Imprinted nanoporous organosilicas for selective adsorption of nitroenergetic targets

Langmuir. 2008 Aug 19;24(16):9024-9. doi: 10.1021/la800615y. Epub 2008 Jul 1.

Abstract

Periodic mesoporous organosilicas incorporating diethylbenzene bridges in their pore walls were applied for the adsorption of nitroenegetic targets from aqueous solution. The materials were synthesized by co-condensing 1,4-bis(trimethoxysilylethyl)benzene (DEB) with 1,2-bis(trimethoxysilyl)ethane to improve structural characteristics. Molecular imprinting of the pore surfaces was employed through the use of a novel target-like surfactant to further enhance selectivity for targets of interest (tri- and dinitrotoluenes) over targets of similar structure ( p-cresol and p-nitrophenol). The headgroup of the commonly used alkylene oxide surfactant Brij76 was modified by esterification with 3,5-dinitrobenzoyl chloride. This provided a target analogue which was readily miscible with the Brij76 surfactant micelles used to direct material mesopore structures. The impact of variations in precursor ratios and amounts of imprint molecule was evaluated. The use of 12.5% of the modified Brij surfactant with a co-condensate employing 30% DEB was found to provide the best compromise between total capacity and selectivity for nitroenergetic targets.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adsorption
  • Molecular Structure
  • Nanostructures / chemistry*
  • Nanostructures / ultrastructure
  • Nitrogen Compounds / chemistry*
  • Organic Chemicals / chemistry*
  • Porosity
  • Silicon Dioxide / chemistry*

Substances

  • Nitrogen Compounds
  • Organic Chemicals
  • Silicon Dioxide