MONTE-CARLO STUDY OF DIBLOCK COPOLYMERS IN DILUTE-SOLUTION

We investigate the conformational changes of symmetric diblock copolymer molecules in dilute athermal solvent due to chemical mismatch between the two blocks using Monte Carlo simulations. Renormalization group calculations based on the two parameter model predict that the effects of chemical mismatch on the size of diblocks appear only as corrections to scaling and that the value of the exponent governing the correction to scaling for the mean squared end-to-end distance of the molecule is 0.225. However, our results show that for strongly incompatable monomers the value of this exponent is much larger. We also find that the chemical mismatch causes the diblock molecule to assume a dumbbell shaped conformation and that the shape changes induced by the chemical mismatch obey a novel scaling relation.