Layer-by-Layer Self-Assembly of Ceramic Particles for Coating Complex Shape Substrates
Key parameters for controlling the layer-by-layer self-assembly of ceramic particles were studied using a model system, which consisted of an Si substrate, 100 and 500 nm silica spheres, and a polycation/polyanion combination that provided binding between the substrate and silica particles, as well as between the silica particle layers. The overall quality of the particle assemblies was mainly dictated by (1) the degree of electrostatic attraction between the negatively charged silica particles and the outermost positively charged electrolyte layer of a polyelectrolyte multilayer and (2) electrostatically repulsive interactions between the silica particles. The surface coverage of the silica particles improved with an increase of NaCl used in deposition of the polyelectrolyte layers and silica particles, and with an increased number of the polyelectrolyte/particle layers deposited. We found that the effects of particle size, polydispersity, and electrolyte concentration in the particle suspension on the surface coverage and morphology of the first silica particle layer deposited on the polyelectrolyte layer surface were highly coupled, and resolution of these effects was important in generating a rational basis for infiltrating a uniform coating of multilayer silica particle assemblies into a cellular structure.
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Document Type: Research Article
New Jersey Center for MicroChemical Systems, Department of Chemical, Biomedical, and Materials Engineering, Stevens Institute of Technology, Hoboken, New Jersey 07030
Department of Chemistry and Chemical Biology, Stevens Institute of Technology, Hoboken, New Jersey 07030
Publication date: 2006-04-01