Molecular Theory of Adsorption in Porous Solids

Yu K. Tovbin

• Contents. Foreword. Symbols. Introduction. The structure of porous bodies. Adsorption isotherms. Transport in porous solids. Intermolecular interactions. Lattice model of adsorption and the theory of fluid. The heterogeneity of the surface of solids. Heterogeneous systems. Adsorption on heterogeneous surfaces. Motion of molecules in cells. Equation of state. Bulk phase. Adsorption on amorphous surfaces. Multilayers on the exposed surface. Slit-shaped pores. Cylindrical pores. Clusters in volume and pores. Thermodynamic characteristics of adsorption systems. Thermodynamic conditions of phase separation. Critical conditions for heterogeneous surfaces. Critical conditions for porous systems. The curves of the vapour–liquid phase separation in slit-like pores. Curves of vapour–liquid phase separation in cylindrical pores. Hysteresis loops with capillary condensation. Size effects. Wide pores. Wide pores and Kelvin equation. The vapour–liquid boundary in the pores. Kinetic equations in the condensed phase. Rates of elementary stages of adsorption and diffusion. Microscopic hydrodynamics. Local transport equation. The equations for the pair distribution functions. Boundary and initial conditions. Models of molecular transport in the bulk phase. The concentration dependence of the transport coefficients in the volume. Molecular models of the transport of molecules in crevices. Concentration dependences of the diffusion coefficients and viscosity. Sliding friction coefficient. Concentration dependences of the thermal conductivity coefficient in slits. The mobility of the fluid in a slit-like micropore: comparison with molecular dynamics. Local mobility of argon. Dynamic characteristics of molecules in narrow cylindrical. Statement of the problem and description of the calculation field. Relaxation dynamics of the liquid phase. Dynamics of the vapour bubble. A system with two bubbles. The structural inhomogeneity of the channel wall. Influence of the wall potential on molecular flows in narrow channels. The movement of the vapour-liquid meniscus in tight slit pores. Molecular flows in narrow pores with small initial perturbations. Wetting and spreading processes. Pores of complex geometry and porous systems. Spherocylindrical pores. Systems of cylinders. Systems of slit-shaped pores. Globular porous systems. Adsorption hysteresis and conditions of its disappearance . Polydisperse system and adsorption porosimetry. Dynamic properties. Equilibrium properties of mixtures of components of comparable size in the bulk phase. Equilibrium distributions of mixture components in the pores. Bulk transport characteristics of binary mixtures. Diffusion coefficients in the slit-like pores. The shear viscosity coefficients. The sliding friction coefficient for the mixture. Spherocylindrical system. Distribution of microimpurities in equilibrium and flows. Large particles. Equilibrium properties of large molecules. Transfer coefficients of rod-shaped molecules. Classification of the pore size. Micropore volume. Microheterogeneity of porous systems. Transport of molecules. Prospects