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树枝状多孔二氧化硅纳米粒子具有中心辐射状孔道结构且孔道尺寸从粒子内部到粒子表面逐渐增加,是一种具有新颖结构的多孔材料。和传统的具有二维六方有序孔道结构的介孔二氧化硅粒子相比,这种粒子具有三维开放性的树枝状骨架结构,因而具有独特的结构优势,即高的孔渗透性和高的粒子内表面的可接触性,从而有利于物质(分子或纳米粒子)沿着中心辐射状的孔道进行输送,在树枝状粒子的内部负载或者与内部的活性位点发生反应。因此,这种粒子是一种很有前景的载体平台,可以用来构筑新型的吸附剂、纳米催化剂和基因药物的递送系统等。本综述首先介绍了一系列的合成方法和对树枝状骨架结构的调控策略,探讨了树枝状多孔结构对物理化学性能的影响,描述了其在催化、纳米生物医学、环境能源等领域的应用性能,并对树枝状多孔二氧化硅粒子的合成方向和应用前景进行了展望。 相似文献
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综述了银基微纳米半导体光催化应用研究进展.指出银基微纳米半导体在可见光辐照下表现出良好的光催化性能(光催化降解有机物或光解水制氢制氧),目前的研究主要集中在简单的含银化合物、含银的异质结构、含银的多金属氧化物和含银的固溶体这几类;并从光催化原理和能隙调节手段入手阐述了决定其光催化性能的因素. 相似文献
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Preparation of epoxidized Eucommia ulmoides gum and its application in styrene‐butadiene rubber (SBR)/silica composites 下载免费PDF全文
In this article, we primarily introduced a method to prepare epoxidized Eucommia ulmoides gum (EEUG) and studied its application as interfacial additive in styrene‐butadiene rubber (SBR)/silica composites. We prepared the EEUG from the Eucommia gum extract solution using E. ulmoides leaves pretreated with enzymatic solutions as the raw material, petroleum ether as the solvent, and peracetic acid (CH3COOOH) as the oxidant under a certain temperature. Accordingly, we focused on studying the effects of a series of factors, such as the mole ratio (γ) of peracetic acid to double bonds of Eucommia gum and reaction time on the epoxidation degree and crystallization degree of Eucommia gum in the epoxidation process, in order to control the properties of the EEUG. Regarding the study of the application of EEUG in SBR/silica composites, we found that the addition of EEUG greatly promoted the properties of SBR/silica composites by improving the dispersion of silica in SBR composites, which possessed excellent mechanical properties, including higher tensile strength, tear strength, 100 and 300% modulus, wear resistance, and low heat buildup. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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G. Markovi? M. Marinovi?-Cincovi? Lj. Tanasi? V. Jovanovi? S. Samar?ija-Jovanovi? N. Vuki? J. Budinski-Simendi? 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2011,85(13):2410-2415
The goal of this work was to study gamma irradiation ageing of rubber blends based on acrylonitrile butadiene rubber (NBR)
and chlorosulphonated polyethylene rubber (CSM) reinforced by silica nano particles. The NBR/CSM compounds (50: 50, w/w) filled
with different content of filler (0–100 phr) were crosslinked by sulfur. The vulcanization characteristics were assessed using
the rheometer with an oscillating disk. The vulcanizates were prepared in a hydraulic press. The obtained materials were exposed
to the different irradiation doses (100, 200, 300 and 400 kGy). The mechanical properties (hardness, modulus at 100% elongation,
tensile strength and elongation at break) and swelling numbers were assessed before and after gamma irradiation ageing. 相似文献
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大黄素键合硅胶固定相的制备及其在核苷碱基药物分离中的研究 总被引:1,自引:0,他引:1
通过γ-[(2,3)-环氧丙氧]丙基三甲氧基硅烷(KH-560)偶联剂将具有抗菌功能的植物有效成分大黄素键合到硅胶上,制备了大黄素液相色谱键合固定相(EDSP)。采用元素分析、红外光谱和热分析对该固定相的结构进行表征。以嘧啶、嘌呤和核苷为溶质探针,并用ODS柱做参比,对固定相的色谱性能及保留机理进行了研究。研究结果表明,该固定相具有类似ODS的反相色谱性能,除疏水作用外,由于大黄素的大π共轭体系,为溶质提供了n-π和π-π作用位点;且两个邻位羟基和两个羰基的存在,能够与溶质之间发生氢键作用和偶极-偶极作用。与ODS柱相比,该固定相在极性化合物分离中占优势,且分析速度较快。此外,实验还发现,该固定相能较好地分离二甲苯同分异构体,预示着该固定相有一定的立体选择性分离能力。 相似文献
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Synthesis and application of cinnamate-functionalized rubber for the preparation of UV-curable films
A butyl rubber derivative that can be cured upon exposure to UV light in the absence of additional chemical additives was developed. This polymer was prepared by the reaction of hydroxyl-functionalized butyl rubber with cinnamoyl chloride to provide a cinnamate functionalized rubber. The cinnamate content was varied by starting with derivatives prepared from butyl rubber containing either 2 or 7 mol% isoprene. The kinetics of the cross-linking was studied by UV–visible spectroscopy and it was found to vary according to the film thickness. The changes in gel content and volume swelling ratio with irradiation time were dependent on the cinnamate content. Toxicity studies suggested that the cross-linked materials do not leach toxic molecules. The approach was also applied to obtain cross-linked films of butyl rubber-poly(ethylene oxide) graft copolymers, leading to surfaces that resisted the adhesion and growth of cells. Thus the approach is versatile and is of particular interest when non-leaching coatings of cross-linked butyl rubber are desired for biomedical or other applications. 相似文献
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