CN-122011517-A - Cellulose nanocrystalline composite photon film and preparation method and application thereof

CN122011517ACN 122011517 ACN122011517 ACN 122011517ACN-122011517-A

Abstract

The invention belongs to the technical field of photonic crystal sensing materials, and relates to a cellulose nanocrystalline composite photonic film, a preparation method and application thereof. The preparation method comprises the steps of preparing cellulose nanocrystals by taking microcrystalline cellulose as a raw material, preparing a cellulose nanocrystal solution by blending the cellulose nanocrystals with water, adding soluble starch into the cellulose nanocrystal solution to prepare a composite membrane solution, pouring the composite membrane solution, and drying to prepare the cellulose nanocrystal composite photon membrane. The cellulose nanocrystalline composite photon film provided by the invention has excellent optical performance and mechanical performance, can rapidly respond and distinguish methanol and ethanol, and has response time not exceeding 20s.

Inventors

CHEN LEI
TENG HUI
Dai Miaoqi
AI CHAO
Zhou Ruizi
CHEN CHONG

Assignees

广东海洋大学
广东海洋大学深圳研究院

Dates

Publication Date: 20260512
Application Date: 20260226

Claims (10)

1. The cellulose nanocrystalline composite photon film is characterized by being formed by compositing cellulose nanocrystalline and soluble starch; Wherein the mass ratio of the cellulose nanocrystalline to the soluble starch is 4-20:1-3.
2. The preparation method of the cellulose nanocrystalline composite photon film is characterized by comprising the steps of preparing cellulose nanocrystalline by acid hydrolysis of microcrystalline cellulose, preparing a cellulose nanocrystalline solution by blending the cellulose nanocrystalline and water, preparing a composite film liquid by adding soluble starch into the cellulose nanocrystalline solution, pouring the composite film liquid, and drying to obtain the cellulose nanocrystalline composite photon film.
3. The preparation method of the cellulose nanocrystalline composite photon film according to claim 2 is characterized in that the acid hydrolysis comprises the steps of mixing microcrystalline cellulose and sulfuric acid solution, stirring, standing to obtain a milky white solution, centrifugally washing the milky white solution to a pale blue solution, dialyzing, carrying out ultrasonic treatment, and freeze-drying to obtain cellulose nanocrystalline.
4. The method for preparing a cellulose nanocrystalline composite photon film according to claim 3, wherein the mass fraction of the sulfuric acid solution is 60%; The molecular weight cut-off of the dialysis is 12-14 kDa.
5. The preparation method of the cellulose nanocrystalline composite photon film according to claim 2, wherein the mass concentration of the cellulose nanocrystalline solution is 0.5% -7.5%.
6. The method for preparing the cellulose nanocrystalline composite photon film according to claim 2, wherein the drying temperature is 22-28 ℃, the humidity is 45%, and the time is 68-76 h.
7. Use of the cellulose nanocrystalline composite photonic film according to claim 1 for identifying methanol and/or ethanol.
8. The use according to claim 7, wherein the identification is visual identification, comprising the steps of contacting the cellulose nanocrystalline composite photonic film with a liquid to be measured, and observing the color change of the cellulose nanocrystalline composite photonic film; If the color of the cellulose nanocrystalline composite photon film is changed from blue or green to green or yellow, judging that the liquid to be detected is ethanol; And if the color of the cellulose nanocrystalline composite photon film is changed from blue or green to orange or dark red, judging that the liquid to be detected is methanol.
9. The method according to claim 7, wherein the identification is an instrumented identification, and the method comprises the steps of measuring the maximum absorption wavelength lambda 0 of the cellulose nanocrystalline composite photon film before contacting the liquid to be measured, measuring the maximum absorption wavelength lambda 1 of the cellulose nanocrystalline composite photon film after contacting the liquid to be measured, calculating the ratio of lambda 1 to lambda 0 , and judging according to the ratio; If the ratio is more than or equal to 1.16, judging that the liquid to be detected is methanol; if the ratio is less than or equal to 1.16, judging that the liquid to be detected is ethanol.
10. The use according to claims 8-9, characterized in that the contact time is 10-20 s.

Description

Cellulose nanocrystalline composite photon film and preparation method and application thereof Technical Field The invention belongs to the technical field of photonic crystal sensing materials, and relates to a cellulose nanocrystalline composite photonic film, a preparation method and application thereof. Background The rapid and accurate identification of methanol and ethanol has important application value in the fields of food safety, industrial process control, medical diagnosis and the like. At present, the identification method is mainly divided into two types, namely an analysis method based on a gas chromatograph and other instruments, wherein the detection precision is high, equipment is expensive, the operation is complex and the rapid detection test paper is difficult to use for on-site rapid screening, and the rapid detection test paper based on a chemical color reaction is convenient to carry and use, generally has the problems of low sensitivity, long response time, incapability of being repeatedly used and the like, and is difficult to meet the real-time detection requirements of low cost and high sensitivity. In recent years, sensing materials based on the principle of optical response have received widespread attention. Among them, cellulose Nanocrystals (CNCs) have demonstrated potential in the field of visual sensing because they can self-assemble to form cholesteric liquid crystal films with structural colors. When the CNC film contacts polar solvents such as methanol, ethanol and the like, the internal hydrogen bond network thereof is recombined, so that the color of the film is reversibly changed, thereby providing possibility for quick and visual identification of the CNC film and the polar solvent. However, CNC films still face the following key problems in practical application, namely, firstly, the films are poor in mechanical strength, easy to damage and deform and insufficient in durability, secondly, the response sensitivity to methanol/ethanol is limited, thirdly, the optical stability is poor, color attenuation is easy to occur in long-term use or storage, and the detection reliability is affected. In order to improve the performance, the CNC is modified by adopting methods such as hydrophobic dye doping or chemical covalent modification and the like in the prior art. However, such methods tend to result in reduced biocompatibility of the material and may introduce toxic byproducts, increasing environmental risks. In addition, when the mechanical properties are improved by adding a toughening component (such as polyethylene glycol), the problem of compatibility between CNC and a modifier is remarkable, and excessive addition can damage the ordered structure of cholesteric liquid crystal, which instead leads to the decrease of the mechanical properties of the film and the weakening of optical response, and is difficult to achieve both strength and sensitivity. Disclosure of Invention Aiming at the problems and defects existing in the prior art, the invention provides a cellulose nanocrystalline composite photon film, and a preparation method and application thereof. In a first aspect, the present invention provides a cellulose nanocrystalline composite photonic film, the cellulose nanocrystalline composite photonic film being formed by compositing cellulose nanocrystals with soluble starch; Wherein the mass ratio of the cellulose nanocrystalline to the soluble starch is 4-20:1-3. The invention provides a preparation method of a cellulose nanocrystalline composite photon film, which comprises the steps of preparing cellulose nanocrystalline by acid hydrolysis of microcrystalline cellulose, preparing a cellulose nanocrystalline solution by blending the cellulose nanocrystalline and water, preparing a composite film liquid by adding soluble starch into the cellulose nanocrystalline solution, pouring the composite film liquid, and drying to prepare the cellulose nanocrystalline composite photon film. Further, in the preparation method of the cellulose nanocrystalline composite photon film, the acid hydrolysis comprises the steps of mixing microcrystalline cellulose and sulfuric acid solution, stirring, standing to obtain a milky white solution, centrifugally washing the milky white solution to a pale blue solution, dialyzing, carrying out ultrasonic treatment, and freeze-drying to obtain cellulose nanocrystalline. Further, in the preparation method of the cellulose nanocrystalline composite photon film provided by the invention, the mass fraction of the sulfuric acid solution is 60%; The molecular weight cut-off of the dialysis is 12-14 kDa. Further, in the preparation method of the cellulose nanocrystalline composite photon film, the mass concentration of the cellulose nanocrystalline solution is 0.5% -7.5%. Further, in the preparation method of the cellulose nanocrystalline composite photon film, the drying temperature is 22-28 ℃, the humidity is 45%, and the time is 68-76 h. I