# US 11,306,186 B2 · Method for preparing intelligent antibacterial and antioxidative film

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- Number: US 11,306,186 B2
- Document ID: US11306186B2
- Status: Granted
- Kind: B2
- Application number: 16/104,955
- Filed: 2018-08-20
- Published: 2018-12-13
- Granted: 2022-04-19
- Earliest claimed: 2017-05-02
- Assignees: Shanghai Ocean University
- Applicants: Shanghai Ocean University
- Inventors: Jing Xie; Zhipeng Tang; Chenwei Chen; Jinfeng Wang; Yuhan Zhang
- Web page: https://patentgrep.com/patent/US11306186B2

## CPC

- C08J 5/18: Manufacture of films or sheets
- A01N 25/10: Macromolecular compounds
- A01N 59/16: Heavy metals; Compounds thereof
- B29C 41/003: {characterised by the choice of material}
- C08J 3/212: {and solid additives}
- C08K 3/22: of metals
- C08K 5/1545: Six-membered rings
- B29K 2029/04: {PVOH, i.e. polyvinyl alcohol (B29K2031/04 takes precedence)}
- B29K 2105/162: {Nanoparticles}
- B29K 2509/02: Ceramics
- C08J 2329/04: Polyvinyl alcohol; Partially hydrolysed homopolymers or copolymers of esters of unsaturated alcohols with saturated carboxylic acids
- C08K 2003/2241: {Titanium dioxide}
- C08K 2201/005: Additives being defined by their particle size in general
- C08K 2201/011: Nanostructured additives
- C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29)
- A01N: PRESERVATION OF BODIES OF HUMANS OR ANIMALS OR PLANTS OR PARTS THEREOF (preservation of food or foodstuff A23); BIOCIDES, e.g. AS DISINFECTANTS, AS PESTICIDES OR AS HERBICIDES (preparations for medical, dental or toiletry purposes which kill or prevent the growth or proliferation of unwanted organisms A61K); PEST REPELLANTS OR ATTRACTANTS; PLANT GROWTH REGULATORS
- B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00)
- C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09)
- B29K: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR {MOULDS, } REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS

## Abstract

A method for preparing an intelligent antibacterial and antioxidative film involves preparing a PVA solution; adding nano-TiO2 to the PVA solution to obtain a PVA-TiO2 solution; determining the optimal amount of nano-TiO2; preparing a PSPC solution; preparing a PSPC-TiO2-PVA solution; and producing a PSPC/TiO2/PVA film. The film has better mechanical performance than saccharide and protein films. Shelf life of food is prolonged as the film possesses antibacterial and antioxidative properties. Furthermore, the film shows different colors in various pH environments. The film has a wide range of applications in food packaging owing to the integration of color development and antibacterial and antioxidative properties.

## Claims

### Claim 1

A method for preparing an intelligent antibacterial and antioxidative film, comprising:
1) adding polyvinyl alcohol (PVA) and deionized water at a weight (g)-volume (mL) ratio of 11:100 into a vessel; placing the vessel in a boiler at 121° C. for 40 minutes; transferring the vessel to a mixer at 40° C. and 50 rpm when a boiler temperature is reduced to 90° C.; adding glycerol into the vessel under stirring to produce a PVA solution;
2) adding nano-TiO2 into the PVA solution under stirring and mixing the nano-TiO2 and the PVA solution for 2 hours to produce a blend; subjecting the blend to ultrasonication for 10 minutes to remove bubbles in the blend so as to produce a PVA-TiO2 solution;
3) dissolving purple sweet potato cyanidin (PSPC) with 5-10 mL of hydrochloric acid under stirring at room temperature and 30 rpm for 4 hours to obtain a PSPC solution; and storing the PSPC solution away from light;
4) placing the PVA-TiO2 solution in a mixer at 40° C. and 50 rpm; adding the PSPC solution to the PVA-TiO2 solution under stirring and mixing the PSPC solution and the PVA-TiO2 solution for 20 minutes to produce a mixture; subjecting the mixture to ultrasonication for 10 minutes to remove bubbles in the mixture so as to produce a PSPC-TiO2-PVA solution; and
5) casting the PSPC-TiO2-PVA solution onto a plate; drying the plate in an oven at 40° C. for 12 hours to remove solvents; storing the plate in a desiccator with a saturated sodium bromide solution for 48 hours to obtain a film; removing the film from the plate and vacuum sealing the film with a high-barrier bag and then placing the sealed film in the desiccator for use.

### Claim 2 (depends on 1)

The method of claim 1, wherein the PVA has a degree of polymerization of 1799.

### Claim 3 (depends on 1)

The method of claim 1, wherein the nano-TiO2 has a particle size of 30 nm.

### Claim 4 (depends on 1)

The method of claim 1, wherein the hydrochloric acid is at pH 3.

### Claim 5 (depends on 1)

The method of claim 1, wherein in step 2) a weight (g)-volume (mL) ratio of the nano-TiO2 to the PVA solution is 0.5-3:100.

### Claim 6 (depends on 5)

The method of claim 5, wherein in step 2) a weight (g)-volume (mL) ratio of the nano-TiO2 to the PVA solution is 1:100.

### Claim 7 (depends on 1)

The method of claim 1, wherein in step 3) a ratio of the PSPC solution to the PVA-TiO2 solution is 20-30:100 by volume.

### Claim 8 (depends on 7)

The method of claim 7, wherein in step 3) a ratio of the PSPC solution to the PVA-TiO2 solution is 26:100 by volume.