阅读说明：本技术 一种聚苯胺/纳米纤维素纤丝复合导电薄膜及其制备方法 (Polyaniline/nano cellulose fiber composite conductive film and preparation method thereof ) 是由 林涛 张能 殷学风 蔺家成 王忠祥 王俊 魏潇瑶 蔡雪 于 2020-07-22 设计创作，主要内容包括：本发明一种聚苯胺/纳米纤维素纤丝复合导电薄膜及其制备方法,所述方法包括步骤1,将苯胺的盐酸溶液与纳米纤维素纤丝溶液混合均匀,苯胺与纳米纤维素纤丝的质量比为(0.1-0.5)：(0.03-0.9),得到均匀体系A；步骤2,在均匀体系A中加入过硫酸铵,得到均匀体系B,将均匀体系B在冰水浴中进行反应,得到反应液；步骤3,将反应液在滤膜上进行抽滤,滤膜上形成聚苯胺/纳米纤维素纤丝复合导电薄膜。本发明采用将苯胺单体在纳米纤维素纤丝上原位聚合的方法来改进聚苯胺的加工性能从而促进聚苯胺实用化,复合薄膜具有优异的机械性能、较高的电导率,在柔性电极、传感器、导电柔性膜等方面具有广阔的应用前景。(The invention relates to a polyaniline/nano cellulose cellosilk composite conductive film and a preparation method thereof, wherein the method comprises the following steps of 1, uniformly mixing a hydrochloric acid solution of aniline and a nano cellulose cellosilk solution, wherein the mass ratio of aniline to nano cellulose cellosilk is (0.1-0.5): (0.03-0.9) to obtain a uniform system A; step 2, adding ammonium persulfate into the uniform system A to obtain a uniform system B, and reacting the uniform system B in an ice-water bath to obtain a reaction solution; and 3, carrying out suction filtration on the reaction solution on a filter membrane to form the polyaniline/nano cellulose fiber composite conductive film on the filter membrane. The invention adopts the method of in-situ polymerization of aniline monomer on the nanometer cellulose fiber to improve the processing performance of polyaniline so as to promote the practicability of polyaniline, and the composite film has excellent mechanical property and higher conductivity and has wide application prospect in the aspects of flexible electrodes, sensors, conductive flexible films and the like.)

1. A preparation method of a polyaniline/nano cellulose fiber composite conductive film is characterized by comprising the following steps:

step 1, uniformly mixing a hydrochloric acid solution of aniline and a nano cellulose silk solution, wherein the mass ratio of aniline to nano cellulose silk is (0.1-0.5): (0.03-0.9) to obtain a uniform system A;

step 2, adding ammonium persulfate into the uniform system A to obtain a uniform system B, and reacting the uniform system B in an ice-water bath to obtain a reaction solution;

and 3, carrying out suction filtration on the reaction solution on a filter membrane to form the polyaniline/nano cellulose fiber composite conductive film on the filter membrane.

2. The method for preparing a polyaniline/nanocellulose filament composite conductive film as claimed in claim 1, wherein in step 3, the polyaniline/nanocellulose filament composite conductive film is peeled off from the filter membrane to obtain the polyaniline/nanocellulose filament composite conductive film.

3. The method for preparing a polyaniline/nanocellulose filament composite conductive film as claimed in claim 1, wherein said aniline hydrochloric acid solution in step 1 is obtained by adding 0.1-0.5g aniline monomer into 0.5-1.5mol/L hydrochloric acid and stirring.

4. The method for preparing the polyaniline/nanocellulose filament composite conductive film as claimed in claim 1, wherein in step 1, the ratio of HCl in hydrochloric acid to the aniline is 0.5-1.5 mol: 0.1-0.5 g.

5. The method for preparing the polyaniline/nanocellulose filament composite conductive film as claimed in claim 1, wherein the mass fraction of nanocellulose filaments in the nanocellulose filament solution in step 1 is 0.3% -1.5%.

6. The method for preparing the polyaniline/nanocellulose filament composite conductive film according to claim 1, wherein the mass ratio of ammonium persulfate to aniline in step 2 is (0.2-1.5): (0.1-0.5).

7. The method for preparing the polyaniline/nanocellulose filament composite conductive film as claimed in claim 1, wherein the ice water bath temperature in step 2 is 0-5 ℃.

8. The method for preparing the polyaniline/nanocellulose filament composite conductive film as claimed in claim 1, wherein the homogeneous system B in step 2 is reacted in an ice-water bath for 4-8 h.

9. A polyaniline/nanocellulose filament composite conductive film obtained by the method for producing a polyaniline/nanocellulose filament composite conductive film according to any one of claims 1 to 8.

Technical Field

The invention belongs to the technical field of composite membrane materials, and particularly relates to a polyaniline/nano cellulose fiber composite conductive film and a preparation method thereof.

Background

Cellulose is a natural renewable high molecular organic substance with the most abundant natural reserves, mainly exists in the cell wall of plants, and is almost regarded as an inexhaustible raw material. The nanometer cellulose fiber (CNF) is obtained by peeling cellulose, has the diameter of 20-50nm and the length of dozens of nanometers to several micrometers, has the characteristics of high length-diameter ratio, good flexibility, high strength, good thermal stability, good biocompatibility and the like, and in addition, the nanometer cellulose fiber has good flexibility and mechanical property, and the fibers are mutually connected in a staggered way, so that a porous structure convenient for ion and electron transmission is easily formed. The surface of the cellulose cellosilk is also attached with hydrophilic functional groups such as hydroxyl, carboxyl and the like, so that the cellulose cellosilk has good moisturizing capability in an electrolyte solution and has wide application prospect in the field of energy storage. The fine nanostructure and high specific surface area of the nanocellulose fibrils facilitate the formation of nanosized conducting polymers. The conductive polymer can be directly grown on the surface of the nano cellulose fiber by an in-situ chemical polymerization or electrochemical codeposition method to form the conductive composite material with different nano structures.

The rich functional groups on macromolecules of the nano cellulose fibrils enable the nano cellulose fibrils to have better reactivity and adsorption capacity, and the nano cellulose fibrils can be compounded with electroactive materials such as carbon nanotubes, graphene, polypyrrole, polyaniline and the like to obtain an electrode material with good electrochemical performance, so that the high-performance composite material which is ultrathin, flexible, self-supporting and free of any adhesive can be prepared. Polyaniline is one of widely researched conductive polymers, and has the excellent characteristics of easy synthesis, modification, low monomer cost, better environmental stability than other conductive polymers and the like.

However, polyaniline has poor comprehensive mechanical properties, is insoluble in common organic solvents and has poor rheological properties, so that the polyaniline is difficult to adopt a traditional forming processing method, which seriously hinders the large-scale popularization and application of the polyaniline in various fields. The problem can be overcome by compounding polyaniline with the nanocellulose filaments through theoretical analysis, but no relevant report exists at present.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides the polyaniline/nano cellulose fiber composite conductive film and the preparation method thereof, and the polyaniline/nano cellulose fiber composite conductive film has excellent mechanical properties, higher conductivity, biodegradability and wide application prospect.

The invention is realized by the following technical scheme:

a preparation method of a polyaniline/nano cellulose fiber composite conductive film comprises the following steps:

step 1, uniformly mixing a hydrochloric acid solution of aniline and a nano cellulose silk solution, wherein the mass ratio of aniline to nano cellulose silk is (0.1-0.5): (0.03-0.9) to obtain a uniform system A;

step 2, adding ammonium persulfate into the uniform system A to obtain a uniform system B, and reacting the uniform system B in an ice-water bath to obtain a reaction solution;

and 3, carrying out suction filtration on the reaction solution on a filter membrane to form the polyaniline/nano cellulose fiber composite conductive film on the filter membrane.

Preferably, in step 3, the polyaniline/nanocellulose fiber composite conductive film is removed from the filter membrane to obtain the polyaniline/nanocellulose fiber composite conductive film.

Preferably, the hydrochloric acid solution of aniline described in step 1 is obtained by adding 0.1-0.5g of aniline monomer to 0.5-1.5mol/L hydrochloric acid and stirring.

Preferably, in step 1, the ratio of HCl in hydrochloric acid to said aniline is between 0.5 and 1.5 mol: 0.1-0.5 g.

Preferably, the mass fraction of the nanocellulose filaments in the nanocellulose filament solution described in step 1 is 0.3% -1.5%.

Preferably, the mass ratio of ammonium persulfate to aniline in the step 2 is (0.2-1.5): (0.1-0.5).

Preferably, the temperature of the ice water bath in the step 2 is 0-5 ℃.

Preferably, the homogeneous system B in the step 2 is reacted in an ice-water bath for 4 to 8 hours.

The polyaniline/nanocellulose fiber composite conductive film is prepared by the method for preparing the polyaniline/nanocellulose fiber composite conductive film.

Compared with the prior art, the invention has the following beneficial technical effects:

the invention relates to a preparation method of a polyaniline/nano cellulose fiber composite conductive film, which utilizes an aniline monomer to generate a CNF/PANI conductive composite material by an in-situ polymerization method on the surface of a nano cellulose fiber, thereby realizing the complementation between polyaniline conductivity and nano cellulose fiber film-forming property. As the polyaniline in an intrinsic state is non-conductive and has conductivity only after being doped with protonic acid, when the polyaniline is doped, the molecular chain of the polyaniline does not change the number of electrons, but is protonated on imine nitrogen atoms to generate polarons, so that holes appear on a doped band of the molecular chain, namely P-type doping occurs. The invention adopts hydrochloric acid as protonic acid dopant and ammonium persulfate as oxidant, and the polyaniline is synthesized by uniformly mixing aniline, hydrochloric acid and nano cellulose filaments, adding ammonium persulfate to react in an ice-water bath and carrying out chemical oxidative polymerization. The reaction process is divided into three stages of a chain induction and initiation period, a chain growth period and a chain termination period in sequence, firstly aniline is slowly oxidized into cationic free radicals, two cationic free radicals form a dimer in a head-tail connection mode, then the dimer is quickly oxidized into a quinoid structure, the aniline dimer of the structure directly undergoes a polymerization reaction with an aniline monomer to form a trimer, the trimer molecule continues to grow to form a higher polymerization degree, the growth mode of the trimer is similar to that of the dimer, and the chain growth is mainly carried out in a head-tail connection mode. The method adopts the method of in-situ polymerization of aniline monomer on the nanometer cellulose fiber to improve the processing performance of polyaniline so as to promote the practicability of polyaniline, and the obtained nanometer cellulose fiber and polyaniline composite film has excellent mechanical performance and higher conductivity and has wide application prospect in the aspects of flexible electrodes, sensors, conductive flexible films and the like.

Drawings

FIG. 1 is an atomic force microscope image of polyaniline obtained in example 1 of the present invention.

Fig. 2 is an atomic force microscope image of the CNF/PANI composite flexible conductive film obtained in example 1 of the present invention.

Fig. 3 is a stretched state diagram of the CNF/PANI composite flexible conductive film obtained in embodiment 2 of the present invention.

Fig. 4 is a folded state diagram of the CNF/PANI composite flexible conductive film obtained in example 2 of the present invention.

Detailed Description

The present invention will now be described in further detail with reference to specific examples, which are intended to be illustrative, but not limiting, of the invention.

The invention relates to a preparation method of a polyaniline/nano cellulose fibril composite conductive film, which comprises the following steps;

step 1, adding 0.1-0.5g aniline monomer into 100ml hydrochloric acid of 0.5-1.5mol/L, and continuously magnetically stirring for 30-60min at room temperature to fully mix;

step 2, adding 10-60g of 0.3 wt% -1.5 wt% CNF aqueous solution into the mixed solution of aniline monomer and hydrochloric acid, and stirring for 30-60min by magnetic force to fully mix;

step 3, adding 0.2-1.5g of ammonium persulfate into the mixed solution, and reacting for 4-8h under the condition of ice-water bath at the temperature of 0-5 ℃;

and 4, filtering the mixed solution after the reaction through a filter membrane with the aperture of 0.45 mu m to form a membrane, slowly drying the membrane at room temperature, and then removing the membrane to obtain the flexible composite membrane.

The invention utilizes the characteristic of good film forming property of the nano cellulose fibers as a base material for synthesizing polyaniline, so that polyaniline is generated on the nano cellulose fibers by aniline monomers in a CNF suspension through in-situ polymerization.