To enhance the process of phenyltrichlorosilane synthesis using gas phase condensation, a series of chloralkanes were introduced. The influence of temperature and chloralkane amount on the synthesis was studied based ...To enhance the process of phenyltrichlorosilane synthesis using gas phase condensation, a series of chloralkanes were introduced. The influence of temperature and chloralkane amount on the synthesis was studied based on the product distribution from a tubular reactor. The promoting effect of chloralkane addition was mainly caused by the chloralkane radicals generated by the dissociation of C–Cl bond. The promoting effect of the chloromethane with more chlorine atoms was better than those with less chlorine atoms. Intermediates detected from the reactions with isoprene and bromobenzene demonstrated that both trichlorosilyl radical and dichlorosilylene existed in the reaction system in the presence of chloralkanes. A detailed reaction scheme was proposed.展开更多
Methylphenyldichlorosilane(MPDS, CH3C6H5 SiC l2) is an important silicone monomer for the synthesis of highperformance polymethylphenylsiloxane polymers. In this work, the mechanism of the synthesis of MPDS from methy...Methylphenyldichlorosilane(MPDS, CH3C6H5 SiC l2) is an important silicone monomer for the synthesis of highperformance polymethylphenylsiloxane polymers. In this work, the mechanism of the synthesis of MPDS from methyldichlorosilane and chlorobenzene by gas phase condensation was studied, and a kinetic model with 35 species and 58 elementary reactions was established. Experiments were carried out in a tubular reactor under a wide range of reaction conditions. The calculated mole fractions of the reactants and products were in a good agreement with the experimental results. A mechanism of the insertion of chloromethylsilylene into the C\Cl bond of chlorobenzene was proposed, which was proved to be the main pathway of MPDS production. The established kinetic model can be used in design and optimization of the industrial reactor for MPDS synthesis.展开更多
A significant enhancement in the thermoelectric performance was observed for three-dimensional conducting aerogels,which were obtained from poly（3,4-ethylenedioxythiophene）：poly（4-styrenesulfonic）（PEDOTrPSS） an...A significant enhancement in the thermoelectric performance was observed for three-dimensional conducting aerogels,which were obtained from poly（3,4-ethylenedioxythiophene）：poly（4-styrenesulfonic）（PEDOTrPSS） and multiwalled carbon nanotubes（MWCNTs） suspensions by adding different concentrations of metallic silver（Ag）.It was found that the electrical conductivity and Seebeck coefficient could be simultaneously increased with the unique structure.Moreover,the conducting aerogels have an ultralow thermal conductivity（0.06 W m^（-1） K^（-1） and a large Brunauer-Emmett-Teller surface area（228 m^2 g^（-1）.The highest figure of merit（zT） value in this study was 7.56×10^（-3） at room temperature upon the addition of 33.32 wt.%Ag.Although the zT value was too low,our work may provide new insights into the design and development of the thermoelectric material for applications.Further investigation with PEDOTrPSS aerogels will be continued to get an economical,lightweight,and efficient polymer thermoelectric material.展开更多
In many heat recovery processes,temperature control of heat source is often required to ensure safety and high efficiency of the heat source equipment.In addition,the management of recovered heat is important for the ...In many heat recovery processes,temperature control of heat source is often required to ensure safety and high efficiency of the heat source equipment.In addition,the management of recovered heat is important for the proper use of waste heat.To this aim,the concept of thermal management controller(TMC),which can vary heat transfer rate via the volume variation of non-condensable gas,was presented.Theoretical model and experimental prototype were established.Investigation shows that the prototype is effective in temperature control With water as the working fluid,the vapor temperature variation is only 1.3℃when the heating power varies from 2.5 to 10.0 kW.In variable working conditions,this TMC can automatically adjust thermal allocation to the heat consumer.展开更多
文摘To enhance the process of phenyltrichlorosilane synthesis using gas phase condensation, a series of chloralkanes were introduced. The influence of temperature and chloralkane amount on the synthesis was studied based on the product distribution from a tubular reactor. The promoting effect of chloralkane addition was mainly caused by the chloralkane radicals generated by the dissociation of C–Cl bond. The promoting effect of the chloromethane with more chlorine atoms was better than those with less chlorine atoms. Intermediates detected from the reactions with isoprene and bromobenzene demonstrated that both trichlorosilyl radical and dichlorosilylene existed in the reaction system in the presence of chloralkanes. A detailed reaction scheme was proposed.
文摘Methylphenyldichlorosilane(MPDS, CH3C6H5 SiC l2) is an important silicone monomer for the synthesis of highperformance polymethylphenylsiloxane polymers. In this work, the mechanism of the synthesis of MPDS from methyldichlorosilane and chlorobenzene by gas phase condensation was studied, and a kinetic model with 35 species and 58 elementary reactions was established. Experiments were carried out in a tubular reactor under a wide range of reaction conditions. The calculated mole fractions of the reactants and products were in a good agreement with the experimental results. A mechanism of the insertion of chloromethylsilylene into the C\Cl bond of chlorobenzene was proposed, which was proved to be the main pathway of MPDS production. The established kinetic model can be used in design and optimization of the industrial reactor for MPDS synthesis.
基金supported by the National Natural Science Foundation of China(51303116)
文摘A significant enhancement in the thermoelectric performance was observed for three-dimensional conducting aerogels,which were obtained from poly（3,4-ethylenedioxythiophene）：poly（4-styrenesulfonic）（PEDOTrPSS） and multiwalled carbon nanotubes（MWCNTs） suspensions by adding different concentrations of metallic silver（Ag）.It was found that the electrical conductivity and Seebeck coefficient could be simultaneously increased with the unique structure.Moreover,the conducting aerogels have an ultralow thermal conductivity（0.06 W m^（-1） K^（-1） and a large Brunauer-Emmett-Teller surface area（228 m^2 g^（-1）.The highest figure of merit（zT） value in this study was 7.56×10^（-3） at room temperature upon the addition of 33.32 wt.%Ag.Although the zT value was too low,our work may provide new insights into the design and development of the thermoelectric material for applications.Further investigation with PEDOTrPSS aerogels will be continued to get an economical,lightweight,and efficient polymer thermoelectric material.
基金the Specialized Research Fund for the Doctoral Program of Higher Education of China(No.20040248055)the Education Ministry Key Investigation Project of Science and Technology(No.306004)
文摘In many heat recovery processes,temperature control of heat source is often required to ensure safety and high efficiency of the heat source equipment.In addition,the management of recovered heat is important for the proper use of waste heat.To this aim,the concept of thermal management controller(TMC),which can vary heat transfer rate via the volume variation of non-condensable gas,was presented.Theoretical model and experimental prototype were established.Investigation shows that the prototype is effective in temperature control With water as the working fluid,the vapor temperature variation is only 1.3℃when the heating power varies from 2.5 to 10.0 kW.In variable working conditions,this TMC can automatically adjust thermal allocation to the heat consumer.
