Critical Effects at 3D Wedge-Wetting

TL;DR

This paper develops a fluctuation theory for 3D wedge-wetting transitions, revealing universal divergence of interfacial roughness near the filling temperature, applicable to various intermolecular forces.

Contribution

It introduces a comprehensive fluctuation theory and a novel effective Hamiltonian model for wedge fluctuation effects in 3D wetting transitions.

Findings

Universal divergence of interfacial roughness as temperature approaches filling point

Development of a Ginzburg criterion for filling transitions

Exact transfer-matrix analysis of a new effective Hamiltonian

Abstract

We show that continuous filling or wedge-wetting transitions are possible in 3D wedge-geometries made from (angled) substrates exhibiting first-order wetting transitions and develop a comprehensive fluctuation theory yielding a complete classification of the critical behaviour. Our fluctuation theory is based on the derivation of a Ginzburg criterion for filling and also an exact transfer-matrix analysis of a novel effective Hamiltonian which we propose as a model for wedge fluctuation effects. The influence of interfacial fluctuations is shown to be very strong and, in particular, leads to a remarkable universal divergence of the interfacial roughness $\xi_{\perp}\sim (T_F-T)^{-1/4}$ on approaching the filling temperature $T_F$, valid for all possible types of intermolecular forces.