▎ 摘　　要

NOVELTY - pH-responsive intelligent controlled-release antibacterial and degradable packaging film comprises active antibacterial layer and barrier layer prepared from biodegradable base material. The active antibacterial layer contains intelligent antibacterial complex prepared from pH-responsive controlled-release mesoporous nano-zinc oxide carrying antibacterial agent; the barrier layer contains modified and dispersed graphene oxide nanosheet material; and the biodegradable base material includes 20-80 pts. wt. polybutylene adipate terephthalate raw material particles, 20-80 pts. wt. polylactic acid raw material particles, 1-10 pts. wt. acetyl tributyl citrate, and 0.1-1 pt. wt. chain extender ADR-4368. USE - The pH-responsive intelligent controlled-release antibacterial and degradable packaging film is useful in food active packaging materials (claimed), and for preservation of perishable and fresh food. ADVANTAGE - The method: achieves release of antibacterial agent consistent with requirements of food preservation; utilizes raw materials, which are biodegradable polymer materials and low-molecular additives, which are harmless to the environment, and are friendly to the environment. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) preparing pH-responsive intelligent controlled-release antibacterial and degradable packaging film, comprising (i) dissolving 1-5 pts. wt. zinc acetate dihydrate and 10-30 pts. wt. urea in 50 pts. wt. distilled water, and reacting to obtain zinc source solution, (ii) dissolving 0.1-1 pts. wt. Poloxamer 188 (F68) and 0.1-2 pts. wt. sucrose in 50 pts. wt. distilled water, and reacting to obtain composite template solution, (iii) adding zinc source solution into three-necked flask, adding composite template solution, stirring for 5-20 minutes, adding acetic acid dropwise to adjust solution pH to 4-5, stirring for 1-3 hours, transferring mixed solution to hydrothermal reactor for sealing, and crystallizing at constant temperature of 70-120degrees Celsius for 24 hours, (iv) cooling to room temperature, centrifuging at 4000-8000 revolutions/minute for 10-30 minutes to obtain white precipitate, washing using distilled water-absolute ethanol mixture, washing precipitate for 3-5 times, and drying at 75degrees Celsius for 6 hours to obtain precursor basic zinc carbonate (Zn2(OH)2CO3), where ratio between distilled water and anhydrous ethanol mixture (v:v) is 75:25, (v) adding precursor powder into crucible in muffle furnace, controlling temperature at 10degrees Celsius/minute, heating at 260degrees Celsius for 1-5 hours, converting precursor into nano-zinc oxide using ethanol as extractant in Soxhlet extractor to obtain mesoporous nano-zinc oxide sample, extracting for 24-94 hours, washing away residual template, and drying at 80degrees Celsius for 12 hours, (vi) monitoring by infrared spectroscopy or thermal gravimetric analysis method, and confirming removal of template agent to obtain mesoporous nano-zinc oxide carrier, (vii) adding 1-2 pts. wt. mesoporous nano-zinc oxide carrier and 1-5 pts. wt. sodium dehydroacetate into 100 pts. wt. 1,2-propanediol, ultrasonically dispersing, stirring for 8-10 hours at room temperature for loading, suction filtrering, rinsing with ethanol for 4-5 times, washing away un-loaded sodium dehydroacetate on surface, adding obtained solid powder into blast drying oven at 60degrees Celsius, and drying for 6 hours to obtain antibacterial agent composite, (viii) adding polybutylene adipate terephthalate and polylactic acid raw material particles into electric heating blast drying oven at 60degrees Celsius, removing water for 24 hours, adding 1-4 pts. wt. antibacterial agent complex, 20-80 pts. wt. polybutylene adipate terephthalate raw material particles, 20-80 pts. wt. polylactic acid raw material particles, 2-10 acetyl tributyl citrate and 0.5 pt. wt. chain extender ADR-4368 into high-speed mixer, and mixing at 1000-4000 revolutions/minute for 10-20 minutes, (ix) setting temperature range of temperature control module using twin-screw extruder to 150-190degrees Celsius, melting mixture, extruding, granulating to prepare active antibacterial particles, and drying for 24 hours at 60degrees Celsius, (x) adding 0.2-2 pts. wt. graphene oxide powder into 100 pts. wt. deionized water, adjusting the pH of liquid to 8 with aqueous ammonia, stirring for 10 minutes, ultrasonically treating for 30 minutes to obtain graphene oxide dispersion, adding 0.02-2 pts. wt. silane coupling agent KH570 (3-methacryloxypropyltrimethoxysilane) into 10-20 pts. wt. absolute ethanol, stirring until dissolve, adding into graphene oxide dispersion, ultrasonically treating for 30 minutes, stirring for 10 minutes, adjusting pH to 4-5 with hydrochloric acid, reacting in water bath at 50degrees Celsius for 30-60 minutes, heating at 70degrees Celsius, reacting for 60-240 minutes, cooling to room temperature, washing, centrifuging with absolute ethanol for 3-5 times to remove unreacted silane coupling agent, and drying at 60degrees Celsius for 12 hours to obtain modified graphene oxide, (xi) adding 0.5-2 pts. wt. modified graphene oxide, 30-70 pts. wt. polybutylene adipate terephthalate raw material particles, 30-70 pts. wt. polylactic acid raw material particles, 1-10 pts. wt. acetyl tributyl citrate and 0.5 pt. wt. chain extender ADR-4368 into high-speed mixer, mixing at 1000-4000 revolutions/minute for 10-20 minutes, (xii) setting temperature range of temperature control module by twin-screw extruder to 150-190degrees Celsius, melt-extruding mixture, and granulating to obtain graphene oxide barrier modified polymer particles, and drying at 60degrees Celsius for 24 hours, (xiii) preparing double-layer film using multilayer co-extrusion casting machine or multilayer co-extrusion blown film machine to obtain final product; and (2) use of pH-responsive intelligent controlled-release antibacterial and degradable packaging film in food active packaging materials, comprising (a) preparing the packaging film into rolls, and storing in environment at lower than 23degrees Celsius and humidity of 50%, (b) cutting the packaging film prepared into rolls along the machine direction based on preset bag width using manual or automatic sealing and cutting equipment to obtain small-size packaging film, (c) folding the small-size packaging film in half along the center line of the mechanical direction, and performing bilateral heat sealing using manual heat sealing machine or automatic sealing and cutting equipment to obtain pH-responsive intelligent controlled-release antibacterial and degradable packaging bags, and (d) weighing the pre-packaged food, and sealing with manual heat-sealing machine or automatic sealing and cutting equipment.