MOFs——一种新型的多孔材料

金属有机骨架(metal-organic frameworks,MOFs)材料由于其具有大的空隙率、比表面和功能性引起了人们的特别关注.它作为多孔材料具有无机和有机多孔材料的综合特性的优势,是目前新功能材料领域的研究热点之一.     

(Ba,Sr)TiO_3/Mg_xZn_(1-x)O核-壳复合陶瓷的制备及表征

纳米粒子由于具有大量的潜在应用,近年来已引起人们极大的关注.通过纳米复合技术(如制备核壳结构的纳米粒子)可以使其获得更多的特殊性质.以氢氧化钡、氢氧化锶、钛酸丁酯为主要原料,采用化学溶液法,在80℃左右的温度下制备了钛酸锶钡纳米晶.硝酸镁和硝酸锌的混合溶液同钛酸锶钡混合并超声搅拌,在室温下制备了具有核壳结构的(Ba,Sr)Ti O3/MgxZn1-xO(BST/MZO)纳米晶.x射线衍射(xRD)和场发射扫描电子显微镜(FESEM)确定所制备样品为纯钙钛矿结构,透射电镜(TEM)表明产品的形貌是核壳结构小球,电子衍射图案进一步证实核和壳均是由十几个到几十个纳米的(Ba,Sr)Ti O3/MgxZn1-xO纳米晶组成的聚集体.采用常规的陶瓷制备技术获得具有核壳结构复合陶瓷,其介电性能明显改善.研究结果表明具有核壳结构的(Ba,Sr)Ti O3/MgxZn1-xO适合作为微波介电材料.     

MOFs用于炔烃/烯烃高效分离的近期研究进展

传统的低碳烃气体分离技术能耗高,容易造成一定的环境压力,如低温蒸馏和溶剂萃取.此外,由于工业和技术的发展以及对产品更高的要求（如纯度）,传统的分离方法已无法满足需求.金属有机框架（MOFs）作为一类相对新颖的多孔有机-无机杂化材料,因其可控的拓扑结构和多样的化学微环境,在低碳烃分离和纯化领域受到广泛关注.文章概述了MOFs作为分离和纯化低碳烃气体吸附剂具有的特性,重点关注了MOFs材料在炔烃/烯烃气体分离领域的应用进展.     

溶胶-凝胶法制备PMMA/SiO_2透明纳米复合材料的研究

有机-无机纳米复合材料(OINC)作为一个新兴的研究领域,吸引了众多的研究者。有机-无机纳米复合材料不同于通常的聚合物/填料复合材料,因为它是由有机相和无机相在纳米至亚微米范围内结合形成的一类材料。其中有机相可以是塑料、尼龙、有机玻璃、橡胶等;无机相可以是金属及其氧化物、陶瓷、半导体等,复合后可以获得集有机相、无机相、纳米粒子的诸多特性于一身的具有许多独特     

具有多相催化性能的金属有机框架的研究进展

相比传统的多孔碳和无机沸石材料,金属-有机骨架(MOFs)具有制备方便、易于修饰、高孔隙率、比表面积大、框架规模大小可调等优点,在气体存储、吸附分离、多相催化、磁学等广泛应用.文章结合作者实验室的研究,介绍了MOFs作为多相催化剂所具有的独特特点;评估了MOFs作为催化剂的潜力,重点从MOFs的结构要素出发总结了MOFs作为多相催化剂的应用现状;讨论了MOFs作为多相催化剂需要重视的问题,为定向合成此类材料在催化方面的应用提供基础和理论价值.     

Mn_7C_3@C核壳型纳米粒子制备及其超级电容器电极特性

以甲烷作为碳源气体,块体锰作为原料,采用一种简单的直流电弧等离子体法成功制备了Mn_7C_3@C核壳型纳米粒子,用于高性能超级电容器的电极材料.所制备的Mn_7C_3@C核壳型纳米粒子平均直径为30~35nm.拉曼光谱结果显示石墨碳壳具有良好的导电性.通过循环伏安、恒电流充放电及电化学交流阻抗谱对Mn_7C_3@C核壳型纳米粒子电极材料进行电化学性能分析,结果表明其具有高比电容、快速充放电等优异的电化学性能.在扫描速率为1mV/s时,比电容最高可达185.8F/g.同时具有良好的循环稳定性,在100mV/s扫描速率下1 000次循环伏安测试后,比电容仍保持为最初的88%,与单纯Mn_7C_3(79%)相比,有明显提高.Mn_7C_3@C核壳型纳米粒子电极材料优异的电化学性能归因于其良好的核壳结构,富缺陷碳层具有良好的导电性,有助于离子的传输和结构的稳定,而内核Mn_7C_3主要产生赝电容,在C和Mn_7C_3的协同作用下产生双电层和赝电容双模式储能机制.     

MOFs材料对室内挥发性有机物吸附和光催化降解的研究进展

金属有机骨架材料(MOFs)由于其高孔隙率、高比表面积和高度可调的物理化学结构在气体吸附领域受到广泛关注.与此同时MOFs的类半导体特性也使其成为了光催化领域内的研究热点.本文将MOFs的吸附与光催化两种作用过程结合讨论,提出MOFs材料基于两种作用协同去除室内低浓度挥发性有机污染物的优势.从修饰MOFs的方法分类,综...     

ZnFe2O4@SiO2纳米核壳结构的合成及磁性随退火温度的演化

采用水热法合成了直径为10~15 nm的ZnFe2O4磁性纳米颗粒,将ZnFe2O4磁性纳米粒子添加到TEOS中,水解后得到ZnFe2O4@SiO2核壳结构的纳米复合材料,TEM图像证实了复合材料具有直径约为20 nm的核壳结构.制备出的ZnFe2O4磁性纳米粒子和ZnFe2O4@SiO2核壳结构纳米复合材料都表现出了顺磁性,温度低于800 ℃时ZnFe2O4磁性纳米粒子仍然具有顺磁性,温度高达580 ℃时ZnFe2O4@SiO2核壳结构纳米复合材料还是显示出了超顺磁性,这意味着ZnFe2O4和ZnFe2O4@SiO2磁性纳米粒子具有良好的磁稳定性.由于SiO2壳具有很好的亲水性和抗酸性,ZnFe2O4@SiO2核壳结构纳米复合材料未来可应用于磁疗法治疗癌症.     

金属有机框架在非均相催化中的载体效应

催化载体效应作为制备含少量稀有金属元素的高活性非均相催化剂的关键因素已被广泛研究.利用金属有机框架（MOFs）在孔径、电子状态和选择性吸附性能方面的可调控性，可研究其载体效应.目前，关于金属纳米粒子（NPs）负载的MOFs(M/MOFs)多相催化研究表明：MOFs载体可以通过载体效应极大地增强催化活性，调节产物的选择性，并且将MOFs用作载体，有利于用NPs制备新型高性能催化剂.文章报道了3种类型的载体效应，即分子筛效应、电荷转移效应和基质吸附效应，同时报道了它们在M/MOFs复合型催化剂上的应用表现.     

基于二氧化碳吸附脱附金属有机框架复合材料的制备

作为温室气体的二氧化碳其实是一种宝贵的资源,通过回收、固定、利用及其资源化不仅可以减少大气污染,还是"变废为宝"的一种有效途径。金属有机框架(MOFs)因其具有超高比表面积和巨大孔容等特点而被广泛应用于二氧化碳吸附脱附,但是因其脱附时需要很多额外能量,因此启发人们在合成MOFs材料时掺杂功能有机材料、引入混合配体或者直接用特定基团修饰,从而制备出拥有特定功能的MOFs材料。本文研究通过溶剂热法制备了掺杂聚多巴胺支撑银(PDA@Ag)于金属有机框架(Ui O-66)中的纳米晶体材料(PDA@Ag/Ui O-66);X射线衍射(XRD)、扫描电子显微镜(SEM)和元素面扫描分析等证实了成功制备出十四面体的纳米晶体材料(PDA@Ag/Ui O-66);热重分析(TGA)表明当引入PDA@Ag后,复合材料(PDA@Ag/Ui O-66)具有更好的热稳定性;通过CO2等温吸附/脱附试验发现,引入PDA@Ag后,复合材料的CO2吸附量反而下降,归因于PDA@Ag覆盖了Ui O-66的吸附位点,但脱附量相对增加了。     

金属-有机骨架(MOFs)的最新研究进展

作为一种新型的多功能分子基材料,金属-有机骨架化合物因其有机-无机杂化特性、结构上的有序性和可裁剪性、微孔性、特殊的光电磁性质及工业上的潜在运用而备受关注。它作为多孔材料,与无机或有机的多孔材料相比具有特殊的优势,是目前新功能材料研究领域的一个热点。文中概述了近些年发展起来的新兴领域:金属-有机骨架薄膜,发光金属-有机骨架材料及纳米级金属-有机骨架材料,对它们的研究进展及设计合成进行了总结。     

Preparation of porous chitosan-poly（acrylic acid）- calcium phosphate hybrid nanoparticles via mineralization

In this work, the preparation of chitosan-poly（acrylic acid）-calcium phosphate hybrid nanoparticles （CS-PAA-CaP NP） based on the mineralization of calcium phosphate （CAP） on the surface of chitosan-poly （acrylic acid） nanoparticles （CS-PAA NPs） was reported. CS-PAA-CaP NPs were achieved by directly adding ammonia to the aqueous solution of CS-PAA nanoparticles or by thermal decomposition of urea in the aqueous solution of CS-PAA nanoparticles, resulting in the mineralization of CaP on the surface of CS-PAA NPs. Through these two routes, especially using urea as a pH-regulator, the precipitation of CS-PAA NPs, a common occurrence in basic environment, was avoided. The size, morphology and ingredient of CS-PAA-CaP hybrid nanoparticles were characterized by dynamic light scattering （DLS）, transmission electron microscope （TEM）, scanning electron microscope （SEM）, thermogravimetry analysis （TGA） and X-ray diffractometer （XRD）. When urea was used as the pH regulator to facilitate the mineralization during the thermal urea decomposition procedure, regular CS-PAA-CaP hybrid nanoparticles with a porosity-structural CaP shells and 400-600 nm size were obtained. TGA result revealed that the hybrid NPs contained approximately 23% inorganic component, which was consistent with the ratio of starting materials. The XRD spectra of hybrid nanoparticles in- dicated that dicalcium phosphate （DCP： CaHPO4） crystal was a dominant component of mineralization. The porous structure of the CS-PAA-CaP hybrid NPs might be greatly useful in pharmaceutical and other medical applications.     

Green synthesized ZnO nanoparticles against bacterial and fungal pathogens

Zinc oxide nanoparticles are known to be one of the multifunctional inorganic nanoparticles with effective antibacterial activity. This study aims to determine the antimicrobial efficacy of green and chemical synthesized ZnO nanoparticle against various bacterial and fungal pathogens. Various microbiological tests were performed using varying concentrations of green and chemical ZnO NPs with sizes 40 and 25 nm respectively. Results prove that green ZnO nanoparticles show more enhanced biocidal activity against various pathogens when compared to chemical ZnO nanoparticles. Also effectiveness of nanoparticles increases with increasing particle dose, treatment time and synthesis method. In addition, the current study has clearly demonstrated that the particle size variation and surface area to volume ratio of green ZnO nanoparticle are responsible for significant higher antimicrobial activity. From the results obtained it is suggested that green ZnO NPs could be used effectively in agricultural and food safety applications and also can address future medical concerns.     

Gas-Solution Interface Technique as a simple method to produce inorganic microtubes with scroll morphology

Over the past decade, numerous studies have dealt with new properties of inorganic nanomaterials with improved characteristics due to a particular morphology, and new facile methods to produce such materials have been reported. Inorganic microtubes can be designed for multifunctional materials with highly specific surface area. These microtubes can act as individual on-chip components of miniature devices or off-chip micromachines. The paper first discusses the main regularities of the reactions at the gas-solution interface and then goes on to present the basic principles of the Gas-Solution Interface Technique(GSIT), thus demonstrating a new way of facile synthesis of inorganic rolled-up microtubes. A distinctive feature of the technique is the formation of a gradient solid layer on the surface of the aqueous solution as a result of the gaseous and liquid reagents interaction. When dried in the air, this thin layer is capable of self-folding into microtubes with specific morphology. The paper considers the specific features of microtubes obtained by GSIT from numerous classes of inorganic compounds, including oxides, hydroxides, sulfides, fluorides. Further areas of possible practical applications of GSIT microtubes are discussed. The prospects of future development of the GSIT are outlined.     

Chiral inorganic nanostructures for theranostics

Inorganic chiral nanomaterials have attracted wide attention because of their superior physical properties and chiroptical activities. Great progress in chiral nanostructure preparation has been made, such as noble metals and semiconductors. In this review, we introduce several chiral nanomaterials with feasible biocompatibility and low cytotoxicity that are promising candidates for biological applications, and we focus on their preparation in terms of their circular dichroism (CD) effects and circular luminescence properties. Additionally, we summarize the working function of chiral nanostructures toward some common diseases with high prevalence, such as Alzheimer’s disease (AD), Parkinson’s disease (PD), diabetes and even cancers. The introduction of inorganic chirality will provide a novel way to diagnose and treat these diseases.     

层状双氢氧化物纳米材料的研究进展

层状双氢氧化物(LDHs)的成分可以在较大范围内调控、特殊的结构和性质以及有着广泛的应用前景,层状双氢氧化物纳米材料的研究吸引了国内外众多学者的关注。本文首先介绍了LDHs的化学组成和结构特点,然后综述了LDHs纳米材料的制备、结构表征及性能等方面的国内外最新研究进展,并阐述了纳米晶植入LDHs主体的复合材料的相关研究,最后对其应用前景进行了展望。     

铜纳米材料的制备及应用研究进展

铜纳米材料因具有独特的性质,被广泛应用于抗磨自修复润滑剂、导电浆料、高效催化剂、抗菌剂等领域.本文综述了目前纳米铜及其复合材料的制备及应用研究进展.主要论述了制备纳米铜的化学方法,包括液相还原法、微乳液法、溶剂热法和其他方法.按照铜与无机物或有机物复合两大类,论述了铜纳米复合材料的制备方法及性能应用.讨论了铜纳米材料的摩擦学性能、抗菌性能、催化性能及光电性能.并对纳米铜及复合材料的制备和应用进行了总结与展望.     

纳米稀土金属有机框架材料的合成及其生物医学应用研究进展

近年来,纳米稀土金属有机框架(MOF)材料的合成及其在生物医学,特别是在肿瘤诊断和治疗方面的应用研究引起了科学家们广泛的关注.一方面,纳米稀土MOF具有独特的光学和磁学性质,可用于生物成像(如荧光成像和磁共振成像等);另一方面,纳米稀土MOF的组成和结构多样,且具有高的比表面和大的孔容,是具有潜力的药物控释载体.这种集多种功能于一身的纳米稀土MOF为开发新型的诊疗一体化试剂提供了一个新的平台.介绍了近年来纳米稀土MOF的合成及其在生物医学方面的应用的研究进展.     

Performance improvement of hybrid polymer membranes for wastewater treatment by introduction of micro reaction locations

This article reviews the progresses on polymer membranes embedded with novel inorganic nanomaterials to provide micro reaction locations (MRLs) in the polymer matrices for wastewater treatment. Ultrafiltration (UF) membranes, especially polyvinylidene fluoride (PVDF) and polysulfone (PSF) membranes, are broadly applied in wastewater treatment. The strategy of embedding functional nanomaterials into the polymer matrices has been extensively investigated to enhance the integrated properties of polymer membrane. Nevertheless, the performance enhancement just comes from physical interactions between nanomaterials and wastes, while the chemical interactions are not involved, thus limiting further improvements. In order to further enhance the integrated properties of polymer membranes, functional inorganic nanomaterials that can chemically react with the wastes are proposed and embedded into the polymer membranes to form many MRLs. In this paper, the strategies for embedding functional nanomaterials such as sulfated TiO₂ deposited SiO₂ nanotubes, solid superacid porous ZrO₂ shell/void/TiO₂ core particles and porous Y_xFe_yZr_1-x-yO₂ coated TiO₂ solid superacid nanoparticles in polymer membranes were presented and the enhancement effect of MRLs on their integrated properties for wastewater treatments was discussed. Therefore, polymer membranes embedded with functional inorganic nanomaterials with MRLs are potentially applied in various wastewater treatments.