Poly hydrogels crystallization

NA Peppas, EW Merrill. Poly(vinyl alcohol) hydrogels Reinforcement of radia-tion-crosslinked networks by crystallization. J Polym Sci Polym Chem 14 441-444, 1976. 

Peppas N, Merrill E. Poly(vinyl alcohol) hydrogels reinforcement of radiation-crosslinked networks by crystallization. Journal of Polymer Science 1976, 14,441 457. 

An example of this analysis is a modified quartz crystal with a (poly(allyI-amine)-ferrocene hydrogel crosslinked with Glucose Oxidase and immersed in liquid electrolyte which has been studied by electroacoustic... 

Zeolites having ZSM-48 topology also crystallize from hydrogels containing other linear organic structure directing agents, such as diamines (2) or various (poly)alkylamines ( ). 

Bray JC, Merrill EW. Poly(vinyl alcohol) hydrogels. Formation by electron beam irradiation of aqueous solutions and subsequent crystallization. J Appl Polym Sci 1973 17 3779-3794. 

Un-cross-linked semicrystalline poly vinyl alcohol) hydrogels were prepared by solvolysis of the corresponding vinyl trifluoroacetate polymers and copolymers. The relationships between polymer crystallinity, hydrogel structure, and mechanical properties in the subject hydrogels were examined. Evidence was presented that comonomers acted to disrupt crystal structure and increase water content. The effects of copolymer structure on surface characteristics important to biomedical applications were examined, and the importance of hydrogel nonionic character was demonstrated through protein binding studies. 

Keywords Cryotropic gelation Poly (vinyl alcohol) hydrogels Time-resolving small angle neutron scattering Ostwald stage-rule Confined polymer crystallization... 

Summary Films of polyacrylic acid hydrogels were produced on a conducting substrate by means of electrochemically Initiated polymerization (EIP). An electrochemical quartz crystal microbalance was used to monitor film growth In situ. Homopolymer and copolymer films of polyacrylic acid and poly-N-isopropyl-acrylamide were characterized by FTIR spectroscopy. The degree of swelling of these films could be tuned via the pH. 

Gels can be made from a number of polymers, including poly[acrylamide-5 fflf-(acrylic acid)], poly(vinyl acetate), poly(dimethyl sUoxane), and polyiso-cyanurates. The poly[acrylamide-5 tor-(acrylic acid)] hydrogels can be made to swell up to 20,000 times, v/v. Thermoreversible gels can be prepared in organic solvents from polyethylene and i-polystyrene, both of which crystallize on cooling but go back in solution on heating. 

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