Morphological control of bicontinuous phase-separated patterns by preparing mixed monolayers using non-amphiphilic s-triazine derivatives with three fluorinated chains

In this study, the morphogenesis of the bicontinuous phase separation in mixed monolayers of a non-amphiphilic fluorocarbon derivative without a hydrophilic group and long-chain fatty acids is discussed. These fluorocarbon derivatives contain an s-triazine ring and three fluorocarbon chains. The corresponding fluorocarbon derivatives exhibit high crystallinity in the monolayers, allowing them to maintain crystalline regularity even in the "sea" region of the mixed monolayer that exhibits phase separation. In controlling the bicontinuous pattern, the formation of complex phase-separated morphology in the mixed system of fluorine-based derivatives and comb polymers, along with the high concentration and low diffusion conditions in the mixed hydrocarbon/fluorocarbon system, were examined. It was observed that the condensed phase domains became angular shape at a low temperature (5 °C), and the surface approached a bicontinuous feature at a high temperature (40 °C). With the formation of hydrogenated condensed domains, the "sea" region of fluorocarbon chains lost its order. At this point, the shape of the nanodomains tended to become more circular.