interface.
  • polyelectrolyte-stabilised magnetic nanoparticles were prepared according to Table 1 by mixing poly(sodium-4-styrene) sulfonate (PSSS) (0.05 g, 7.14 x 10 "7 mol [sample 1 ] or 0.1 g, 1 .43 x 10 "6 mol [sample 2] dissolved in 10 mL water) with cobalt nitrate hexahydrate (0.15 g, 0.5 mmol) and iron chloride tetrahydrate (0.2 g, 1 mmol) dissolved in 25 mL of deoxygenated Millipore water and carrying out a co-precipitation reaction using ammonium hydroxide (NH 4 OH) (20 mL, 30v/v%) at 80-90 °C for 2 hours.
  • PSSS poly(sodium-4-styrene) sulfonate
  • NH 4 OH ammonium hydroxide
  • the resulting magnetic colloid was washed with water until pH neutral and dried under vacuum to yield strongly magnetic black powder: referred to as PSSS-CoFe 2 0 4 nanoparticles.
  • the resulting nanoparticles prepared were composed of PSSS and metal ions in the molar ratios listed in Table 1 .
  • Stabilised magnetic nanoparticles comprising various magnetic nanoparticles can be prepared using this method and can be utilised as the magnetic component in this invention.
  • the preparation of the nanowires was as follows. PSSS-magnetic nanoparticles (5 mL of a 4 x10 "5 g/mL suspension of nanoparticles in ethanol) were dispersed in a water (5 mL) and NH 4 OH (0.1 mL, 30v/v%) solution by manual shaking to form aqueous solutions (referred to as the 'magnetic solution'). A solution of dichloromethane (DCM) (1 OmL) and silicon or titanium alkoxide precursor (tetraethylorthosilicate [TEOS] or titanium isopropoxide) (9 x 10 "3 mol) was prepared in a beaker. The magnetic solution was then carefully transferred on top of the DCM/precursor solution in order to form a bi-layer. The reaction vessel was then placed on top of a magnet for several hours; until brown magnetic material collected at the bottom of the beaker near the magnetic surface.
  • DCM dichloromethane
  • TEOS tetraethylor
  • Figures 2 and 3 show TEMs of coated nanowires prepared according to the phase transfer method of the present invention.
  • Figures 2A and 2B show different magnifications of silica coated cobalt ferrite nanowires.
  • Figure 2C shows that the silica coated linear nanowires take up a non-parallel, scattered arrangement in the absence of a magnetic field.
  • Figure 2D we see that the silica coated nanowires remain responsive to an external field - they line up in a parallel arrangement upon application of the external magnetic field.
  • Figures 3A and 3B show different magnifications of titania coated cobalt ferrite nanowires.
  • Figure 3C shows that the titania coated linear nanowires take up a non-parallel, scattered arrangement in the absence of a magnetic field.
  • Figure 3D we see that the titania coated nanowires remain responsive to an external field - they line up in a parallel arrangement upon application of the external magnetic field.
  • Emulsions consisting of magnetic nanoparticles stabilising water-in-oil and oil-in-water emulsions can be used to form stable suspensions of materials. Initially, magnetic
  • nanoparticles were prepared by co-precipitation of a solution containing iron chloride tetrahydrate (0.79 g, 4 mmol) and cobalt nitrate hexahydrate (0.58 g, 2 mmol) in 100 mL deoxygenated Millipore water using ammonium hydroxide (NH 4 OH) (20 mL, 30v/v%) at 80-90 °C for 2 hours.
  • NH 4 OH ammonium hydroxide
  • the resulting magnetic colloid was washed with water until pH neutral and dried under vacuum to yield a strongly magnetic black powder: referred to as CoFe 2 0 4 nanoparticles.
  • An emulsion was prepared by mixing a dry sample of magnetic nanoparticles (0.1 g, 0.4 mmol) in water (0.7 mL), followed by the addition of oleic acid (24.6 mL, 0.078 mol). The reactants were mixed by sonication and vigorous stirring so as to create an emulsion.
  • the emulsion can be destabilised by placing the sample vessel on top of a magnet, where the nanoparticles move the bottom of the flask, destroying the stable emulsion and yielding a layered bi-phasic system.
  • the magnetic nanoparticle sample used to prepare the nanoparticles causes a change in the appearance of the resulting nanowire structures Figure 4.
  • the magnetic nanoparticles utilised were polyelectrolyte stabilised magnetic nanoparticles, namely poly(sodium-4-styrenesulfonate) stabilised cobalt ferrite (PSSS- CoFe 2 0 4 ).
  • PSSS is a negatively charged polyelectrolyte, which is used as a stabiliser during the preparation of CoFe 2 0 4 nanoparticles and it hinders or prevents flocculation/agglomeration of the nanoparticles.
  • the PSSS-stabilised CoFe 2 0 4 nanoparticles were prepared with different concentrations of PSSS. Sample 1 was prepared using a high concentration of PSSS. Sample 2 was prepared using a lower concentration of PSSS, as shown in Table 1.
  • Dcore - diameter of the core D hy d - hydrodynamic diameter; Pdl - Polydispersity index.
  • Sample 1 prepared with higher concentrations of poly(sodium-4-styrenesulfonate) exhibits lower magnetisation per kilogram owing to the larger amount of PSSS on the particles.
  • Sample 2 prepared with lower concentrations of poly(sodium-4-styrenesulfonate) exhibits higher magnetisation per kilogram owing to the smaller amount of PSSS on the particles.
  • Particles from both samples are relatively monodisperse showing low Pdl values.
  • Figure 4 we can see the effect of using the different magnetic nanoparticle samples (i.e. Sample 1 or Sample 2 supra) to prepare silica coated nanowires, with all other parameters and concentrations remaining constant.
  • TEM images a, b and c depict silica coated nanowires formed using Sample 1 PSSS- CoFe 2 0 4 .
  • TEM images d, e and f depict silica coated nanowires formed using Sample 2 PSSS- CoFe 2 0 4 .
  • TEM images a, b and c illustrate shorter, narrower nanowires when compared with TEM images d, e, and f, where the nanowires have a larger aspect ratio, are longer in length (they stretch across the TEM grid squares), have a thicker width, and have a more ordered appearance.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Health & Medical Sciences (AREA)
  • Nanotechnology (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Organic Chemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • Bioinformatics & Cheminformatics (AREA)
  • General Physics & Mathematics (AREA)
  • Animal Behavior & Ethology (AREA)
  • Materials Engineering (AREA)
  • Medicinal Chemistry (AREA)
  • Pharmacology & Pharmacy (AREA)
  • Epidemiology (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • Composite Materials (AREA)
  • Toxicology (AREA)
  • Physical Or Chemical Processes And Apparatus (AREA)

Abstract

Les réactions par transfert de phase (PTC) constituent l'une des technologies les plus efficaces et universelles, qui sont utilisées en synthèse organique dans l'industrie et dans des laboratoires de recherche. Les réactions par transfert (PTC) de phase sont beaucoup utilisées pour la production de tensioactifs, de polymères, d'arômes et de parfums, de produits pétrochimiques, de produits agrochimiques, de colorants, de produits pharmaceutiques et d'explosifs. La présente invention porte sur un procédé permettant d'amorcer des réactions par transfert de phase par l'application d'un champ magnétique. La présente invention porte également sur un procédé pour la préparation de structures de type nanofil revêtues stables utilisant une catalyse par transfert de phase et/ou des réactions de condensation amorcées par voie magnétique.
PCT/EP2012/066789 2011-08-29 2012-08-29 Réactions par transfert de phase Ceased WO2013030240A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
EP11179226.3 2011-08-29
EP11179226 2011-08-29

Publications (1)

Publication Number Publication Date
WO2013030240A1 true WO2013030240A1 (fr) 2013-03-07

Family

ID=46727251

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2012/066789 Ceased WO2013030240A1 (fr) 2011-08-29 2012-08-29 Réactions par transfert de phase

Country Status (1)

Country Link
WO (1) WO2013030240A1 (fr)

Citations (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3992432A (en) 1967-04-05 1976-11-16 Continental Oil Company Phase transfer catalysis of heterogeneous reactions by quaternary salts
US4206094A (en) * 1976-06-09 1980-06-03 California Institute Of Technology Method for producing a biological reagent
US4283438A (en) * 1979-12-26 1981-08-11 Magnavox Government And Industrial Electronics Company Method for individually encapsulating magnetic particles
US4460778A (en) 1983-04-28 1984-07-17 General Electric Company Phase transfer catalysts
US4694104A (en) 1982-08-09 1987-09-15 Gaf Corporation Phase transfer catalysts
US4973771A (en) 1986-01-06 1990-11-27 Mallinckrodt, Inc. Phase transfer catalysts
US5232782A (en) * 1989-12-27 1993-08-03 Rhone-Poulenc Chimie Magnetizable "core-shell" microspheres based on a cross-linked organopolysiloxane and a process for their preparation
US5279936A (en) * 1989-12-22 1994-01-18 Syntex (U.S.A.) Inc. Method of separation employing magnetic particles and second medium
US6548264B1 (en) * 2000-05-17 2003-04-15 University Of Florida Coated nanoparticles
EP1337219A2 (fr) 2000-11-24 2003-08-27 Nanosolutions GmbH Transfert de phase de nanoparticules
US20050165120A1 (en) 2004-01-22 2005-07-28 Ashavani Kumar Process for phase transfer of hydrophobic nanoparticles
US20060133954A1 (en) * 2004-12-21 2006-06-22 Instrumentation Laboratory Company Resuspension of magnetizable particles
US20060228421A1 (en) * 2005-04-08 2006-10-12 Nanobiomagnetics, Inc. Device for moving magnetic nanoparticles through tissue
US20070059782A1 (en) * 2005-09-13 2007-03-15 Graham Henry A Magnetic particle tagged blood bank reagents and techniques
US20070059705A1 (en) * 2003-08-08 2007-03-15 Huachang Lu Fluorescent magnetic nanoparticles and process of preparation
US20100215851A1 (en) 2007-04-25 2010-08-26 Tetsuya Shoji Method of producing core/shell composite nano-particles

Patent Citations (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3992432A (en) 1967-04-05 1976-11-16 Continental Oil Company Phase transfer catalysis of heterogeneous reactions by quaternary salts
US4206094A (en) * 1976-06-09 1980-06-03 California Institute Of Technology Method for producing a biological reagent
US4283438A (en) * 1979-12-26 1981-08-11 Magnavox Government And Industrial Electronics Company Method for individually encapsulating magnetic particles
US4694104A (en) 1982-08-09 1987-09-15 Gaf Corporation Phase transfer catalysts
US4460778A (en) 1983-04-28 1984-07-17 General Electric Company Phase transfer catalysts
US4973771A (en) 1986-01-06 1990-11-27 Mallinckrodt, Inc. Phase transfer catalysts
US5279936A (en) * 1989-12-22 1994-01-18 Syntex (U.S.A.) Inc. Method of separation employing magnetic particles and second medium
US5232782A (en) * 1989-12-27 1993-08-03 Rhone-Poulenc Chimie Magnetizable "core-shell" microspheres based on a cross-linked organopolysiloxane and a process for their preparation
US6548264B1 (en) * 2000-05-17 2003-04-15 University Of Florida Coated nanoparticles
EP1337219A2 (fr) 2000-11-24 2003-08-27 Nanosolutions GmbH Transfert de phase de nanoparticules
US20070059705A1 (en) * 2003-08-08 2007-03-15 Huachang Lu Fluorescent magnetic nanoparticles and process of preparation
US20050165120A1 (en) 2004-01-22 2005-07-28 Ashavani Kumar Process for phase transfer of hydrophobic nanoparticles
US20060133954A1 (en) * 2004-12-21 2006-06-22 Instrumentation Laboratory Company Resuspension of magnetizable particles
US20060228421A1 (en) * 2005-04-08 2006-10-12 Nanobiomagnetics, Inc. Device for moving magnetic nanoparticles through tissue
US20070059782A1 (en) * 2005-09-13 2007-03-15 Graham Henry A Magnetic particle tagged blood bank reagents and techniques
US20100215851A1 (en) 2007-04-25 2010-08-26 Tetsuya Shoji Method of producing core/shell composite nano-particles

Similar Documents

Publication Publication Date Title
Mosayebi et al. Synthesis, functionalization, and design of magnetic nanoparticles for theranostic applications
Li et al. Magnetic Fe3O4 nanoparticles: synthesis and application in water treatment
Khajeh et al. Nanoadsorbents: classification, preparation, and applications (with emphasis on aqueous media)
Lu et al. Colloidal nanoparticle clusters: functional materials by design
Rossi et al. Magnetic nanomaterials in catalysis: advanced catalysts for magnetic separation and beyond
Nguyen From formation mechanisms to synthetic methods toward shape-controlled oxide nanoparticles
DE60130757T2 (de) Silizium beschichtete nanopartikel
Keçili et al. The use of magnetic nanoparticles in sample preparation devices and tools
Okoli et al. Comparison and functionalization study of microemulsion-prepared magnetic iron oxide nanoparticles
Lu et al. Magnetic nanoparticles: synthesis, protection, functionalization, and application
Zou et al. Core–Shell Magnetic Particles: Tailored Synthesis and Applications
Rossi et al. Recent advances in the development of magnetically recoverable metal nanoparticle catalysts
Bui et al. Surface-protective assistance of ultrasound in synthesis of superparamagnetic magnetite nanoparticles and in preparation of mono-core magnetite-silica nanocomposites
Zhang et al. Highly efficient treatment of oily wastewater using magnetic carbon nanotubes/layered double hydroxides composites
Chang et al. Membrane emulsification and solvent pervaporation processes for the continuous synthesis of functional magnetic and Janus nanobeads
EP2780422A1 (fr) Procédé de fabrication de particules pourvues d'un revêtement de surface très poreux
US20240093005A1 (en) Polymer-coated nanoparticles, composite nano-emulsion and macro-emulsion
KR102387805B1 (ko) 복합구조 메조결정 나노입자 및 그의 제조방법
Ahmad et al. Iron oxide nanoparticles: An efficient nano-catalyst
da Silva et al. The role of magnetic nanomaterials in miniaturized sample preparation techniques
Kertmen et al. Acetate-induced disassembly of spherical iron oxide nanoparticle clusters into monodispersed core–shell structures upon nanoemulsion fusion
Cid Synthesis of NPs by microemulsion method
US8197890B2 (en) Method of making dendritic magnetic nanostructures
Husein Preparation of nanoscale organosols and hydrosols via the phase transfer route
CN102527407A (zh) 两亲磁性载钯纳米氧化铁及其乳液的制备与应用

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 12750795

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 12750795

Country of ref document: EP

Kind code of ref document: A1