Anomalous interfacial architecture in laponite aqueous suspensions on a gold surface

A technique of the surface plasmon resonance was used to test self-organization in aqueous suspensions of laponite platelets near the gold surface. The laponite concentrations in water covered the range C=1-4 wt%. The kinetics of electtophoretic mobility changes during aging of laponite suspensions was also measured. Formation of equilibrium structure follows the stretched exponential model with the same one-half index (beta approximate to 0.50) for all laponite concentrations. The changes in an effective refractive index, Delta n(e), at the Au/aqueous laponite interface were estimated. The data evidenced about possibility of formation of depleted aqueous laponite architecture with anomalously small effective value of refractive index. Such anomaly can reflect the repelling of hydrated laponite platelets from the gold surface. (C) 2017 Elsevier B.V. All rights reserved.