01953nas a2200181   4500008004100000022001400041245008300055210006900138260007100207300001400278490000800292520126200300100002501562700002701587700001701614700002801631856011201659       2009                        eng d  a1520-610600aSelf-assembly of silica particles in a nonionic surfactant hexagonal mesophase0 aSelfassembly of silica particles in a nonionic surfactant hexago  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcMAR  a3423-34300 v1133 a<p>We investigate the process of self-assembly, and the resultant structures in composites of silica particles with a hexagonal mesophase of a nonionic surfactant and water. We report a systematic transition in behavior when the particle size is increased relative to the characteristic mesophase spacing. Water dispersible cage-like silsesquioxanes that are molecular analogues of silica particles and are smaller than the mesophase spacing swell the space between the surfactant cylinders. Silica particles comparable to the characteristic hexagonal spacing partition into the hexagonal phase and into strandlike particulate aggregates. Even larger particles phase separate from the hexagonal phase to form particulate strands that organize with a mesh size comparable to the wavelength of visible light. This self-assembly is reversible and the particles disperse by breaking up the aggregates on heating the composite into the isotropic phase. On cooling from the isotropic phase into the hexagonal, the particles are expelled from the growing hexagonal domains and finally impinge to form strandlike aggregates. Unusually, the isotropization temperature is increased in the composites as the particles nucleate the formation of the hexagonal phase.</p>1 aSharma, Kamendra, P.1 aKumaraswamy, Guruswamy1 aLy, Isabelle1 aMondain-Monval, Olivier  uhttps://library.ncl.res.in/content/self-assembly-silica-particles-nonionic-surfactant-hexagonal-mesophase-0