Microporous hydrogels

Swelling Kinetics of Hydrogels Hydrogels, Microporous Hydrogels, and Macroporous Hydrogels Superporous Hydrogels (SPHs)... 

Bhagat, S. D. Kim, Y.-H. Suh, K.-H. Ahn, Y.-S., Yeo, J.-G. Han, J.-H., Snperhydrophobic silica aerogel powders with simultaneous surface modification, solvent exchange and sodium ion removal from hydrogels, Micropor. Mesopor. Mater., 2008, 112, 504-509... 

Badiger, MV McNeill, ME Graham, NB, Porogens in the Preparation of Microporous Hydrogels based on Poly(ethylene oxides). Biomaterials 14,1059, 1993. 

Membranes made by interfacial polymerization have a dense, highly crosslinked polymer layer formed on the surface of the support membrane at the interface of the two solutions. A less crosslinked, more permeable hydrogel layer forms under this surface layer and fills the pores of the support membrane. The dense, crosslinked polymer layer, which can only form at the interface, is extremely thin, on the order of 0.1. im or less, so the membrane permeability is high. Because the polymer is highly crosslinked, its selectivity is also high. Although the crosslinked interfacial polymer layer determines membrane selectivity, the nature of the microporous support film affects membrane flux... 

In some cases, the rate-controlling polymeric membrane is not compact but porous. Microporous membranes can be prepared by making hydrophobic polymer membranes in the presence of water-soluble materials such as polyethylene glycol), which can be subsequently removed from the polymer matrix by dissolving in aqueous solution. Cellulose esters, loosely cross-linked hydrogels and other polymers given in Table 4.2 also give rise to porous membranes. 

Reactive or catalytic systems are based on pH-responsive hydrogels where the chosen reaction generates a pH shift, which in mm leads to a swelling change in the hydrogel. This response can either be used to increase the internal mesh size to increase solute diffusivity in the gel phase for a diffusive membrane [44] or alternatively the gel can be used as a mechanical valve within the pores of a microporous membrane such that a convective flux may be mmed on or off in response to analyte... 

The dependence of the xerogel porosity on the conditions of gelation has been investigated [22]. In the early work of Sing and Madeley [21,22] a microporous product was obtained from the hydrogel prepared from sodium silicate and sulfuric acid at pH 3.5. Mesoporous structures developed when the reaction was carried out... 

Ge Q, Shao J, Wang Z, Yan Y. Effects of the synthesis hydrogel on the formation of zeolite LTA membranes. Micropor Mesopor Mater 2012, 151 303-310. 

Sannino A, Madaghiele M, Conversano F, Mele G, Maffezzoli A, Netti PA, Ambrosio L, Nicolais L (2004) Cellulose derivative-hyaluronic acid-based microporous hydrogels cross-linked through divinyl sulfone (DVS) to modulate equilibrium sorption capacity and network stability. Biomacromolecules 5 92-96... 

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