CN-118930918-B - Preparation method and application of carboxymethyl cellulose/polyvinyl alcohol high-barrier antibacterial composite film of immobilized nano copper sulfide

Abstract

The invention belongs to the field of functional materials, and provides a preparation method and application of a carboxymethyl cellulose/polyvinyl alcohol high-barrier antibacterial composite film of immobilized nano copper sulfide. Comprises dissolving carboxymethyl cellulose in an alkali urea system, adding cuprammonium ion solution and sodium sulfide solution, reacting, dialyzing, and obtaining immobilized copper sulfide carboxymethyl cellulose solution. Then, polyvinyl alcohol was added to the above solution, and a composite film was prepared by a casting evaporation method. The invention uses carboxymethyl cellulose as a fixing agent, a stabilizing agent and a growth template, does not add any surfactant or chemical stabilizing agent, has the advantages of green preparation method, no toxicity and low cost, and greatly improves the fixing effect of copper sulfide by virtue of the long-chain stabilizing effect of the carboxymethyl cellulose and the excellent film forming property of polyvinyl alcohol. The copper sulfide can convert near infrared light into heat energy so as to locally heat up to achieve the aim of sterilization. The composite film provided by the invention is applied to the field of food antibacterial packaging.

Inventors

• YANG GUIHUA
• ZHANG XU
• JIANG QIMENG
• CHEN JIACHUAN
• LIU KEFENG

Assignees

• 齐鲁工业大学(山东省科学院)

Dates

Publication Date

20260512

Application Date

20240823

Claims (5)

1. 1. The preparation method of the carboxymethyl cellulose/polyvinyl alcohol high-barrier antibacterial composite film of the immobilized nano copper sulfide is characterized by comprising the following steps of: Dissolving carboxymethyl cellulose in an alkali urea system, adding a cuprammonium ion solution and a sodium sulfide solution, and uniformly mixing to obtain a first mixed solution; the mass ratio of the carboxymethyl cellulose to the cuprammonium ion solution to the sodium sulfide solution is 2:1:1-1.5; the mass volume ratio of the carboxymethyl cellulose to the alkali urea solution is 1-5 g/100 mL; The concentration of the copper ammonia complex ion solution is 0.02-0.04M; the concentration of the sodium sulfide solution is 0.025-0.04M; heating the mixed solution to react, and dialyzing after the reaction is completed to obtain carboxymethyl cellulose immobilized copper sulfide solution; Uniformly mixing a polyvinyl alcohol solution with the carboxymethyl cellulose immobilized copper sulfide solution to obtain a second mixed solution; the mass ratio of the carboxymethyl cellulose to the polyvinyl alcohol is 1-5:1-7; forming a film by the second mixed solution casting method to obtain the composite material; The high barrier refers to high barrier property to water vapor, oxygen and air.
2. 2. The method for preparing the carboxymethyl cellulose/polyvinyl alcohol high-barrier antibacterial composite film with immobilized nano copper sulfide according to claim 1, wherein the reaction condition is that the reaction is carried out for 30-60 min at 30-80 ℃.
3. 3. The method for preparing the carboxymethyl cellulose/polyvinyl alcohol high-barrier antibacterial composite film with the immobilized nano copper sulfide as set forth in claim 1, wherein microwave heating is adopted, and the power of microwaves is 700-1000W.
4. 4. A carboxymethyl cellulose/polyvinyl alcohol high barrier antimicrobial composite film of immobilized nano copper sulfide prepared by the method of any one of claims 1-3.
5. 5. The application of the carboxymethyl cellulose/polyvinyl alcohol high-barrier antibacterial composite film of the immobilized nano copper sulfide in preparing antibacterial packages, which is characterized in that applicable objects of the antibacterial packages comprise foods.

Description

Preparation method and application of carboxymethyl cellulose/polyvinyl alcohol high-barrier antibacterial composite film of immobilized nano copper sulfide Technical Field The invention belongs to the field of functional materials, and particularly relates to a preparation method of a carboxymethyl cellulose/polyvinyl alcohol high-barrier antibacterial composite film of immobilized nano copper sulfide, which can be used in the related fields of food antibacterial packaging and the like. Background The disclosure of this background section is only intended to increase the understanding of the general background of the invention and is not necessarily to be construed as an admission or any form of suggestion that this information forms the prior art already known to those of ordinary skill in the art. With the increasing serious ecological environment problems caused by nondegradable petroleum-based plastic packaging products, the development of the environment-friendly degradable antibacterial food packaging material with excellent performance for antibacterial preservation of foods becomes one of the important challenges facing the industry. The food packaging film prepared from the green degradable biomass raw material replaces the traditional non-degradable petroleum-based plastic material, so that the ecological environment problem can be effectively relieved, and the antibacterial fresh-keeping function of the packaging film can be realized by loading antibacterial nanoparticles so as to achieve the purpose of prolonging the shelf life of food. Copper sulfide is a transition metal sulfide and has excellent optical properties such as photo-induced heating, visible light absorption and the like. The nano copper sulfide has strong absorption at the near infrared, can convert near infrared light into heat energy so as to locally heat up to achieve the aim of sterilization, and has good killing and inhibiting effects on gram-positive bacteria and gram-negative bacteria. Cellulose is polysaccharide with the widest distribution and the highest content in the nature, and is a green degradable biomass resource. The cellulose molecular chain contains a large number of hydroxyl groups, and a supermolecular structure can be formed through hydrogen bonding, so that the cellulose molecular chain can be further used as a green harmless growth template of nano copper sulfide. Meanwhile, the cellulose has a better stabilizing effect on the nano copper sulfide, and can effectively prevent copper sulfide particles from agglomerating. The cellulose is utilized to synthesize nano copper sulfide particles and then is compounded with polyvinyl alcohol to form a film, so that a green and efficient synthesis method of the nano particles can be explored, high-value utilization of biomass resources can be realized, and the method has wide application prospect and market demand. Patent CN114957753a discloses a high-strength copper sulfide/nanocellulose/polyvinyl alcohol near-infrared shielding heat-insulating film, copper sulfide is deposited on nanocellulose by adding toxic triethylamine, and the prepared heat-insulating film is mainly used for near-infrared shielding heat insulation, not only is toxic substances used, but also has to be improved in antibacterial and barrier properties as a packaging film for antibacterial fresh-keeping. At present, copper sulfide has more generation paths, and the curing effect of copper sulfate with different generation paths on cellulose is greatly different. Under the same production path, the accelerating effect of different modified celluloses on the solidification of copper sulfate is also greatly different. Thus, no method for preparing copper sulfide/nanocellulose/polyvinyl alcohol films with high antibacterial and high barrier properties has been found in the industry. Disclosure of Invention In order to solve the problems, the invention provides a preparation method and application of a high-barrier antibacterial composite film for fruit and vegetable packaging, which has obvious antibacterial effect, is green and degradable, and is nontoxic and harmless to the environment. The method for preparing the copper sulfide by using the green nontoxic carboxymethyl cellulose solution is simple in operation, high in efficiency, green, pollution-free and low in requirements on operation environment and operation equipment. The high-barrier high-strength antibacterial composite film has great potential in the field of food packaging of fruits, vegetables and the like. The research of the invention discovers that in the reaction process of the cuprammonium ion solution and sodium sulfide, the long-chain stabilization of the carboxymethyl cellulose can effectively promote the solidification of copper sulfate on the carboxymethyl cellulose, and the antibacterial and barrier properties of the composite film are obviously improved. In order to achieve the above purpose, the present invention adopts