Double-shell microcapsules containing butyl stearate were prepared through interfacial polymerization. The outer shell is polyurea formed through polymerization of toluene-2,4-diisocyanate (TDI) and diethylene triamine, and the inner shell is polyurethane (PU) formed through polymerization of TDI and polypropylene glycol 2000 (PPG2000). Styrene maleic anhydride copolymer was used as emulsifier. The effects of core to monomer ratio and dosage of PPG2000 on core content and encapsulation efficiency of microcapsules were investigated. The core content has a maximum at core to monomer ratio of 3-4, and the encapsulation efficiency has a maximum value of 95% at core to monomer ratio of 2. The prepared microcapsules were smooth and compact and have an obvious latent heat of 85 J/g. The shell structure of microcapsules was polyurea and PU. The average diameter of the microcapsules was 1-5 lm. The stabilities of the double-shell microcapsule, such as anti-ethanol wash and antiheat properties are obviously improved than those of single-shell microcapsule.

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The natural cotton stalk (CS) bark fiber was obtained through degumming of CS bark, and then treated by sodium hydroxide solution. To investigate the influence of sodium hydroxide treatment on the properties of the natural CS bark fiber, the fineness, length, breaking strength, X‐ray diffraction, and morphology were tested. The results showed that the fineness, length, and crystallinity of the fiber decreased when the fiber was treated by sodium hydroxide solution. When the sodium hydroxide content increased from 10 to 50 g/L, the strengths of the fiber increased. The surface of the fiber after treating was bright compared with before treating, and the single cell had convolutions after alkali treating. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

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With the development of wearable electronic devices, there has been extensive research interest in portable energy supply systems. In this study, traditional cotton fabrics are finished with a water repellent coating and a single-sided polyurethane (PU) coating to impart hydrophobicity. The hydrophobic lightweight cotton fabric can float on the surface of the pyrrole polymerization system solution. With increasing polymerization time, the pyrrole continues to polymerize and deposit on the side in contact with the fabric, resulting in a one-sided conductive fabric.The highest doping level was obtained for the polypyrrole (PPy) coating for polymerization time of 12 h. For PPy coating thickness of 18 μm, the square resistance was as low as 220 Ω/sq. The PPy-12 fabric electrode showed excellent electrochemical performance and cycling stability. An interdigitated pattern was etched on the surface of the one-sided conductive fabric (PPy-12) using a N, Ndimethylformamide solution. Fabric micro-supercapacitors were obtained by assembling with a H 2 SO 4 /PVA gel electrolyte. The fabric micro-supercapacitor exhibited good flexibility and electrochemical energy storage properties. For current density of 0.08 mA/cm 2 and power density of 19.1 μW/cm 2 , the energy density of the device was 0.09 μWh/cm 2 . After 3000 cycles, the micro-supercapacitor retained approximately 85% of the capacitance. Thus, fabric-based flexible microsupercapacitors have excellent application potential in the field of energy storage.

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