共查询到20条相似文献,搜索用时 46 毫秒
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采用二苯胺磺酸钠还原四氯合金酸的方法,在室温条件下,用SDS(十二烷基硫酸钠)、SDBS(十二烷基苯磺酸钠)作表面活性剂,成功地合成了金纳米粒子.分别讨论了还原剂二苯胺磺酸钠、表面活性剂(SDS、SDBS)及四氯台金酸的浓度等对金纳米粒子的粒径和形貌的影响.通过控制反应条件,可以合成出平均粒径大约为10、14、30、36nm的金纳米粒子.利用透射电镜(TEN)、紫外-可见(UV-Vis)吸收光谱对金纳米粒子进行了表征.研究结果表明不同的SDS或SDBS/HAuCl4的摩尔比,对金纳米粒子的尺寸大小有影响. 相似文献
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采用侧柏叶提取液还原氯金酸制备负载型金纳米催化剂,通过乙醇选择氧化反应,筛选出催化性能较好的TiO2载体。以TiO2载体为载体,考察了Au负载量、焙烧温度、催化剂用量、碳酸氢钠添加量及催化剂反应条件(时间、温度、压力)等因素对乙醇选择氧化反应的影响。结果表明,1.5%Au/TiO2催化剂(Au负载量为1.5%,质量分率,下同)催化乙醇选择氧化反应性能最佳,产物为乙醛、乙酸乙酯和缩醛,0.5%碳酸氢钠添加剂可抑制缩醛的生成,并可显著提高乙醇转化率和乙酸乙酯选择性。通过优化催化反应条件(1.5%Au/TiO2催化剂焙烧温度为400℃、用量为0.4 g、反应温度为100℃、氧气压力为3 MPa、反应时间为3 h时),乙醇转化率为47.9%,乙酸乙酯选择性为89.1%。 相似文献
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使用一锅法成功制备了水溶性聚酰胺酸盐稳定的金纳米催化剂(AuNPs-PAAS),将该催化剂用于伯醇的催化氧化.利用紫外-可见分光光度计,X射线衍射仪(XRD),透射电子显微镜(TEM)等表征方法对催化剂进行了表征.结果表明,金纳米粒子在聚酰胺酸溶液中处于均匀分散状态,金纳米尺寸约为5 nm.将制备的纳米金催化剂用于伯醇的氧化,评价了其在伯醇氧化成羧酸反应中的催化性能,结果显示,在空气为氧化剂,水为溶剂的条件下,AuNPs-PAAS对伯醇的催化氧化为高效的准均相催化过程,高选择性得到羧酸产物,通过调节溶液的pH值,可以很容易的实现产物与反应体系分离和催化剂的回收和循环利用. 相似文献
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Molecularly imprinted polymers with photo-luminescent properties (PLMIPs) and PLMIPs-based hybrids have been widely studied in recent years because of their integrated merits from molecular imprinting technologies and PL properties. PLMIPs have superior capabilities for signal transducer and molecular recognition, exhibiting great potential as the constructing platforms for promising applications. During the past decade, numerous researches have mentioned PLMIPs. In terms of unique merits and important applications of PLMIPs, a timely, comprehensive and in-depth review on PLMIPs is significant and is still lacking currently. This review systematically summarizes recent advances of PLMIPs, focusing on different synthetic methods and applications. Based on different components and structures, PLMIPs include different categories. Synthetic methods majorly involve encapsulation polymerization of nanomaterials (fluorophores) into MIPs, copolymerization of fluorescent monomers, electro-polymerization, photo-polymerization, etc. Various engineering structures and luminescence properties of PLMIPs are highlighted Potential applications of PLMIPs mention significant research fields, including chemo/bio-detection, bio-imaging, functionalized separation materials, versatile sensing materials, optical devices, etc. We also discuss present status, probable challenges and future perspectives of PLMIPs. This review is desirable for scientists from broad research fields and can promote further development of MIPs-based functional materials, luminescent hybrid materials and other advanced optical materials. 相似文献
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Although in its infancy, the field of micro reaction technology is growing rapidly, with many research groups investigating the practical advantages associated with reaction miniaturisation. With this in mind, the following Feature Article aims to provide an overview of the progress made in the past decade, paying particular attention to the field of synthetic organic chemistry. 相似文献
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In this review, we summarize recent advances in the synthesis of hybrid nanoparticles in miniemulsions since 2009. These hybrid nanoparticles include organic–inorganic, polymeric, and natural macromolecule/synthetic polymer hybrid nanoparticles. They may be prepared through encapsulation of inorganic components or natural macromolecules by miniemulsion (co)polymerization, simultaneous polymerization of vinyl monomers and vinyl-containing inorganic precursors, precipitation of preformed polymers in the presence of inorganic constituents through solvent displacement techniques, and grafting polymerization onto, from or through natural macromolecules. Characterization, properties, and applications of hybrid nanoparticles are also discussed. 相似文献
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We summary recent advances of transformable NPs for nanomedicine. In this review, the transformation of NPs is divided into three groups including changes in size, surface charge and morphology, which is induced by internal stimuli, such as pH, enzyme, receptor or external stimuli, such as light, temperature. 相似文献
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Recent advances in the synthetic applications of the oxazaborolidine-mediated asymmetric reduction 总被引:1,自引:0,他引:1
Byung Tae Cho Author Vitae 《Tetrahedron》2006,62(33):7621-7643
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Masoud Mokhtary 《Journal of the Iranian Chemical Society》2016,13(10):1827-1845
Unsupported nanoparticles are often less stable, and usually coagulation is unavoidable during the catalytic reactions. To generate stable nanoparticles with good activity, stabilizing the surface is required. Protection has been performed by the addition of polymers or long-chain alkyl surfactants with polar functional groups that attached to the nanoparticle surface via covalent or electrostatic interactions. Alternatively, nanoparticles have been immobilized or grafted onto inorganic supports to improve their stabilization and recycling ability. In this article, the green catalytic processes and recent advances in organic transformations catalyzed by magnetically retrievable catalysts are reviewed. Prior to this, methods for the synthesis of catalysts immobilized on magnetic nanoparticles are addressed briefly. 相似文献
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纤维染料是使纤维着色的物质,其分析检测对纺织、环保、法庭科学、古文物研究等诸多领域都有重要的意义。然而纤维染料的种类繁多、成分复杂,加之高灵敏度以及原位无损检测的分析需求日益突出,使得纤维染料的分析面临挑战。尽管如此,研究人员一直致力于高效、灵敏、无损的纤维染料分析新方法和新技术的研究,目前已经开发了多种纤维染料的分析方法,这些方法可大致分为3类:光谱法、色谱法及质谱法。该文综述了纤维染料的特点及纤维染料的检测方法及最新研究进展,并对未来纤维染料检测方法的发展进行了展望,为更好地开展纤维染料的分析提供了参考。 相似文献
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Yanchang Shen 《Journal of organometallic chemistry》2006,691(8):1452-1461
Fluorinated vinylstannanes have attracted much interest in recent years because they provided a useful and convenient methodology for the introduction of monofluoro, difluoro, trifluoro or polyfluoro functionality into organic molecules with retention of configuration, particularly in the synthesis of fluorine-containing naturally occurring compounds. The new methodologies discussed in this review are, therefore, potentially useful in organic synthesis particularly in the medicinal and agricultural chemistry for the synthesis of fluorine-containing biologically active compounds. 相似文献
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A mini-review: As the top-down approach for miniaturisation of technology reaches its inherent limitations, robust strategies to build nanoscale machinery components, which have the ability to convert an input energy into motion, from the molecular level up, become increasingly important. Nature is certainly the most proficient in the control of molecular level motion; nevertheless, many successes have been enjoyed in the pursuit of mimicking key aspects of nature’s molecular machines, including two state switches, ion pumps, unidirectional rotary motors and molecular robots that can move molecular cargo. This mini-review outlines of some of the most impressive recent examples towards this end. 相似文献