Abstract
If a finite strip of an Ising lattice is placed between two baths, a membrane is formed in which the particles being transported can undergo a phase transition. The steady‐state properties of this system are investigated using computer simulation (by a new, more efficient Monte Carlo procedure) and Bragg–Williams approximations for two kinds of kinetics, based on nearest‐neighbor attractions between the particles. A comparison with the steady‐state behavior of the H/Pd system indicates that H–H interactions are not responsible for the α − β phase transition. It is suggested that an allosteric mechanism is involved.