Carbon nanotube nanofluids have wide application prospects due to their unique structure and excellent properties.In this study,the thermal conductivity properties of carbon nanotube nanofluids and SiO2/water nanoflui...Carbon nanotube nanofluids have wide application prospects due to their unique structure and excellent properties.In this study,the thermal conductivity properties of carbon nanotube nanofluids and SiO2/water nanofluids were compared and analyzed experimentally using different preparation methods.The physical properties of nanofluids were tested using a Malvern Zetasizer Nano Instrument and a Hot Disk Thermal Constant Analyzer.Combined with field synergy theory analysis of the heat transfer performance of nanofluids,results show that the thermal conductivity of carbon nanotube nanofluids is higher than that of SiO2/water nanofluids,and the thermal conductivity of nanofluid rises with the increase of mass fraction and temperature.Moreover,the synergistic performance of carbon nanotube nanofluids is also superior to that of SiO2/water nanofluids.When the mass fraction of the carbon nanotube nanofluids is 10%and the SiO2/water nanofluids is 8%,their field synergy numbers and heat transfer enhancement factors both reach maximum.From the perspective of the preparation method,the thermal conductivity of nanofluids dispersed by high shear microfluidizer is higher than that by ultrasonic dispersion.This result provides some reference for the selection and use of working substance in a microchannel cooling concentrated photovoltaic and thermal(CPV/T)system.展开更多
以烷基噻并[3,2-b]噻吩修饰的苯并[1,2-b:4,5-b']二噻吩(BDT)为给电单元、苯并噻二唑(BT)/氟代苯并噻二唑(FBT)作缺电单元、烷基噻吩作π桥,合成了两个窄带隙交替共聚物:PTTBDT-DTBT和PTTBDT-DTFBT。对比研究发现:通过在聚合物主链...以烷基噻并[3,2-b]噻吩修饰的苯并[1,2-b:4,5-b']二噻吩(BDT)为给电单元、苯并噻二唑(BT)/氟代苯并噻二唑(FBT)作缺电单元、烷基噻吩作π桥,合成了两个窄带隙交替共聚物:PTTBDT-DTBT和PTTBDT-DTFBT。对比研究发现:通过在聚合物主链结构上引入氟取代基,聚合物的溶解性变差、热稳定性提高、吸收光谱发生蓝移、加深了HOMO能级。基于倒置型光伏器件的初步测试结果显示:PTTBDT-DTFBT相比未氟代PTTBDT-DTBT,开路电压(VOC)从0.76 V增加到0.82 V,填充因子(FF)亦从53.04%增至54.52%,虽然短路电流密度(JSC)从6.62 mA cm^(-2)到6.28 mA cm^(-2)略有下降,最终能量转换效率(PCE)从2.67%提高到2.81%。可见通过在聚合物的骨架引入氟原子是一种改善聚合物太阳能电池性能的有效方案。展开更多
基金supported by the National Natural Science Foundation of China(NO.51766012)Inner Mongolia Financial Innovation Funding Project in 2017+1 种基金Inner Mongolia Natural Science Foundation of China(NO.2019MS05025)the Inner Mongolia Science and Technology Major Project of China(NO.201905)。
文摘Carbon nanotube nanofluids have wide application prospects due to their unique structure and excellent properties.In this study,the thermal conductivity properties of carbon nanotube nanofluids and SiO2/water nanofluids were compared and analyzed experimentally using different preparation methods.The physical properties of nanofluids were tested using a Malvern Zetasizer Nano Instrument and a Hot Disk Thermal Constant Analyzer.Combined with field synergy theory analysis of the heat transfer performance of nanofluids,results show that the thermal conductivity of carbon nanotube nanofluids is higher than that of SiO2/water nanofluids,and the thermal conductivity of nanofluid rises with the increase of mass fraction and temperature.Moreover,the synergistic performance of carbon nanotube nanofluids is also superior to that of SiO2/water nanofluids.When the mass fraction of the carbon nanotube nanofluids is 10%and the SiO2/water nanofluids is 8%,their field synergy numbers and heat transfer enhancement factors both reach maximum.From the perspective of the preparation method,the thermal conductivity of nanofluids dispersed by high shear microfluidizer is higher than that by ultrasonic dispersion.This result provides some reference for the selection and use of working substance in a microchannel cooling concentrated photovoltaic and thermal(CPV/T)system.
文摘以烷基噻并[3,2-b]噻吩修饰的苯并[1,2-b:4,5-b']二噻吩(BDT)为给电单元、苯并噻二唑(BT)/氟代苯并噻二唑(FBT)作缺电单元、烷基噻吩作π桥,合成了两个窄带隙交替共聚物:PTTBDT-DTBT和PTTBDT-DTFBT。对比研究发现:通过在聚合物主链结构上引入氟取代基,聚合物的溶解性变差、热稳定性提高、吸收光谱发生蓝移、加深了HOMO能级。基于倒置型光伏器件的初步测试结果显示:PTTBDT-DTFBT相比未氟代PTTBDT-DTBT,开路电压(VOC)从0.76 V增加到0.82 V,填充因子(FF)亦从53.04%增至54.52%,虽然短路电流密度(JSC)从6.62 mA cm^(-2)到6.28 mA cm^(-2)略有下降,最终能量转换效率(PCE)从2.67%提高到2.81%。可见通过在聚合物的骨架引入氟原子是一种改善聚合物太阳能电池性能的有效方案。
