COLL 506 |
| G.V. Rama Rao1, Dimiter N Petsev1, Qiang Fu1, and Gabriel P. Lopez2. (1) Center for Micro-Engineered Materials, Department of Chemical and Nuclear Engineering, The University of New Mexico, 203, Farris Engineering Center, The University of New Mexico, Albuquerque, NM 87131, (2) Chemical Engineering and Chemistry, University of New Mexico, MSC01 1120, Albuquerque, NM 87131 |
| We report the preparation and characterization of mesoporous hybrid materials that incorporate stimuli-responsive polymers (SRPs) which exhibit some unusual properties. In this work poly(N-isopropylacrylamide) (PNIPAAM) a SRP was grafted into the mesopores of silica particles using atom transfer radical polymerization. Nitrogen porosimetry, transmission electron microscopy and X-ray diffraction analyses confirmed that polymerization occurred uniformly within the porous network. These materials exhibit an unusual minimum in the nitrogen adsorption and desorption isotherms, and is contrary to the general trend of increase in adsorption with increase in partial pressure of nitrogen. We proposed a model based on hydrophilic and hydrophobic interactions to explain the observed minimum. The results of the model are corroborated well with that of the isotherms obtained with various hydrophilic and hydrophobic polymer grafted mesoporous silica particles. These materials have potential applications in creation of a new generation of biomimetic, nanofunctional materials for molecular transport control and controlled release systems. |
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“Smart” Polymers on Surfaces and Colloids
8:30 AM-11:30 AM, Thursday, April 1, 2004 Marriott -- Grand Ballroom J, Oral
Division of Colloid and Surface Chemistry |