pH-sensitivity of fast responsive superporous hydrogels

• DOI: 10.1163/156856200744390
• Publication Date: 2002-07-27T11:59:25Z
• Authors: Richard A. Gemein...; Jun Chen; Haesun Park; Kinam Park
• Keywords: Acrylamides; Microscopy, Electron, Scanning; Hydrogels; 02 engineering and technology; Hydrogen-Ion Concentration; 0210 nano-technology

Stimuli-sensitive hydrogels (or smart hydrogels) are that swell or shrink in response to small changes environmental conditions which they placed. While the extent of swelling shrinking may be large, kinetics such is slow, since diffusion water into and out hydrogel a slow process. To obtain fast responses, we have prepared superporous (SPHs) can extremely regardless their dimensions. The orders magnitude faster than expected for nonporous same Water molecules taken up SPHs by capillary forces, this makes uptake much diffusion. ratio poly(acrylamide- co -acrylic acid) (p(AM-co-AA)) was dependent on pH ionic strength medium. effect most pronounced observed at all values. made around 5 showed transient maximum when exposed 1.2 medium due low hydrogen ion concentration inside SPHs. p(AM-co-AA) repeated alternating between 7.5, quite occurring matter minute. This sensitivity make stimuli sensitive useful many applications not previously possible. These materials used where single-piece more advantageous microparticulates.