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Journal of Nanomaterials
Volume 2011 (2011), Article ID 439756, 6 pages
http://dx.doi.org/10.1155/2011/439756
Research Article

Photoresponsive Release from Azobenzene-Modified Single Cubic Crystal NaCl/Silica Particles

1Department of Chemical and Nuclear Engineering and Center for Micro-Engineered Materials, The University of New Mexico, Albuquerque, NM 87106, USA
2SCB Innovation Accelerator, Dow Corning Corporation, 2200 W. Salzburg Road, P.O. Box 0994, Midland, MI 48686, USA
3Advanced Material Laboratory, Sandia National Laboratories, Albuquerque, NM 87185, USA
4Transmission Electron Microscopy Labs, The University of New Mexico, Albuquerque, NM 87131, USA

Received 3 November 2010; Accepted 13 January 2011

Academic Editor: Yung-Sung Cheng

Copyright © 2011 Xingmao Jiang et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Azobenzene ligands were uniformly anchored to the pore surfaces of nanoporous silica particles with single crystal NaCl using 4-(3-triethoxysilylpropylureido)azobenzene (TSUA). The functionalization delayed the release of NaCl significantly. The modified particles demonstrated a photocontrolled release by trans/cis isomerization of azobenzene moieties. The addition of amphiphilic solvents, propylene glycol (PG), propylene glycol propyl ether (PGPE), and dipropylene glycol propyl ether (DPGPE) delayed the release in water, although the wetting behavior was improved and the delay is the most for the block molecules with the longest carbon chain. The speedup by UV irradiation suggests a strong dependence of diffusion on the switchable pore size. TGA, XRD, FTIR, and NMR techniques were used to characterize the structures.