writer：Lee, Jun-Young; Tan, Bien; Cooper, Andrew I.
keywords：ScCO2
source：期刊
specific source：Macromolecules (Washington, DC, United States) (2007), 40(6), 1955-1961
Issue time：2007年

We present here a methodol. to produce highly porous cross-linked hydrogel materials by templating concd. CO2-in-water (C/W) emulsions. Poly(vinyl alc.) (PVA), blended PVA/PEG, and naturally derived chitosan materials were produced via this route.  The technique can be carried out at moderate temps. and pressures (25, <120 bar) using inexpensive hydrocarbon surfactants such as PVAc-based block copolymers which are composed of biodegradable blocks.  This methodol. opens up a new solvent-free route for the prepn. of porous biopolymers, hydrogels, and composites, including materials which cannot readily be produced by foaming.