非传统表面活性剂制备硅基介孔材料新进展

因无机多孔材料在诸多领域具有潜在的应用前景,其合成路线的研究一直备受研究者的广泛关注。本文综述了非传统表面活性剂在硅基介孔材料合成中的研究进展。阐述了有机小分子、离子液体和新型硅源等非传统表面活性剂作为模板剂制备硅基介孔材料的现状。与利用传统表面活性剂的合成路线相比,以非传统表面活性剂为模板的制备路线在合成过程中体现了诸多优势,为硅基多孔材料的合成提供了新的思路。     

表面活性剂引导合成非硅基介孔材料的研究进展

非硅基介孔材料由于其突出的结构特性和特殊的光、电、磁性质,广泛应用于许多研究领域,使该类材料的合成逐渐成为研究者关注的焦点。本文综述了国内外近年来表面活性剂引导合成非硅基介孔材料的研究进展,阐述了离子型表面活性剂和非离子型表面活性剂作为模板剂及混合模板剂合成介孔碳、介孔金属氧化物等非硅基介孔材料的现状,归纳了合成该类介孔材料的最佳工艺条件,总结了不同模板剂引导合成的非硅基介孔材料特点,同时列表对比了不同类型表面活性剂合成该类材料的性能参数和应用领域,并对其发展进行了展望,即表面活性剂的绿色化、材料的功能化、合成过程的共模板化是未来发展的主流方向。     

介孔材料的制备及应用研究

近年来,有序介孔材料由于其特有的结构和性质得到了国内外研究者的广泛关注.本文综述了有序介孔材料的制备方法和研究进展,主要包括模板法和溶剂挥发诱导自组装法.详细介绍了硅基、锡基、铝基、钛基、碳基介孔材料的研究现状、特性、以及在催化、生物医药、环境保护等方面的应用进展,指出了存在的问题和研究方向.     

超临界流体技术在模板剂萃取方面的应用

介孔材料作为一种新型的功能材料，在结构上具有一系列独特的优点，备受广大科学研究者的关注。由于介孔材料在合成过程中使用了大量模板剂，因此模板剂的去除问题就成为研究的重点之一。本文主要综述了介孔材料的合成过程及超临界流体技术在萃取模板剂方面的应用。     

硬脂酸单甘酯模板法制备介孔硅材料及功能化

以硬脂酸单甘酯非离子表面活性剂为模板剂,采用模板法自组装合成了具有介孔结构的新型纯硅基材料,并在此基础上添加镁铝改性合成了新型功能化介孔材料,采用XRD和N2物理吸附 脱附等方法进行表征,结果表明,活性物种进入了介孔硅的骨架并保持了介孔结构特征,活性物种在母体表面分散较好。以十八酸和丙三醇的酯化反应作为探针反应考察其催化性能,结果表明,功能化介孔材料有较好的酯化反应活性。     

硅基介孔材料的制备与应用研究进展

硅基介孔材料是通过有机与无机物组份间的超分子组装或协同效应而杂化形成。它具有较大的孔容、高的比表面积、有序且可调的孔道结构,其孔道表面可进行物理吸附或新的化学修饰。这为介孔材料的功能化与应用研究提供了有力的保证。对硅基介孔材料的基本制备方法作了介绍,重点对国内外硅基介孔材料的应用研究进展进行了综述。     

木质素基介孔碳材料的制备及应用进展

木质素是自然界中唯一可提供再生性芳香基化合物的非石油类资源,酚羟基的可替代性、低成本及其高含碳量使其成为合成可持续介孔碳的优选前体。本文分别介绍了采用硬模板法、软模板法、双模板法、活化法、水热法以及溶胶-凝胶法制备木质素基介孔碳材料的最新研究进展。分析对比了采用不同方法制备的介孔碳材料所具有的孔道结构和形貌特点,并详细说明了其在吸附、催化、药物缓释和超级电容器等主要方面的应用。最后根据木质素基介孔碳材料在制备及应用过程中所面临的困境,提出发展一种简单、绿色、低成本的合成方法用以制备新型介孔结构的高性能复合型木质素基介孔碳材料将成为今后主要的研究方向。     

有序介孔聚合物的研究进展

综述了以自组装法、硬模板法和软模板法合成有序介孔聚合物及介孔碳的研究进展。对上述3种制备方法及原理进行了比较,指出目前以嵌段共聚物进行自组装以及采用软模板法制备介孔聚合物的途径更有利于制备有序的介孔聚合物及介孔碳。讨论了采用自组装法及软模板法时,嵌段共聚物的种类、模板剂的类型、聚合物前躯体的结构等对所制备的介孔聚合物以及介孔碳的形貌、介孔结构、骨架结构以及介孔材料的物理化学性能的影响。指出目前在介孔聚合物以及介孔碳的研究中,主要问题是如何提高介孔聚合物的有序性以及其介孔结构的稳定性。最后对有序介孔聚合物及介孔碳的发展方向及应用领域进行了展望。     

调湿陶瓷砖制备与性能研究

以火山灰及钾钠石粉为主要原料,无机硅基介孔材料为性能提升助剂材料,采用陶瓷砖生产工艺制备调湿陶瓷砖。重点研究了无机硅基介孔材料及釉料喷涂量对调湿砖性能的影响。实验结果表明：在硅基介孔材料添加量为2%、喷釉量为70 g/m²时,制备出吸湿量为385 g/m²、放湿量为370 g/m²,抗折强度达15.2 MPa的调湿陶瓷砖。     

硬模板法合成晶态介孔金属氧化物研究进展

晶态介孔金属氧化物材料因具有窄的孔径分布、大的比表面积、有序的孔道结构以及高度晶化的孔壁而在工业催化、光电等领域有着广泛的应用.在各种制备方法中,硬模板法因制备方法简单、条件温和、产物孔道结晶度高而受到了广泛关注.对硬模板法中介孔硅模板和介孔碳模板进行了介绍;总结了近年来硬模板法合成氧化铬、氧化铁、氧化铈、氧化镁和氧化钴等晶态介孔材料的研究进展;概述了该材料的发展趋势和应用前景.     

超临界流体技术在催化剂制备方面的应用

超临界流体技术是近年来发展起来的新技术。对超临界流体技术的特点及在催化剂制备方面的应用进行了概述。介绍分析了超临界流体干燥技术、超临界流体造粒技术、超临界流体模板和超临界流体沉积技术的技术原理、特点和研究进展。并在此基础上总结了超临界流体在催化剂制备方面的发展方向和今后研究工作的重点。     

超临界流体技术制备生物柴油的研究进展

综述了超临界流体技术制备生物柴油的最新研究进展。介绍了反应机理和反应动力学、工艺操作条件、原料中的水和游离脂肪酸、共溶剂和附加催化剂对酯交换反应的影响,并提出了超临界流体技术的优势、存在问题以及发展方向。     

Role and effect of supercritical fluid extraction of template on the Ti(IV) active sites of Ti-MCM-41

Supercritical fluid (supercritical carbon dioxide mixed with methanol) has been used as an extraction medium for the removal of template for a series of titanosilicates. Mesoporous titanosilicates Ti-MCM-41 with variable Si/Ti ratio (200–25) have been prepared by hydrothermal method. The location and coordination of titanium in the calcined and extracted titanosilicate mesoporous molecular sieve was studied by FTIR, UV–Vis spectroscopy, photoluminescence spectra, ²⁹Si NMR, combined with XRD and TG/DTA. Up to 97% template can be removed by extraction and the extracted material are hydrophobic in character. Removal of template by supercritical fluid extraction have no effect what so ever on the elemental composition of Ti-MCM-41 as well as it improves the structural ordering which was confirmed by XRD. Unequivocal evidences are presented to confirm the presence of same chemical environment of active titanium site after extraction, as present in as-synthesized material. It was also reported that, the entire extracted solid exhibited catalytic activity superior to that of the calcined product for epoxidation of cyclohexene because of the hydrophobic character and unchanged active framework titanium site.     

Supercritical Fluid Extraction of a Novel Template from Mesoporous Zirconia and the Effect on Porous Structure

Mesoporous zirconia was synthesized by a new and simple method. Zirconium n-propoxide was used as the zirconium source. A small, inexpensive nonsurfactant, triethanolamine, was used as the template. The template was removed by thermal treatment in air and supercritical fluid extraction using CO₂. The structure of the resulting materials was characterized by X-ray diffraction, transmission electron microscopy, and N₂ adsorption-desorption analyses. The materials are found to have narrowly distributed average pore diameters and wormhole-like pore channels. However, higher surface area and larger pore volume are exhibited after supercritical fluid extraction with CO₂. The removal of the template by thermal treatment also leads to condensation and mild shrinkage of the zirconia framework.     

KIT-6新型介孔分子筛的合成与表征

以P123为模板剂,正硅酸乙酯为硅源,采用水解法制备了介孔分子筛KIT-6,通过X射线衍射、傅立叶红外检测、N2吸附脱附、扫描电子显微镜对样品进行表征,结果表明该样品具有Ia3d立方相介孔材料的有序特征,为弯曲的棒状形貌。其比表面积为813．7m2／g,孔径为8．2nm。     

Wet-chemistry processing of powdery raw material for high-tech ceramics

The purpose of this study was to develop wet-chemistry approaches for the synthesis of ultradispersed and mesoporous metal oxide powders and powdery composites intended for usage in the production of ceramic materials with desired properties. The focus is on the development of template synthesis of mesoporous metal silicates as well as obtaining nano- and subnanopowders by a modified sol-gel technique and template methods. Families of mesoporous (2 to 300 nm) metal silicates and nano-oxides and subnanopowders (4 to 300 nm) were synthesized by the template method and modified sol-gel technique, respectively. Texture and morphology of the obtained objects have been studied by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, Brunauer-Emmett-Teller analysis, and N₂ adsorption-desorption. It was found that morphological parameters of the metal oxide obtained by the modified sol-gel technique depend nonlinearly on the initial molar ratio value of the sol stabilizer and metal in the reaction medium as well as the nature of the stabilizer. It has been shown that the nature of structure-directing components determines the morphology of the silicate obtained by the template method: dispersion and shape of its particles. The developed laboratory technology corresponds to the conception of soft chemistry and may be adapted to the manufacture of ultradispersed materials for catalysis, solar cells, fuel cells, semiconductors, sensors, low-sized electronic devices of new generation, etc.     

超临界流体技术与化工过程强化

化工过程强化是通过减小设备体积、简化工艺或提高设备生产能力达到提高效率、减少废弃物的排放、降低成本、降低物耗等的目的。与传统方法相比,超临界流体技术作为一种新兴的技术提高了效率、简化了工艺、节约了材料、无二次污染,达到了过程强化的目的。介绍了超临界流体技术的优势,从而得到过程强化的效果。     

Development of molecularly imprinted co-polymeric devices for controlled delivery of flufenamic acid using supercritical fluid technology

This work reports the development of a novel class of affinity co-polymeric materials using supercritical fluid technology. Polymeric materials with molecular recognition to flufenamic acid, were first synthesized in supercritical carbon dioxide (scCO₂) using the drug as template. Molecularly imprinted co-polymers of methacrylic acid (MAA) or N-isopropyl acrylamide (NIPAAm) crosslinked with ethylene glycol dimethacrylate (EGDMA) were synthesized using different crosslinking degrees and template:monomer ratios, at 65 °C and 21 MPa. High-pressure NMR experiments confirmed that the nature of the interactions between the drug and the functional monomers during the polymerization step are mainly hydrogen bonds. scCO₂-assisted impregnation revealed that the imprinted matrices were able to uptake higher amounts of flufenamic acid. This effect was particularly evidenced in the more crosslinked matrices, with P(MAA-EGDMA) imprinted copolymers binding up to 101.5 mg drug/g polymer against only 50.5 mg/g in the non-imprinted copolymer. In vitro drug delivery experiments showed that imprinted co-polymers release the drug in a more sustained way than the corresponding non-imprinted matrices. Overall it was shown that supercritical fluid technology is a viable approach for the development of self-assembly molecular recognition polymers with potential application in controlled drug delivery systems.     

精对苯二甲酸生产工艺新进展

介绍了近年以对二甲苯（PX）和对苯二甲酸（PTA）为原料生产聚酯的基本情况,以及以PX为原料的液相空气氧化法与加氢精制法生产PTA的工艺.着重论述扩大PTA生产规模、开辟生产PX新技术路线的最新动态,以及新型催化剂和超临界技术的应用等.