Chitosan Biopolymers

Henderson, W., Olsen, G.M., and Bonnington, L.S. (1994) Immobilized phosphines incorporating the chiral biopolymers chitosan and chitin./. Chem. Soc. Comm., 1863-1864. 

In view of the conductive and electrocatalytic features of carbon nanotubes (CNTs), AChE and choline oxidases (COx) have been covalently coimmobilized on multiwall carbon nanotubes (MWNTs) for the preparation of an organophosphorus pesticide (OP) biosensor [40, 41], Another OP biosensor has also been constructed by adsorption of AChE on MWNTs modified thick film [8], More recently AChE has been covalently linked with MWNTs doped glutaraldehyde cross-linked chitosan composite film [11], in which biopolymer chitosan provides biocompatible nature to the enzyme and MWNTs improve the conductive nature of chitosan. Even though these enzyme immobilization techniques have been reported in the last three decades, no method can be commonly used for all the enzymes by retaining their complete activity. 

Grant, J., Cho, J., Allen, C. (2006). Self-assembly and physicochemical and rheological properties of a polysaccharide-surfactant system formed front the cationic biopolymer chitosan and nonionic sorbitan esters. Langmuir, 22,4327- 4335. 

Chen, C.-C. and Chung, Y.-C. (2006) Arsenic removal using a biopolymer chitosan sorbent. Journal of Environmental Science and Health, Part A Toxic/Hazardous Substances and Environmental Engineering, 41(4), 645-58. 

In an interesting illustration of the first strategy, Sakaguchi and coworkers covalently attached hemoglobin to an aminopropyl silica particle and then polymerized organoalkoxysilanes on the surface of the hemoglobin-modified silica particle.85 The template was removed via treatment with oxalic acid.85 In more recent work, Zhang and coworkers utilized a similar approach. In their case, the sphere was made from the functionalized biopolymer, chitosan.86 The model template protein, bovine serum albumin, was covalently attached to the chitosan microsphere and then coated with a composite sol prepared from TEOS and an aminosilane.86... 

Multiwalled carbon nanotubes were solubilized in an aqueous solution of the biopolymer chitosan (CHIT) [56]. A 0.50 w/v % CHIT stock solution was prepared by dissolving ehitosan flakes in hot (80-90 °C) aqueous 0.05 M HCl. The solution was eooled at room temperature, and its pH adjusted to 3.5-5.0 using a concentrated NaOH solution. CNTs were solubilized in CHIT solutions (0.50-3.00 mg of CNT mL ) by ultrasonic agitation for 15 minutes. An aliquot of 30 pL of the eolloidal solution of CNT-CHIT was plaeed on the surface of GCE and dried for 2 hours at room temperature. 

Tirmizi, S.A., Iqbal, J., and Isa, M. 1996. Collection metal ions present in water samples of different sites of Pakistan using biopolymers chitosan. J. Chem. Soc. Pakistan 18, 312-315. 

Keywords Biopolymer, chitosan, active food packaging, membrane, permselective, antimicrobial, bioactive... 

Wang SF et al (2005) Biopolymer chitosan/montmorillonite nanocomposites preparation and characterization. Polym Degrad Stab 90(1) 123... 

On the other hand, we already described the study of C-13 NMR and X-ray photoelectron spectral analysis for chitosan to clarify the electronic structure in the formation of properties of biological molecule from the DFT calculations [3] and to understand the changes in adsorption behavior of chemically modified biopolymer chitosan (crosslinked biopolymer) [4],... 

No, H. K., Prinyawiwatkul, W, and Meyers, S. P., Chapter 19, Treatment of wastewaters with the biopolymer chitosan, in Handbook of Carbohydrate Engineering, Taylor Francis Group, LLC (2005], 535-562. 

Lu, L.H., Chen, W, 2010. Biocompatible composite actuator a supramolecular structure consisting of the biopolymer chitosan, carbon nanotubes, and an ionic Uquid. Adv. Mater. 22,3745-3748. 

Keywords biopolymer, chitosan, latex, concrete, mechanical properties, SEM, XRD, performance. 

This paper presents the results of a study into the effect of two polymeric additions for concrete (latex and the biopolymer chitosan) on a microstuctural scale (by means of SEM and XRD), as well as on the mechanical performance of concrete (compressive and tensile testing). Several concrete samples were prepared with 0-4 % of each polymer with 1 % increments. The concrete samples where tested at 7 and 28 days. 

In more recent studies (51, 52) the biopolymer chitosan was used as an emulsifier in food double emulsions. Chitosan has surface activity and seems to stabilize W/OAV emulsions. Chitosan reacts with anionic emulsifiers such as sodium dodecyl sulfate at certain ratios to form a water-insoluble complex that has strong emulsification capabilities. Chitosan solution was used to form double emulsions of OAV/0 as intermediates fi om which by a simple procedure of stripping the water the authors formed interesting porous spherical particles of chitosan (52). 

A variety of supports have been explored for supporting a thin film of IL [44, 45], such as flame-dried silica [43], mesoporous silica [46], diatomic earth [24], and other oxides. The biopolymer chitosan consisting mainly of 2-amino-2-deoxy-(l,4)-P-D-glucopyranose units is well suited because of its high polarity [47]. Also, carbon nanotubes are feasible supports when their surface is suitably modified for anchoring the thin film of IL, for example, by covalently binding one layer of the IL [48]. Polymers resins are modified by covalently bound ILs [39, 49-51] frequently without covering the material with additional IL. A summary on suitable support materials is presented in Chapter 3. 

As a cationic biopolymer, chitosan may react with any other anionically charged polyelectrolyte, giving rise to the formation of PEC [101, 104]. There are reports of PEC between chitosan and carboxymethyl cellulose (CMC) [105-108], alginate [109-112], poly(acrylic acid) [107, 113, 114], pectin [73, 115-117], carrageenans [118-121], heparin [122] and others [123-131]. 

Kienzle-Sterzer C.A., Rodriguez-Sanchez D., Rha C.K., Flow behavior of a cationic biopolymer Chitosan, Polym.r Bull,... 

Brack HP, Tirmizi SA, Risen WM Jr (1997) A spectroscopic and viscometric study of the metal ion-induced gelation of the biopolymer chitosan. Polymer 38 2351-2362... 

Concerning the cleaning of industrial sewage, both national and international standards are high. A nonwoven of reclaimed fibres is good value and functional, and can substitute for costly synthetic fibre materials. The nonwoven can be used to adsorb heavy metal ions (Pb(+2) ions, Cu(+2) ions, Zn(+2) ions), acid dyes (C.l. acid red 27, C.l. acid red 88) and oils (basic oil SN 150, diesel, crude oil). This requires a particular kind of surface modification treatment. For example, the woollen nonwoven is treated with biopolymer chitosan and low temperature plasma to ensure that heavy metals are better adsorbed. Investigations have shown that woollen reclaimed fibres are especially well suited to adsorb Pb (+2) ions. The adsorption of copper and zinc is also clearly improved through chitosan and plasma treatment. 

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