Considerable improvement in the dispersion of purified single-walled carbon nanotubes (SWNTs) in an epoxy composite was obtained through functionalization of the SWNTs by using an optimized H2SO4/70% HNO3 acid treatment and subsequent fluorination. Epoxy composites containing 1 wt % nanotubes were processed by dissolving the functionalized SWNTs in dimethylformamide and mixing with the epoxy resin thereafter. The functionalized nanotubes were observed to be highly dispersed and well integrated in the epoxy composites. The enhancement of mechanical properties of the latter was indicated by a 30% increase in modulus and 18% increase in tensile strength. This work demonstrates the practical use of combining acid treatment and fluorination to achieve functionalization and unroping of SWNTs. The functionalized SWNTs can be integrated into epoxy composites through the formation of strong covalent bonds in the course of epoxy ring-opening esterification and curing chemical reactions.

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In order to increase the electrical contact area between TiO2 particles and stainless steel (StSt) substrates of the dye-sensitized solar cells (DSSCs), StSt foil was roughened electrochemically using sulfuric acid with some additives. Compared with the DSSC with nontreated StSt substrate, DSSC with this roughened StSt substrate showed a 33% increase in light-to-electricity conversion efficiency with negligible effect on open circuit voltage (Voc) and fill factor. Electrochemical impedance spectroscopy clearly confirmed that the increased performance was due to a decreased electrical resistance at the TiO2/StSt interface.

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The dilational rheological behavior of gelatin molecules adsorbed at the air-water interface has been studied as a function of sodium dodecyl sulfate (SDS) concentration for a 7 wt % gelatin-SDS solution at 40 degrees C. Binding of SDS molecules to the gelatin strands disrupts the cross-linked network structure of adsorbed gelatin molecules and results in a reduction of the surface elastic modulus of the adsorbed layer that continues until the bulk SDS concentration reaches 1 mM. Beyond this SDS concentration, the dilational rheological properties of the adsorbed gelatin layer are indistinguishable from those of pure SDS adsorbed layers.