Obtaining porous polymeric membranes by using cellulose acetate and functionalized carbon nanostructures, used to reduce microbiological contaminants in effluent or water bodies, comprises e.g. forming polymer solution of cellulose acetate

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Obtaining porous polymeric membranes by using cellulose acetate and functionalized carbon nanostructures, used to reduce microbiological contaminants in effluent or water bodies, comprises e.g. forming polymer solution of cellulose acetate

NOVELTY – Obtaining porous polymeric membranes by using cellulose acetate and functionalized carbon nanostructures, comprises: e.g. (a) preparing a polymer solution by using a mixture of cellulose acetate and acetone, followed by a complete homogenization of the solution by stirring; (b) obtaining a polymer solution of cellulose acetate; (c) adding a functionalized carbon nanostructure to water, in which the functionalized carbon nanostructure is graphene oxide or graphene oxide decorated with silver nanoparticles; and (d) obtaining a functionalized carbon nanostructure dispersion in water. USE – The process is useful for obtaining porous polymeric membranes exhibiting antimicrobial activity against any microorganism comprising bacteria, fungi or virus, where the porous polymeric membranes are useful for reducing microbiological contaminants in effluent or water bodies, in treatment processes and/or disinfection of water, the bacteria comprise Escherichia coli, Staphylococcus aureus (both preferred), Pseudomonas aeruginosa, Salmonella typhimurium, Salmonella enteritidis, Bacillus cereus, Bacillus subtilis, Enterococcus faecalis, Enterococcus faecium, Vibrio cholerae, Vibrio parahaemolyticus, Campylobacter jejuni, Acinetobacter baumannii, Clostridium botulinum, Clostridium perfringens, Clostridium tetani, Listeria monocytogenes, Gordonia amicalis, Klebsiella pneumoniae (carbapenemase), Streptococcus pneumoniae, Yersinia enterocolitica, Citrobacter spp., Providencia spp., Serratia marcescens, Erwinia ananatis, Alcaligenes faecalis, Neisseria sp., Legionella sp. or Mycobacterium tuberculosis, the fungi comprise Candida albicans, Saccharomyces cerevisiae, Rhizopus oryzae, Rhizopus nigricans, Rhizopus stolonifer, Fusarium oxysporum, Fusarium venenatum, Aspergillus niger, Aspergillus fumigatus, Aspergillus flavus, Penicillium roqueforti, Penicillium notatum, Penicillium chrysogenum, Paracoccidioides brasiliensis, Histoplasma capsulatum, Sporothrix schenckii, Blastomyces dermatitidis, Trichoderma reesei or Trichophyton sp., and the viruses comprise Herpes simplex virus type 1, HIV type 1, hepatitis B virus, influenza viruses, tacaribe virus or respiratory syncytial virus (all claimed). The porous polymeric membranes are further useful in ultrafiltration processes and reverse osmosis and as coating materials in packaging and as air purifying filter components for environments that require sterile and/or controlled atmosphere. The ability of the porous polymeric membrane to reduce microbiological contaminants in water bodies was tested against Escherichia coli using biological assay. The result showed that the membrane (made of cellulose acetate and graphene oxide decorated with silver nanoparticles) (0.1%) inhibited viable cells of microbiological contaminants by 100% in water bodies after 12 hours of exposure. ADVANTAGE – The process: makes the biodegradable porous polymeric membranes which can be reused for several cycles without significant loss of efficiency for the treatment or disinfection of the water body or effluent until complete saturation; utilizes the surface which is a smooth surface, free of roughness, and made of material that is inert to the polymer solution; and utilizes the means to enable the control of membrane thickness, capable of providing a uniform thickness throughout the length of the membrane. The porous polymeric membranes: have antimicrobial activity preferably against Escherichia coli, and Staphylococcus aureus, giving a reduction ratio of viable cells of such microorganisms of 20-100% after contact between the membrane and the microorganisms for a period of 6-24 hours, where the microorganisms may be present in aqueous or gaseous medium, the contact between the membrane and the microorganisms is preferably for a period of 12 hours, and the aqueous medium comprises water bodies or effluents, the effluents comprise industrial wastewater, hospital sewage, domestic wastewater or effluent coming from water treatment plants (claimed); and can be obtained in simple and reproducible process using inexpensive energy. DETAILED DESCRIPTION – Obtaining porous polymeric membranes by using cellulose acetate and functionalized carbon nanostructures as raw materials, comprises: (a) preparing a polymer solution by using a mixture of cellulose acetate and acetone, followed by a complete homogenization of the solution by stirring; (b) obtaining a polymer solution of cellulose acetate; (c) adding a functionalized carbon nanostructure to water, in which the functionalized carbon nanostructure is graphene oxide or graphene oxide decorated with silver nanoparticles; (d) obtaining a functionalized carbon nanostructure dispersion in water; (e) adding the dispersion obtained in step (d) to the polymer solution obtained in step (b) slowly, dropwise, to ensure compatibility of functionalized carbon nanostructure charge with the polymer solution or polymer matrix; (f) spreading the solution obtained in step (e) on a surface comprising means to enable the control of the thickness of the membrane; (g) immersing immediately the surface containing the dispersed polymer solution obtained in step (f) in a container containing deionized water (nonsolvent) at room temperature until the complete detachment of the membrane of the surface, in which when the bath in nonsolvent occurs, the inversion of stages and pores are formed; (h) coagulating the polymer and thus obtaining porous polymeric membranes on the basis of biodegradable polymer of cellulose acetate and of functionalized carbon nanostructures; and (i) drying the polymeric membrane obtained in (h). INDEPENDENT CLAIMS are also included for: (1) the porous polymeric membranes comprising cellulose acetate and the functionalized carbon nanostructure, and obtained by the above method; and (2) reducing microbiological contaminants in effluent or water bodies by using at least one porous polymeric membrane, comprising: exposing at least 50 ml of liquid effluent containing microbiological contaminants through at least one sheet of membrane with flow and pressure variables according to aqueous matrix to be treated for a period of 6-24 hours, maintaining the pH constant at 5.5-7; optionally, drying the membrane at room temperature and/or in an oven under vacuum or with air circulation; and optionally, reusing the membrane in the reduction process of microbiological contaminants.

Main Application Field

A97 (Miscellaneous goods not specified elsewhere – including papermaking, gramophone records, detergents, food and oil well applications.); B04 (Natural products and polymers. Including testing of body fluids (other than blood typing or cell counting), pharmaceuticals or veterinary compounds of unknown structure, testing of microorganisms for pathogenicity, testing of chemicals for mutagenicity or human toxicity and fermentative production of DNA or RNA. General compositions.); J01 (Separation – including evaporation, crystallisation, solvent extraction, chromatography, dialysis, osmosis including drying gases and/or vapours, and separation of solids from gases, liquids and other solids. Isotope separation, filter materials (including molecular sieves for separation), and centrifuges (except where used for analysis) (B01D, B03, B04, B07B).)

INVENTORS:

MORAES ANA CAROLINA MAZARIN DE
FARIA ANDREIA FONSECA DE
GONÇALVES MARIA DO CARMO
ALVES OSWALDO LUIZ
ANDRADE PATRÍCIA FERNANDA

690_GRAFENO

Patent number: BR102013026639-A2

PATENT STATUS:

For information contact Inova Unicamp

FOR ADDITIONAL INFORMATION:

parcerias@inova.unicamp.br

+55 (19) 3521-5207 / 2607

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