Alloying of Microporous Carbons by using Formation of Molecular Cluster Quasi-lattice

Study on Cluster Formation Mechanism of Water Molecules Carbon Micropores by using in situ Small Angle X-ray Scattering

Abstract

The in situ small-angle X-ray scatterings (SAXS) of water adsorbed on pitch-based activated carbon fibers (ACF) of pore width w=0.8 and 1.1nm were measured at 303K and different relative pressures. The SAXS spectrum of ACF of w=1.1nm on desorption course did not overlap that on adsorption course, showing hysteresis. The density fluctuation data from Ornstein-Zernike analysis for the SAXS profiles indicated that water molecules form great clusters in the course of adsorption, but desorption proceeds through uniform molecular evaporation. These results indicate the formation of water molecular clusters in the hidden surface spaces. The in situ SAXS analyses can give an essential information for the design of new carbon-alloy materials by molecular adsorption.