MODEL-CALCULATIONS FOR WETTING TRANSITIONS IN POLYMER MIXTURES

Partially compatible binary mixtures of linear flexible polymers are considered in the presence of a wall which preferentially adsorbs one component. Using a Flory-Huggins type mean field approach, it is shown that in typical cases at two-phase coexistence the wall is always 'wet', i. e. coated with a macroscopically thick layer on the preferred phase, and the transition to the non wet state occurs at volume fractions of the order of 1/ ROOT N (Where N is the chain length) at the coexistence curve. The relation of our results to previous work and possible experimental consequences are also briefly mentioned.