储氢气用新型纳米级复合聚合物材料

美国伯克利国家实验室的研究人员开发出一种新型聚合物纳米复合材料,他们相信这一成果代表了储氢技术的重大突破。氢气清洁,唯一的燃烧副产品是水,因此长期以来被视为理想的化石燃料替代能源。但是,氢气很难安全储存以及高密度压缩。     

聚合物形状记忆材料及其纤维、纳米复合体系的研究

本文回顾了形状记忆聚合物材料的理论研究。详细介绍了近年来形状记忆聚合物结构改性方面的研究情况，指出软硬段含量、交联度等对形状记忆材料的影响；同时介绍了纤维、纳米粒子改性形状记忆聚合物材料的研究状况，最后对聚合物形状记忆材料的前景并口应用，特别是医疗上的应用作了分析介绍。     

聚合物纳米复合材料的制备技术

<正>1 概述聚合物纳米复合材料是近年来涌现出来的一种新型复合材料,它是通过在聚合物基体中分散少量具有纳米尺寸的填料粒子制成的,如聚已内酯,层状粘土纳米复合材料。由于纳米粒子具有一些特殊性质,如纳米尺度效应、大的比表面积、体积效应、与聚合物基体强的界面相互作用等,使得聚合物纳米复合材料在力学和热力学等性能上获得改善。目前有多种方     

纳米羟基磷灰石/聚合物骨修复材料的研究进展

纳米羟基磷灰石因其具有良好的生物相容性和生物活性,被广泛应用于骨组织的修复与替代材料.但由于磷灰石本身力学性能较差限制了其应用范围,因此,提高及制备综合性能优越的纳米羟基磷灰石/聚合物复合生物材料是当今研究的热门领域.本文综述了近年来n-HA/聚合物复合材料的国内外研究进展情况,并对此类材料存在的问题进行了分析,探讨了n-HA骨修复材料的发展方向.     

有机聚合物／无机化合物纳米复合阻燃材料研究进展

综述了有机聚合物／无机化合物纳米复合阻燃材料的研究和应用现状。阐述的纳米复合阻燃材料包括有机聚合物／层状硅酸盐纳米复合材料、有机聚合物／碳纳米管纳米复合材料、有机聚合物／二氧化硅纳米复合材料、有机聚合物／石墨纳米复合材料等。与传统无机阻燃剂填充阻燃材料相比,这类新型纳米复合阻燃材料的填料与基体的亲合性、基体的物理力学性能和阻燃性能等均得到改善。     

有机聚合物/无机物纳米复合阻燃材料的制备研究

根据国内外文献报道,综述了有机聚合物/无机物纳米复合阻燃材料的几种制备方法,重点对插层法、共混法进行了较为详细的介绍,并对这些方法的原理、适用范围和优缺点进行了述评,最后指出了今后制备技术的主要发展方向.     

聚合物/纳米无机填料复合阻燃材料的研究进展

介绍了以纳米三氧化二锑、氢氧化铝、氢氧化镁、层状硅酸盐作为添加物的聚合物基阻燃复合材料的制备方法.通过分析复合材料的极限氧指数、热释放率峰值和拉伸强度发现:随着纳米添加物的粒径的变小,极限氧指数提高,热释放率值降低,但对于不同的聚合物基的复合材料力学性能的变化并不一致.改性剂的使用有助于提高阻燃性能和力学性能,不同的改性剂产生的效果并不一样.同时,采用包覆的方法对填料进行改性,阻燃性能和力学性能大大提高.     

杜邦合作开发纳米级金属聚合物合金技术

杜邦工程塑料（DuPont Engineering Polymers）最近宣布和Power-Metal Technologies公司开展一项长期合作,进一步开发和商品化MetaFuse纳米晶体金属／聚合物混合技术。一年前,杜邦工程塑料与Morph Technologies签署了一份类似的合作协定,将这项技术应用到汽车市场。     

Catalysis and the hydrogen economy

Perspectives regarding the current and future production of hydrogen are offered. It is important to appreciate that most of the worlds current production of H₂ is captively produced and not easily committed to a major new market need (such as H₂ for fuel cells). The size and capital investment, energy intensiveness, as well as delivery issues restrict the simple extension of existing SMR plants to fill the void needed in H₂ production for a H₂ economy. Forecasts suggest future H₂ needs exceed 14 times the worlds current production of H₂; this volume coupled by restrictions of CO₂ co-production would seem to limit the options for future H₂ production. Production of H₂ by new process technologies, including CH₄ decomposition, CO₂ reforming, biohydrogen, photodecomposition of water, etc. are discussed. Catalysis will play multiple roles in all aspects of H₂ production. Multiple needs exist for catalysts with respect to the photodecomposition of water, CPO based processes, highly active and low cost WGS catalysts, catalysts to assist in the capture and storage of CO₂, improved hydrocarbon reforming, improved electrocatalysts and photocatalysts, improved hydrodesulfurization catalysts, and biophotolytic catalysts for decomposing water. Today, no single technology seems to offer a near term solution, although it appears that solar, photodecomposition of water offers a potential solution with respect to sustainability issues, the amount of H₂ needed, no CO₂ co-product, and energy needs; however the solar photodecomposition of water has many technical hurdles remaining which suggest it is decades away from large scale, cost effective implementation.     

Towards an ammonia-mediated hydrogen economy?

Materialization of a hydrogen economy could provide a solution to significant global challenges. In particular, the possibility of improving the efficiency and simultaneously minimizing the environmental impact of energy conversion processes, together with the opportunity to reduce the dependency of fossil fuels, are main drivers for the currently increasing research and development efforts. However, significant technological breakthroughs are necessary for making a hydrogen economy feasible. In particular, it is necessary to develop appropriate hydrogen storage and transportation technologies. Recently, metal ammine salts were proposed as safe, reversible, high-density and low-cost hydrogen carriers. Here, we discuss how this development could provide a platform for using ammonia as a fuel for the hydrogen economy. We do that by comparing various possible hydrogen carriers with respect to energy and cost efficiency, infrastructure requirements, safety concerns and also environmental impact. Based on this, it appears that in several scenarios, the use of metal ammines offers significant new opportunities.     

我国典型城市氢能经济性和低成本氢源探索分析

氢能经济性一直是氢能与燃料电池汽车产业发展关注的重点。本文构建了一种简洁、有效的加氢站氢气成本计算模型,可适用于现阶段已投入运行的加氢站经济性研究计算。应用该成本计算模型,通过实地调研,本文得到了张家口、郑州、盐城、佛山等地典型加氢站的氢气成本,经对比分析可知,由于氢气来源、储运距离、应用端市场规模等现实条件不同,加氢站的氢能经济性具有很大差异。为进一步提升氢能经济性、探索加氢站氢气成本低于40CNY/kg的可行性,本文以张家口市氢气来源于风电电解水制氢的某加氢站为例,详细分析其氢气成本构成情况,得出低成本氢源开发对于降低加氢站氢气成本具有重要意义。本文还根据氢能产业发展现状和在交通领域的应用前景,从降低氢气制取成本、氢气储运成本、加氢站固定资产折旧及运营成本等方面为进一步提升氢能经济性、降低加氢站氢气成本提出建议。     

纳米复相陶瓷

纳米复相陶瓷已成为陶瓷研究领域的研究热点，本文综述了纳米复相陶瓷的分类、材料设计、粉体制备、烧结及增韧机理。     

纳米复相陶瓷

纳米复相陶瓷以其优异的性能受到大家的关注，成为陶瓷研究领域的研究热点。本文在介绍纳米复相陶瓷分类、材料设计和制备的同时，着重阐述了纳米复相陶瓷中纳米颗粒对材料的显微结构和性能的影响。     

煤制氢解决PVC生产企业氯平衡实现循环经济

分析了目前我国PVC、烧碱生产企业状况。提出了通过配套固定床煤气发生炉产生氢气和煤气的建议:将氢气用于消化电石法PVC生产过程中的多余氯气(生产氯化氢),而剩余煤气则在固碱生产中作为燃料使用。详细叙述了煤气发生炉配套变压吸附装置生产氢气的工艺流程,并阐述了综合利用过程。     

Nanocomposite alkyd coatings

Organophilic montmorillonite intercalants were prepared by a cation‐exchange process between Na⁺ ions of montmorillonite and ammonium salt of octadecylamine. Fourier transform infrared (FTIR) spectrometry and X‐ray diffraction analyses of the compounds were carried out. The layer spacings of both modified and unmodified montmorillonites were calculated with Bragg's law. FTIR and X‐ray profiles showed organophilic characteristics for the modified montmorillonite, the layer spacing of which increased by two orders of magnitude with respect to that of the unmodified montmorillonite. The prepared organoclay was incorporated into an alkyd‐based clear coating, and X‐ray profiles showed an exfoliated structure for the organoclay alkyd coating. The application of the prepared organoclay to alkyd‐based clear coatings showed a significant enhancement of the hardness and impact strength of the coating film compared with those of unmodified montmorillonite equally incorporated into the coating formulations. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2639–2642, 2006     

纳米复合材料的研究进展

纳米复合材料是功能材料范围内研究的热点。文中介绍了纳米复合材料的制备方法和技术 ,讨论了国内外高聚物 /纳米复合材料和纳米复合涂料的研究现状 ,并展望了其发展趋势。     

Small AgNP in the Biopolymer Nanocomposite System

In this work, ultra-small and stable silver nanoparticles (AgNP) on chitosan biopolymer (BP/AgP) were prepared by in situ reduction of the diamminesilver(I) complex ([Ag(NH₃)₂]⁺) to create a biostatic membrane system. The small AgNP (3 nm) as a stable source of silver ions, their crystal form, and homogeneous distribution in the whole solid membrane were confirmed by transmission electron microscopy (TEM), scanning electron microscopy (SEM), and atomic force microscopy (AFM). The X-ray photoelectron spectroscopy (XPS) and Auger analysis were applied to investigate the elemental composition, concentration, and chemical state of surface atoms. It was found that ultra-small metallic nanoparticles might form a steady source of silver ions and enhance the biostatic properties of solid membranes. Ultra-small AgNP with disturbed electronic structure and plasmonic properties may generate interaction between amine groups of the biopolymer for improving the homogeneity of the nanometallic layer. In this work, the significant differences between the typical way (deposition of ex-situ-prepared AgNP) and the proposed in-situ synthesis approach were determined. The improved thermal stability (by thermogravimetry and differential scanning calorimetry (TG/DSC) analysis) for BP/AgP was observed and explained by the presence of the protective layer of a low-molecular silver phase. Finally, the antibacterial activity of the BP/AgP nanocomposite was tested using selected bacteria biofilms. The grafted membrane showed clear inhibition properties by destruction and multiple damages of bacteria cells. The possible mechanisms of biocidal activity were discussed, and the investigation of the AgNP influence on the bacteria body was illustrated by AFM measurements. The results obtained concluded that the biopolymer membrane properties were significantly improved by the integration with ultra-small Ag nanoparticles, which added value to its applications as a biostatic membrane system for filtration and separation issues.