The rapid development of communication technology and high-frequency electronic devices has created a need for more advanced electromagnetic interference(EMI)shielding materials.In response to this demand,a study has ...The rapid development of communication technology and high-frequency electronic devices has created a need for more advanced electromagnetic interference(EMI)shielding materials.In response to this demand,a study has been conducted to develop multifunctional carbon nanofibers(CNFs)/polyaniline(PANI)aerogels with excellent electromagnetic interference shielding,flame retardancy,and thermal insulation performance.The process involved freeze-drying of electrospun CNFs and PANI nanoparticles followed by in situ growth PANI to coat the CNFs,creating the core-shell structured CNFs/PANI composite fiber and its hybrid aerogels(CP-3@PANI).The interaction between PANI and aniline(ANI)provides attachment sites,allowing additional ANI adsorption into the aerogel for in situ polymerization.This results in PANI uniformly covering the surface of the CNFs,creating a core-shell composite fiber with a flexible CNF core and PANI shell.This process enhances the utilization rate of the ANI monomer and increases the PANI content loaded onto the aerogel.Additionally,effective connections are established between the CNFs,forming a stable,conductive three-dimensional network structure.The prepared CP-3@PANI aerogels exhibit excellent EMI shielding efficiency(SE)of 85.4 dB and specific EMI SE(SE d^(-1))of 791.2 dB cm^(3)g^(-1)in the X-band.Due to the synergistic flame-retardant effect of CNFs,PANI,and the dopant(phytic acid),the CP-3@PANI aerogels demonstrate outstanding flame-retardant and thermal insulation properties,with a peak heat release rate(PHRR)as low as 7.8 W g^(-1)and a total heat release of only 0.58 kJ g^(-1).This study provides an effective strategy for preparing multifunctional integrated EMI shielding materials.展开更多
本文通过利用基于钴金属有机骨架材料(ZIF-67)的高表面积和良好的结晶度作为前驱体,通过氮气气氛高温煅烧后形成C-ZIF-67材料,并通过原位聚合法,在C-ZIF-67材料表面生长密度均匀的聚苯胺(PANI)化合物,最终获得C-ZIF-67/PANI复合材料。采...本文通过利用基于钴金属有机骨架材料(ZIF-67)的高表面积和良好的结晶度作为前驱体,通过氮气气氛高温煅烧后形成C-ZIF-67材料,并通过原位聚合法,在C-ZIF-67材料表面生长密度均匀的聚苯胺(PANI)化合物,最终获得C-ZIF-67/PANI复合材料。采用CV、GCD和EIS电化学技术研究了C-ZIF-67/PANI复合电极在1 M硫酸电解液中的储能性能。最终表明,C-ZIF-67/PANI5复合电极可提供450.5 F g−1的比电容,并且在电流密度为8 A g−1下经过5000次的充放电循环测试后,比电容值仍保持初始比电容值的71%,表现其良好的循环稳定性。In this paper, the cobalt metal-organic framework material (ZIF-67) with high surface area and good crystallinity was used as the precursor. The C-ZIF-67 material was formed after calcination at high temperature under N2 atmosphere. Then, through the in-situ polymerization method, the polyaniline (PANI) compound with a uniform density was grown on the surface of the C-ZIF-67 material, and finally the C-ZIF-67/PANI composite material was obtained. The electrochemical techniques such as cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS) were employed to investigate the energy storage performance of the C-ZIF-67/PANI composite electrode in 1 M sulfuric acid electrolyte. Eventually, it was demonstrated that the C-ZIF-67/PANI5 composite electrode could provide a specific capacitance of 450.5 F g⁻¹, and after 5000 charge-discharge cycling tests at a current density of 8 A g⁻¹, the specific capacitance value still remained 71% of the initial specific capacitance value, indicating its good cyclic stability.展开更多
Vanadium oxide(VO_(X))with tunable interlayer spacing and variable valence states of vanadium ions offers tremendous opportunities in aqueous electrochromic devices but is still challenging.Herein,a poly aniline(PANI)...Vanadium oxide(VO_(X))with tunable interlayer spacing and variable valence states of vanadium ions offers tremendous opportunities in aqueous electrochromic devices but is still challenging.Herein,a poly aniline(PANI)-VO_(X)composite material has been designed,increasing the conductivity and the structure stability.Owning to these virtues,the PANI-VO_(X)composite material achieves a high capacitance of 332 mAh·g^(-1)at 0.1 A·g^(-1)and a superior cycling performance(72%ΔT retention after 500 cycles).Importantly,in-situ Raman spectroscopy has been utilized to reveal the rapid formation of Zn_(3)(OH)_(2)V_(2)O_(7)·nH_(2)O and the reversible change of PANI-VO_(X),which can further assist the development of aqueous electrochromic devices.This work highlights the understanding of the Zn^(2+)electrochromic mechanism and sheds some light on organic-inorganic composite electrochromic materials.展开更多
基金the financial support from the Shenzhen Biodegradable Polymer Materials and Materials Genetic Evaluation Research Project Team (JCYJ20220818100217037)Science and Technology Program of Shenzhen (JSGG20200924171000001)+4 种基金the Key-Area Research and Development Program of Guangdong Province (2019B010941001)the Guangdong Provincial Key Laboratory of Energy Materials for Electric Power(2018B030322001)the National Key Research and Development Program of China (2018YFB0704100)Joint Laboratory of Radiation Protection and Material Genetic Engineering Applications in Nuclear Facilitiessupported by the Pico Center at SUSTech CRF which receives support from the Presidential Fund and Development and Reform Commission of Shenzhen Municipality。
文摘The rapid development of communication technology and high-frequency electronic devices has created a need for more advanced electromagnetic interference(EMI)shielding materials.In response to this demand,a study has been conducted to develop multifunctional carbon nanofibers(CNFs)/polyaniline(PANI)aerogels with excellent electromagnetic interference shielding,flame retardancy,and thermal insulation performance.The process involved freeze-drying of electrospun CNFs and PANI nanoparticles followed by in situ growth PANI to coat the CNFs,creating the core-shell structured CNFs/PANI composite fiber and its hybrid aerogels(CP-3@PANI).The interaction between PANI and aniline(ANI)provides attachment sites,allowing additional ANI adsorption into the aerogel for in situ polymerization.This results in PANI uniformly covering the surface of the CNFs,creating a core-shell composite fiber with a flexible CNF core and PANI shell.This process enhances the utilization rate of the ANI monomer and increases the PANI content loaded onto the aerogel.Additionally,effective connections are established between the CNFs,forming a stable,conductive three-dimensional network structure.The prepared CP-3@PANI aerogels exhibit excellent EMI shielding efficiency(SE)of 85.4 dB and specific EMI SE(SE d^(-1))of 791.2 dB cm^(3)g^(-1)in the X-band.Due to the synergistic flame-retardant effect of CNFs,PANI,and the dopant(phytic acid),the CP-3@PANI aerogels demonstrate outstanding flame-retardant and thermal insulation properties,with a peak heat release rate(PHRR)as low as 7.8 W g^(-1)and a total heat release of only 0.58 kJ g^(-1).This study provides an effective strategy for preparing multifunctional integrated EMI shielding materials.
文摘本文通过利用基于钴金属有机骨架材料(ZIF-67)的高表面积和良好的结晶度作为前驱体,通过氮气气氛高温煅烧后形成C-ZIF-67材料,并通过原位聚合法,在C-ZIF-67材料表面生长密度均匀的聚苯胺(PANI)化合物,最终获得C-ZIF-67/PANI复合材料。采用CV、GCD和EIS电化学技术研究了C-ZIF-67/PANI复合电极在1 M硫酸电解液中的储能性能。最终表明,C-ZIF-67/PANI5复合电极可提供450.5 F g−1的比电容,并且在电流密度为8 A g−1下经过5000次的充放电循环测试后,比电容值仍保持初始比电容值的71%,表现其良好的循环稳定性。In this paper, the cobalt metal-organic framework material (ZIF-67) with high surface area and good crystallinity was used as the precursor. The C-ZIF-67 material was formed after calcination at high temperature under N2 atmosphere. Then, through the in-situ polymerization method, the polyaniline (PANI) compound with a uniform density was grown on the surface of the C-ZIF-67 material, and finally the C-ZIF-67/PANI composite material was obtained. The electrochemical techniques such as cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS) were employed to investigate the energy storage performance of the C-ZIF-67/PANI composite electrode in 1 M sulfuric acid electrolyte. Eventually, it was demonstrated that the C-ZIF-67/PANI5 composite electrode could provide a specific capacitance of 450.5 F g⁻¹, and after 5000 charge-discharge cycling tests at a current density of 8 A g⁻¹, the specific capacitance value still remained 71% of the initial specific capacitance value, indicating its good cyclic stability.
基金financially supported by the National Natural Science Foundation of China(No.62471271)Shandong Provincial Natural Science Foundation(No.ZR2021YQ42)the Taishan Young Scholar Program of Shandong Province
文摘Vanadium oxide(VO_(X))with tunable interlayer spacing and variable valence states of vanadium ions offers tremendous opportunities in aqueous electrochromic devices but is still challenging.Herein,a poly aniline(PANI)-VO_(X)composite material has been designed,increasing the conductivity and the structure stability.Owning to these virtues,the PANI-VO_(X)composite material achieves a high capacitance of 332 mAh·g^(-1)at 0.1 A·g^(-1)and a superior cycling performance(72%ΔT retention after 500 cycles).Importantly,in-situ Raman spectroscopy has been utilized to reveal the rapid formation of Zn_(3)(OH)_(2)V_(2)O_(7)·nH_(2)O and the reversible change of PANI-VO_(X),which can further assist the development of aqueous electrochromic devices.This work highlights the understanding of the Zn^(2+)electrochromic mechanism and sheds some light on organic-inorganic composite electrochromic materials.
