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

Xingmao Jiang, Nanguo Liu, Roger A. Assink, Yingbing Jiang, C. Jeffrey Brinker
2011 Journal of Nanomaterials  
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)
more » ... pyl 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.
doi:10.1155/2011/439756 fatcat:w7eqvnllcjc35o2u223ym7666m