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1.
防辐射材料的研究进展   总被引:1,自引:0,他引:1  
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。  相似文献   

2.
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。  相似文献   

3.
稀土元素因其独特的电子结构而具有光、电、磁、激光等特性,被誉为新材料的宝库,尤其是稀土配合物具有的Antenna效应,使发光强度明显增强.含稀土的高分子材料既具有稀土离子的发光性能,又具有高分子材料质量轻、抗冲击力强和易加工成型等优点,从而引起广泛的关注.我们曾用直接掺杂法制备含稀土配合物的光学树脂,但因稀土配合物与树脂的亲和性较小,难以均匀地.  相似文献   

4.
含稀土铽(Ⅲ)配合物透明树脂的制备及性能研究   总被引:13,自引:1,他引:12  
含稀土元素的有机高分子 具有稀土离子独特的光、电、磁特性,又具有有机高分子材料优良的性能,是极具潜在应用价值的功能材料,早在1963年,Wolff和Pressley首次研究以高分子为基质的稀土荧光材料,引起了人们的广泛兴趣,80年代以来,高分子链上直接键合稀土配合物的研究也引起了化学家的注意。Okamoto和李文连等在较高稀土浓度下仍可以制成透明柔韧的薄膜。而由于稀土无机物与树脂的相容性差,难以均匀地分散到树脂中,所以获得发光功能高分子体相材料十分困难,本文首次报道将几种稀土铽(Ⅲ)配合物复合于苯乙烯(St)/甲基丙烯酸(HMA)的共聚体系之中,制备了具有发光功能的透明树脂,对其相关性能进行了研究,考察了稀土元素含量、组分配比等因素对聚合物透明性和发光性能的影响,结果表明:高分子网络给稀土配合物提供了稳定的化学环境,有利于展现其优良的发光性能,同时,稀土配合物赋予了光学树脂新的功能性。  相似文献   

5.
石墨烯以其优异的力学、光学、电学和热学性能,得到日益广泛的关注和研究。本文介绍了石墨烯的结构、性能和特点,并对石墨烯的改性方法进行了概括。本文着重综述了高分子/石墨烯纳米复合材料的研究现状和进展,并介绍了高分子/石墨烯纳米复合材料的三种制备方法,即原位插层聚合法、溶液插层法和熔融插层法。此外,还对高分子/石墨烯纳米复合材料的应用前景进行了展望,并对石墨烯复合材料研究存在的问题和未来的研究方向进行了讨论。  相似文献   

6.
开发了反胶束模板-原位聚合纳米复合法制备聚苯胺(PANI)/Ce(OH)3-Pr2O3·3H2O/石墨纳米薄片(NanoG)纳米复合材料的方法。膨胀石墨在乙醇水溶液中经超声处理制得石墨纳米薄片,以苯胺的氯仿溶液为油相,稀土金属离子Pr^3+、Ce^3+水溶液为水相,依靠表面活性剂十六烷基三甲基溴化铵(CTAB)自组装形成的反胶束为模板。制备PANI/Ce(OH)3-Pr2O3·3H2O/NanoG复合材料。利用红外光谱(FTIR)、扫描电镜(SEM)、透射电镜(TEM)和X-射线衍射(XRD)对该复合材料进行了表征和分析,研究了其导电性能和热性能。结果表明,PANI/Ce(OH)3-Pr2O3·3H2O/NanoG复合材料各相分散均匀,稀土纳米粒子在体系中以棒状的形态分布。热重分析表明,该复合材料的热稳定性明显提高;导电性研究说明,石墨纳米薄片的特殊的结构(较大的径厚比)对其在聚合物基体中形成导电网络具有重要作用:PANI/Pr2O3-Ce(OH)3/NanoG纳米复合材料的渗滤阀值低于1.0wt%。  相似文献   

7.
在W/O微乳液体系中,制备了稀土铁氧体/聚丙烯酰胺磁性复合微型,并利用磁天平法对其磁响应性进行了研究。结果表明:复合微型的磁响应性与稀土离子磁矩有关,高磁矩稀土离子Dy^3 的加入能够较大地改善复合微型的磁响应性;镝铁氧体/聚丙烯酰胺磁性复合微球的磁响应性与镝含量有关,当n(Dy^3 ):n(∑Fe)=0.20时微球磁响应性最强。  相似文献   

8.
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.  相似文献   

9.
羟基磷灰石(HA)是人类与动物骨骼中主要无机物组成成分,因其具有良好的生物相容性、生物活性和骨传导作用,作为新型合成生物材料已应用于骨组织的修复与替代技术。本文在介绍HA主要制备方法(如:沉淀法、乳液法、水热反应法、溶胶-凝胶法、机械化学法、固态合成法、水解法、超声化学法、热解法、模板法和电沉积法等)和应用的基础上,重点综述了各类天然高分子与HA复合材料的制备及应用研究进展。天然高分子,如:纤维素、淀粉、甲壳素、壳聚糖、蛋白(包括胶原蛋白、明胶、角蛋白、丝蛋白和植物蛋白)等,与HA复合后制备的天然高分子复合羟基磷灰石材料,在保持其生物相容性的同时,又能改善复合材料的机械性能与生物活性,使其可用于医用材料、载体材料和吸附分离材料。最后,本文指出为了满足生物体内的特殊环境(如强的韧性、与骨生长速度匹配性能等)及不同领域的要求,天然高分子复合HA材料需要发展的方向。  相似文献   

10.
通过共挤出包覆-热压法制备了具有隔离结构的聚丙烯(PP)/碳纳米管(CNTs)电磁屏蔽复合材料。 其中,CNTs随机分布于PP基体中形成导电相,该导电复合物作为包覆层包敷在纯PP颗粒表面,形成包覆复合粒子,经热压后形成隔离导电网络。 结果表明,所制备的隔离结构复合材料呈现良好的导电性能,可获得较低的导电逾渗值0.28%(体积分数);在CNTs质量分数为5.6%时,该复合材料电磁屏蔽性能达到25.6 dB,同时具有良好的力学性能。 本文结果表明,共挤出包覆-热压法制备隔离结构导电复合材料方法简单可控、绿色环保,对开发高性能电磁屏蔽复合材料具有重要指导意义。  相似文献   

11.
Novel polyaniline/gadolinium (PANI/Gd) composites were successfully synthesized by “in‐situ” polymerization at the presence of rare earth Gd coordination complex and D‐tartaric acid (an a dopant). It is rarely to find the studies on related field to add rare earth Gd coordination complex as fillers. Fourier transform infrared (FTIR) spectra, X‐ray diffraction (XRD) and scanning electron microscope (SEM) were used to examine the structure and surface appearance characterization of materials. The thermal stability performance of composites was investigated by thermogravimetry and derivative thermogravimetry (TG‐DTG). Electrochemical performance was measured by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge–discharge test. The magnetic property was investigated by physical property measurement system (PPMS). The structure and surface appearance characterization and the magnetic properties jointly demonstrate the polymerization of rare earth Gd coordination complex and PANI–D‐tartrate (DTA) not only simple physical mixing but also chemical mixing. TG‐DTG analysis suggests that thermal stability of PANI/Gd composites is higher than that of PANI–DTA. Electrochemical performance tests and SEM indicate that the composite (PANI/Gd = 3.3:1,mass ratio) has the most regular morphology and best specific capacitance. The magnetization of the composite (PANI/Gd = 3.3:1,mass ratio)is evidently smaller compared with PANI–DTA and rare earth Gd coordination complex. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

12.
稀土复合弹性材料的制备和力学性能   总被引:8,自引:4,他引:4  
利用稀土醇盐与季铵盐化的吡啶改性丁苯橡胶乳液反应,制备含稀土PSBR胶片,然后与天然橡胶并用,获得含稀土复合材料弹性材料发现其物理力学性能有明显提高。通过红外光谱、差示扫描热量计以及交联密度分析,讨论了其结构与性能的关系。  相似文献   

13.
Rare earth composite cobalt ferrite ionic magnetic fluids were prepared by precipitation in the presence of Tri-sodium citrate. The sample phase, structure and particle sizes were determined by X-ray diffraction transmission and electron microscopy. It is clear that the particles appear as variously sized balls, Cobalt ferrite with sizes of 12-15 nm, Dysprosium cobalt ferrite and Yttrium cobalt ferrite with sizes of 6-8 nm. By adding rare earth ions, the average diameter of the magnetic nanoparticles was decreased. The decrease in diameter was explained using a micro-model of rare earth modification. The effect of rare earth ion modification on the saturation magnetization and magnetic induction of magnetic fluids was carried out using a Gouy magnetic balance and a spectrophotometer. The result shows that saturation magnetization and magnetic induction can be improved by adding Dy3+. By adding Y3+, magnetic induction was increased. However, the saturation magnetization then decreased. A theory of the mechanism of rare earth ion modification is discussed in detail.  相似文献   

14.
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.  相似文献   

15.
Monodisperse magnetic composite particles (MCP) were prepared and characterized for a study of magnetic field-responsive fluids. Magnetic composite particles used are iron oxide-coated polymer composite particles, which were synthesized through in situ coating of iron oxide onto pre-existing polymer particles by the reduction of ferrous fluids. For a uniform and bulk coating of iron oxide, the porous structure was introduced into the substrate polymer particles through a two-step seeded polymerization method. Moreover, surface cyano-functionality was born from acrylonitrile unit of substrate polymer and it played an important role in obtaining successful uniform coating. The structure of the composite particle was analyzed by using a thermo gravimetric analysis (TGA) and a X-ray diffraction (XRD) analysis. The magnetization property of the particle was also observed. Then, the rheological properties of monodisperse magnetorheological (MR) suspensions of magnetic composite particles were examined under a magnetic field using a parallel-plate type commercial rheometer. From the rheological measurements, it was found that MR properties of the magnetic composite suspensions are dependent on the iron oxide content and the fluid composition.  相似文献   

16.
聚氨酯/环氧树脂IPN复合抛光材料的制备及性能研究   总被引:1,自引:0,他引:1  
本研究采用聚氨酯与环氧树脂(PU/EP)作为胶黏剂形成互穿网络(IPN),以无机磨料和稀土抛光剂为分散相,通过一定的成型工艺制备成复合抛光材料。通过固化前后的红外光谱,分析了PU、EP两者之间的反应;热重分析表明PU/EP IPN复合抛光材料的耐热性能比纯的PU和EP有显著提高;体视显微镜照片显示该复合抛光材料具有微孔结构;力学及应用性能研究显示当胶黏剂含量为25%时性能最佳;且在PU/EP=2时,抛光后的玻璃透光率保持原有的97%,且耐磨性得到大幅度提高。  相似文献   

17.
The alkaline-earth–rare-earth–aluminate systems phosphors are the new types of phosphors, which process very bright, safer, and excellent photoluminescence. Because of hydrolysis, however, the capacity of luminescent materials will fall down and the use value of luminescent materials will also be lost. Water-resistant polymers, which can form a kind of water-resistant clad on the surface of luminescent material powder, will solve this problem and the significance of its application is important. In this study, the polymethyl methacrylate (PMMA)/rare earth composite luminescent materials were prepared through grafting emulsion polymerization of methyl methacrylate onto the surface of luminescent materials. To study the structure and properties of the PMMA/rare earth composite luminescent materials, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and photoluminescent properties were measured. From the curves of FTIR and TGA, we can find that the organic parts are attached with the inorganic parts in the PMMA/rare earth composite luminescent materials. The results of luminescent decay curves show that the resistance to water of the PMMA/rare earth composite luminescent materials is much better than that of the unmodified luminescent materials because the organic parts had been grafted on the luminescent materials.  相似文献   

18.
含双噻唑高分子及其螯合物的制备和磁性能研究进展   总被引:2,自引:0,他引:2  
设计和合成有机及高分子磁性材料是当前国内外十分关注的课题,本课题组在先前研究的基础上,以电子理论和磁性理论为指导,从分子设计出发,合成出含双噻唑新型芳杂环聚合物及其过渡金属离子或稀土离子螯合物,测定了它们的磁性能,研究高分子结构、螯合物组成与磁性能的关系,探索产生磁性的机理.发现本研究体系的高分子螯合物具有顺磁居里温度(Tp)高,剩余磁场(Mr)少,矫顽力(Hc)低,是一类很好的软磁性材料,呈现出有一定特色的磁性能.本文综述了含双噻唑高分子过渡金属螯合物、稀土金属螯合物、纳米碳管接枝高分子及其螯合物的制备和磁性能研究,以及典型螯合物的非常规磁性现象的发现和机理探索研究.  相似文献   

19.
除传统的催化、 吸附分离和离子交换外, 主客体组装化学赋予了沸石分子筛材料独特的物理化学性质和广阔的应用前景. 本文聚焦光致发光沸石分子筛复合材料, 综述了这类材料最新的研究进展, 总结了不同发光客体, 如稀土金属、 金属簇、 量子点/碳点等与沸石分子筛形成的复合材料的制备方法与组装策略, 介绍了该类复合材料的光致发光性质和潜在应用, 探究了复合材料中可能存在的量子限域、 分子间相互作用、 能量转移和电子转移等对发光的影响, 并对未来光致发光沸石分子筛复合材料的发展前景进行了展望.  相似文献   

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