纳米纤维素复合相变储能气凝胶制备进展

超轻质材料气凝胶具有超低密度、高比表面积等性能,是高分子材料领域的研究热点之一.综述了纤维素气凝胶的制备、纤维素复合相变储能材料的制备等.纳米纤维素特殊的物性及其模板效应,以纳米纤维素为软模板,自组装制备纳米纤维素复合相变储能气凝胶.探讨了纳米纤维素复合相变储能气凝胶的应用趋势.     

无机-有机核壳结构纳米复合粒子研究进展

采用耦合剂、LBL等技术,通过模板反应、乳液聚合等制备了无机-有机核壳结构纳米粒子。结果表明,无机纳米粒子能均匀分散在有机体中,或包覆于有机物的外层,有效防止了纳米粒子的团聚;该类材料不仅具有核、壳两类材料的性能,也具有某些独特的性能,其在光、电、磁及光催化等领域具有良好的应用前景,应加强该类材料的制备和应用技术研究,挖掘其潜在价值。     

聚酰亚胺/无机粒子复合材料的制备及其性能研究进展

综述了聚酰亚胺(PI)与无机粒子复合的研究进展,着重介绍了复合材料的溶胶-凝胶法、插层复合法、机械共混法三种制备方法。将PI与无机材料复合可得到集有机材料和无机材料优异性能于一体的复合材料,改善了传统PI存在的不足。无机粒子改性后的PI在不明显降低材料的热性能和力学性能的同时富集了无机小分子高模量、耐氧化、耐摩擦等性能,优化了材料的性能。引入无机纳米粒子,材料的内部分子堆积、相互作用等发生改变,对气体的选择透过性有很大的改善。改性后的PI具有可控的介电性能、膨胀性能等。     

基于偶氮苯的超分子凝胶材料的研究进展

基于偶氮苯的光响应型凝胶对光刺激可以保证连续性和精确性感知, 并在刺激过程中有显著的响应行为性, 是目前研究最多的光响应材料之一。本文将含偶氮苯的凝胶体系分成超分子有机凝胶、超分子水凝胶、超分子凝胶体系和有机无机杂化型体系, 较系统地综述了近三年来基于偶氮苯的光响应型超分子凝胶的结构特点和研究进展。重点阐述了凝胶因子的分子大小和形态, 涵盖了小分子、树枝状大分子、嵌段共聚物、超支化分子等;分析了发挥自组装驱动力的超分子之间的作用, 涵盖了氢键、静电相互作用、π-π作用、疏水效应等;总结了自组装聚集形态的构造, 涵盖了胶束、囊泡、纤维束、纳米棒等;最后展望了各类凝胶体系在光控开关、药物释放、生物材料等领域的应用前景。     

浅谈纳米PVC的开发

一、概论 纳米塑料是指聚合物纳米复合材料，即由纳米尺寸的超细微无机：粒子填充到聚合物基体中的复合材料。聚合物复合材料将有机聚合物的柔韧性好、密度低、易于加工等优点与无机填料的强度和较高硬度颗粒复合后得到具有高抗冲高强度的PVC树脂。由于有一种组分是以纳米量级的微粒参与复合，以接近分子水平的微粒复合于基质中。     

有机-无机纳米复合材料的制备及其在膜技术中的应用前景

无机-有机纳米复合材料综合了无机、有机和纳米材料的优良特性,形成重要的多功能新材料,在许多领域具有广阔应用前景.本文介绍了无机-有机纳米复合材料的几种主要制备方法,着重强调了由溶胶凝胶法制备的该类材料在膜技术中的应用情况,最后指出该类材料在膜技术中的应用前景.     

超分子聚合物纳米复合材料的研究进展

超分子聚合物纳米复合材料作为一种有别于传统聚合物基纳米复合材料的新型纳米复合材料而深受人们的重视。本文综述了纳米碳材料类超分子纳米复合材料的研究进展,并着重评述了无机-聚合物和金属-聚合物类超分子纳米复合材料的研究进展,并对其它的超分子纳米复合材料的研究现状作了介绍。     

分子间自组装盘状液晶材料研究进展

综述了近十年来国内外报道的分子间自组装盘状液晶的研究进展;重点阐述了通过分子间氢键或金属离子配位键自组装的盘状液晶小分子和超分子液晶的液晶性能、掺杂了无机纳米粒子的通过氢键形成的液晶材料的光电性能及其在有机光伏器件中的应用;最后总结了不同类分子间自组装盘状液晶的性能优势。综合文献报道可知,引入分子间氢键或配位键可以更好地实现盘状液晶在特定功能材料中的应用,并且自组装的盘状液晶还可与纳米粒子形成复合物,得到具有特定功能的纳米复合材料。     

纳米粒子改性聚酰亚胺现状及进展

由于聚酰亚胺(PI)材料存在亲水性较弱、加工成型性较难、电导率较低等缺陷，需要通过纳米粒子改性聚酰亚胺改善其性能。基于不同纳米粒子改性聚酰亚胺，综述并评论了国内外聚酰亚胺纳米复合材料的研究现状，阐述了有机纳米粒子(CNC、FEP)、无机纳米粒子(陶瓷材料、金属纳米粒子、蜂窝芯材)、有机-无机纳米粒子(POSS、MWCNTs-COOH、OGO)复合改性聚酰亚胺性能的原理和效果，分析了聚酰亚胺复合杂化过程中面临的问题和改进方法，结合目前聚酰亚胺复合材料发展集中在合成工艺改进、填料优化改性等方面的研究趋势，提出了聚酰亚胺未来的研究方向。     

橡胶纳米填料复合材料研究进展

纳米复合材料是指分散相尺寸至少有一维是在１～１００ｎｍ之间的复合材料。由于纳米相尺寸效应、大的比表面积以及强的界面相互作用,使得纳米复合材料的性能极大地优于相同组分的常规复合材料。因此,制备纳米材料是获得高性能复合材料的重要方法之一,也成为世界各国近年来纷纷进行的热门研究方向。美国的“星球大战计划”、“信息高速公路”,欧共体的“尤里卡计划”,以及我国的“８６３计划”,都把制备纳米材料列为重点发展项目。一、纳米粒子的特性当粒子尺寸进入纳米数量级时,粒子就会产生包括表面效应、体积效应和ｋｕｂｏ效应等…     

Role of non-functionalized oxide nanoparticles on mechanical properties and toughening mechanisms of epoxy nanocomposites

Over the past few decades, the use of epoxy resins has gained significant attention from worldwide researchers due to its advantages in structural applications in various sectors like automotive, construction, and aerospace industries. This article summarizes and reviews the research on mechanical properties and toughening mechanism of epoxy composites filled with non-functionalized oxide nanoparticles. The incorporation of nanomaterials into the polymer matrix has been considered to be the most effective route to improve the mechanical properties of polymer composites. But the inherent brittle nature and cross-linking ability of epoxy makes it vulnerable to crack initiation and crack growth and limits its use in advanced structural applications. Recently, various kinds of nanofillers such as carbon nanotubes (CNTs), organic and inorganic oxide nanoparticles have attracted industrial interest due to their excellent mechanical, thermal, and electrical properties which can provide a dramatic improvement in the properties of epoxy composites but their dispersion issue, agglomeration and bundling problems deteriorate several important mechanical parameters of the epoxy composites. To date, no review article focused on the role of non-functionalized oxide nanoparticles on the improvement in mechanical properties of the reinforced epoxy composites. This review article assesses and summarizes some most recent findings on the de-agglomeration process, mechanical properties, and toughening mechanisms of epoxy nanocomposites reinforced with four types of most preferred non-functionalized oxide nanoparticles such as Al₂O₃, TiO₂, SiO_2, and ZrO₂.     

Regenerated cellulose aerogel: Morphology control and the application as the template for functional cellulose nanoparticles

This article focuses on controlling the morphology of regenerated cellulose aerogel (RCA) and its application as a template for the preparation of functional cellulose nanoparticles (FCNPs). RCA is prepared by lyophilizing cellulose hydrogel which is fabricated through a sol–gel method in sodium hydroxide (NaOH)/urea aqueous solution. The morphology of RCA is adjusted by varying the gelation temperature and time. With the gelation temperature and time increasing, lamellar RCA transforms into strings of cellulose nanoparticles. Subsequently, RCA with the morphology of "strings of nanoparticles" is modified through the bulk condensation of l -lactic acid and RCA. Eventually, the prepared functionalized RCA (FRCA) is dispersed in an organic solvent to obtain purified FCNPs. The results demonstrate that single FCNP can be obtained by dispersing FRCA in dimethyl sulfoxide. Moreover, the prepared FCNPs have uniform size, good thermal-stability, and increasing hydrophobicity, which are ideal candidates for polymer composites in terms of fillers.     

纳米材料改性水性聚氨酯研究进展

综述了近几年纳米材料对水性聚氨酯的改性研究,包括天然高分子纳米材料改性、黏土矿石类纳米材料改性、纳米碳素材料改性、金属与金属氧化物纳米材料改性。化学改性能提高纳米材料与聚合物基质间的相容性,有利于得到稳定的复合乳液。物理共混改性能更好地将纳米材料的优异特性赋予复合材料。在水性聚氨酯中均匀分散的纳米粒子可以显著提高复合材料的热稳定性与力学性能。开发高效实用的纳米材料有机化改性技术和优化复合材料的制备工艺将是未来制备高性能水性聚氨酯纳米复合材料的发展趋势。     

Effect of morphology on the permeability,mechanical and thermal properties of polypropylene/SiO2 nanocomposites

Spherical silica nanoparticles with 20 and 100 nm diameters and organic‐template layered silica nanoparticles synthesized by the sol‐gel method were melt blended with a polypropylene (PP) matrix in order to study and quantify their effect on the oxygen and water vapor permeability and mechanical and thermal behavior. With regard to barrier properties, the spherical nanoparticles barely increased the oxygen permeability at low loads (≤10 wt%); meanwhile the layered nanoparticles dramatically increased it even at low loading (<5 wt%) probably due to the percolation effect. The changes in water vapor permeability were similar to those in oxygen permeability. The repulsive interaction between nanoparticles and PP forms interconnecting voids where the gas permeates. Tensile stress–strain tests showed that the composites present up to a 56% increase in the elastic modulus with spherical nanoparticles at 20 wt%, while layered nanoparticles show a decrease probably due to agglomerations and voids. Thermogravimetric analysis under inert conditions showed that the nanoparticles improved the PP thermal degradation process through the adsorption of volatile compounds on their surface, where the smaller spherical nanoparticles show the greatest stabilization. © 2015 Society of Chemical Industry     

Prussian Blue: A Nanozyme with Versatile Catalytic Properties

Nanozymes, nanomaterials with enzyme-like activities, are becoming powerful competitors and potential substitutes for natural enzymes because of their excellent performance. Nanozymes offer better structural stability over their respective natural enzymes. In consequence, nanozymes exhibit promising applications in different fields such as the biomedical sector (in vivo diagnostics/and therapeutics) and the environmental sector (detection and remediation of inorganic and organic pollutants). Prussian blue nanoparticles and their analogues are metal–organic frameworks (MOF) composed of alternating ferric and ferrous irons coordinated with cyanides. Such nanoparticles benefit from excellent biocompatibility and biosafety. Besides other important properties, such as a highly porous structure, Prussian blue nanoparticles show catalytic activities due to the iron atom that acts as metal sites for the catalysis. The different states of oxidation are responsible for the multicatalytic activities of such nanoparticles, namely peroxidase-like, catalase-like, and superoxide dismutase-like activities. Depending on the catalytic performance, these nanoparticles can generate or scavenge reactive oxygen species (ROS).     

In situ preparation of magnetite/cuprous oxide/poly(AMPS/NIPAm) for removal of methylene blue from waste water

In situ techniques have attracted great attention for the formation of nanomaterials with controlled sizes, shapes and dispersion within supramolecular hydrogels. In the present work, the doping of copper oxides onto magnetite nanoparticles into hydrogels based on sodium 2‐acylamido‐2‐methylpropanesulfonate (AMPS) and N‐isopropylacrylamide NIPAm copolymers was investigated. The contents, morphology and thermal stability of magnetite, cupreous oxide and doped copper oxides onto the magnetite nanoparticles were evaluated. The optimum conditions for removal the cationic dye methylene blue (MB), such as solution pH, concentration of adsorbents, contact time and stirring time, were determined to investigate the effect of MB concentrations on the removal efficiencies of the prepared adsorbents. The recyclability of the prepared AMPS/NIPAm composites for the removal of MB was examined for up to six cycles without changes in removal effectiveness. © 2018 Society of Chemical Industry     

硫化物光催化剂的形貌控制及光催化性能的研究进展

无机纳米材料的结构、维度、形貌、尺寸等因素对它们的功能性能有着直接影响。CdS、ZnS以及其复合纳米材料在光、电、磁、催化和力学等方面有着特殊的性能,这与晶体形态和形貌紧密相关,因此制备可控粒度、形状、取向的CdS等硫化物半导体纳米材料,研究其结构、形貌对光催化性能的影响,对新型高效光催化材料的研究与开发具有重要的意义。本文重点介绍了近几年硫化物形貌和粒径的控制的研究进展以及此类光催化剂在光催化分解水制氢和降解有机染料等方面的应用。     

色氨酸辅助合成光催化活性增强的球形纳米TiO2

以L-色氨酸（L-Trp）为生物模板,采用简单水解及煅烧后制备了球形结构TiO₂纳米光催化剂。通过X射线衍射、扫描电子显微镜、红外光谱、紫外-可见漫反射光谱、光致发光光谱和N₂吸附-解吸等方法对制得的TiO₂纳米材料进行表征。在催化剂合成过程中,L-Trp作为生物模板发挥至关重要的作用,能够指导球形结构纳米TiO₂的形成。考察了不同煅烧温度下制备的TiO₂样品光催化活性,结果表明550℃时制备的TiO₂样品具有优异的光催化活性,紫外光照射30min对甲基橙溶液的降解率达到95%左右,主要是由于较大比表面积和球形结构的协同效应。光催化剂稳定性实验表明,所制备的TiO₂纳米材料可作为一种实用有效的光催化剂用于紫外光照射下降解有机染料。同时,对L-Trp辅助下球形结构TiO₂纳米颗粒的可能生长机理进行讨论。     

Synthesis of hybrid Pt/TiO2 (anatase)/MWCNTs nanomaterials by a combined sol–gel and polyol process

In the present study, hybrid Pt/TiO₂/MWCNTs nanomaterials are prepared successfully by a combined sol–gel and polyol process. The as-prepared nanomaterials are characterized by X-ray diffraction, high resolution transmission electron microscopy, and thermogravimetry analysis. In addition, its catalytic performance by converting CO into CO₂ is also evaluated. Experimental results show that the hybrid Pt/TiO₂/MWCNTs nanomaterials exhibit a mixture of anatase TiO₂ and Pt phases. Multi-wall carbon nanotubes serve as an excellent supporting material where anatase TiO₂ nanoparticles are decorated with well-distributed Pt nanoparticles. Excellent catalytic performance can be revealed for the hybrid Pt/TiO₂/MWCNTs nanomaterials. When compared with its Pt/TiO₂ counterparts where ～ 100% CO conversion occurred at 150 °C, almost 100% conversion of CO into CO₂ can be observed at a temperature ranged from 30 °C to 100 °C.     

Block copolymer–nanoparticle composites: Structure,functional properties,and processing

The incorporation of nanoscopic particles into ordered nanostructures afforded by block copolymers can provide control over particle distribution and orientation. This could enable the development of engineered nanomaterials that have enhanced properties such as mechanical, optical, electrical, or barrier. Deployment of large scale processing methods is necessary for the successful technological exploitation of the functional properties of nanoparticle-containing block copolymer hybrids. To this end, fundamental knowledge of the local structure, hierarchical morphology, structure-property relations, and influence of processing on all these is essential. This review addresses these issues. The successful localization of nanoparticles in ordered block copolymer matrices as well as the overall properties of the block copolymer–nanoparticle composites depend on the features of nanoparticles and of block copolymers, and can be modulated by the addition of small molecules. Incorporation of nanoparticles in block copolymers can be achieved by melt-mixing, solvent-based processing, or a combination of these two. Subsequent application of external fields such as shear, thermal, electrical, or magnetic can further improve the long-range internal structure and the functional properties of block copolymer–nanoparticle composites.