title: Effect of anionic surfactants on synthesis and self-assembly of silica colloidal nanoparticles.
abstract: Effects of the anionic surfactants, sodium dodecyl sulfate and sodium oleate, on the formation and properties of silica colloidal nanoparticles were investigated. At a concentration of approximately 1 x 10(-3) M, adsorption of anionic surfactants increased particle size, monodispersity, and negative surface charge density of synthesized silica particles. As uniformity of particle size and particle-particle interactions increase, colloidal photonic crystals readily self-assemble without extensive washing of the synthesized silica nanoparticles. The photonic crystals diffract light in the visible region according to Bragg's law. The assembled colloidal particle arrays exhibit a face-centered cubic structure in dried thin films. This study offers a new approach for producing ordered colloidal silica thin films.
authors.affiliation: Environmental Sciences Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831, USA. wangw@ornl.gov
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: Baohua
authors.initials: B
authors.lastname: Gu
authors.forename: Liyuan
authors.initials: L
authors.lastname: Liang