The effect of chemically reduced graphene oxide （CRGO） on the phase separation behavior of poly（methyl methacrylate）/poly（styrene-co-acrylonitrile） （PMMA/SAN） blends and the simultaneous response of rheologica...The effect of chemically reduced graphene oxide （CRGO） on the phase separation behavior of poly（methyl methacrylate）/poly（styrene-co-acrylonitrile） （PMMA/SAN） blends and the simultaneous response of rheological and conductive behavior of PMMA/SAN/CRGO nanocomposites upon annealing above the phase-separation temperatures were investigated. The introduction of CRGO causes the decrease of binodal temperature and the increase of spinodal temperature for PMMA/SAN blends and then enlarges their metastable regime. During annealing, the well-dispersed CRGO in the homogeneous blend matrix tends to be selectively located in the SAN-rich phase with the evolution of phase separation and then the CRGO further agglomerates effectively in the SAN-rich phase to form the conductive pathway. Thermal-induced dynamic percolation is observed for both the resistivity p and dynamic storage modulus G＇ as a function of annealing time. The resistivity variation is ascribed to the agglomeration of CRGO in the SAN-rich phase, while the modulus evolution is attributed to the combined contribution of phase separation for blend matrix and the agglomeration of CRGO in the SAN-rich phase.展开更多
High performance supercapacitors were constructed using ionic liquid 1-ethyl-3-methylimidazolium thi- ocyanate（EmimSCN）-based electrolyte with chemically reduced graphene oxide（CRGO） as electrodes. Propylene carbo...High performance supercapacitors were constructed using ionic liquid 1-ethyl-3-methylimidazolium thi- ocyanate（EmimSCN）-based electrolyte with chemically reduced graphene oxide（CRGO） as electrodes. Propylene carbonate（PC） was selected as the solvent due to its stable physical and electrochemical properties. Then, in-depth study of the concentration and temperature effects on the electrochemical properties of the EmimSCN/PC electrolyte was carried out. Electrochemical measurements revealed that 2.0 mol/L EmimSCN/PC electrolyte delivered good electrochemical performance（131 F/g of the specific capacity after 3000 cycles at room temperature）. Moreover, the assembled supercapacitors exhibited good capacitive behavior at an extending temperature（397 F/g of the specific capacity after 3000 cycles at 50 ℃）, demonstrating that the EmimSCN/PC electrolyte is a promising candidate for safe high-power supercapacitors.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.51273173 and 51003093)the Research Foundation of Education Bureau of Zhejiang Province(No.Y200908238)
文摘The effect of chemically reduced graphene oxide （CRGO） on the phase separation behavior of poly（methyl methacrylate）/poly（styrene-co-acrylonitrile） （PMMA/SAN） blends and the simultaneous response of rheological and conductive behavior of PMMA/SAN/CRGO nanocomposites upon annealing above the phase-separation temperatures were investigated. The introduction of CRGO causes the decrease of binodal temperature and the increase of spinodal temperature for PMMA/SAN blends and then enlarges their metastable regime. During annealing, the well-dispersed CRGO in the homogeneous blend matrix tends to be selectively located in the SAN-rich phase with the evolution of phase separation and then the CRGO further agglomerates effectively in the SAN-rich phase to form the conductive pathway. Thermal-induced dynamic percolation is observed for both the resistivity p and dynamic storage modulus G＇ as a function of annealing time. The resistivity variation is ascribed to the agglomeration of CRGO in the SAN-rich phase, while the modulus evolution is attributed to the combined contribution of phase separation for blend matrix and the agglomeration of CRGO in the SAN-rich phase.
基金Supported by the National Natural Science Foundation of China（No.21203116）, the Scientific Research Fund of San-qin Scholar, China（No.BJll-26）, the Natural Science Foundation of Shaanxi Province, China（No.2015JM5151） and the Scientific Research Fund of Shaanxi University of Science and Technology, China[No.XSG（4）006].
文摘High performance supercapacitors were constructed using ionic liquid 1-ethyl-3-methylimidazolium thi- ocyanate（EmimSCN）-based electrolyte with chemically reduced graphene oxide（CRGO） as electrodes. Propylene carbonate（PC） was selected as the solvent due to its stable physical and electrochemical properties. Then, in-depth study of the concentration and temperature effects on the electrochemical properties of the EmimSCN/PC electrolyte was carried out. Electrochemical measurements revealed that 2.0 mol/L EmimSCN/PC electrolyte delivered good electrochemical performance（131 F/g of the specific capacity after 3000 cycles at room temperature）. Moreover, the assembled supercapacitors exhibited good capacitive behavior at an extending temperature（397 F/g of the specific capacity after 3000 cycles at 50 ℃）, demonstrating that the EmimSCN/PC electrolyte is a promising candidate for safe high-power supercapacitors.
