Publication Type : Journal Article
Publisher : Nanotechnology
Source : Nanotechnology, Volume 20, Number 42, p.425602 (2009)
Url : http://stacks.iop.org/0957-4484/20/i=42/a=425602
Campus : Coimbatore
School : School of Engineering
Department : Electronics and Communication
Year : 2009
Abstract : Nanoporous materials have become indispensable in many fields ranging from photonics, catalysis and semiconductor processing to biosensor infrastructure. Rapid and energy efficient process fabrication of these materials is, however, nontrivial. In this communication, we describe a simple method for the rapid fabrication of these materials from colloidal dispersions of Polymethyl Silsesquioxane nanoparticles. Nanoparticle–polymer composites above the decomposition temperature of the polymer are examined and the entropic gain experienced by the nanoparticles in this rubric is harnessed to fabricate novel highly porous films composed of nanoparticles. Optically smooth, hydrophobic films with low refractive indices (as low as 1.048) and high surface areas (as high as 1325nbsp;m 2nbsp;g −1 ) have been achieved with this approach. In this communication we address the behavior of such systems that are both temperature and substrate surface energy dependent. The method is applicable, in principle, to a variety of nanoparticle–polymer systems to fabricate custom nanoporous materials.
Cite this Research Publication : V. Korampally, Yun, M., Dr. T. Rajagopalan, Dasgupta, P. K., Gangopadhyay, K., and Gangopadhyay, S., “Entropy driven spontaneous formation of highly porous films from polymer–nanoparticle composites”, Nanotechnology, vol. 20, p. 425602, 2009.