Carbohydrate-attached fullerene derivative for selective localization in ordered...

A carbohydrate-based fullerene derivative (AcMal₇-C₆₁) is designed, synthesized and applied to a lamellar-forming high-χ block copolymer system, poly(3-hexylthiophene)-block-peracetylated maltoheptaose (P3HT-b-AcMal₇), to actualize an ordered donor/acceptor (D/A) network. A well-defined D/A lamellar structure of the P3HT-b-AcMal₇:AcMal₇-C₆₁ blend with sub-10 nm domain features is achieved upon thermal annealing. The AcMal₇-C₆₁ molecules are localized in the phase-separated AcMal₇ nanodomains without causing the formation of fullerene crystals while maintaining the lamellar morphology up to 1:0.5 (D:A) blending ratio. The cross-sectional TEM observation and GISAXS measurement reveals that the P3HT-b-AcMal₇ tends to spontaneously organize into lamellar structures oriented perpendicular to the film surface at the air/film interface while the domain orientation at the bottom interface depends on the nature of the substrate.