Well Ordered Polymer Melts with Sub 5-Nanometer Domains upon Blending Surfactants with Selectively Associating Additives

Applications employing block copolymers such as templating mesoporous inorganic structures and patterning would benefit from reduction in domain size formed in well-ordered block copolymer templates. The extent to which the domain size can be reduced is limited by the minimum required segregation strength, $\chi N$, where $N$ determines the size of block copolymer chains and the domain size. We have shown that disordered block copolymer surfactants with molar mass less than 15 kg/mol, can be made to undergo disorder-to-order transition by blending selectively associating homopolymers as well as small molecule additives with multi-point, non-ionic interactions. Blending with selectively associating additives result in an increase in segregation strength $\chi N$ through an increase in apparent $\chi$. The resulting domain sizes were found to be as low as 5 nm which is significantly lower than that seen for a typical block copolymer template.