CN107236085A - A kind of method that large area quickly prepares stretching discoloration photon crystal water gel duplicature - Google Patents

Abstract

The invention relates to a method for rapidly preparing a stretched color-changing photonic crystal hydrogel double-layer film in a large area, and belongs to the field of nanocomposite materials. The method is to add acrylamide, photoinitiator and N, N-methylenebisacrylamide to 50wt% high-concentration composite microspheres prepared by emulsion polymerization of styrene, methyl methacrylate and acrylic acid, mix and inject into the glass plate In the process, ultraviolet light triggers the formation of a photonic crystal hydrogel monolayer film; then water is used as a solvent, inorganic nanoparticles are used as a crosslinking agent, acrylamide and/or acrylates are used as monomers, catalysts and/or initiators are added, and mixed It is uniformly poured into the photonic crystal hydrogel film, and the stretchable and color-changing photonic crystal hydrogel bilayer film is formed under the conditions of ultraviolet light triggering or standing at room temperature. The double-layer film can be rapidly stretched and discolored, has a simple method, can be prepared in a large area, has excellent mechanical properties, and can be repeatedly used. It has good application prospects in anti-counterfeiting, optical mechanical sensor devices and bionic skin.

Description

A large-area rapid preparation method of stretched color-changing photonic crystal hydrogel bilayer film

technical field

The invention relates to a method for rapidly preparing a stretched color-changing photonic crystal hydrogel double-layer film in a large area, and belongs to the field of nanocomposite materials.

Background technique

Due to the periodic ordered structure of photonic crystal hydrogels, which have unique optical properties, they have many applications in optical sensing devices, anti-counterfeiting, camouflage, etc., and have attracted more and more attention from researchers. However, most of the current research is limited to the stimulus response to temperature, pH, solvent, etc., and the color change caused by the load force change is rarely reported, which reduces the application of photonic crystal hydrogels in mechanical sensors. The reported methods of mechanical force response are mainly based on isotropic colloidal crystal arrays, but there are some problems: either it is not recoverable, or it cannot be prepared in a large area, or the preparation method is long and cumbersome, or the adjustable wavelength is relatively slow. Narrow, the range of variation is small, which limits its application.

Contents of the invention

The object of the present invention is to address the deficiencies in the above technologies, and propose a method for rapidly preparing a stretched color-changing photonic crystal hydrogel double-layer film in a large area.

The purpose of the present invention is achieved through the following technical solutions.

A method for quickly preparing a stretched color-changing photonic crystal hydrogel bilayer film in a large area, the specific steps are as follows:

Step 1. Add acrylamide, photoinitiator and N, N-methylenebisacrylamide to the high concentration (50wt%) composite microspheres prepared by emulsion polymerization of styrene, methyl methacrylate and acrylic acid, and mix well After being injected into the glass plate, ultraviolet light triggers the formation of a photonic crystal hydrogel monolayer film with a thickness;

Step 2, mix water, crosslinking agent, monomer and initiator, or water, crosslinking agent, monomer, catalyst and initiator; Stretchable and color-changing photonic crystal hydrogel bilayer film is formed under the condition of setting. The mass ratio of the inorganic nanoparticles to water is any value from 1:100 to 15:100.

The mass ratio of acrylamide and composite microspheres in the single-layer film in step 1 is 3:100 to 10:100; the mass ratio of N,N-methylenebisacrylamide to composite microspheres is 0.1:100 to 0.5: 100.

The thickness of the single-layer film in step 1 is 0.05-0.15 mm.

The monomer described in step 2 is acrylamide, acrylate or acrylamide and acrylate.

The acrylates include: any one or more of N-isopropylacrylamide, N-methylolacrylamide, N,N-dimethylacrylamide, methacrylamide, acrylic acid, and methacrylic acid A mixture, the concentration of the acrylamide or acrylate is 2mol/L-5mol/L.

The cross-linking agent described in step 2 is inorganic nanoparticles.

The inorganic nanoparticles include any one or a mixture of clay, titanium dioxide, aluminum oxide, zinc oxide or zirconium oxide.

When using UV light initiation, the initiators used include: 2,4,6 -Trimethylbenzoyl-diphenylphosphine oxide, 2-methyl-1-[4-methylthiophenyl]-2-morpholinyl-1-propanone or 2-hydroxy-4'-(2 Any of -hydroxyethoxy)-2-methylpropiophenone; when initiating under the condition of standing at room temperature, the initiator used is any one of potassium persulfate, ammonium persulfate and dibenzoyl oxide kind.

When using ultraviolet light to initiate, the concentration of the initiator is 0.2-3g/L, and the polymerization time is 30-120min; minute.

The catalyst in step 2 is any one of N,N,N',N'-tetramethylethylenediamine, triethanolamine or sodium thiosulfate, and the concentration is 0.8mL/L.

Beneficial effect

(1) The preparation method of the photonic crystal hydrogel bilayer film with stretchable color change is simple, and the preparation can be completed within 2 hours, and it can be prepared on a large glass plate in a large area, which is convenient for promotion and application.

(2) The maximum stress borne by the double-layer film is 280kPa, and the elongation at break is 166%, which is better than the mechanical properties of the single-layer film.

(3) Within the deformation range of 57%, the double-layer film can change from red to blue, and the wavelength of visible light can be changed from 656nm to 451nm, basically covering the entire visible wavelength range, and the adjustment wavelength range is wide.

Description of drawings

Fig. 1 is in the embodiment 1 of the present application, prepares the photonic crystal hydrogel bilayer film in the large area between 20 * 20cm glass plates before the polymerization physical picture;

Fig. 2 is the contrast tensile stress-strain figure of monolayer film and bilayer film prepared in the embodiment 1 of the present application;

The reflectance spectrogram of the bilayer film stretching process prepared in the embodiment 1 of Fig. 3 of the present application;

Fig. 4 is a stress-strain diagram and a reflectance spectrum diagram during cyclic stretching of the bilayer film prepared in Example 1 of the present application.

detailed description

In order to make the above objects, features and advantages of the present invention more comprehensible, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Example 1

A large-area rapid preparation method for the preparation of a stretched color-changing photonic crystal hydrogel double-layer film of the present application specifically includes the following steps:

(1) 8g styrene, 1g methyl methacrylate and 1g acrylic acid prepare high concentration (50wt%) composite microspheres by emulsion polymerization, then add 0.25g acrylamide and 0.015g N, N-methylenebisacrylamide In a centrifuge tube equipped with 5g of high-concentration composite microspheres (50wt%), after mixing evenly, pour it into two glass plates of 20×20cm with 0.06mm thick rubber gaskets, and induce polymerization for 30min by ultraviolet light to obtain photons Crystalline hydrogel monolayers.

(2) 10.0g of zirconia sol with a mass fraction of 15%, 0.32g of acrylic acid, and 4.0g of N,N-dimethylacrylamide were added to a 50mL reaction flask containing 6.5g of ultrapure water, and stirred under magnetic force Nitrogen was passed for 20 minutes, 0.045 g of 2-hydroxyl-4'-(2-hydroxyethoxy)-2-methylpropiophenone was added, nitrogen was passed into the liquid above the liquid level, and nitrogen gas was continued to stir for 15 minutes to obtain zirconia nanocomposite water Gel prepolymer.

(3) The obtained photonic crystal hydrogel monolayer film is tightly clamped between two 20×20cm glass plates with 0.5mm thick rubber spacers, and then the zirconia nanocomposite hydrogel prepolymerization liquid Add it from one side, as shown in Figure 1, UV light triggers polymerization for 40 minutes to obtain a photonic crystal hydrogel bilayer film.

The mechanical properties of the photonic crystal hydrogel single-layer film and double-layer film prepared in Example 1 are tensile tested with an electronic universal material testing machine, and the tensile speed is 10mm/min, as shown in Figure 2: the single-layer The maximum stress that the film bears is 75kPa, and the elongation at break is 50%. The maximum stress that the double-layer film bears is 280kPa, and the elongation at break is 166%. The excellent mechanical properties of the double-layer film can be seen through comparison.

For the optical properties of the photonic crystal hydrogel bilayer film prepared in Example 1, its reflection spectrum was measured with a fiber optic spectrometer, as shown in FIG. 3 . The photonic crystal hydrogel double-layer film can change from red to blue, and within the range of 57% deformation, the wavelength of visible light changes from 656nm to 451nm, basically covering the entire visible light wavelength range, which is unprecedented in single-layer films appeared.

For the photonic crystal hydrogel double-layer film prepared in Example 1, five cyclic tensile tests were carried out with a universal material testing machine, and the corresponding reflection wavelength test was carried out with a fiber optic spectrometer, as shown in FIG. 4 . During the cyclic stretching process, the wavelength of visible light of the double-layer film is repeatedly changed between 656nm and 451nm, which has good recoverability and repeatability.

The method for rapidly preparing a large-area stretched color-changing photonic crystal hydrogel double-layer film provided by the present invention has been described in detail above. In this paper, specific examples are used to illustrate the implementation of the present invention. The above examples The description is only used to help understand the method and core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation and scope of application. In summary , the contents of this specification should not be construed as limiting the present invention.

Claims (10)

1. A method for rapidly preparing stretched color-changing photonic crystal hydrogel bilayer membranes in a large area, characterized in that: the specific steps are as follows: Step 1. Add acrylamide, photoinitiator and N, N-methylenebisacrylamide to the high-concentration composite microspheres prepared by emulsion polymerization of styrene, methyl methacrylate and acrylic acid, mix well and inject into the glass In the plate, ultraviolet light triggers the formation of a photonic crystal hydrogel monolayer film with a thickness; Step 2, mix water, crosslinking agent, monomer and initiator, or water, crosslinking agent, monomer, catalyst and initiator; Under certain conditions, a stretchable and color-changing photonic crystal hydrogel bilayer film is formed; the mass ratio of the cross-linking agent to water is 1:100-15:100. 2. A method for quickly preparing a large-area stretched color-changing photonic crystal hydrogel bilayer film as claimed in claim 1, characterized in that: the cross-linking agent in step 2 is an inorganic nano-particle. 3. A kind of method for rapidly preparing stretched color-changing photonic crystal hydrogel double-layer film in a large area as claimed in claim 1 or 2, characterized in that: the inorganic nanoparticles include: clay, titanium dioxide, aluminum oxide, oxide Any one or a mixture of zinc or zirconia. 4. a kind of method for rapidly preparing stretched color-changing photonic crystal hydrogel double-layer film in a large area as claimed in claim 1, is characterized in that: the monomer described in step 2 is acrylamide, acrylates or acrylamide and Acrylics. 5. A kind of method for quickly preparing stretched color-changing photonic crystal hydrogel double-layer film in a large area as claimed in claim 1 or 4, characterized in that: said acrylates include: N-isopropylacrylamide, Any one or more mixtures of N-methylolacrylamide, N,N-dimethylacrylamide, methacrylamide, acrylic acid, and methacrylic acid, the concentration of the acrylamide or acrylate is 2mol/ L～5mol/L. 6. A kind of method for quickly preparing stretched color-changing photonic crystal hydrogel double-layer film in a large area as claimed in claim 1, is characterized in that: the mass ratio of acrylamide and composite microspheres in the single-layer film described in step one 3:100～10:100; the mass ratio of N,N-methylenebisacrylamide and composite microspheres is 0.1:100～0.5:100. 7. A method for quickly preparing a large-area stretched color-changing photonic crystal hydrogel double-layer film as claimed in claim 1, characterized in that: the thickness of the single-layer film in step 1 is 0.05-0.15 mm. 8. A kind of method for rapidly preparing stretched color-changing photonic crystal hydrogel double-layer film in a large area as claimed in claim 1, characterized in that: when using ultraviolet light to initiate in step 2, the initiators used include: 2, 4,6-Trimethylbenzoyl-diphenylphosphine oxide, 2-methyl-1-[4-methylthiophenyl]-2-morpholinyl-1-propanone or 2-hydroxy-4' -Any one of (2-hydroxyethoxy)-2-methylpropiophenone; when initiating under the condition of standing at room temperature, the initiators used are potassium persulfate, ammonium persulfate and dibenzoyl oxide of any kind. 9. A method for quickly preparing a large-area stretched color-changing photonic crystal hydrogel bilayer film as claimed in claim 1, characterized in that: when step 2 is initiated by ultraviolet light, the concentration of the initiator is 0.2-3g /L, the polymerization time is 30 to 120 minutes; when initiated under the condition of standing at room temperature, the concentration of the initiator is 1 g/L, and the polymerization time is greater than or equal to 30 minutes. 10. A method for rapidly preparing a stretched color-changing photonic crystal hydrogel bilayer film in a large area as claimed in claim 1, wherein the catalyst in step 2 is N, N, N', N'-Tetra Any one of methylethylenediamine, triethanolamine or sodium thiosulfate, the concentration is 0.8mL/L.