AbstractThe transport ofp‐nitrophenol across films formed from surfactant‐free poly(butyl methacrylate) latices has been investigated with a view to better understanding the morphology of, and morphological changes occurring in, such films. The importance of the temperature and time, both of film formation and of storage, are identified and related to the state of coalescence of the latex particles within the films. especially with respect to interparticle boundar