Research Progress of Radiation-proof Material

综述了X射线、γ射线和中子辐射屏蔽材料的研究现状,其中在稀土高分子防辐射材料的设计与制备方面有所侧重,并且对纳米技术的应用、屏蔽材料的优化设计等进行了简单分析、介绍,指出了未来防辐射材料研究的可能的几个主要发展方向：纳米技术及稀土材料在防辐射材料方面的应用及研究;综合辐射屏蔽材料的设计与制备,使材料兼具质轻、无毒、体积小、屏蔽范围广、屏蔽性能持久等性能;屏蔽材料物理性能优化,以提升材料拉伸强度、硬度、耐腐蚀性等;屏蔽材料的优化设计方法、遗传算法、MCNP程序、梯度材料设计等的研究与应用;以上几个方向的交叉研究与应用。     

防辐射材料的研究进展

综述了X射线、γ射线和中子辐射屏蔽材料的研究现状,其中在稀土高分子防辐射材料的设计与制备方面有所侧重,并且对纳米技术的应用、屏蔽材料的优化设计等进行了简单分析、介绍,指出了未来防辐射材料研究的可能的几个主要发展方向:纳米技术及稀土材料在防辐射材料方面的应用及研究;综合辐射屏蔽材料的设计与制备,使材料兼具质轻、无毒、体积小、屏蔽范围广、屏蔽性能持久等性能;屏蔽材料物理性能优化,以提升材料拉伸强度、硬度、耐腐蚀性等;屏蔽材料的优化设计方法、遗传算法、MCNP程序、梯度材料设计等的研究与应用;以上几个方向的交叉研究与应用。     

稀土基中子和伽马复合屏蔽材料

随着航空航天、核技术等领域的发展和核能的广泛利用，对核辐射屏蔽材料的性能也提出更高的要求。核反应中产生的中子、伽马射线的穿透能力较强，危害较大，所以对于中子、伽马辐射屏蔽材料的研究成为辐射防护研究的重点。稀土元素具有较高的中子吸收截面和高原子序数，逐渐被科研人员重视并应用于中子、伽马辐射屏蔽材料的研发中。本文简述了稀土材料在辐射屏蔽材料领域的应用，介绍了稀土元素与中子和伽马射线的作用原理；根据基体材料的类别将稀土基中子和伽马辐射屏蔽材料分为稀土金属基、稀土聚合物基、稀土玻璃基三类，分别介绍了三类稀土基复合屏蔽材料的研究进展，并分析了稀土材料用于中子、伽马辐射屏蔽存在的问题与展望。     

(W+B_4C)/Al复合材料中子屏蔽性能的蒙特卡罗模拟

使用MCNP5程序模拟了能量为14.88 Me V的快中子在(W+B_4C)/Al和W/Al复合材料中的输运过程,并与铅硼聚乙烯、聚乙烯以及钨进行对比。计算了各屏蔽材料的中子衰减性能、中子透射能谱以及中子俘获过程中释放γ射线的透射能谱,为中子屏蔽材料的选择提供了理论依据。模拟结果和实际结果吻合,证实了蒙特卡罗方法的可靠性。模拟结果也可以得出,对于快中子,高原子序数材料的屏蔽效果要好于低原子序数材料,含钨45%的复合材料的屏蔽性能与商用铅硼聚乙烯的屏蔽效能相近,但是激发γ射线能量低于铅硼聚乙烯,考虑到成分可调控性、使用温度以及力学性能等因素,(W+B_4C)/Al复合材料是一种极具应用潜力的新型中子屏蔽材料。     

电磁屏蔽材料的研究进展

介绍了电磁屏蔽材料在军用和民用领域的重要性;简要阐述了电磁屏蔽的机理;综述了4种不同电磁屏蔽材料的优缺点以及研究现状,分别为金属型、表面导电型、填充复合型和本征型导电聚合物电磁屏蔽材料;分析并提出了3种提高电磁屏蔽效能的方式,分别为多孔结构设计、多层结构设计、复合填料优化.     

电磁屏蔽材料的研究进展

介绍了电磁屏蔽材料在军用和民用领域的重要性;简要阐述了电磁屏蔽的机理;综述了4种不同电磁屏蔽材料的优缺点以及研究现状,分别为金属型、表面导电型、填充复合型和本征型导电聚合物电磁屏蔽材料;分析并提出了3种提高电磁屏蔽效能的方式,分别为多孔结构设计、多层结构设计、复合填料优化.     

碳系填料填充聚合物基电磁屏蔽材料研究进展北大核心CSCD

电子电器设备的大量应用,使得电磁环境越来越复杂,对电磁屏蔽材料的需求也不断增长。与传统的金属填料相比,碳系填料具有品种多、质量轻、电导率高、来源广、耐腐蚀等独特优势,在聚合物基电磁屏蔽领域有着广阔的应用前景。本文主要介绍了炭黑、石墨、石墨烯、碳纳米管、碳纤维等碳系填料的结构与性能特点,并从填料形状,表面处理,复合技术等角度综述了近年来碳系填料填充改性制备聚合物基电磁屏蔽材料方面的研究进展。     

碳系填料填充聚合物基电磁屏蔽材料研究进展

电子电器设备的大量应用,使得电磁环境越来越复杂,对电磁屏蔽材料的需求也不断增长。与传统的金属填料相比,碳系填料具有品种多、质量轻、电导率高、来源广、耐腐蚀等独特优势,在聚合物基电磁屏蔽领域有着广阔的应用前景。本文主要介绍了炭黑、石墨、石墨烯、碳纳米管、碳纤维等碳系填料的结构与性能特点,并从填料形状,表面处理,复合技术等角度综述了近年来碳系填料填充改性制备聚合物基电磁屏蔽材料方面的研究进展。     

凹凸棒石:从矿物材料到功能材料

凹凸棒石(attapulgite)是一种天然的一维纳米级含水富镁铝硅酸盐黏土矿物,具有纳米棒状晶体结构、纳米孔道和表面活性基团,作为重要的基础材料在农业、化工、环保、吸附分离和复合材料等领域得到了广泛应用.近年来,凹凸棒石纳米化技术取得快速发展,天然凹凸棒石矿物中的棒晶束或聚集体得以高效解离成单分散的纳米棒晶,同时保留了硅酸盐黏土矿物的环境友好特性,实现了黏土矿物材料向纳米材料的转变.凹凸棒石集纳米棒晶和纳米孔道于一体的独特结构,使其既可以通过棒晶和表面基团构筑纳米复合材料,也可以通过其纳米孔道构筑杂化功能材料.因此,凹凸棒石成为构筑形形色色功能材料的"新宠",实现了黏土矿物材料的纳米功能化应用.本文在介绍凹凸棒石晶体结构及理化性质的基础上,重点综述了凹凸棒石棒晶束解离纳米化、结构调控和新型功能材料构筑(吸附材料、胶体材料、杂化材料、聚合物复合材料、仿生涂层、催化和能源材料)等方面的最新研究进展,并展望了凹凸棒石研究与功能化应用的发展前景,旨在为凹凸棒石乃至其他黏土矿物及其功能材料的研究起到抛砖引玉的作用.     

聚(3,4-乙烯二氧噻吩)在电磁屏蔽领域的应用

随着现代电子信息技术的迅猛发展,电磁干扰问题日益严重,发展综合性能优异的电磁屏蔽材料具有重要意义.聚(3,4-乙烯二氧噻吩)(poly(3,4-ethylenedioxythiophene),PEDOT)具有分子结构简单、能隙小、电导率高等特点,为高性能电磁屏蔽材料的实现提供了新途径.同时,随着对材料电磁屏蔽性能研究的深入以及制备技术的进步,将PEDOT与其他材料复合,通过合理的组分选择与结构设计,可以协同发挥各组分间电磁匹配特性,从而使PEDOT更好地满足柔性显示、智能可穿戴设备、高频器件、高精密电子设备等应用领域对电磁屏蔽材料"厚度薄、密度低、屏蔽强、屏蔽带宽宽"的具体要求.近年来,较多的研究致力于此并取得重要的成果.本文对以PEDOT为功能组分的电磁屏蔽材料的最新研究进展进行了综述,将近年来PEDOT及其与不同功能组分复合(包括导电组分、磁性组分及无电磁特性组分)构筑的电磁屏蔽材料体系的制备及电磁性能进行归纳总结,重点讨论电磁组分、微观结构与电磁屏蔽特性的联系,及其电磁屏蔽机理与性能优化方式,并对PEDOT在电磁屏蔽研究领域的机遇与挑战进行了展望.     

Electromagnetic Interference Shielding Polymers and Nanocomposites - A Review

Intrinsically conducting polymers (ICP) and conductive fillers incorporated conductive polymer-based composites (CPC) greatly facilitate the research in electromagnetic interference (EMI) shielding because they not only provide excellent EMI shielding but also have advantages of electromagnetic wave absorption rather than reflection. In this review, the latest developments in ICP and CPC based EMI shielding materials are highlighted. In particular, existing methods for adjusting the morphological structure, electric and magnetic properties of EMI shielding materials are discussed along with the future opportunities and challenges in developing ICP and CPC for EMI shielding applications.     

Current trends in spinel based modified polymer composite materials for electromagnetic shielding

The present article deals with current trends in spinel based modified polymer composite materials for applications in the field of electromagnetic shielding. The interaction between the various spinel based materials and polymers is an emerging field of studies among various researchers. The thermal stability, electrical conductivity, the bonding between the metal ferrites and the polymer plays an important role in the interaction of electromagnetic radiation. These properties also effect the mechanism of the EM waves for the shielding applications. Considering these all properties, polyaniline appears to be an suitable polymer for electromagnetic shielding applications. Polyaniline composites not only reinforced the properties of spinel materials but also enhanced the dielectric properties of the composite material. When carbon based materials such as graphene, graphene oxide and CNT was added along with spinel material in polyaniline based composite, they accelerate the electrical properties and enhances the shielding applications. In this paper the various synthesis methods, fabrication methods of polyaniline, and the properties of polyaniline based composites have been discussed. In addition, the various salient features and futuristic challenges of polyaniline based composite materials for EMI shielding applications were attempted to make a well equipped material for radar absorption.     

羰基铁粉/银核-壳粒子及其复合材料的制备与电磁特性

运用液相化学还原银技术, 制备了羰基铁粉/银核-壳复合粒子; 以该复合粒子为屏蔽填料, 制备了一种宽频、高效的新型电磁屏蔽橡胶材料. 分析了该屏蔽填料的表面形貌和组成, 研究了其电磁特性对电磁屏蔽橡胶材料屏蔽效能的影响规律. 结果表明, 具有完整核壳结构的羰基铁粉/银复合粒子兼具优异的磁性能和高导电率, 用其组成的电磁屏蔽橡胶材料对电磁波能同时产生较强的吸收损耗和反射损耗, 屏蔽效能(SE)优于传统的屏蔽橡胶材料.     

Design and Synthesis Strategies: 2D Materials for Electromagnetic Shielding/Absorbing

Two-dimensional (2D) materials possess special physical and chemical properties. They have been proved to have potential application advantage in the microwave absorption (MA) and electromagnetic interference (EMI) shielding. Particularly, they exhibit positive shielding and absorbing response to EMI. Here, the research progress of preparation, electromagnetic performance and microwave shielding/absorbing mechanisms of 2D composite materials are introduced. Effective preparation routes including introducing heteroatoms, constructing unique structures and 2D composite materials are described. Furthermore, the application prospects and challenges for the development of novel EMI materials are expatiated.     

Progress in the Foaming of Polymer-based Electromagnetic Interference Shielding Composites by Supercritical CO2

As a critical action plan formulated for peaking carbon dioxide emissions, polymeric electromagnetic interference (EMI) shielding materials based on CO₂ foaming technology have recently been attracting widespread attention in both research and industry, attributable to their efficient use of CO₂, high specific strength, corrosion resistance and low-cost characteristics. In the past decade, the emergence of novel design concepts and preparation techniques for CO₂ foaming technology has led to the development of new high-performance EMI shielding materials in this field. This review summarizes the research progress made to date on the fabrication of EMI shielding composite foams by supercritical carbon dioxide (scCO₂) foaming. We also explore the structure-activity relationships between the component/distribution and EMI shielding properties. Additionally, the application prospects and development challenges of new EMI shielding composite foams are described.     

Biopolymer-Based Aerogels for Electromagnetic Wave Shielding and Absorbing

The rapid development of communication technology and electronic industry has brought unprecedented serious electromagnetic interference (EMI) and electromagnetic wave (EMW) pollution. Although EMI shields and EMW absorbers based on metal or magnetic materials were used to solve these problems, they have long been criticized for their high price, high density and easy corrosion. In order to achieve low density and efficient dissipation of electromagnetic energy, aerogels stand out among manifold materials. However, constructing aerogels with good EMI shielding or EMW absorption performance and acceptable mechanical properties is not an easy task. Burgeoning biopolymers, such as cellulose, lignin, chitin/chitosan and alginate, breathe new life into aerogels for high-efficiency EMW shielding and absorbing. Here, we reviewed the contributions of biopolymers in the fields of aerogels for EMW shielding and absorbing. At the same time, some challenges and outlook were also pointed out, aiming to promote the advance of aerogel-based EMI shields and EMW absorbers as well as the rational utilization of biopolymers.     

Intrinsically conducting polymers for electromagnetic interference shielding

This paper summarizes and reviews the research on electromagnetic interference (EMI) shielding with intrinsically conducting polymers (ICPs), mainly polyaniline (PANI) and polypyrrole (PPY), and their composites in various frequency ranges. ICPs are new alternative candidates for EMI shielding applications due to their lightweight, corrosion resistance, ease of processing, and tunable conductivities as compared with typical metals. More importantly, the dominant shielding characteristic of absorption other than that of reflection for metals render ICPs more promising materials in applications requiring not only high EMI shielding effectiveness but also shielding by absorption, such as in stealth technology. Copyright © 2005 John Wiley & Sons, Ltd.     

Electromagnetic interference shielding Ti_3C_2T_x-bonded carbon black films with enhanced absorption performance

The demand for flexible and freestanding electromagnetic interference(EMI) shielding materials are more and more urgent to combat with serious electromagnetic(EM) radiation pollution.Twodimensional Ti_3C_2T_x is considered as promising EMI shielding material to graphenes because of the low cost and high electrical conductivity.However,the shielding performance still needs to be optimized to decrease the reflection effectiveness(SE_R) and increase absorption effectiveness(SEA).Herein,we prepared Ti_3C_2T_x-bonded carbon black films with a porous structure.The SE_R decreased from 20 dB to12 dB and the SEA increased from 31 dB to 47 dB.The best EMI shielding effectiveness can be as high as60 dB with SE_A of 15 dB and SE_R of45 dB.Their calculated specific shielding effectiveness can be as high as8718 dB cm~2/g.These results indicate that the porous structure can enhance the absorption of the EMI shielding films,resulting from the enhanced scattering and reflectio n.Conseque ntly,this work provides a promising MXene-based EMI shielding film with lightweight and flexibility.     

Recent progress in MXene and graphene based nanocomposites for microwave absorption and electromagnetic interference shielding

There is widespread use of telecommunication and microwave technology in modern society, and raised the electromagnetic interference (EMI) issue to alarming situation due to apprehensive demand and growth of 5G technology undesirably disturbing the human health. The two dimensional (2D) materials including graphene and MXenes are already been used for variety of electronic devices due to their exceptional electrical, mechanical, optical, chemical, and thermal properties. MXene is composed of metal carbides, in which mainly metals are the building blocks for dielectrics, semiconductors, or semimetals. However, the strong interfaces with electromagnetic waves (EM) are variable from terahertz (THz) to gigahertz (GHz) frequency levels and are widely used in EMI and Microwave absorption (MA) for mobile networks and communication technologies. The use of different organic materials with metal, organic, inorganic fillers, polymers nanocomposite and MXene as a novel material has been studied to address the recent advancement and challenges in the microwave absorption mechanism of 2D materials and their nanocomposites. In this concern, various techniques and materials has been reported for the improvement of shielding effectiveness (SE), and theoretical aspects of EMI shielding performance, as well stability of 2D materials particularly MXene, graphene and its nanocomposites. Consequently, various materials including polymers, conducting polymers, and metal–organic frameworks (MOF) have also been discussed by introducing various strategies for improved MA and control of EMI shieling. Here in this comprehensive review, we summarized the recent developments on material synthesis and fabrication of MXene based nanocomposites for EMI shielding and MA. This research work is a comprehensive review majorly focuses on the fundamentals of EMI/MA.  The recent developments and challenges of the MXene and graphene based various structures with different polymeric composites are described in a broader perspective.