Silver nanoparticle monolayers on poly(ethylene imine) covered mica produced by colloidal self-assembly

摘要: Abstract Monodisperse silver particles were synthesized according to the method of Creighton et al. by reduction AgNO 3 solutions with NaBH 4 in presence polyvinyl alcohol as stabilizing agent. Bulk characteristics nanoparticles aqueous carried out measuring their extinction spectrum, fluorescence, diffusion coefficients using PCS and electrophoretic mobilities. The average hydrodynamic diameter PVA covered was 44 nm, being fairly independent ionic strength pH range 3–9. It also shown that radius did not change within prolonged storage suspensions (up 75 days), indicating sols quite stable. A similar value 45 ± 8 nm determined from SEM measurements. mobility measurements showed zeta potential insensitive decreased strength, attaining −45 mV for I  = 10 −5  M −25 mV −2 M. Additionally, kinetics particle deposition on mica modified adsorption a saturated layer poly(ethylene imine) (PEI) studied. Surface concentration directly counting number over various surface areas atomic force microscopy working semicontact mode. maximum −3 102 μm , which corresponds coverage degree 16%. kinetic run good agreement theoretical predictions stemming random sequential (RSA) model. This allowed one determine size Ag core, 20 nm thickness layer, equal 12 nm.