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2013) Effect of alcohol pretreatment in conjunction with atmospheric pressure plasmas on hydrophobizing ramie fiber surfaces, To improve interfacial adhesion between hydrophilic cellulose fiber and hydrophobic polymer matrix, ramie fibers were pretreated with isopropanol and n-butanol and then plasma treated using an atmospheric pressure plasma apparatus. For the plasma-treated fibers, the scanning electron microscopy shows increased surface roughness and the X-ray photoelectron spectroscopy analysis shows a significant increase of C-C bond in isopropanol-pretreated group, whereas for n-butanol-pretreated group the raise of C=O bonds is most noticeable. For both alcohol-pretreated and plasma-treated groups, the water contact angles increase significantly. Microbond pull-out test shows interfacial shear strengths of fiber/polypropylene (PP) samples increase by 47 and 34%, respectively, for the two groups compared with the control. Therefore, it can be concluded that the reaction between both alcohols and cellulose induced by plasma can indeed create a fiber surface with increased roughness and decreased polarity, and thus is more compatible to PP.

Obtaining air-stable and high-performance flexible n-type single-walled carbon nanotube (SWCNT)-based thermoelectric films used in wearable electronic devices is a challenge. In this work, the microstructure and thermoelectric properties of n-type SWCNTbased films have been optimized via doping C 60 and its derivative into polyethylenimine/ single-walled carbon nanotube (PEI/SWCNT) films. The result demonstrated that the dispersity of triethylene glycol-modified C 60 (TEG-C 60 ) was better in PEI/SWCNT films than that of pure C 60 . Among the prepared composite films, TEG-C 60 -doped PEI/SWCNT (TEG-C 60 /PEI/SWCNT) films exhibited the highest TE performance, achieving a peak electrical conductivity of 923 S cm −1 with a Seebeck coefficient of −42 μV K −1 at a TEG-C 60 /SWCNT mass ratio of 1:100. Compared to that of PEI/SWCNT, the power factor was increased significantly from 40 to 162 μW m −1 K −2 after the addition of TEG-C 60 , which was higher than that of films after the addition of C 60 . In addition, the n-type doped SWCNT films had good air stability at high temperatures, and the Seebeck coefficients of C 60 /PEI/SWCNT and TEG-C 60 /PEI/SWCNT at 120 °C were still negative and remained at 92% and 85%, respectively, after 20 days. Furthermore, a flexible TE device consisting of five pairs of p−n junctions was assembled using the optimum hybrid film, which generated a maximum output power of 3.6 μW at a temperature gradient of 50.2 K. Therefore, this study provides a facile way to enhance the thermoelectric properties of n-type carbon nanotube-based materials, which have potential application in flexible power generators.

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