纳米复合材料力学性能的研究

本文从薄膜和块体材料两个方面介绍了近年来有关纳米复合材料力学性能的研究成果。综述了薄膜和块体纳米复合材料优异的力学性能及其产生机制,并指出了进一步研究方向。     

高性能MXenes纳米复合材料研究进展

二维过渡金属碳/氮化物(MXenes)以其优异的力学和电学性能,在多个领域展示出巨大的应用前景。近年来,高性能MXenes纳米复合材料(包括一维纤维、二维薄膜和三维块体)的研究取得了显著进展,但其力学性能仍远低于MXenes纳米材料的本征力学性能,这主要归因于MXenes纳米复合材料中存在的孔隙缺陷、MXenes纳米片取向度低以及界面相互作用弱等关键科学问题。针对上述问题,本文首先讨论了MXenes纳米材料的本征力学性能,总结讨论了不同类型高性能MXenes纳米复合材料的发展历程,并介绍了高性能MXenes纳米复合材料的最新研究进展,包括如何消除孔隙缺陷、提高MXenes纳米片的取向度以及增强界面相互作用。同时,介绍了高性能MXenes纳米复合材料在电热、热伪装、电磁屏蔽、传感以及储能等领域的应用。最后,梳理了高性能MXenes纳米复合材料存在的挑战,并展望了未来的发展方向。     

纳米金属钨的制备研究进展

综述了近年来的纳米金属钨的粉体、薄膜及块体材料制备方法的研究进展及其微结构与力学性能。     

氧化石墨烯纳米带与氧化石墨烯增强热塑性聚氨酯薄膜的制备及性能

利用纵向裂解多壁碳纳米管制备了氧化石墨烯纳米带,并采用溶液成型的方法制得氧化石墨烯纳米带-氧化石墨烯(GONRs-GO)/热塑性聚氨酯(TPU)复合材料薄膜。场发射扫描电镜和X射线衍射分析结果显示,GONRs与GO间相互剥离并均匀地分散在TPU基体中;氧气透过率(OTR)和力学性能测试表明,GONRs和GO具有协同增强TPU复合材料薄膜的阻隔和力学性能的作用。当GONRs和GO在TPU中添加量均为1.5%(质量分数)时,GONRs-GO/TPU复合材料薄膜的阻隔和力学性能达到最佳。相比于纯TPU薄膜,该GONRs-GO/TPU复合材料薄膜的OTR降低了83.94%,拉伸断裂强度、屈服强度、扯断伸长率则分别提高了59.28%,59.54%和15.0%。     

高能球磨纳米CeO2/Zn复合粉末的热压烧结

采用真空热压工艺制备了纳米CeO2/Zn复合材料块体,并用正交实验法研究了热压工艺参数对复合材料块体相对密度的影响.结果表明:随着粉末球磨时间的增加,复合材料块体内纳米颗粒分散越均匀,基体晶粒不断细化;块体的相对密度随着热压温度、压力的提高和保温时间的延长而增加,其中热压温度的影响最大,压力影响次之,保温时间影响最小;制得的纳米复合材料块体可加入到热浸镀锌液中.     

纳米复合薄膜及其在果蔬保鲜中的应用

纳米复合包装薄膜一般为聚合物基纳米复合材料,可分为纳米材料/合成聚合物复合材料与纳米材料/天然聚合物复合材料。阐述了这2种复合材料的制备方法和性能特点,综述了纳米TiO2复合薄膜、纳米SiO2复合薄膜、纳米CaCO3复合薄膜、纳米银复合薄膜在果蔬保鲜中的应用研究,并展望了纳米复合薄膜在果蔬保鲜应用方面的研究方向。     

基于第一性原理的氧化银纳米薄膜光学性质的研究北大核心CSCD

采用密度泛函理论构建了氧化银表面结构,并分析了薄膜厚度对结构稳定性及光学性质的影响规律,得出了氧化银(100)、(110)和(111)纳米薄膜的折射率、介电函数。研究表明,纳米薄膜的折射率、介电函数在可见光波段均低于块体,对(100)和(110)面来说,随着薄膜厚度的增加,其折射率、介电函数实部逐渐增加并接近于块体。而对于消光系数来讲,这三个表面构成的纳米薄膜均低于块体,尤其(111)面的吸收相对于另外两个面来说更小,其中21层和24层相对更小。因此可以得出结论:由氧化银纳米薄膜构建的光存储和磁光存储纳米薄膜器件,具有更高的透过率。     

基于第一性原理的氧化银纳米薄膜光学性质的研究

采用密度泛函理论构建了氧化银表面结构,并分析了薄膜厚度对结构稳定性及光学性质的影响规律,得出了氧化银(100)、(110)和(111)纳米薄膜的折射率、介电函数。研究表明,纳米薄膜的折射率、介电函数在可见光波段均低于块体,对(100)和(110)面来说,随着薄膜厚度的增加,其折射率、介电函数实部逐渐增加并接近于块体。而对于消光系数来讲,这三个表面构成的纳米薄膜均低于块体,尤其(111)面的吸收相对于另外两个面来说更小,其中21层和24层相对更小。因此可以得出结论:由氧化银纳米薄膜构建的光存储和磁光存储纳米薄膜器件,具有更高的透过率。     

紫外辐照对EVOH/纳米SiO2复合材料性能的影响

用硅烷偶联剂y-氨丙基三乙氧基硅烷（KH550）对纳米SiO2进行改性,采用熔融共混法制备了合SiO2的质量分数为5％的乙烯-乙烯醇共聚物（EVOH）／纳米SiO2复合材料,并吹塑成薄膜,将复合膜进行不同时间、不同强度的紫外辐照处理。利用FTIR、TEM、SEM对纳米SiO2和复合材料进行了表征分析,测试了复合材料紫外辐照处理前后的阻隔性能和力学性能。结果表明：纳米SiO2与偶联剂KH550形成化学键合,经紫外辐照处理的EVOH／纳米SiO2复合膜的力学性能、阻隔性能得到了较大地提高。     

纳米晶金属块体材料制备技术与力学性能研究进展

主要总结了纳米晶金属块体材料的制备技术与力学性能的研究进展.讨论了各种制备技术的特点与现存的问题,以及纳米晶金属块体材料的强度、塑性、应变速率敏感性、超塑性、变形机制与断裂机制等力学性能问题.     

新型抗凝血纳米复合材料的制备及其性能研究

利用溶液插层法合成了新型的硅橡胶/氧化石墨-十六烷基三甲基溴化铵-肝素抗凝血纳米复合材料.通过FT-IR、XRD、SEM和机械性能测试了解改性氧化石墨微观纳米结构对材料宏观性能的影响;溶血试验和血小板粘附试验测定表明硅橡胶/改性氧化石墨抗凝血纳米复合材料的血液相容性得到极大的改善;这种新型的、兼具优良血液相容性和良好力学性能的复合材料可望在生物医学工程方面得到应用.     

碳纳米管增强聚合物复合材料力学性能及摩擦磨损性能研究进展

本文主要就近几年来碳纳米管、增强聚合物复合材料制备及其力学性能、摩擦磨损性能影响方面研究进展,作一简要介绍.     

Al/CNT nanocomposite fabrication on the different property of raw material using a planetary ball mill

In recent years, significant research has been focused on the development of carbon nanotube (CNT) reinforced aluminum nanocomposites, which are quickly emerging because of their lightweight, high strength and other mechanical properties. The potential applications of these composites include the automotive and aerospace industries. In this study, powder metallurgy techniques are employed to fabricate aluminum (Al)/CNT nanocomposites with different raw material properties with optimized conditions. We successfully fabricated three different samples, including un-milled Al, un-milled Al with CNT and milled Al with CNT nanocomposites, in the presence of additional CNTs with various experimental conditions using a planetary ball mill. Scanning electron microscopy and field emission scanning electron microscopy are used to evaluate the particle morphology and CNT dispersion. The CNTs are well dispersed on the surface of the fabricated milled Al with CNT nanocomposites than un-milled Al with CNT nanocomposites for milling. The fabricated Al/CNT nanocomposites are processed by a compacting, sintering and rolling process. Vickers hardness measurements are used to characterize the mechanical properties. The hardness of the Al/CNT nanocomposites are improved milled Al with CNT nanocomposite compared other fabricated composites.     

石材防护用纳米改性不饱和聚酯的合成及性能分析

制备了不饱和聚酯(UP)及纳米改性UP材料,着重介绍了纳米复合型UP的性能及在石材防护领域中的应用．研究结果表明,UP／MMT及UP／MMT SiO2的原位插层纳米复合材料各种性能下降,而UP／SiO2纳米复合材料综合性能提高,作为石材防护胶性能贡献突出。     

Mechanical properties of carbon nanotubes and their polymer nanocomposites

More than 10 years have passed since carbon nanotubes (CNT) have been found during observations by transmission electron microscopy (TEM). Since then, one of the major applications of the CNT is the reinforcements of plastics in processing composite materials, because it was found by experiments that CNT possessed splendid mechanical properties. Various experimental methods are conducted in order to understand the mechanical properties of varieties of CNT and CNT-based composite materials. The systematized data of the past research results of CNT and their nanocomposites are extremely useful to improve processing and design criteria for new nanocomposites in further studies. Before the CNT observations, vapor grown carbon fibers (VGCF) were already utilized for composite applications, although there have been only few experimental data about the mechanical properties of VGCF. The structure of VGCF is similar to that of multi-wall carbon nanotubes (MWCNT), and the major benefit of VGCF is less commercial price. Therefore, this review article overviews the experimental results regarding the various mechanical properties of CNT, VGCF, and their polymer nanocomposites. The experimental methods and results to measure the elastic modulus and strength of CNT and VGCF are first discussed in this article. Secondly, the different surface chemical modifications for CNT and VGCF are reviewed, because the surface chemical modifications play an important role for polymer nanocomposite processing and properties. Thirdly, fracture and fatigue properties of CNT/polymer nanocomposites are reviewed, since these properties are important, especially when these new nanocomposite materials are applied for structural applications.     

聚合物基纳米复合材料的界面作用研究进展

将聚合物与纳米粒子复合制备性能优异的聚合物基纳米复合材料是近20年来科学界的研究热点,其中聚合物与纳米粒子间的界面作用对复合材料的性能起着关键性作用。从界面结构、力学性能、热性能及计算机仿真模拟等方面综述了聚合物基纳米复合材料的界面研究进展,并对这一领域的研究进行了展望。     

Si3N4／SiC纳米复合陶瓷的制备,结构和性能

Ｓｉ３Ｎ４／ＳｉＣＵ纳米复合陶瓷是近年发展起来的高温高温度结构材料，它通过纳米ＳｉＣ颗粒在Ｓｉ３Ｎ４基体中的弥散达到强化增韧的效果。研究表明，这种增韧方法所获得的室温和高温机械性能均远远高于其它的增韧方法。本文综述了Ｓｉ３Ｎ４／ＳｉＣ纳米复合陶瓷在制备、结构和性能方面的研究成果，指出了尚待解决的问题和今后的研究方向。     

聚合物/层状粘土纳米复合材料阻燃性能研究进展

聚合物／层状粘土(PLC)纳米复合材料是近十年来研究的热点。由于PLC纳米复合材料具有常规聚合物复合材料所没有的结构、形态以及较常规材料更加优越的力学性能、耐热性能、气液体的阻隔性能等，所以具有广泛的工业应用前景。文中综述了PLC纳米复合材料的制备、性能、结构及其在阻燃方面应用研究的现状。     

Effect of graphene oxide on the physical,mechanical and thermo-mechanical properties of neoprene and chlorosulfonated polyethylene vulcanizates

The present research work demonstrated the effect of graphene oxide (GO) on the physical, mechanical, thermo-mechanical etc., properties of neoprene (CR) and chlorosulfonated polyethylene (CSPE) vulcanizates. CR and CSPE based nanocomposites were prepared by both solution intercalation and melt intercalation methods. The changes obtained in the morphology, cure characteristics, mechanical, thermal, thermo-mechanical properties of the rubber nanocomposites have been widely investigated. X-ray diffraction analysis (XRD) and transmission electron microscopic (TEM) analysis of the samples revealed partial exfoliated structure of GO containing rubber composites. Mechanical, thermal, cure and thermo-mechanical properties of the elastomeric nanocomposites were improved compared to the neat rubbers.     

Developing the mechanical models for nanomaterials

This paper revisits some of the well-known models in the mechanics of structurally heterogeneous media for the purpose of analysing their suitability to describe properties of nanomaterials (nanoparticles and nanocomposites) and their mechanical behaviour including statics, dynamics, stability and fracture. The paper gives an overview of existing knowledge on the nanomaterials and nanotechnologies, with the emphasis on their mechanical properties. A number of the macro-, meso- and micromechanical models are then reviewed and new nanomechanical models are suggested based on the knowledge accumulated within the micromechanics of composite materials. New directions of research in nanomechanics of materials are also pointed out.As an example of application of the developed models, the paper contains results of determination of the effective properties for particular nanocomposites.