Macroporous hydrogel

Fig. 6. Schematic representation of macroporous PHEMA hydrogel sponges. Interstitial spaces between polymer droplets create a macroporous structure 1-20 pm in size, whereas the polymer network creates a 1-100 nm mesh size in the polymer phase.

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

Dong, L. C., Yan, Q., and Hoffman, A. S. Controlled release of amylase from a thermal and pH-sensitive, macroporous hydrogel. J. Controlled Release 1992, 19, 171-178. 

Thermal and pH sensitive heterogeneous copolymer hydrogels which contain silicone rubber domains within a temperature and pH sensitive copolymer of NIPA and acrylic acid have been synthesized by Dong et al. [60]. These materials contained macropores when swollen and collapsed much faster than homopolymers of iV-isopropylacrylamide. Biocatalyst immobilization using copolymers of NIPA and NN - dimethylaminopropylmethacrylamide have also been studied [61]. 

N. S. Patil, J. S. Dordick, and D. G. Rethwisch, Macroporous poly(sucrose acrylate) hydrogel for controlled release of macromolecules, Biomaterials, 17 (1996) 2343-2350. 

Wu, X.S., Hoffmann, A.S. and Yager, P. (1992) Synthesis and characterization of thermally reversible macroporous poly( N-isopropylacryl-arn ide) hydrogels. /. Polym. Sci. Part A Polym. Chem., 30,2121-2129. 

Macroporous gels Another technique to obtain fast-responsive hydrogels is to create voids (pores) inside the hydrogel matrix, so that the response rate becomes a function of the microstructure rather than the size or the shape of the gel samples (Okay 2000). For a polymer network having an interconnected pore structure, absorption or desorption of water occurs through the pores by convection, which is much faster than the diffusion process that dominates the non-porous hydrogels. 

Wall FT (1942) Statistical thermodynamics of mbber. J Chem Phys 10 132-134 Wall FT (1943) Statistical thermodynamics of mbber. III. J Chem Phys 11 527-530 Wall FT (1951) Statistical thermodynamics of mbber elasticity. J Chem Phys 19 1435-1439 Yan Q, Hoffman AS (1995) Synthesis of macroporous hydrogels with rapid swelling and deswelling properties for delivery of macromolecules. Polymer 36 887-889 Yoshida R, Uccida K, Kaneko Y, Sakai K, Kikuchi A, Sakurai Y, Okano T (1995) Comb-type grafted hydrogels with rapid deswelling response to temperature changes. Nature 374 240-242 Zerbi G (1999) Modem Polymer Spectroscopy. Wiley-VCH, Weinheim... 

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