共查询到20条相似文献,搜索用时 15 毫秒
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多孔材料具有孔隙率高、比表面积大、导热系数低、体积密度小及化学性质稳定等优点,在吸附与分离、催化剂载体、隔热材料、能量储存、传感器等领域拥有广阔的应用前景。基于孔直径的大小可将多孔材料分为三类:孔径大于50nm的大孔材料(Macroporous materials),孔径介于2~50nm的介孔材料(Mesoporous materials)和孔径小于2nm的微孔材料(Microporous materials)。但是,由于孔径的限制,这三类材料的应用均存在一定的局限性。多级孔材料兼具通透性好、孔隙结构发达、体积密度小、比表面积和孔体积大等优点,打破了传统单级孔材料孔结构单一的局限,因此越来越受到研究人员的关注。然而,多级孔材料在制备中仍存在较多问题。例如,其合成过程通常会涉及到两种及两种以上的方法,制备工艺复杂;现有的多级孔材料的制备成本高,孔结构难以控制。因此,研究者们主要从优化多级孔材料的制备工艺以及降低生产成本等方面入手,制备出孔径均一且可控的多级孔材料。多级孔材料主要有大孔-介孔材料(Macro-mesoporous materials)、微孔-介孔材料(Micro-mesoporous materials)以及含有两种或多种不同孔径的介孔-介孔材料(Meso-mesoporous materials)。大孔-介孔材料常见的制备方法有模板法、发泡法、溶胶-凝胶法及熔盐法等;微孔-介孔材料的主要制备方法有化学活化法、模板法和水热法等;介孔-介孔材料的制备方法主要有水热法、模板法、溶胶-凝胶法及自组装法等。本文综述了近年来多级孔材料的最新研究进展,分别对大孔-介孔、微孔-介孔及介孔-介孔材料的制备方法进行了介绍,并简要分析了未来本领域研究的发展趋势。 相似文献
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纳米纤维素在可降解包装材料中的应用 总被引:1,自引:1,他引:0
目的综述纳米纤维素在可降解包装材料中的应用研究。方法总结国内外纳米纤维素在包装领域的最新研究,简述纳米纤维素的制备方法与特性,详细介绍纳米纤维素在生物质薄膜材料、生物质发泡材料、缓释抗菌材料和纸张中的应用研究,以及纳米纤维素功能性材料在包装中的研究进展,并讨论纳米纤维素应用在食品包装中的安全问题。结果纳米纤维素性能优异、绿色环保,作为可降解包装材料的增强成分可以提高复合材料的力学性能和阻隔性能,并可赋予材料特殊的功能。结论纳米纤维素在包装领域有着巨大的应用潜力,利用农作物及其剩余物制备纳米纤维素拥有广阔的发展前景。 相似文献
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Xiao Han Khalil T. Hassan Alan Harvey Dejan Kulijer Adrian Oila Michael R. C. Hunt Lidija Šiller 《Advanced materials (Deerfield Beach, Fla.)》2018,30(23)
Aerogels are the least dense and most porous materials known to man, with potential applications from lightweight superinsulators to smart energy materials. To date their use has been seriously hampered by their synthesis methods, which are laborious and expensive. Taking inspiration from the life cycle of the damselfly, a novel ambient pressure‐drying approach is demonstrated in which instead of employing low‐surface‐tension organic solvents to prevent pore collapse during drying, sodium bicarbonate solution is used to generate pore‐supporting carbon dioxide in situ, significantly reducing energy, time, and cost in aerogel production. The generic applicability of this readily scalable new approach is demonstrated through the production of granules, monoliths, and layered solids with a number of precursor materials. 相似文献
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B-C-N系超硬材料的研究进展 总被引:7,自引:0,他引:7
超硬材料的合成是目前材料科学研究领域的热门课题之一,近年来,由于碳基和硼基超硬材料的理论设计和发现,引起了人们在实验3和理论上对硬度与金刚石接近,基至超过金刚石的材料研究兴趣。在B-C-N系超硬材料中,除了金刚石和立方氮化硼(c-BN)以外,α-CaN4,立方氮碳化硼以及富勒烯等材料,也正日益受到国际材料界的重视,本文就B-C-N系超硬材料的最新研究进展做一综述。 相似文献
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Andreas Walther 《Advanced materials (Deerfield Beach, Fla.)》2020,32(20):1905111
Soft matter systems and materials are moving toward adaptive and interactive behavior, which holds outstanding promise to make the next generation of intelligent soft materials systems inspired from the dynamics and behavior of living systems. But what is an adaptive material? What is an interactive material? How should classical responsiveness or smart materials be delineated? At present, the literature lacks a comprehensive discussion on these topics, which is however of profound importance in order to identify landmark advances, keep a correct and noninflating terminology, and most importantly educate young scientists going into this direction. By comparing different levels of complex behavior in biological systems, this Viewpoint strives to give some definition of the various different materials systems characteristics. In particular, the importance of thinking in the direction of training and learning materials, and metabolic or behavioral materials is highlighted, as well as communication and information-processing systems. This Viewpoint aims to also serve as a switchboard to further connect the important fields of systems chemistry, synthetic biology, supramolecular chemistry and nano- and microfabrication/3D printing with advanced soft materials research. A convergence of these disciplines will be at the heart of empowering future adaptive and interactive materials systems with increasingly complex and emergent life-like behavior. 相似文献
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Aluminium foam‐sandwiches which are applied in car bodies, e.g., as side impact protection structures, are loaded not only by quasistatic, but also by cyclic forces. If these fatigue loadings induce damage of the foam‐sandwich structure, the stiffness, strength and impact behaviour may be adversely affected. The present study shows results of bending fatigue tests on an Aluminium foam‐sandwich material that was manufactured by a powder metallurgy process with succesive rolling and foaming. The sandwich had a foam core with 10 mm and outer sheet layers with thickness 1 mm. Alternating bending tests with normal stresses parallel to the sheet plane were realised using a servoelectric fatigue testing machine. The sinusoidal loading was momentum controlled with a load ratio of R = –1 and frequencies up to 50 Hz. The fatigue limit was calculated from 18 tests using the stair case method with an ultimate number of cycles of 107. The cyclic deformation behaviour within the HCF‐ and the LCF‐regime was determined from hysteresis loops of the bending moment versus the bending angle which were measured at selected load cycles during each test.The material shows pronounced cyclic hardening at the beginning of the fatigue loading due to work hardening processes mainly within the sheet layers. Afterwards, a cyclic neutral behaviour occurs until the end of the test. Damage by fatigue crack initiation generally starts within the sheet layers, mostly near large and deep pores within the gauge length. Subsequently, the cracks propagate firstly within the sheet layers and after that through the foamed core of the sandwich perpendicular to the bending axis. 相似文献
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固体粒子冲蚀磨损研究进展 总被引:37,自引:0,他引:37
固体粒子冲蚀磨损是引起材料破坏或设备失效的一个重要原因,本文简要介绍塑性材料和脆性材料的主要冲蚀理论,综述环境因素、粒子性能和材料性质的影响。 相似文献
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The search for new materials for tailor‐made applications and new devices involves not only solid‐state chemists, physicists or materials engineers, but also the area molecular and organo‐metallic chemistry, and even biochemistry. This is especially clear in the field of organic–inorganic multifunctional materials, whose design necessitates to investigate new concepts and principles developed in these different disciplines. Here, the authors review the structure‐magnetic property relationships in layered structures, made of organic and inorganic subunits. 相似文献
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