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Single-walled carbon nanotubes (SWCNTs) synthesized by the improved arc discharge method were modified with a fluorocarbon chain, and the maintenance of trypsin activity upon adsorption from the subphase to the interfacial monolayer of SWCNTs was evaluated. The adsorption of trypsin on the fluorocarbon-modified SWCNT monolayer was confirmed by morphological and spectroscopic evaluations. Fiber morphology studies revealed that the fluorocarbon-modified SWCNT monolayer was covered by trypsin, and a trypsin-derived amide band was detected in the infrared spectra of the multilayers. After adsorption onto the fluorocarbon-modified SWCNT film, the ability of trypsin to cleave the fluorescent casein chain was maintained even at 160 °C. Furthermore, circular dichroism (CD) spectra showed that the second-order structure of the activity of trypsin adsorbed on the fluorocarbon-modified SWCNT was maintained up to nearly 200 °C. At 200 °C, the enhancement of emission intensity by casein chain cleavage was negligible, and the CD signal resulting from the negative Cotton effect was completely altered at 250 °C.

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A technique for improving the dispersibility of fluorocarbon-modified, singlewalled carbon nanotubes (SWCNTs) in fluorinated polymers was investigated. Furthermore, we aimed to achieve uniaxial orientation of SWCNT aggregates via a simple high-temperature drawing method to yield fluoropolymer-based nanocomposites containing uniform dispersed SWCNTs. Highly waterrepellent SWCNTs were mixed with phase-separable fluorinated polymers by the chemical modification of their surfaces with fluorocarbons. Introducing a fluorinated phosphonic acid surfactant with a high-sublimation temperature as the third component to improve dispersibility in the polymer matrix resulted in an innovative improvement. The uniform dispersed SWCNTs in the matrix improved the crystallinity, crystallization temperature, and mechanical characteristics of the composites. The high-temperature uniaxial orientation of the composite material reduced differences in the physical properties in the polymer due to differences in the initial dispersibility. This effect was expected since the drawing process promoted the deagglomeration of SWCNTs in the matrix. However, optimal physical properties were observed in SWCNT-oriented composite samples with an excellent initial dispersion.

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