The current work focused on the investigation of charge and separation characteristics of nanofiltration （NF） membrane embracing dissociated functional groups under different electrolyte solutions. The electro-kinet...The current work focused on the investigation of charge and separation characteristics of nanofiltration （NF） membrane embracing dissociated functional groups under different electrolyte solutions. The electro-kinetic method was carried out to assess the membrane volume charge density （X） with different salt concentrations ranging from 0.1 to 10 mol. m-3 and different electrolyte species, such as type 1-1, type 2-1 and type 3-1. The Donnan steric pore model-dielectric exclusion （DSPM- DE） model was employed to evaluate the separation characteristics of the NF membrane for wide range of electrolyte concentration （from 25.7 to 598.9mol·m^-3）. The results indicated that the dissociation of the hydro- philic functional groups and the specific adsorption contributed to charge formation on membrane surface. The former played a dominant role in type 1-1 and type 2-1 electrolytes at dilute aqueous solutions （0.1-0.5 mol · m^3）. However, for type 3-1 electrolyte, specific adsorp- tion should contribute to the charge effect to a large extent. Moreover, the correlation between the volume charge density and feed concentration was in accordance with Freundlich isotherm. Furthermore, it was found that the separation characteristic of NF membrane could be evaluated well by DSPM-DE model coupling with electro-kinetic method in a whole concentration range.展开更多
Efficiently converting the random vibration energy widely existed in human activities and natural environments into electricity is significant to the local power supply of sensor nodes in the internet of things.Howeve...Efficiently converting the random vibration energy widely existed in human activities and natural environments into electricity is significant to the local power supply of sensor nodes in the internet of things.However,the conversion efficiency of energy harvester is relatively low due to the limitation of device’s intrinsic frequency.In this work,a multi-layered,wavy super-structuredtriboelectric nanogenerator(SS-TENG)is designed,whose output performances can be greatly promoted by combining the charge excitation mechanism.The steel sheet acts not only as an electrode but also as a supporter for the overall frame of SSTENG,which effectively improves the space utilization rate and results in a volume charge density up to 129 mC·m^(−3).In addition,the resonant frequency width of the SS-TENG can be widened by changing the parameters of the superstructure.For demonstration,the SS-TENG can sustainably drive two temperature and humidity sensors in parallel by harvesting vibration energy.This work may provide an effective strategy for harvesting vibration energy and broadening frequency response.展开更多
基金Acknowledgements This research was supported by the National Natural Science Foundation of China （Grant No. 20706050）.
文摘The current work focused on the investigation of charge and separation characteristics of nanofiltration （NF） membrane embracing dissociated functional groups under different electrolyte solutions. The electro-kinetic method was carried out to assess the membrane volume charge density （X） with different salt concentrations ranging from 0.1 to 10 mol. m-3 and different electrolyte species, such as type 1-1, type 2-1 and type 3-1. The Donnan steric pore model-dielectric exclusion （DSPM- DE） model was employed to evaluate the separation characteristics of the NF membrane for wide range of electrolyte concentration （from 25.7 to 598.9mol·m^-3）. The results indicated that the dissociation of the hydro- philic functional groups and the specific adsorption contributed to charge formation on membrane surface. The former played a dominant role in type 1-1 and type 2-1 electrolytes at dilute aqueous solutions （0.1-0.5 mol · m^3）. However, for type 3-1 electrolyte, specific adsorp- tion should contribute to the charge effect to a large extent. Moreover, the correlation between the volume charge density and feed concentration was in accordance with Freundlich isotherm. Furthermore, it was found that the separation characteristic of NF membrane could be evaluated well by DSPM-DE model coupling with electro-kinetic method in a whole concentration range.
基金the National Key Research and Development Program(No.2021YFA1201602)the NSFC(No.62004017)+3 种基金the Fundamental Research Funds for the Central Universities(No.2021CDJQY-019)the Graduate Research and Innovation Foundation of Chongqing,China(No.CYB22047)J.C.also wants to acknowledge the supports from the Natural Science Foundation of Chongqing(No.cstc2021jcyjmsxmX0746)the Scientific Research Project of Chongqing Education Committee(No.KJQN202100522).
文摘Efficiently converting the random vibration energy widely existed in human activities and natural environments into electricity is significant to the local power supply of sensor nodes in the internet of things.However,the conversion efficiency of energy harvester is relatively low due to the limitation of device’s intrinsic frequency.In this work,a multi-layered,wavy super-structuredtriboelectric nanogenerator(SS-TENG)is designed,whose output performances can be greatly promoted by combining the charge excitation mechanism.The steel sheet acts not only as an electrode but also as a supporter for the overall frame of SSTENG,which effectively improves the space utilization rate and results in a volume charge density up to 129 mC·m^(−3).In addition,the resonant frequency width of the SS-TENG can be widened by changing the parameters of the superstructure.For demonstration,the SS-TENG can sustainably drive two temperature and humidity sensors in parallel by harvesting vibration energy.This work may provide an effective strategy for harvesting vibration energy and broadening frequency response.
