期刊文献+
共找到37篇文章
< 1 2 >
每页显示 20 50 100
Layered Structural PBAT Composite Foams for Efficient Electromagnetic Interference Shielding 被引量:1
1
作者 Jianming Yang Hu Wang +2 位作者 Yali Zhang Hexin Zhang junwei gu 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第2期273-286,共14页
The utilization of eco-friendly,lightweight,high-efficiency and high-absorbing electromagnetic interference(EMI)shielding composites is imperative in light of the worldwide promotion of sustainable manufacturing.In th... The utilization of eco-friendly,lightweight,high-efficiency and high-absorbing electromagnetic interference(EMI)shielding composites is imperative in light of the worldwide promotion of sustainable manufacturing.In this work,magnetic poly(butyleneadipate-coterephthalate)(PBAT)microspheres were firstly synthesized via phase separation method,then PBAT composite foams with layered structure was constructed through the supercritical carbon dioxide foaming and scraping techniques.The merits of integrating ferroferric oxideloaded multi-walled carbon nanotubes(Fe3O4@MWCNTs)nanoparticles,a microcellular framework,and a highly conductive silver layer have been judiciously orchestrated within this distinctive layered configuration.Microwaves are consumed throughout the process of“absorption-reflection-reabsorption”as much as possible,which greatly declines the secondary radiation pollution.The biodegradable PBAT composite foams achieved an EMI shielding effectiveness of up to 68 dB and an absorptivity of 77%,and authenticated favorable stabilization after the tape adhesion experiment. 展开更多
关键词 Electromagnetic interference shielding Layered structure Supercritical carbon dioxide foaming Poly(butyleneadipateco-terephthalate) MICROCELLULAR
下载PDF
Flexible and Robust Functionalized Boron Nitride/Poly(p‑Phenylene Benzobisoxazole)Nanocomposite Paper with High Thermal Conductivity and Outstanding Electrical Insulation
2
作者 Lin Tang Kunpeng Ruan +3 位作者 Xi Liu Yusheng Tang Yali Zhang junwei gu 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第2期423-437,共15页
With the rapid development of 5G information technology,thermal conductivity/dissipation problems of highly integrated electronic devices and electrical equipment are becoming prominent.In this work,“high-temperature... With the rapid development of 5G information technology,thermal conductivity/dissipation problems of highly integrated electronic devices and electrical equipment are becoming prominent.In this work,“high-temperature solid-phase&diazonium salt decomposition”method is carried out to prepare benzidine-functionalized boron nitride(m-BN).Subsequently,m-BN/poly(pphenylene benzobisoxazole)nanofiber(PNF)nanocomposite paper with nacremimetic layered structures is prepared via sol–gel film transformation approach.The obtained m-BN/PNF nanocomposite paper with 50 wt%m-BN presents excellent thermal conductivity,incredible electrical insulation,outstanding mechanical properties and thermal stability,due to the construction of extensive hydrogen bonds andπ–πinteractions between m-BN and PNF,and stable nacre-mimetic layered structures.Itsλ∥andλ_(⊥)are 9.68 and 0.84 W m^(-1)K^(-1),and the volume resistivity and breakdown strength are as high as 2.3×10^(15)Ωcm and 324.2 kV mm^(-1),respectively.Besides,it also presents extremely high tensile strength of 193.6 MPa and thermal decomposition temperature of 640°C,showing a broad application prospect in high-end thermal management fields such as electronic devices and electrical equipment. 展开更多
关键词 Poly(p-phenylene-2 6-benzobisoxazole)nanofiber Boron nitride Thermal conductivity Electrical insulation
下载PDF
High-Efficiency Electromagnetic Interference Shielding of rGO@FeNi/Epoxy Composites with Regular Honeycomb Structures 被引量:21
3
作者 Ping Song Zhonglei Ma +2 位作者 Hua Qiu Yifan Ru junwei gu 《Nano-Micro Letters》 SCIE EI CAS CSCD 2022年第3期244-256,共13页
With the rapid development of fifth-generation mobile com-munication technology and wearable electronic devices,electromagnetic interference and radiation pollution caused by electromagnetic waves have attracted world... With the rapid development of fifth-generation mobile com-munication technology and wearable electronic devices,electromagnetic interference and radiation pollution caused by electromagnetic waves have attracted worldwide attention.Therefore,the design and development of highly efficient EMI shielding materials are of great importance.In this work,the three-dimensional graphene oxide(GO)with regular honeycomb structure(GH)is firstly constructed by sacrificial template and freeze-dry-ing methods.Then,the amino functionalized FeNi alloy particles(f-FeNi)are loaded on the GH skeleton followed by in-situ reduction to prepare rGH@FeNi aerogel.Finally,the rGH@FeNi/epoxy EMI shielding com-posites with regular honeycomb structure is obtained by vacuum-assisted impregnation of epoxy resin.Benefitting from the construction of regular honeycomb structure and electromagnetic synergistic effect,the rGH@FeNi/epoxy composites with a low rGH@FeNi mass fraction of 2.1 wt%(rGH and f-FeNi are 1.2 and 0.9 wt%,respectively)exhibit a high EMI shielding effectiveness(EMI SE)of 46 dB,which is 5.8 times of that(8 dB)for rGO/FeNi/epoxy composites with the same rGO/FeNi mass fraction.At the same time,the rGH@FeNi/epoxy composites also possess excellent thermal stability(heat-resistance index and temperature at the maximum decomposition rate are 179.1 and 389.0°C respectively)and mechanical properties(storage modulus is 8296.2 MPa). 展开更多
关键词 Electromagnetic interference shielding rGO@FeNi Epoxy resins Honeycomb structures
下载PDF
实践类课程开展课程思政教学改革的思考与实践——以高分子材料制备与成型创新实验为例 被引量:5
4
作者 秦建彬 史学涛 +3 位作者 张广成 狄西岩 顾军渭 闫毅 《大学化学》 CAS 2022年第3期132-136,共5页
开展课程思政教学改革是高校实现三全育人的有效途径,是高校实现立德树人根本任务的重要举措。高分子材料制备与成型创新实验是高分子材料与工程专业的必修专业综合实践类课程,该课程具有思政元素丰富、现场实践教学感染力强等优势。本... 开展课程思政教学改革是高校实现三全育人的有效途径,是高校实现立德树人根本任务的重要举措。高分子材料制备与成型创新实验是高分子材料与工程专业的必修专业综合实践类课程,该课程具有思政元素丰富、现场实践教学感染力强等优势。本文以高分子材料制备与成型创新实验为例,从实践类课程开展课程思政教学改革的意义、探索、实践和长效机制等方面进行了系统论述,总结了在实践类课程中开展课程思政教育的具体方法、优势和意义。 展开更多
关键词 课程思政 实践类课程 高分子材料科学与工程 教学改革
下载PDF
Lightweight,Flexible Cellulose-Derived Carbon Aerogel@Reduced Graphene Oxide/PDMS Composites with Outstanding EMI Shielding Performances and Excellent Thermal Conductivities 被引量:41
5
作者 Ping Song Bei Liu +5 位作者 Chaobo Liang Kunpeng Ruan Hua Qiu Zhonglei Ma Yongqiang guo junwei gu 《Nano-Micro Letters》 SCIE EI CAS CSCD 2021年第6期126-142,共17页
In order to ensure the operational reliability and infor-mation security of sophisticated electronic components and to protect human health,efficient electromagnetic interference(EMI)shielding materials are required t... In order to ensure the operational reliability and infor-mation security of sophisticated electronic components and to protect human health,efficient electromagnetic interference(EMI)shielding materials are required to attenuate electromagnetic wave energy.In this work,the cellulose solution is obtained by dissolving cotton through hydrogen bond driving self-assembly using sodium hydroxide(NaOH)/urea solution,and cellulose aerogels(CA)are prepared by gelation and freeze-drying.Then,the cellulose carbon aerogel@reduced graphene oxide aerogels(CCA@rGO)are prepared by vacuum impregnation,freeze-drying followed by thermal annealing,and finally,the CCA@rGO/polydimethylsiloxane(PDMS)EMI shielding composites are prepared by backfilling with PDMS.Owing to skin-core structure of CCA@rGO,the complete three-dimensional(3D)double-layer con-ductive network can be successfully constructed.When the loading of CCA@rGO is 3.05 wt%,CCA@rGO/PDMS EMI shielding composites have an excellent EMI shielding effectiveness(EMI SE)of 51 dB,which is 3.9 times higher than that of the co-blended CCA/rGO/PDMS EMI shielding composites(13 dB)with the same loading of fillers.At this time,the CCA@rGO/PDMS EMI shielding composites have excellent thermal stability(T_(HRI) of 178.3℃)and good thermal conductivity coefficient(λ of 0.65 W m^(-1) K^(-1)).Excellent comprehensive performance makes CCA@rGO/PDMS EMI shielding composites great prospect for applications in lightweight,flexible EMI shielding composites. 展开更多
关键词 POLYDIMETHYLSILOXANE Electromagnetic interference shielding Cellulose carbon aerogel Reduced graphene oxide
下载PDF
Breaking Through Bottlenecks for Thermally Conductive Polymer Composites:A Perspective for Intrinsic Thermal Conductivity,Interfacial Thermal Resistance and Theoretics 被引量:19
6
作者 junwei gu Kunpeng Ruan 《Nano-Micro Letters》 SCIE EI CAS CSCD 2021年第7期118-126,共9页
Rapid development of energy,electrical and electronic technologies has put forward higher requirements for the thermal conductivities of polymers and their composites.However,the thermal conductivity coefficient(λ)va... Rapid development of energy,electrical and electronic technologies has put forward higher requirements for the thermal conductivities of polymers and their composites.However,the thermal conductivity coefficient(λ)values of prepared thermally conductive polymer composites are still difficult to achieve expectations,which has become the bottleneck in the fields of thermally conductive polymer composites.Aimed at that,based on the accumulation of the previous research works by related researchers and our research group,this paper proposes three possible directions for breaking through the bottlenecks:(1)preparing and synthesizing intrinsically thermally conductive polymers,(2)reducing the interfacial thermal resistance in thermally conductive polymer composites,and(3)establishing suitable thermal conduction models and studying inner thermal conduction mechanism to guide experimental optimization.Also,the future development trends of the three above-mentioned directions are foreseen,hoping to provide certain basis and guidance for the preparation,researches and development of thermally conductive polymers and their composites. 展开更多
关键词 Thermally conductive polymer composites Intrinsic thermal conductivity Interfacial thermal resistance Thermal conduction models Thermal conduction mechanisms
下载PDF
A Perspective for Developing Polymer-Based Electromagnetic Interference Shielding Composites 被引量:22
7
作者 Yali Zhang junwei gu 《Nano-Micro Letters》 SCIE EI CAS CSCD 2022年第6期39-47,共9页
The rapid development of aerospace weapons and equipment,wireless base stations and 5G communication technologies has put forward newer and higher requirements for the comprehensive performances of polymer-based elect... The rapid development of aerospace weapons and equipment,wireless base stations and 5G communication technologies has put forward newer and higher requirements for the comprehensive performances of polymer-based electromagnetic interference(EMI)shielding composites.However,most of currently prepared polymer-based EMI shielding composites are still difficult to combine high performance and multi-functionality.In response to this,based on the research works of relevant researchers as well as our research group,three possible directions to break through the above bottlenecks are proposed,including construction of efficient conductive networks,optimization of multi-interfaces for lightweight and multifunction compatibility design.The future development trends in three directions are prospected,and it is hoped to provide certain theoretical basis and technical guidance for the preparation,research and development of polymer-based EMI shielding composites. 展开更多
关键词 Polymer composites Electromagnetic interference shielding Conductive network LIGHTWEIGHT
下载PDF
Structural Design Strategies of Polymer Matrix Composites for Electromagnetic Interference Shielding:A Review 被引量:25
8
作者 Chaobo Liang Zhoujie gu +3 位作者 Yali Zhang Zhonglei Ma Hua Qiu junwei gu 《Nano-Micro Letters》 SCIE EI CAS CSCD 2021年第11期322-350,共29页
With the widespread application of electronic communication technology,the resulting electromagnetic radiation pollution has been significantly increased.Metal matrix electromagnetic interference(EMI)shielding materia... With the widespread application of electronic communication technology,the resulting electromagnetic radiation pollution has been significantly increased.Metal matrix electromagnetic interference(EMI)shielding materials have disadvantages such as high density,easy corrosion,difficult processing and high price,etc.Polymer matrix EMI shielding composites possess light weight,corrosion resistance and easy processing.However,the current polymer matrix composites present relatively low electrical conductivity and poor EMI shielding performance.This review firstly discusses the key concept,loss mechanism and test method of EMI shielding.Then the current development status of EMI shielding materials is summarized,and the research progress of polymer matrix EMI shielding composites with different structures is illustrated,especially for their preparation methods and evaluation.Finally,the corresponding key scientific and technical problems are proposed,and their development trend is also prospected. 展开更多
关键词 Polymer matrix composites Electromagnetic interference shielding Structural design
下载PDF
Hierarchically Multifunctional Polyimide Composite Films with Strongly Enhanced Thermal Conductivity 被引量:14
9
作者 Yongqiang guo Hua Qiu +2 位作者 Kunpeng Ruan Yali Zhang junwei gu 《Nano-Micro Letters》 SCIE EI CAS CSCD 2022年第2期94-106,共13页
The development of lightweight and integration for electronics requires flexible films with high thermal conductivity and electromagnetic interference(EMI) shielding to overcome heat accumulation and electromagnetic r... The development of lightweight and integration for electronics requires flexible films with high thermal conductivity and electromagnetic interference(EMI) shielding to overcome heat accumulation and electromagnetic radiation pollution.Herein,the hierarchical design and assembly strategy was adopted to fabricate hierarchically multifunctional polyimide composite films,with graphene oxide/expanded graphite(GO/EG) as the top thermally conductive and EMI shielding layer,Fe_(3)O_(4)/polyimide(Fe_(3)O_(4)/PI) as the middle EMI shielding enhancement layer and electrospun PI fibers as the substrate layer for mechanical improvement.PI composite films with 61.0 wt% of GO/EG and 23.8 wt% of Fe_(3)O_(4)/PI exhibits high in-plane thermal conductivity coefficient(95.40 W(m K)^(-1)),excellent EMI shielding effectiveness(34.0 dB),good tensile strength(93.6 MPa) and fast electric-heating response(5 s).The test in the central processing unit verifies PI composite films present broad application prospects in electronics fields. 展开更多
关键词 EMI shielding Flexible films POLYIMIDE Thermal conductivity
下载PDF
Mechanically strong and folding-endurance Ti_(3)C_(2)T_(x) MXene/PBO nanofiber films for efficient electromagnetic interference shielding and thermal management 被引量:14
10
作者 Lei Wang Zhonglei Ma +3 位作者 Yali Zhang Hua Qiu Kunpeng Ruan junwei gu 《Carbon Energy》 SCIE CAS 2022年第2期200-210,共11页
Electromagnetic interference(EMI)shielding materials with excellent flexibility and mechanical properties and outstanding thermal conductivity have become a hot topic of research in functional composites.In this study... Electromagnetic interference(EMI)shielding materials with excellent flexibility and mechanical properties and outstanding thermal conductivity have become a hot topic of research in functional composites.In this study,the“sol-gel-film conversion technique”is used to assemble polyetherimidefunctionalized Ti_(3)C_(2)T_(x) nanosheets(f-Ti_(3)C_(2)T_(x))with poly(p-phenylene-2,6-benzobisoxazole)(PBO)nanofibers(PNFs),followed by dialysis and vacuum drying to prepare f-Ti_(3)C_(2)T_(x)/PNF films with lamellar structures.When the loading of f-Ti_(3)C_(2)T_(x) is 70 wt%,the f-Ti_(3)C_(2)T_(x)/PNF film presents optimal comprehensive properties,with an EMI shielding effectiveness(SE)of 35 dB and a specific SE/thickness((SSE,SE/density)/t)of 8211 dB cm^(2)/g,a tensile strength of 125.1 MPa,an in-plane thermal conductivity coefficient(λ)of 5.82 W/(m K),and electrical conductivity of 1943 S/m.After repeated folding for 10,000 cycles,the EMI SE and the tensile strength of f-Ti_(3)C_(2)T_(x)/PNFs films still remain 33.4 dB and 116.1 MPa,respectively.Additionally,the f-Ti_(3)C_(2)T_(x)/PNF film also shows excellent thermal stability,flame retardancy,and structural stability.This would provide a novel method for the design and fabrication of multifunctional composite films and considerably expand the applications of MXene-and PNF-based composites in the fields of EMI shielding and thermal management. 展开更多
关键词 electromagnetic interference shielding PBO nanofibers thermal management Ti_(3)C_(2)T_(x)MXene
下载PDF
Significantly Enhanced Electromagnetic Interference Shielding Performances of Epoxy Nanocomposites with Long-Range Aligned Lamellar Structures 被引量:6
11
作者 Lei Wang Zhonglei Ma +3 位作者 Hua Qiu Yali Zhang Ze Yu junwei gu 《Nano-Micro Letters》 SCIE EI CAS CSCD 2022年第12期617-629,共13页
High-efficiency electromagnetic interference(EMI)shielding materials are of great importance for electronic equipment reliability,information security and human health.In this work,bidirectional aligned Ti_(3)C_(2)T_(... High-efficiency electromagnetic interference(EMI)shielding materials are of great importance for electronic equipment reliability,information security and human health.In this work,bidirectional aligned Ti_(3)C_(2)T_(x)@Fe_(3)O_(4)/CNF aerogels(BTFCA)were firstly assembled by bidirectional freezing and freeze-drying technique,and the BTFCA/epoxy nanocomposites with long-range aligned lamellar structures were then prepared by vacuum-assisted impregnation of epoxy resins.Benefitting from the successful construction of bidirectional aligned three-dimensional conductive networks and electromagnetic synergistic effect,when the mass fraction of Ti_(3)C_(2)T_(x) and Fe_(3)O_(4) are 2.96 and 1.48 wt%,BTFCA/epoxy nanocomposites show outstanding EMI shield-ing effectiveness of 79 dB,about 10 times of that of blended Ti_(3)C_(2)T_(x)@Fe_(3)O_(4)/epoxy(8 dB)nanocomposites with the same loadings of Ti_(3)C_(2)T_(x) and Fe_(3)O_(4).Meantime,the corresponding BTFCA/epoxy nanocomposites also present excellent thermal stability(T_(heat-resistance index) of 198.7℃)and mechanical properties(storage modulus of 9902.1 MPa,Young’s modulus of 4.51 GPa and hardness of 0.34 GPa).Our fabricated BTFCA/epoxy nanocomposites would greatly expand the applications of MXene and epoxy resins in the fields of information security,aerospace and weapon manufacturing,etc. 展开更多
关键词 Electromagnetic interference shielding Epoxy nanocomposites Ti_(3)C_(2)Tx Fe_(3)O_(4) Bidirectional aligned three-dimensional conductive networks
下载PDF
Balloon-occluded retrograde transvenous obliteration with lauromacrogol sclerosant foam for gastric varices
12
作者 Zhiyang Wu Wei Wu +8 位作者 Cheng Tao Qin Liu Wenchang Li Qinbing Wang Wei Huang junwei gu Xiaoyan Fei Zhongmin Wang Xiaoyi Ding 《Journal of Interventional Medicine》 2022年第3期138-142,共5页
Objectives:To evaluate the safety and efficacy of balloon-occluded retrograde transvenous obliteration(BRTO)using lauromacrogol sclerosant foam for gastric varices(GVs)with gastrorenal venous shunts.Methods:Data of GV... Objectives:To evaluate the safety and efficacy of balloon-occluded retrograde transvenous obliteration(BRTO)using lauromacrogol sclerosant foam for gastric varices(GVs)with gastrorenal venous shunts.Methods:Data of GV patients treated with BRTO using lauromacrogol sclerosant foam in 2016–2020 were retrospectively analyzed along with procedural success rate,complications,and follow-up efficacy.Results:A total of 31 patients were treated with BRTO.The sclerosant foam was prepared by mixing iodinated oil,lauromacrogol,and air at a 1:2:3 ratio.The BRTO procedure was successfully completed in 93.5%of patients.One patient was allergic to the lauromacrogol injection.A mild postoperative fever occurred in three patients.One patient experienced grand mal seizures after the procedure.There was no significant difference in the median Child-Turcotte-Pugh scores before versus after BRTO.Complete GV resolution was observed in 93.1%of patients.One patient underwent endoscopic treatment for the development of high-risk esophageal varices.Another patient underwent transjugular intrahepatic portosystemic shunt placement for the aggravation of ascites.Conclusions:Lauromacrogol sclerosant foam is safe and effective in patients undergoing BRTO for GV. 展开更多
关键词 Gastric varices Gastrorenal shunt Balloon-occluded retrograde transvenous obliteration SCLEROTHERAPY
下载PDF
Hierarchical design of FeCo-based microchains for enhanced microwave absorption in C band 被引量:18
13
作者 Yixuan Han Mukun He +5 位作者 Jinwen Hu Panbo Liu Zhongwu Liu Zhonglei Ma Wenbo Ju junwei gu 《Nano Research》 SCIE EI CSCD 2023年第1期1773-1778,共6页
Microwave absorbing materials(MAMs)has been intensively investigated in order to meet the requirement of electromagnetic radiation control,especially in S and C band.In this work,FeCo-based magnetic MAMs are hydrother... Microwave absorbing materials(MAMs)has been intensively investigated in order to meet the requirement of electromagnetic radiation control,especially in S and C band.In this work,FeCo-based magnetic MAMs are hydrothermally synthesized via a magnetic-field-induced process.The composition and morphology of the MAMs are capable of being adjusted simultaneously by the atomic ratio of Fe2+to Co2+in the precursor.The hierarchical magnetic microchain,which has a core–shell structure of twodimensional FexCo1−xOOH nanosheets anchored vertically on the surface of a one-dimensional(1D)Co microchain,shows significantly enhanced microwave absorption in C band,resulting in a reflection loss(RL)of lower than−20 dB at frequencies ranging from 4.4 to 8.0 GHz under a suitable matching thickness.The magnetic coupling of Co microcrystals and the double-loss mechanisms out of the core-shell structure are considered to promote the microwave attenuation capability.The hierarchical design of 1D magnetic MAMs provides a feasible strategy to solve the electromagnetic pollution in C band. 展开更多
关键词 one-dimensional micromagnets hierarchical structure microwave absorbing material magnetic coupling double-loss mechanisms
原文传递
Hierarchical construction of CNT networks in aramid papers for high-efficiency microwave absorption 被引量:11
14
作者 You Wu Li Chen +7 位作者 Yixuan Han Panbo Liu Haihong Xu guanze Yu Yingying Wang Tao Wen Wenbo Ju junwei gu 《Nano Research》 SCIE EI CSCD 2023年第5期7801-7809,共9页
Carbon nanotubes(CNTs)incorporated polymeric composites have been extensively investigated for microwave absorption at target frequencies to meet the requirement of radar cross-section reduction.In this work,a strateg... Carbon nanotubes(CNTs)incorporated polymeric composites have been extensively investigated for microwave absorption at target frequencies to meet the requirement of radar cross-section reduction.In this work,a strategy of efficient utilization of CNT in producing CNT incorporated aramid papers is demonstrated.The layer-by-layer self-assembly technique is used to coat the surfaces of meta-aramid fibers and fibrils with CNT,providing novel raw materials available for the large-scale papermaking.The hierarchical construction of CNT networks resolves the dilemma of increasing CNT content and avoiding the agglomeration of CNT,which is a frequent challenge for CNT incorporated polymeric composites.The composite paper,which contains abundant heterogeneous interfaces and long-range conductive networks,is capable of reaching a high permittivity and dielectric loss tangent at a low CNT loading,its complex permittivity is,so far,adjustable in the range of(1.20−j0.05)to(25.17−j18.89)at 10 GHz.Some papers with optimal matching thicknesses achieve a high-efficiency microwave absorption with a reflection loss lower than−10 dB in the entire X-band. 展开更多
关键词 layer-by-layer self-assembly aramid fiber carbon nanotube(CNT) composite paper radar absorbing materials
原文传递
Thermally conductive polyvinyl alcohol composite films via introducing hetero-structured MXene@silver fillers 被引量:12
15
作者 Mukun Li Yuyao Sun +3 位作者 Dianying Feng Kunpeng Ruan Xia Liu junwei gu 《Nano Research》 SCIE EI CSCD 2023年第5期7820-7828,共9页
Ag nanoparticles were in-situ grown on the surface of MXene nanosheets to prepare thermally conductive hetero-structured MXene@Ag fillers.With polyvinyl alcohol(PVA)as the polymer matrix,thermally conductive MXene@Ag/... Ag nanoparticles were in-situ grown on the surface of MXene nanosheets to prepare thermally conductive hetero-structured MXene@Ag fillers.With polyvinyl alcohol(PVA)as the polymer matrix,thermally conductive MXene@Ag/PVA composite films were fabricated by the processes of solution blending,pouring,evaporative self-assembly.With the same mass fraction,MXene@Ag-III(MXene/Ag,2:1,w/w)presents more significant improvement in thermal conductivity coefficient(λ)than MXene@Ag,single MXene,Ag,simply blending MXene/Ag.MXene@Ag-III/PVA composite films show dual functions of excellent thermal conductivity and electromagnetic interference(EMI)shielding.When the mass fraction of MXene@Ag-III is 60 wt.%,the in-planeλ(λ_(∥)),through-planeλ(λ_(⊥)),EMI shielding effectiveness(EMI SE)are 3.72 and 0.41 W/(m∙K),32 dB,which are increased by 3.1,1.3,105.7 times than those of pure PVA film(0.91 and 0.18 W/(m∙K),0.3 dB),respectively.The 60 wt.%MXene@Ag-III/PVA composite film also has satisfying mechanical and thermal properties,with Young’s modulus,glass transition temperature,heat resistance index of 3.8 GPa,58.5 and 175.3℃,respectively. 展开更多
关键词 hetero-structured MXene@Ag fillers polyvinyl alcohol composite films thermal conductivity electromagnetic interference shielding
原文传递
PBO fibers/fluorine-containing liquid crystal compound modified cyanate ester wave-transparent laminated composites with excellent mechanical and flame retardance properties 被引量:5
16
作者 Zheng Liu Xiaoli Fan +4 位作者 Junliang Zhang Lixin Chen Yusheng Tang Jie Kong junwei gu 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2023年第21期16-29,共14页
Bisphenol A dicyanate ester resins modified by fluorine-containing liquid crystal compound(LCFE)are applied as polymer matrix(LCFE-BADCy),poly(p-phenylene-2,6-benzobisoxazole)(PBO)fibers as rein-forcements,and fluorin... Bisphenol A dicyanate ester resins modified by fluorine-containing liquid crystal compound(LCFE)are applied as polymer matrix(LCFE-BADCy),poly(p-phenylene-2,6-benzobisoxazole)(PBO)fibers as rein-forcements,and fluorine/adamantane PBO precursor(pre FABPBO)as interfacial compatibilizer to prepare the corresponding PBO fibers/FABPBO/LCFE-BADCy wave-transparent laminated composites.LCFE could improve the order degree of BADCy cured network,in favor of enhancing the wave-transparent perfor-mance,mechanical properties,and intrinsic thermal conductivity.The dielectric constant and dielectric loss of PBO fibers/FABPBO/LCFE-BADCy composites are highly temperature(25–200℃)and frequency(10^(4)–10^(7) Hz and 8.2–12.4 GHz)stable with the value of 2.49 and 0.003 under 10^(6) Hz at 25℃,and the corresponding wave transmission efficiency is 95.0%,higher than that of 92.5%for PBO fibers/BADCy com-posites.The interlamellar shear strength and flexural strength are respectively 50.7 MPa and 682.5 MPa,38.1%and 16.2%higher than those of PBO fibers/BADCy composites.Besides,the volume resistivity,breakdown voltage,heat resistance index,glass transition temperature,flame retardant grade,and ul-timate oxygen index of PBO fibers/FABPBO/LCFE-BADCy composites are respectively 5.3×10^(15)Ωcm,29.75 kV/mm,217.2℃,245.7℃,V-1 grade,and 33.6%,expected to be performed as a new generation of“lightweight/loading/wave-transparent”electromagnetic window materials in advanced military weapons and civil communication base station. 展开更多
关键词 Bisphenol A dicyanate ester(BADCy)resins Fluorine-containing liquid crystal compound Poly(p-phenylene-2 6-benzobisoxazole) (PBO)fibers Fluorine/adamantane PBO precursor Wave-transparent laminated composites
原文传递
Branched Fluorine/Adamantane Interfacial Compatibilizer for PBO Fibers/Cyanate Ester Wave-Transparent Laminated Composites 被引量:5
17
作者 Zheng Liu Xiaoli Fan +5 位作者 Muyi Han Hao Li Junliang Zhang Lixin Chen Qiju Zhu junwei gu 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2023年第8期939-950,共12页
Comprehensive Summary Branched fluorine/adamantane PBO precursor(preFABPBO),synthesized via random co-condensation between 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoro propane,1,3-adamantanedicarbonyl dichloride,and tri... Comprehensive Summary Branched fluorine/adamantane PBO precursor(preFABPBO),synthesized via random co-condensation between 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoro propane,1,3-adamantanedicarbonyl dichloride,and trimesoyl chloride,is performed as interfacial compatibilizer,bisphenol A dicyanate ester(BADCy)resin as polymer matrix,and poly(p-phenylene-2,6-benzobisoxazole)(PBO)fibers as reinforcements to prepare PBO fibers/FABPBO-BADCy wave-transparent laminated composites by high temperature molding.The mechanical properties,wave-transparent performances,and heat resistances of PBO fibers/BADCy composites are simultaneously improved by the addition of preFABPBO.The interlaminar shear strength(ILSS)and flexural strength of PBO fibers/FABPBO-BADCy composites are 48.9 and 665.3 MPa,respectively,increased by 33.2%and 13.3%compared to those of PBO fibers/BADCy composites(36.7 and 587.4 MPa).The dielectric constant and dielectric loss values at 106 Hz are 2.53 and 0.003,respectively,lower than those of PBO fibers/BADCy composites(3.06 and 0.006),and the corresponding wave transmission efficiency is 94.8%,which also presents excellent stability over the wide temperature(25-200℃)and frequency range(103-107 Hz and 8.2-12.4 GHz).Meanwhile,the heat resistance index and glass transition temperature are 229.9℃and 247.5℃,also better than those of PBO fibers/BADCy composites(229.6℃and 247.1℃). 展开更多
关键词 Polymers Interface Materials science Mechanical properties Wave-transparent laminated composites
原文传递
Block copolymer functionalized quartz fibers/cyanate ester wave-transparent laminated composites
18
作者 Jiani Zhang Zheng Liu +3 位作者 Muyi Han Junliang Zhang Yusheng Tang junwei gu 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2023年第8期189-197,共9页
A block copolymer of PDMS-b-PGMA is synthesized by polymerizing glycidyl methacrylate(GMA)via reversible addition-fragmentation chain transfer(RAFT)polymerization applying a polydimethylsiloxane(PDMS)based macro-RAFT ... A block copolymer of PDMS-b-PGMA is synthesized by polymerizing glycidyl methacrylate(GMA)via reversible addition-fragmentation chain transfer(RAFT)polymerization applying a polydimethylsiloxane(PDMS)based macro-RAFT agent,which is then performed to functionalize the quartz fibers(QFs@PDMS-b-PGMA)via a simple coating process.Finally,the QFs@PDMS-b-PGMA/bisphenol A dicyanate ester(BADCy)wave-transparent laminated composites are fabricated by high-temperature molding.Nuclear magnetic resonance(NMR)spectroscopy,Fourier transform infrared(FT-IR)spectroscopy and size ex-clusion chromatography(SEC)demonstrate the successful preparation of PDMS-b-PGMA with expected structure.When the molar mass and coating amount of PDMS-b-PGMA are respectively 8100 g/mol and 2.0 wt.%,QFs@PDMS-b-PGMA/BADCy wave-transparent laminated composites present optimal mechan-ical properties and wave-transparent performance.The interlaminar shear strength(ILSS)and flexural strength are 53.6 and 552.0 MPa,respectively.Meanwhile,the dielectric constant and dielectric loss val-ues are 2.61 and 0.0028 at 1 MHz(wave transmittance of 93.8%),showing good stability at different frequencies(102-106 Hz and 8.4-12.4 GHz)and temperatures(25-250℃). 展开更多
关键词 Bisphenol A dicyanate ester(BADCy)resins Quartz fibers(QFs) Wave-transparent laminated composites Block copolymer
原文传递
Low dielectric constant and highly intrinsic thermal conductivity fluorine-containing epoxy resins with ordered liquid crystal structures
19
作者 Xuerong Fan Zheng Liu +1 位作者 Shuangshuang Wang junwei gu 《SusMat》 SCIE EI 2023年第6期877-893,共17页
Epoxy resins with a high dielectric constant and low intrinsic thermal conductivity coefficient cannot meet the current application requirements of advanced electronic and electrical equipment.Therefore,novel fluorine... Epoxy resins with a high dielectric constant and low intrinsic thermal conductivity coefficient cannot meet the current application requirements of advanced electronic and electrical equipment.Therefore,novel fluorine-containing liquid crystal epoxy compounds(TFSAEy)with fluorinated groups,biphenyl units,and flexible alkyl chains are first synthesized via amidation and esterification reactions.Then,4,4′-diaminodiphenylmethane(DDM)is used as a curing agent to prepare the corresponding fluorine-containing liquid crystal epoxy resins.The obtained dielectric constant(ε)and dielectric loss(tanδ)values of TFSAEy/DDM at 1 MHz are 2.54 and 0.025,respectively,which are significantly lower than those of conventional epoxy resins(E-51/DDM,3.52 and 0.038).Additionally,the intrinsic thermal conductivity coefficient(λ)of TFSAEy/DDM is 0.36 W/(m⋅K),71.4%higher than that of E-51/DDM(0.21 W/(m⋅K)).Meanwhile,the corresponding elastic modulus,hardness,glass transition temperature,and heat resistance index of TFSAEy/DDM are 5.73 GPa,0.35 GPa,213.5◦C,and 188.7℃,respectively,all superior to those of E-51/DDM(3.68 GPa,0.27 GPa,107.2℃,and 174.8℃),presenting potential application in high-heating electronic component packaging and printed circuit boards. 展开更多
关键词 epoxy resins fluorine-containing groups highly intrinsic thermal conductivity liquid crystal structure low dielectric constant
原文传递
Janus(BNNS/ANF)-(AgNWs/ANF)thermal conductivity composite films with superior electromagnetic interference shielding and Joule heating performances 被引量:28
20
作者 Yixin Han Kunpeng Ruan junwei gu 《Nano Research》 SCIE EI CSCD 2022年第5期4747-4755,共9页
Highly thermal conductivity materials with excellent electromagnetic interference shielding and Joule heating performances are ideal for thermal management in the next generation of communication industry,artificial i... Highly thermal conductivity materials with excellent electromagnetic interference shielding and Joule heating performances are ideal for thermal management in the next generation of communication industry,artificial intelligence and wearable electronics.In this work,silver nanowires(AgNWs)are prepared using silver nitrate as the silver source and ethylene glycol as the solvent and reducing agent,and boron nitride(BN)is performed to prepare BN nanosheets(BNNS)with the help of isopropyl alcohol and ultrasonication-assisted peeling method,which are compounded with aramid nanofibers(ANF)prepared by chemical dissociation,respectively,and the(BNNS/ANF)-(AgNWs/ANF)thermal conductivity and electromagnetic interference shielding composite films with Janus structures are prepared by the"vacuum-assisted filtration and hot-pressing"method.Janus(BNNS/ANF)-(AgNWs/ANF)composite films exhibit"one side insulating,one side conducting"performance,the surface resistivity of the BNNS/ANF surface is 4.7×10^(13) Ω,while the conductivity of the AgNWs/ANF surface is 5,275 S/cm.And Janus(BNNS/ANF)-(AgNWs/ANF)composite film with thickness of 95 pm has a high in-plane thermal conductivity coefficient of 8.12 W/(m·K)and superior electromagnetic interference shielding effectiveness of 70 dB.The obtained composite film also has excellent tensile strength of 122.9 MPa and tensile modulus and 2.7 GPa.It also has good temperature-voltage response characteristics(high Joule heating temperature at low supply voltage(5 V,215.0℃),fast response time(10 s)),excellent electrical stability and reliability(stable and constant real-time relative resistance under up to 300 cycles and 1,500 s of tensile-bending fatigue work tests). 展开更多
关键词 thermal conductivity composite film Janus structure aramid nanofibers electromagnetic interference shielding performance Joule heating
原文传递
上一页 1 2 下一页 到第
使用帮助 返回顶部