Stresses at the Interface of Micro with Nano

Abstract

Bicontinuous meso/macroporous materials with ordered tubular mesopores are inherently unstable with stresses built in at the interface of the nano/micro fractal dimensions. This is concluded by comparing the macroscopic dimensions and the unit cell size of native monoliths with those of monoliths stabilized against shrinkage by a conformal polymer coating on all macro- and mesoporous surfaces. The enhanced tendency for shrinking at the nanoscopic level is attributed to a syneresis-like mechanism where hydrogen bonding between hydroxyl groups in the concave internal surfaces of the tubular nanosized mesopores causes contraction.