原位沉析法制备有序排列四氧化三铁/壳聚糖纳米复合材料的研究

生物矿物由于具有完美结构及独特的生物活性,使其成为制备新型有彬无机杂化纳米复合材料的思想来源,在目前制备的有机／无机纳米复合材料中,纳米粒子在聚合物基质中大部分是无规分散的,但无机纳米颗粒在有机物中的有序排列是生命体中的一种根本体现,有序排列会使材料的性能更加优异。人骨的主要成分是纳米羟基磷灰石晶体和胶原,羟基磷灰石晶体是沿着胶原纤维的长轴方向有序排列的,这使得人骨不仅具有生物活性,而且具有非常好的力学性能。     

聚合物基无机纳米复合材料的制备方法Ⅰ.原位生成法

无机纳米颗粒因其巨大的表面能有很强的团聚趋势,用常规复合方法难以制得聚合物基无机纳米复合材料。本文对聚合物基无机纳米复合材料的复合形式和制备方法进行了探讨,分为两篇对原位生成法,直接分散法,同时形成法的原理和方法进行综论。本篇主要讨论原位生成法的基本原理,关键技术和制备过程。     

基于介孔分子筛MCM-41“有机-无机”互穿结构纳米复合材料体系研究

采用硅烷偶联剂KH550对介孔分子筛MCM-41内、外表面进行改性,并利用氮气吸附-脱附,傅里叶红外光谱以及小角X衍射等进行表征,其结果显示KH550分子被引入MCM-41纳米孔道中,且—NH_2基团成功嫁接到MCM-41纳米颗粒表面.凝胶液相色谱实验结果证实本文中采用的双酚A型环氧树脂为低分子量环氧.随后,采用原位聚合的方法制备不同MCM-41含量环氧树脂纳米复合材料.最后,利用正电子湮没寿命谱测量复合材料自由体积孔洞;利用透射电镜,动态热机械分析和交流击穿对复合材料宏观性能进行研究.复合材料超薄切片TEM观察结果显示,在低MCM-41添加含量时,MCM-41颗粒可在复合材料中良好分散.同时,环氧分子在外施作用力和硅烷偶联剂功能作用下引入纳米孔道,形成"有机-无机"互穿结构复合材料体系,增强MCM-41和环氧树脂间相互作用力,在低MCM-41添加含量下提高复合材料玻璃化温度(15.1%↑)和击穿电压(22.6%↑).     

聚合物基无机纳米复合材料的制备方法Ⅱ.直接分散法和同时形成法

聚合物基无机纳米复合材料制备的关键问题是无机纳米粒子在聚合物基体中保持其纳米尺度的分散,本文主要讨论直接分散法、同时形成法制备聚合物基无机纳米材料的基本原理和技术要点。     

稀土掺杂上转换纳米颗粒-金属有机骨架复合材料的研究进展

稀土掺杂上转换纳米颗粒-金属有机骨架复合材料是一类新型的功能复合材料. 它不仅结合了稀土掺杂上转换纳米颗粒和金属有机骨架这两种材料的特性, 体现了两者复合后的协同效应, 还具有设计灵活和功能易拓展等优势. 本文聚焦稀土掺杂上转换纳米颗粒-金属有机框架复合材料的最新发展, 总结了该类复合材料的制备方法, 介绍了其在生物和催化等领域的应用, 并对其面临的挑战和发展前景进行了展望.     

高抗冲聚苯乙烯/粘土纳米复合材料的制备、热稳定性及流变性能

用双螺杆挤出共混法制备了高抗冲聚苯乙烯 (HIPS) 有机蒙脱土 (Org MMT)插层纳米复合材料以及HIPS 无机蒙脱土 (MMT)常规复合材料 .分别用TGA和毛细管流变仪研究了它们的热性能与流变性能 ,并比较了两种结构材料的性能差异 .结果表明 ,纳米复合材料比纯HIPS和常规的复合材料具有更好的热稳定性和流动性 ,前者具有更强的剪切变稀行为 .此外 ,当蒙脱土达到纳米级分散时 ,复合材料的表面也变得更加平整光滑 .     

有机/无机纳米复合材料的研究进展

有机／无机纳米复合材料以其优异的性能越来越受到人们的关注。本文分析总结了有机／无机纳米复合材料的制备方法、性能及其应用,着重介绍了溶胶一凝胶法和原位聚合法。参考文献28篇。     

细乳液聚合法制备有机/无机纳米复合材料

无机纳米粒子的引入可以使聚合物材料获得抗菌、导电和防紫外等诸多特性,但无机纳米粒子在聚合物基质中易团聚、引入量少,难以充分发挥其优点。细乳液聚合法基于其独特的成核方式--液滴成核,能够提高无机纳米粒子在聚合物基中的分散性和引入量,且复合材料的形貌易于控制,是目前制备特殊形貌有机/无机纳米复合材料的一种有效手段。本文介绍了有机/无机复合纳米材料的细乳液制备过程,综述了近年来不同无机纳米粒子与有机基质复合的研究进展,例如：纳米SiO₂、纳米ZnO、金属纳米粒子、纳米氧化石墨烯等。最后就其发展现状提出了几点建议。     

聚集诱导发光有机小分子无机纳米复合材料的研究进展

有机-无机复合荧光纳米材料制备简便,生物相容性好,成像性能优异,在化学和生物传感、生物成像、催化及能源材料等领域受到很多关注.传统的荧光有机小分子与无机材料复合时,常发生荧光猝灭,而聚集诱导发光(Aggregation-InducedEmission,AIE)有机小分子在聚集态具有高发光量子产率,为有机-无机复合荧光纳米材料的研究提供了机遇.由于AIE有机小分子功能化的无机纳米材料独特的优点,人们对其设计、合成及应用进行了较多研究.综述了AIE有机小分子和多种类型的无机纳米结构(金属纳米颗粒、钙钛矿材料、层状材料、氧化物、硫化物等)复合材料的制备和应用的新进展,特别是在化学和生物传感、生物成像、药物输运、光热治疗、催化以及能源等领域的应用,并对其发展前景进行了展望.     

聚酰亚胺/纳米MgO复合材料的制备与性能研究

采用直接分散法将纳米MgO颗粒均匀分散在聚酰胺酸溶液中,经旋涂、热亚胺化制得聚酰亚胺/纳米MgO复合材料.利用傅里叶变换红外光谱(FTIR)、X射线衍射(XRD)、扫描电子显微镜(SEM)、紫外可见光谱(UV-Vis)、热重分析(TGA)和纳米划痕等测试技术对复合材料的结构和性能进行了表征.结果表明,平均粒径约为20 nm的纳米MgO颗粒均匀地分散在聚酰亚胺基体中,有机无机两组分相容性良好;复合材料在可见光区具有优良的光学透明性,在近紫外光区随着纳米MgO含量的增加呈现出了显著的紫外屏蔽性能;纳米MgO的加入能大幅提高复合薄膜的抗划伤性能,在100μN的划痕力下,划痕深度由纯聚酰亚胺的57.4 nm降至10 nm左右,且划痕的宽度也明显减小;尽管复合材料的热稳定性能较纯聚酰亚胺略有下降,但在300℃以下仍具有较好的热稳定性.     

Transparent flexible ZnO/MWCNTs/pbma ternary nanocomposite film with enhanced mechanical properties

Functional organic-inorganic nanocomposites with high transparency show significant potential application in many fields. However, it is still a great challenge to prepare flexible transparent nanocomposites due to the intrinsic stiffness of the nanoparticles and the poor interaction between nanoparticles and organic matrices. In this work, a transparent ternary nanocomposite film with enhanced mechanical performance is fabricated by two-steps. First, the transparent ternary ZnO/MWCNTs/n-butyl methacrylate (BMA) nanodispersion is prepared by mixing the ZnO/BMA and MWCNTs/BMA dispersions directly. Then, the ternary nanocoposites film is fabricated via in-situ bulk polymerization of the above nanodispersions. As a result, the tensile strength of the ZnO/MWCNTs/poly-n-butyl methacrylate (PBMA) ternary film is enhanced by 42% and the elongation at break is three times that of ZnO/PBMA nanocomposite. The hardness of the film increases from 5B to 1H with 40 wt% ZnO. These results indicate that ZnO and MWCNTs can improve the mechanical properties of the composite significantly. Importantly, the ternary nanocomposite film still remains high transparency and exhibit excellent UV-shielding performance. The as-prepared transparent multifunctional nanocomposite films have promising applications in optical materials and devices, such as optical filters, contact lenses and protection packing.     

反胶束模板制备聚甲基丙烯酸甲酯/无机纳米粒子/石墨纳米复合材料及其表征

以甲基丙烯酸甲酯(MMA)和三氯甲烷(CHCl₃)为油相制备反胶束微乳液, 依靠表面活性剂十六烷基三甲基溴化铵(CTAB)自组装形成的“微反应器”作为模板成功地制备了PMMA/Eu(OH)₃/EG和PMMA/Ni(OH)₂/EG纳米复合材料. 并用红外光谱(IR)、扫描电镜(SEM)、透射电镜(TEM)、X射线衍射(XRD)和差热-热重(TG-DTA)对该复合材料进行了表征和分析. 研究结果表明, 反胶束法可以有效地应用于有机-无机纳米复合材料的制备.     

Transparent poly(bisphenol A carbonate)-based nanocomposites with high refractive index nanoparticles

Transparent organic-inorganic nanocomposites were successfully synthesized from sulfonic acid-modified poly(bisphenol A carbonate) (SPC) and TiO₂ or ZrO₂ nanoparticles. The dispersibility of nanoparticles was significantly improved by both the surface treatment of nanoparticles with phosphoric acid 2-ethylhexyl esters (PAEH) and the introduction of a sulfonic acid moiety into the PC chain. It was found that in some cases, crystallization of the matrix caused a reduction in transparency. Efficient dispersion of nanoparticles and the absence of crystallization resulted in highly transparent nanocomposites with up to 42 wt% TiO₂ and 50 wt% ZrO₂ nanoparticles. The refractive indices of the nanocomposites based on SPC increased with the increasing amount of nanoparticles. Theoretical equation based on Maxwell-Garnett effective medium theory provided reasonably close estimation of the refractive indices to the experimentally observed values. The prepared nanocomposites had lower thermal stability than the host matrix polymers.     

Functional inorganic nanofillers for transparent polymers

The integration of inorganic nanoparticles into polymers has been used for the functionalization of polymer materials with great success. Whereas in traditional polymer composites, micron sized particles or agglomerates typically cause significant light scattering hampering optical applications, in nanocomposites the particle dimensions are small enough for the production of highly transparent composites. A challenge for the generation of such materials is to develop an integrated synthesis strategy adapting particle generation, surface modification and integration inside the polymer. Surface grafting using polymerizable surfactants or capping agents allows for linking the particles to the polymer. Novel techniques such as in situ polymerization and in situ particle processing are beneficial to avoid aggregation of inorganic particles inside the polymer matrix. The functions associated with inorganic fillers are widespread. Layered silicates and related materials are nowadays commercially available for improving mechanical and barrier properties in packaging. With the availability of highly transparent materials, the focus has shifted towards optical functions such as luminescence and UV-protection in transparent polymers. IR-active fillers are used in laser-holography for transparent poly(methyl methacrylate) (PMMA) nanocomposites. Refractive index modulation and ultrahigh refractive index films were developed based on inorganic materials such as PbS. The integration of magnetic nanoparticles has a great potential for applications such as electromagnetic interference shielding and magneto-optical storage.This tutorial review will summarize functions associated with the integration of inorganic nanofillers in polymers with a focus on optical properties.     

单分散双相可溶四氧化三铁纳米微粒的多醇法制备及磁性

以具有生物相容性的三嵌段共聚物聚氧乙烯-聚氧丙烯-聚氧乙烯为表面活性剂,利用多醇合成法制备了Fe3O4纳米微粒;采用X射线粉末衍射仪、傅立叶变换红外光谱仪及透射电子显微镜分析了Fe3O4纳米微粒的晶体结构、化学结构及显微结构,采用振动样品磁强计测定了其磁性能.结果表明,所制得的Fe3O4磁性纳米微粒结晶度高,在室温下显示近似超顺磁性.采用Langevin方程对Fe3O4纳米微粒的磁滞回线进行拟合,结果显示其为磁性单畴.此外,Fe3O4磁性纳米微粒在无机和有机溶剂中均具有很好的分散性,显示出广阔的应用前景.     

Ordered nanostructured ceramic–metal composites through multifunctional block copolymer-metal nanoparticle self-assembly

A novel strategy for fabrication of ordered ceramic–metal nanocomposites was demonstrated by multifunctional block copolymer/metal nanoparticle self-assembly. Hybrid organic–inorganic block copolymer poly(3-methacryloxypropyl-T8-heptaisobutyl-polyhedral oligomeric silsesquioxane-block-N,N-dimethylaminoethyl methacrylate) was synthesized and used as a bi-functional structure directing agent for ligand-stabilized platinum nanoparticles to form ordered organic–inorganic nanocomposites with dense loading of inorganic species in both microphase separated domains. Subsequently, thin films of the hybrid material were converted to ordered silica (ceramic)–platinum (metal) nanocomposites via UV-assisted ozonolysis. This is the first time ordered ceramic–metal nanocomposites were achieved through a bottom-up approach, opening up opportunities for the design and synthesis of a broad range of ordered inorganic–inorganic nanocomposites.     

Photochemical Method of Controlling Dispersity of Nanostructures of Transition Metals

Original methods of photochemical preparation of stable mono- (Cu, Ag, Au, Ni, Pd, Pt) and bimetallic nanoparticles in the form of optically transparent compact films on quartz surface and of volume dispersions in porous inorganic (silica glasses) and organic (MF-4SK fluorocarbon) materials, solid polymers (polyvinyl alcohol, polyethylene glycol, gelatin, latexes), and in liquid media (glycerol) are reviewed. The results of studies of spectral and structural characteristics of nanophase films under various experimental conditions are presented. Experimental mechanistic models and ways of controlling disperse composition of metal colloids, which can be used for photochemical synthesis of nanophase systems, are proposed.     

Fabrication of transparent Pu/Zro2 nanocomposite coatings with high refractive index

<正>Transparent ZrO_2-polyurethane nanocomposites with high refractive index were prepared by dispersing ZrO_2 nanoparticles in a polyurethane matrix via ligand molecule engineering.TEM showed that the inorganic particles were well dispersed within the polymeric network with no significant macroscopic agglomeration.By controlling the phase separation it was possible to obtain transparent zirconia nanostructured coatings,characterized by improved mechanical and thermal properties.UV-Vis spectra indicated that the coatings still maintained transparency in the visible light.The refractive index of the UV-cured films depends linearly on the ZrO_2 content and varies from 1.475 to 1.625(20 wt%) at 633 nm.These coatings could find advanced applications in coatings of optical and electronic devices.     

A novel poly-benzoxazinyl functionalized polyhedral oligomeric silsesquioxane and its nanocomposite with polybenzoxazine

The novel poly-benzoxazinyl functionalized polyhedral oligomeric silsesquioxane macromonomer (BZ-POSS), containing 7.6 benzoxazine groups per molecule on average was synthesized from octaaminophenylsilsesquioxane, p-cresol and paraformaldehyde. BZ-POSS was well miscible with bisphenol A-based benzoxazine (BBZ) melt. By ring-opening copolymerization of BBZ and BZ-POSS under condition similar to that used for polymerizing neat BBZ, the transparent and uniform BBZ/BZ-POSS organic-inorganic hybrid nanocomposites were prepared. The nano-scale dispersion of POSS cores in the nanocomposite was verified by powder X-ray diffraction and transmission electron microscopy studies. Dynamic mechanical analyses and thermal gravimetric analysis indicated that thermal stabilities, cross-link densities and the flame retardance of the nanocomposites were increased in comparison with neat PBBZ resin, although only small amounts of inorganic POSS cores were incorporated into the systems. Structural analyses of BZ-POSS and BBZ/BZ-POSS nanocomposites are discussed herein.     

Molybdenum disulfide-polymer nanocomposite structures with different sequences of alternating inorganic and organic layers

The reactions of charge-transfer-activated molybdenum disulfide with polymers (polyethylene glycol, poly(ethylene oxide), poly(vinyl alcohol), and polyhexamethylene guanidine hydrochloride) produce nanocomposite compounds, the composition and structure of which are determined by the nature of activated MoS₂. In nanocomposites prepared in single-layer dispersions of molybdenum disulfide, the layers of inorganic and organic components regularly alternate. In nanocomposites, formed by the intercalation of the polymers into particles of nanocrystalline MoS₂, the polymeric molecules are accomodated within spaces between the layers of the inorganic matrix, resulting in the formation of microheterogeneous systems. The structures of these nanocomposite compounds were proposed based on the X-ray powder diffraction and electron microscopy data.