Electrospinning of fibers composed of poly(3‐hexylthiophene) (P3HT), fullerene derivative, phenyl‐C61‐butyric acid methyl ester (PCBM), and single‐walled carbon nanotubes (SWNT) is reported. While of great promise for photovoltaic applications, morphological control of functional structures is a great challenge for most processing methods. It is demonstrated that the use of a tailor‐made block‐copolymer for dispersion of individual SWNT enables the preparation of stable dispersions of individual tubes that may be further cospun from chloroform solutions with PCBM and P3HT into submicron fibers. The block copolymer used to mediate the colloidal and interfacial interactions in the combined system enables the spinning of centimeters long and uniform fibers. Structural characterization indicates a high degree of ordering and alignment within the fibers and absorption and quenching of the photoluminescence indicate significant interactions among the components. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 49: 1263–1268, 2011

Triblock copolymers, polyethylene oxide-(hexa-p-phenylene)-polyethylene oxide, were synthesized and used for dispersing single-walled carbon nanotubes (SWNT) in organic solvents. The resulting dispersions comprise mostly of individual tubes, as indicated by transmission electron microscopy at cryogenic temperatures. The dispersions could be dried and redispersed by the addition of a solvent, offering a useful method of application of predispersed SWNT. In situ optical spectroscopy indicates that the block copolymers which self-assemble in the native solution physically adsorb to the SWNT surface via the hexa-p-phenylene moiety. The noncovalent, weak adsorption competes with the polymer self-assembly, as clearly indicated by the emission spectra. The balance between self-assembly and adsorption is sensitive to the length of ethylene oxide side chains. The approach presented here may serve for optimization of the structure and composition of polymeric dispersants where one can chose between a long tail and a long adsorbing moiety, according to the specific needs presented by different applications of SWNT.

The colorimetric data yield insight into the degree of lipid binding of the molecules tested. The film assay is particularly advantageous for analysis of semi-solid (gel or lotion) formulations, elucidating the lipid interaction characteristics of specific molecular components within the mixtures. The new colorimetric film assay constitutes a generic, rapid, and easily applicable platform for predicting and screening interactions of pharmaceutical compounds and complex formulations with lipid barriers.