功能性POSS聚合物及其应用

多面体低聚倍半硅氧烷(POSS)是一类具有纳米分子尺寸和有机-无机杂化结构的化合物。这种以无机Si—O—Si键组成的框架为核,外围被有机取代基所包围的特殊结构,具有独特的物理性质和化学反应性。采用物理或共聚的方法使其与其他聚合物复合,得到具有特殊功能的有机/无机纳米复合高分子材料,可用于诸多领域,近年来备受关注。本文在介绍POSS分子结构特点的基础上,详细阐述POSS聚合物的合成方法、特点和功能性,着重讨论了POSS在超疏水表面与抗结冰涂层、两亲聚合物、形状记忆材料中的应用及研究现状,并展望了功能性POSS聚合物的发展前景。     

多面体齐聚倍半硅氧烷的合成及应用研究进展

多面体齐聚倍半硅氧烷(Polyhedral Oligomeric Silasesquioxane,POSS)本身作为一种分子水平上的纳米有机/无机杂化体,由于几乎能够改性所有传统材料而引起人们的极大关注。这种杂化体可以通过多种合成方法得到,为新型杂化材料的设计提供了便利。本文综述了近年来有关POSS的合成方法、POSS基聚合物的研究及其在电子材料、航空航天材料、多孔材料、发光材料等方面的应用研究进展并对其发展前景予以展望。     

多面齐聚硅倍半氧烷研究进展

总结了多面齐聚硅倍半氧烷的研究进展,主要介绍了它的合成方法、合成机理和应用,着重介绍了它在二氧化硅模型、树枝状大分子、多孔材料以及聚合物纳米杂化材料中的应用。     

树形大分子/金属配合物及其纳米复合材料的制备与性能研究进展

树形大分子是具有确定代数和末端基的蓬勃发展的新型合成高分子。大量具有不同的中心核、支链和末端基团的树形大分子已经被合成和应用于不同的领域,其功能化和应用是目前树形大分子研究领域的热点。本文综述了树形大分子/金属配合物及其纳米复合材料的制备与性能的研究进展,重点介绍了树形大分子/金属配合物材料和树形大分子/金属纳米复合材料的制备与性能研究的最新进展。     

带功能基的笼形倍半硅氧烷合成进展

笼形倍半硅氧烷(POSS)是基于化学键合作用而形成的分子内杂化体系,这种有着规整立体结构同时具有单纳米尺度的有机无机杂化分子引起了研究人员的广泛关注,独特的纳米笼形结构也为分子水平上改进高分子的科学研究提供了可能性.本文综述了多面体倍半硅氧烷(POSS)的结构、性能与合成方法,重点介绍了巯基POSS、金属杂化POSS、...     

聚合物纳米杂化材料的控制合成、自组装及功能化

聚合物纳米杂化材料的制备及功能化是当前国际前沿研究课题之一.特殊结构的聚合物可以通过分子间特殊相互作用,在纳米尺度上自发地组装成具有特殊结构和形态的集合体,这类材料在新材料、电子以及生物医学等领域具有广泛的应用前景.本文介绍国内外,特别是厦门大学在双亲性分子及嵌段共聚物的模板自组装、基于POSS单体纳米构筑单元以及POSS嵌段聚合物自组装的有机/无机纳米杂化材料、模板控制导电高分子材料纳米形态构筑等领域材料的可控合成和组装,与此同时对相关材料的性能及功能化应用进行了简要的讨论.     

新型生物医用材料: 肽类树枝状大分子及其生物医学应用

肽类树枝状大分子是近年来发展起来的一类新型生物医用高分子材料, 它在具有普通树枝状大分子的特征如规整性、高度支化、表面呈现高密度功能团、尺度为纳米级、通过可控制备可得到单一分子量等之外, 同时还具有类似蛋白一样的球状结构、好的生物相容性、水溶性、耐蛋白酶水解、生物降解等独特的性能. 肽类树枝状大分子的上述特点, 使其在生物医学应用中显示出诱人的前景. 本综述从肽类树枝状大分子的制备出发、详尽介绍了肽类树枝状大分子的功能化及其在疾病诊断和治疗中的应用等方面的研究进展, 籍此推动肽类树枝状大分子在生物医学领域的研究与开发.     

反应型POSS杂化纳米材料合成及其对聚合物的改性研究进展

多面体低聚笼型倍半硅氧烷(POSS)是一类分子内有机-无机杂化材料。该材料因为同时含有笼型的Si—O—Si核及键合在Si顶点上可设计的有机基团,所以兼具无机材料高的强度和耐温性以及有机基团灵活的可设计性,可广泛用于聚合物的改性。反应型POSS是指POSS上的有机基团与其改性聚合物有较高的反应活性,可以共价键合于聚合物分子链上,提高POSS在聚合物基体中的分散性,增强其界面粘接作用,更大程度提高聚合物的性能。本文综述了近年来反应型POSS的合成,POSS在聚合物增韧补强、耐热阻燃性能、介电性能改性等领域的研究进展,总结了POSS改善无机纳米粒子在聚合物改性体系分散性能方面的研究进展,并指出了今后的发展方向。     

POSS/聚氨酯复合材料结构与性能的研究进展

多面体低聚倍半硅氧烷(POSS)是新兴的有机/无机杂化材料,其特殊的笼状结构可以从纳米尺度上影响聚氨酯体系的结晶行为、微相分离程度、交联密度等结构特征。少量添加即可大幅提高聚氨酯的耐水性、热稳定性、力学性能,以及阻燃性能、黏结性能、韧性等。本文从POSS/聚氨酯复合材料的结构出发,介绍了化学合成POSS基聚氨酯及物理共混POSS/聚氨酯复合材料,总结分析了悬垂型、星型、串珠型以及物理混合POSS基聚氨酯复合材料的结构特点,以及POSS结构差异对其复合材料性能的影响与影响机理。     

笼型倍半硅氧烷及其在阻燃聚合物中的应用

笼型倍半硅氧烷(POSS)是一种新型的有机-无机杂化材料,是基于化学键作用形成的分子内杂化结构。由于其独特的分子结构,与聚合物复配后形成的杂化材料不但能够明显改善聚合物基体的力学性能、加工性能和光电性能,同时能够显著提高聚合物的耐热性能和燃烧性能。本文简要综述了POSS单体的结构特点及几种在阻燃聚合物中常用到的带有特种结构官能团POSS的合成方法,分析了POSS的加入对聚合物阻燃机理的影响,重点介绍了近年来POSS在阻燃聚合物中的应用研究进展,并展望了今后的研究方向和重点。     

Synthesis of new polyhedral oligomeric silsesquioxane derivatives as some possible antimicrobial agents

1,3-Dipolar cycloaddition reactions were studied to synthesize Polyhedral oligomeric silsesquioxane (POSS)-based norbornyl imide derivatives containing izoxazoline groups in good yields. And also 1,3-dipolar cycloaddition reactions of azomethine ylides with POSS-based norbornene dipolarophiles for a synthesis of the novel POSS-based norbornane-fused spiro-1,3-indandionolylpyrrolidines are reported. All newly synthesized POSS compounds were structurally characterized by FTIR, ¹H, ¹³C NMR, HRMS and GC/MS analyses.     

Dendrimers with electroactive units in the core or in each branching centre

Interest in dendrimers is mostly focused on their capability of performing specific functions which, in their turn, derive from the possibility of incorporating in predetermined sites of the structure selected functional groups (‘pieces of information’). From a topological viewpoint we can distinguish dendrimers containing electroactive units (a) in the core, (b) in the branches, (c) in the surface, (d) in the core and in the branches, (e) in the core and in the surface, (f) in the branches and in the surface, and (g) in the core, branches and surface. In this article we review the behaviour of dendrimers with electroactive units buried in the core and dendrimers with electroactive units in each branching centre investigated in our laboratory. To cite this article: M. Venturi, P. Ceroni, C. R. Chimie 6 (2003).     

树状高分子的功能化进展

介绍了近年来高分子化学领域中十分活跃的树状高分子的研究状况,对目前树状高分子的最新功能化进展进行了评述,着重介绍了具有光活性、电活性、生物活性的树状高分子,以及树状高分子与富勒烯的衍生物。     

Nanofabrication with metal containing dendrimers

Dendrimers are versatile building blocks for "bottom-up" nanofabrication because they combine molecular structure and nanoscale dimensions. Moreover, dendrimers can be functionalized at their numerous peripheral end groups, in their core, along their branches, and in the voids of their interior. This Frontier highlights the potential of metal containing dendrimers for nanofabrication.     

含倍半硅氧烷的杂化聚合物

从杂化材料的形成方式 ,说明含倍半硅氧烷类杂化材料是基于化学键合作用形成的分子内杂化体系 ,是一类新型高性能的有机_无机杂化材料。介绍了倍半硅氧烷的结构、合成方法及性能特点 ,重点阐述了多面齐聚倍半硅氧烷类杂化聚合物的性能特点及其发展趋势。     

Synthesis and characterization of fillers of controlled structure based on polyhedral oligomeric silsesquioxane cages and their use in reinforcing siloxane elastomers

Four polyhedral oligomeric silsesquioxane (POSS) cages with vinyl groups were linked to a central siloxane core by hydrosilylation. The goal was to obtain filler particles of sizes between those of the POSS cages themselves and the much larger silica particles typically used to reinforce elastomers. The hydrosilylation reaction was monitored with Fourier transform infrared spectroscopy and proton nuclear magnetic resonance, and the resulting structure was confirmed by mass spectrometry. Simply blending these POSS-based fillers into silanol-terminated poly(dimethylsiloxane) (PDMS) had little effect on the mechanical properties, but bonding them to PDMS provided considerable reinforcement. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 3314–3323, 2003     

Conformation and distribution of groups on the surface of amphiphilic polyether-co-polyester dendrimers: effect of molecular architecture

Amphiphilic polyester-co-polyether (PEPE) dendrimers synthesized from poly(ethylene glycol) (PEG) were examined to understand the influence of alterations in the architecture of dendrimers on their conformation at interfaces and distribution of various groups on their surface. Effect of changes in the number of branching points, type of terminal functional groups and generation of dendrimer was primarily evaluated. Dendrimers were deposited on mica by spin coating at 0.1 mg/mL. Tapping mode atomic force microscopy (AFM) was employed for the visualization of dendrimer topographies while, X-ray photoelectron spectroscopy (XPS), AFM phase and force imaging were used as the tools for characterization of their surfaces. Individual dendrimer molecules could be imaged by AFM, which showed that they are round or oval in topography. Dendrimers were also flattened on mica but the extent of flattening differed with the chemical structure; for instance, third generation dendrimers were more flattened than second generation dendrimers whereas, dendrimers with higher number of branches had greater height above the mica surface. Hydrophilic and hydrophobic groups present towards the aerial interface existed in distinct zones rather than being distributed randomly, except in dendrimer with higher number of branches. The percentage of various hydrophobic groups on the surface of dendrimer was enhanced by increase in the number of branches but, was lowered by the presence of hydroxyl groups as the pendant terminal groups. Furthermore, the core of dendrimers was not always located towards the centre, its position was found to be altered by the number of branching points, type of terminal functional groups and the generation of dendrimer.     

Cubic Polyhedral Oligomeric Silsesquioxane Based Functional Materials: Synthesis,Assembly, and Applications

Organically modified cubic polyhedral oligomeric silsesquioxanes (POSS) have attracted increasing attention in the design of novel functional hybrid materials for applications such as porous materials, liquid crystals, semiconductors, high‐temperature lubricants, fuel cells, and lithium batteries. The nanosized POSS moiety can be conveniently modified on the periphery with a variety of functional groups to lead to hybrid materials with desired functions. In addition, suitable mono‐functionalized POSS derivatives can be incorporated into polymers as side chains via various synthetic strategies to offer a wide class of functional polymeric materials with tunable physical properties for targeted applications. In this Focus Review, we aim to summarize the recent developments on the chemistry and applications of POSS‐based molecules and polymers. Moreover, the properties as well as assembly behavior of the POSS‐based functional hybrid materials will be reviewed, and the relationship of the performance of the hybrid materials with the intrinsic nature of the POSS unit will be addressed.     

Phosphorus dendrimers: from synthesis to applications

Various methods of synthesis of phosphorus dendrimers are presented, in particular a fast method which allows creating each generation in only one step, while multiplying by 5 the number of end-groups. These methods of synthesis can easily be modified to place selectively on the surface, inside, within the branches or at the core, functional groups chosen according to the properties or the applications which they can bring. In many cases, the size of the dendrimer (its generation) has an influence on these properties. Various applications in the fields of catalysis, materials, and biology are presented. To cite this article: Anne-Marie Caminade et al., C. R. Chimie 6 (2003).