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.
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.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.