Hydrogels temperature effect

Annealing temperature, poly(vinyl alcohol) hydrogel property effect, 228-241 Arg-Gly-Asp-Ser, ftinction, 221 Arg-Gly-Asp-Ser-cairying microspheres, leukocyte activation, 220-227... 

DETERMINATION OF WATER LOSS OF SWOLLEN HYDROGEL UNDER EFFECT OF TEMPERATURE... 

Chatterjee S., Bohidar H.B. 2005. Effect of cationic size on gelation temperature and properties of gelatin hydrogels. International Journal of Biological Macromolecules 35, 81-88. 

A Afrassiabi, AS Hoffman, LA Cadwell. Effect of temperature on the release rate of biomolecules from thermally reversible hydrogels. J Membrane Sci 33 191-200,... 

Liquid crystals are mainly used for decorative purposes in cosmetics. Cholesteric liquid crystals are particularly suitable because of their iridescent color effects, and find applications in nail varnish, eye shadow, and lipsticks. The structure of these thermotropic liquid crystals changes as a result of body temperature, resulting in the desired color effect. In recent times, such thermotropic cholesteric liquid crystals have been included in body care cosmetics, where they are dispersed in a hydrogel. Depending whether this dispersion requires stirring or a special spraying process, the iridescent liquid crystalline particles are distributed statistically in the gel (Estee Lau-... 

Wang, S.F., Chen, T., Zhang, Z.L., Pang, D.W., and Wong, K.Y., Effects of hydrophobic room-temperature ionic liquid l-butyl-3-methylimidazolium tetrafluoroborate on direct electrochemistry and biocatalysis of heme proteins entrapped in agarose hydrogel films, Electrochem. Commun., 9, 1709-1714, 2007. 

From this perspective, temperature-responsive hydrogels are reviewed as agents in the design of effective polymeric structures for thermo-responsiveness as Intelligent Materials . 

In contrast to these approaches based on nonspecific interactions, Zhang and coworkers described a molecularly imprinted hydrogel based on the ther-moresponsive PNIPAM [184], This hydrogel was prepared by copolymerization of a metal chelate monomer iV-(4-vinyl)-benzyl iminodiacetic acid, which formed a coordination complex with the template protein in the presence of Cu ions, A-isopropylacrylamide, acrylamide, and IV.lV-methylenebisacrylamide as crosslinker. The interaction of the imprinted thermoresponsive hydrogel with the protein could be switched between coordination effects and electrostatic attraction by addition or omission of Cu ions. Furthermore, this imprinted hydrogel allowed switching of lysozyme adsorption by changing the temperature. 

The thin NIPAAm hydrogel layers were covalently attached to the surface, therefore the swelling was confined to one direction perpendicular to the substrate. The degree of anisotropy was calculated from ratio of l/0p and swelling ratio. This ratio was found to be between 1.2-1.3. Such a study describing the effect of hydrophilic comonomer on Tc of PNIPAAm provides an opportunity to formulate thermoresponsive hydrogel layers with desired transition temperature and swelling behavior for various applications. 

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