Poly electrolyte hydrogel

Huang, Y, Yu, H., and Xiao, C. pH-sensitive cationic guar gum/poly (acrylic acid) poly electrolyte hydrogels Swelling and in vitro drug release. Carbohydr. Polym., 69, 774-783 (2007). 

RA Siegel, M Falamarzian, BA Firestone, BC Moxley. pH controlled release from hydrophobic poly electrolyte copolymer hydrogels. J Controlled Release 8 179-182, 1988. 

The contraction occurs only for poly electrolyte gels and not for neutral (non-charged) hydrogels. 

There was some interest in making a gel using acrylic acid and its salts. Iwakura et al. reported on an EDLC capacitor using a cross-linked potassium poly(acrylate) hydrogel. ° The capacitance with a polymer electrolyte was 150 F/g, which was a little higher than with the aqueous KOH electrolyte (144 F/g).The effect was attributed to pseudocapacitance owing to the use of the hydrogel in the capacitor cell. Moreover, the capacitance retention after 20000 cycles was found to be 82% of the initial capacitance for the polymer-based electrolyte while it was only 72% for the aqueous KOH electrolyte. 

Some of the most useful polyphosphazenes are fluoroalkoxy derivatives and amorphous copolymers (11.27) that are practicable as flame-retardant, hydrocarbon solvent- and oil-resistant elastomers, which have found aerospace and automotive applications. Polymers such as the amorphous comb polymer poly[bis(methoxyethoxyethoxy)phosphazene] (11.28) weakly coordinate Li " ions and are of substantial interest as components of polymeric electrolytes in battery technology. Polyphosphazenes are also of interest as biomedical materials and bioinert, bioactive, membrane-forming and bioerodable materials and hydrogels have been prepared. 

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... 

Hitherto, there have also been some reports on the use of polymers containing ionic moieties except for polymeric ILs to functionalize CNTs [127-130]. For instance, Yoshida et al. [128] found that a slightly concentrated solution (20 g/L) of an ionic electrolyte of poly(pyridinium-l,4-diyl-iminocarbony 1-1,4-phenylene-methylene chloride) was most appropriate for stable dispersion of SWCNTs in water to form a SWCNT-containing gel. This ionic polymer, capable to act both as a dispersant and as a gelator, may contribute to the development of a novel hydrogel filled with CNTs for the biological, medical, and pharmaceutical applications. 

Other important applications of poly(VPA) and its copolymers are as polymer electrolyte membranes for fuel cells,in the medical field as components in dental cements,bone reconstruction, hydrogels for drug delivery, and in ion exchange membranes. ... 

Effect of varying poly(styrene sulfonic acid) content in poly(vinylalcohol)-poly(styrene sulfonic acid) blend membrane and its ramification in hydro-gen-oxygen polymer electrolyte fuel cells were investigated. Imaging of the hydrogel formation during the dissolution was performed in a non-invasive way by means of the MRI. Water self-diffusion coefficients and water release kinetics of these materials have been characterized by NMR imaging technique, which validate the use of this membrane in polymer electrolyte fuel cells (PEFCs). 

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