Synthesis of Porous Emulsion-Templated Polymers Using High Internal Phase CO2-in-Water Emulsions

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• 作者：R. Butler ; I. Hopkinson ; and A. I. Cooper
• 刊名：Journal of the American Chemical Society
• 出版年：2003
• 出版时间：November 26, 2003
• 年：2003
• 卷：125
• 期：47
• 页码：14473 - 14481
• 全文大小：517K
• 年卷期：v.125,no.47(November 26, 2003)
• ISSN：1520-5126

文摘

Highly porous emulsion-templated materials were synthesized by polymerization of concentratedCO₂-in-water (C/W) emulsions. The method does not use any organic solvents, in either the synthesis orpurification steps, and no solvent residues are left in the materials. It was found that the emulsion stabilityis strongly affected both by the nature of the surfactant and by the viscosity of the aqueous continuousphase. By optimizing these parameters, it was possible to generate a highly porous, low-densitypolyacrylamide material with a pore volume of 5.22 cm³/g, an average pore diameter of 9.72 m, and abulk density of 0.14 g/cm³. We have broadened the scope of this approach significantly by identifyinginexpensive hydrocarbon surfactants to stabilize the C/W emulsions (e.g., Tween 40) and by developingredox initiation routes that allow the synthesis to be carried out at modest temperatures and pressures (20C, 65 bar). We have also extended the method to the polymerization of monomers such as hydroxyethylacrylate, which suggests that it is possible to prepare a range of solvent-free biomaterials by this route.