Chitosan polyvinyl alcohol

Miguez, M.J.B. Rodrigues, B.C. Sanchez, M.N.M. Laran-jeira, M.C.M. Preparation and scanning electronic microscopy study of chitosan/polyvinyl(alcohol)-encapsu-lated crude urease extract. J. Microencapsulation 1997, 14 (5), 639-646. 

Another approach to improve the properties of chitosan hydrogels is via the preparation of polymer composites. Porous hydrogels of N-carboxymethyl chitosan/polyvinyl alcohol were prepared by Lee et al. [99]. Hydroxypropyl chitosan was combined with sodium alginate for the formation of biodegradable hydrogels [100]. Chitosan-hyaluronic acid composite was prepared by Tan et al. [101]. 

Parida U.K., Nayak A.K., Binhani B.K., Nayak P.L. S)mthesis and characterization of chitosan-polyvinyl alcohol blended with cloisite 30B for controlled release of the anticancer drug curcumin. Journal of Biomaterials and Nanobiotechnology. 2011 2 414-425. 

Sdehi, E., Madaeni, S. S., Rajabi, L., Derakshan, A. A., Daraei, S., and Vatanpour, V. 2013. Static and dynamic adsorption of copper ions on chitosan/polyvinyl alcohol thin adsorptive membranes Combined effect of polyethylene glycol and aminated multi-walled carbon nanotubes. Chem. Eng. J. 215-216 791-801. 

Blends or composites were also prepared especially by Hirano in the same way as mentioned previously for chitin [63], Other systems were proposed in the literature and listed previously [1, 2], Some of them are described in detail, for example, chitosan/ polyamide 6 and chitosan/polyamide 66 [119,120], chitosan/cellulose using a common solvent [121,122], chitosan/poly(oxyethylene) (POE) [123], chitosan/polyvinylpyrrolidone (PVP), chitosan/polyvinyl alcohol (PVA) [123,124], chitosan/polycaprolactone [124-126], chitosan/ collagen [127], chitosan/PHB [128], and chitosan/cellulose fibres [129]. In some case, the polymers are crosslinked in the blends [130]. Hydrogels or films have been prepared by mixing chitosan solution with monomers, initiator and cross-linker followed by copolymerization [131,132]. 

Abou-Aiad, T.H.M., Abd-El-Nour, K.N., Hakim, l.K. and Elsabee, M.Z. (2005) Dielectric and interaction behavior of chitosan/polyvinyl alcohol and chitosan/polyvinyl pyrrolidone blends with some antimicrobial activities. Polymer, 47, 379-389. 

Srinivase, P.C., Ramesh, M.N., Kumar, K.R., and Tharanathan, R.N. 2003. Properties and sorption studies of chitosan-polyvinyl alcohol blend fihns. Carbohydr. Polym. 53 431-438. 

AN, 0-Carboxy methyl chitosan/cellulose acetate blend nano filtration membrane was prepared in acetone solvent. It had been tested to separate chromium and copper fiom effluent treatment. The highest rejection was observed to be 83.40% and 72.60%, respectively (Alka et al., 2010). A chitosan/cellulose acetate/polyethylene glycol ultra filtration membrane was prepared with DMF as solvent. It was focused to be efficient in removing chromium from artificial and tannery effluent wastewater. The highest rejection rate was responding (Sudha et al., 2008).Cross-linked chitosan/polyvinyl alcohol blend beads were prepared and studied for the adsorption capacity of Cd from wastewater. The maximum adsorption of Cd(II) ions was foimd to be 73.75% at pH 6 (Kumar et al., 2009). 

Kumar, M., Tripathi, B. R, and Shahi, V. K. (2009). Cross-linked chitosan/polyvinyl alcohol blend beads for removal and recovery of Cd(II) from waste v/ater. Journal of Hazardous Materials 172(2-3), 1041 8. 

Arvanitoyannis, I., Kolokuris. 1.. Nakayama, A., Yamamoto. N.. and Aiba, S. (1997) Physico-chemical studies of chitosan-polyvinyl alcohol blends plastidzed with sorbitol and sucrose. Carbohydr. Pdym., 34, 9-19. 

Mixture polymeric coating chitosan-polyvinyl alcohol have high strength and elasticity, increased biodegradating ability and good solubility in water. Moistureabsorbing capacity of such films is somewhat lower than that of individual chitosan. 

Wang F, Ge M (2013) Fibrous mat of chitosan/polyvinyl alcohol/containing cerium(III) for the removal of chromium(VI) from aqueous solution. Text Res J 83(6) 628-637. doi 10.1177/0040517512454188... 

Another trend observed during the past decade was the coating of liposomes with mucoadhesive polymers. Liposomes are coated with chitosan, long-ehain polyvinyl alcohol, and polyacrylates bearing a cholesteryl group [90]. Chitosan-eoated liposomes showed superior adhesion properties to rat intestine in vitro than the other polymer-eoated liposomes. In vivo, chitosan-coated liposomes containing insulin substantially reduced blood glueose levels after oral administration in rats, whieh were sustained up to 12 hr after administration [90]. 

Recently a metal ion-imprinted membrane was developed for selective separation of silver ions [215]. Chitosan and polyvinyl alcohol were blended in the presence of... 

Mucoadhesives are generally macromolecular organic polymers made from natural (gelatin, agarose, chitosan, hyaluronic acid) or synthetic polymers (polyvinylpyrrolidone (PVP), polyacrylates, polyvinyl alcohol, cellulose derivates). They possess hydrophilic groups that can... 

Sriamornsak P, Thirawong N, Nunthanid J, Puttipipatkhachorn S, Thongborisute J, Takeu-chi H (2008) Atomic force microscopy imaging of novel self-assembling pectin-liposome nanocomplexes. Carbohydr Polym 71 (2) 324—329 Takeuchi H, Yamamoto H, Niwa T, Hino T, Kawashima Y (1994) Mucoadhesion of polymer-coated liposomes to rat intestine in vitro. Chem Pharm Bull 42(9) 1954-1956 Takeuchi H, Yamamoto H, Niwa K, Hino T, Kawashima Y (1996) Enteral absorption of insulin in rats from mucoadhesive chitosan-coated liposomes. Pharm Res 13 896-901 Takeuchi H, Kojima H, Yamamoto H, Kawashima Y (2000) Polymer coating of liposomes with a modified polyvinyl alcohol and their systemic circulation and RES uptake in rats. J Control Rel 68(2) 195-205... 

Coating Technique This technique usually deposits a hydrophUic layer such as HEC, polyvinyl alcohol, chitosan, polyacrolein, and polyethylenimine on a hydrophobic one [13,71,85,86]. The coating layers prepared are, however. 

In hydrophilic membranes the separating layer is most commonly made from crosslinked polyvinyl-alcohol (PVA), however, polyimides or natural polymers like chitosan or cellulose acetate (CA) are also used (Fig. 9). 

The dense polyvinyl alcohol layer is supported by a porous PAN substrate membrane. Polyelectrolyte material and chitosan, a natural product, are also potentially useful for dehydration by Silicone... 

Natural, semi-natural, or synthetic polymer powders such as cellulose, chitin/chitosan, acetylcellulose, nylon, PVC, and PVA powders were used as solid media. PVA (polyvinyl alcohol) gave the highest intensity ( R= 7.2). while, chitosan and nylon gave relatively high intensities. However, when they are prepared as film with smooth surface, then the relative CL intensities became weak like a solid of glass plate. 

Polymeric thickeners Gums Acacia Alginates Carageenan Chitosan Collagen Tragacanth Xantham Celluloses Sodium carboxymethyl Hydroxyethyl Hydroxypropyl Hyd roxypro pyl m ethyl Acrylic acids Carbomers Polycarbophil Colloidal solids Silica Clays Microcrystalline cellulose Hydrogels Polyvinyl alcohol Polyvinylpyrrolidone Thermoreversible polymers Poloxamers... 

A biodegradable thermoplastic composition comprising polyvinyl alcohols, polyurethanes or polyacrylates, cellulose fibers, and chitosan is disclosed in U.S. Pat. No. 5,306,550 [125]. 

Pancreatic ribonuclease is markedly inhibited by heparinoids but not by mucopolysaccharides, with sulphated polyvinyl alcohol >sulphated corn amylosOsulphated cellulose > sulphated corn amylopectin> sulphated dextran, sulphated pectic acid, polyvinyl sulphonate with 2 T 7 per cent sulphur>sulphated nitro chitin, sulphated nitro chitosan and heparin . Single injections of heparin in mice result in significant inhibition of the acid alkaline ribonuclease of the liver after the injection. This probably explains the accumulation of ribonucleic acid in tissue culture cells in the presence of heparin. Heparin also inhibits rat acid phosphatase, glucuronidase , catalase , fumarase and elastase. 

The work of Binsu et al. has focused on the phosphonic functionalization of chitosan combined with polyvinyl alcohol and has yielded the highest fuel cell... 

Sung JH, Hwang MR et al (2010) Gel characterisation and in vivo evaluation of minocycline-loaded wound dressing with enhanced wound healing using polyvinyl alcohol and chitosan. Int J Pharm 392 232-40... 

Polyvinyl alcohol Chitosan lactate Pectin Carbomer Polycarbophil... 

Dubey et al. [74] improved the BC membrane by the impregnation of chitosan [Mw 100-300 kDa]. The composite membrane was dried under vacuum. The potential of the composite membrane for the pervaporative separation of the ethanol/water azeotrope was comparable to that of a polyvinyl alcohol [PVA] membrane [74]. The normalized flux, selectivity, and PSI of the composite membrane were 42.8 kg pm m h , 9.2 and 350 kg pm m h , respectively. Compared with the PVA membrane, BC membrane impregnated with chitosan had excellent dimensional stability, better mechanical strength, and improved thermal stability. 

Hydroxyl Polysaccharides (cellulose, agarose, dextran, chitin, chitosan), inorganic glass, polyvinyl alcohol, polyhydroxyethyl methacrylate Cyanogen bromide, triazine method, cyclic frans-2,3-carbonate reaction, carbonylation, periodate oxidation, epoxide activation [168-181]... 

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