Controlling the various phase-separated patterns in mixed monolayers of non-amphiphilic fluorinated derivatives and hydrogenated comb copolymers

Abstract

Mixed monolayers were prepared on the water surface of non-amphiphilic fluorinated derivatives, as well as hydrocarbon-based comb copolymers, whose intermolecular interactions could be tuned using a copolymerization method. The phase-separated morphologies of the monolayers could also be controlled. Diamino-s-triazine rings, which were critical in morphology formation, were introduced into the hydrophilic groups of the comb copolymers for the phase-separated patterning. The phase-separation pattern was precisely controlled using various parameters, such as the chain length of the fluorinated derivatives, composition of the comb copolymers, mixing ratio, subphase temperature, and surface pressure. The obtained sea-island phase-separated patterns were classified into domain-like, circular, non-circular linear, donut-like, and centrally protruding circular domain morphologies. At 35 °C, a new nucleation phenomenon was observed inside the donut-shaped pattern that had developed through coagulation. During the phase separation of the current system, crystalline regularity was achieved in the fluorinated sea region around the domain, which was generally a continuous phase.