Chitosan films

A cobalt(II)-chitosan chelate has been prepared by soaking a chitosan film in C0CI2 aqueous solution. The chitosan chelated Co(II) through both oxygen and nitrogen atoms in the chitosan chain. The tetracoordinated, high-spin Co(II)-chitosan chelate could be used as a catalyst, and the polymerization of vinyl acetate was carried out in the presence of Na2S03 and water at pH 7 and normal temperature. The polyvinyl acetate possessed a random structure [114,115]. 

Mango fruits (Mangifera indica) were kept in carton boxes whose top surface was covered with either chitosan film or with low-density polyethylene (positive control) and stored at room temperature (27 1 °C at 65% RH). The CO2 and O2 levels measured on day 3 were 23-26% and 3-6%, and at the... 

The chitosan-bonded hydroxyapatite bone-filHng paste was made as follows. Chitosan (0.5 g) was dissolved in malic acid (0.5 g) solution made with saline, and a chitosan film was formed by mixing this solution with hydrox-... 

Y. Miao and S.N. Tan, Amperometric hydrogen peroxide biosensor with silica sol-gel/chitosan film as immobilization matrix. Anal. Chim. Acta 437, 87-93 (2001). 

Jamet, A.A. and Larios, O.M.C. 2001. Chitosan film effects on papaya osmotic dehydration. In Proceedings of the International Congress on Engineering and Food, ICEF 8 (J. Welti-Chanes, G.V. Barbosa-Canovas, and J.M. Aguilera, eds), Vol. 2, pp. 1330-1334. Technomic Publisher, Lancaster, PA. 

Chitosan films are also transparent in the UV and visible regions of the light spectrum and thus have little effect on most optical detection methods. Also, chitosan s amine groups are more reactive in aqueous environments compared to other polyamines because of the low pKa value possessed by the primary amine (6.3 for chitosan vs. 10.5 for polylysine). Finally, other advantages of chitosan are that it is safe, abundant and inexpensive. 

Zhang Y-Y, HuX, Tang K, Zou G-L (2006) Immobilization of hemoglobin on chitosan films as mimetic peroxidases. Process Biochem 41 2410-2416... 

Cetinus SA, Oztop HN (2000) Immobilization of catalase on chitosan film. Enzyme Microb Technol 26 497-501... 

Figure 4.6 shows the XRD patterns of pure clay (sodium montmoril-lonite), neat chitosan, chitosan/clay, chitosan /CNTs and chitosan/ CNT-clay composite. Neat chitosan film shows weak crystalline... 

Senel S, Ikinci G, Kas S, et al. Chitosan films and hydrogels of chlorhexidine gluconate for oral mucosal delivery. Int ] Pharm 2000 193 197-203. 

Figure 5. AFM images of bare surface (A), chitosan film (B), MC composite (C) and AChE immobilized on MC (D). (Reproduced with permission from Du et al. Sensors and Actuators B 2007, 127, 531-535).

Chen, M.C., Yeh, G.H.C., and Chiang, B.H. 1996. Antimicrobial and physicochemical properties of methylcellulose and chitosan films containing a preservative. Journal of Food Processing and Preservation 20 379-390. 

Un, J.H., He, C.Y., Zhang, L.J., and Zhang, S.S. (2009) Sensitive amperometric immunosensor for alpha-fetoprotein based on carbon nanombe/gold nanoparficle doped chitosan film. Analytical Biochemistry,... 

In another interesting research work, it was shown that the deposition of chitosan films of different thicknesses on tmcoated paper sheets improves the optical properties, printability and permeability properties as well [55]. 

Electrode preparation. A 0.5 % w/w chitosan solution was prepared according to Burchardt et al The PDDA-chitosan film modified electrode was prepared by immobilizing 5 pL of PDDA-chitosan solution [60 pL PDDA (10 % w/w) and 40 uL chitosan (0.5 % w/w)] on the surface of glassy carbon electrode. After drying at room temperature, it was used directly for ECL detection. 

Baskar, D., Balu, R., and Kumar, T.S. (2011) Mineralization of pristine chitosan film through biomimetic process. Int. J. Biol. Macromol., 49 (3), 385-389. 

HPCHLiq. [U.S. Cosmetics] Hydroxy-propyl chitosan film former fw hair careimxls. 

The chitosan film characteristics, however, varied from one report to another. Differences in the sources of chitin used to produce chitosan, chitosan properties, solvents used, methods of film preparation, and types and amounts of plasticizers used affected the quality of the chitosan films [247, 248]. The filmforming ability of chitosan extracted from crawfish has also been reported [249]. 

---