自组装合成超分子液晶聚合物研究进展

从电荷转移作用、离子相互作用、氢键作用组装、金属配位组装、光化学组装5个方面综述了通过分子自组装合成超分子液晶聚合物的近年来的最新研究成果,并介绍了超分子液晶聚合物的应用及发展前景。     

Janus颗粒的制备与应用研究进展

Janus颗粒作为一种在形貌或者结构上非中心对称的材料,因其在可控分子识别和自组装等领域的优良特性,受到研究者的广泛关注。常见的制备Janus颗粒的方法有固定化技术、微流体技术、Pickering乳液法以及相分离法等。随着研究的深入,开发Janus颗粒的新型制备技术并且拓宽其应用范围,仍然是材料科学领域中颇具挑战性的工作。本文总结了近年来Janus颗粒在制备及应用方面的研究进展,为进一步研究Janus颗粒提供参考。     

两亲Janus纳米片的制备及胶体与界面性质研究进展

该文首先综述了两亲Janus纳米片制备方法的研究进展，包括界面保护法、乳液界面自组装溶胶-凝胶法、模板辅助溶胶-凝胶法以及嵌段共聚物自组装法。接着，系统介绍了两亲Janus纳米片在水溶液中的胶体特性及其在油水体系中的界面特性。最后，简要介绍了两亲Janus纳米片的应用领域，并对未来两亲Janus纳米片制备方法和胶体与界面特性的研究方向进行了展望。     

基于氢键自组装的侧链聚硅氧烷液晶的研究进展

通过与传统的侧链聚硅氧烷液晶的对比,阐述了氢键自组装侧链聚硅氧烷液晶独特的优点;简要介绍了羧基-羧基体系、羧基-吡啶体系、羧基-咪唑体系氢键自组装侧链聚硅氧烷液晶的研究现状,此外,还根据类似的非聚硅氧烷型液晶体系设想了羧基-氨基吡啶体系氢键自组装侧链聚硅氧烷液晶和酚羟基-吡啶体系氢键自组装侧链聚硅氧烷液晶;并概述了液晶常用的表征方法.     

1,3,4-噻二唑类液晶化合物的研究进展

综述了近年来1,3,4-噻二唑类液晶化合物的研究进展,该类化合物形成棒状液晶、楔形液晶、弓形液晶、Polycatenar液晶、盘状液晶的分子结构及其自组装形成的液晶相结构。介绍了分子中末端基团、烷基链数目、刚性核长度等结构常数对液晶自组装结构的的影响。与含氧的杂环类似物1,3,4-噁二唑液晶化合物相比,1,3,4-噻二唑类液晶化合物的液晶性、光电性等更加优越。液晶方面类比表明,它具有更好的液晶性质。     

金纳米颗粒组装体中粒子数目的精确可逆调控研究

通过正硅酸乙酯水解生成二氧化硅,包裹金纳米粒子部分表面,在溶液相中有效制备出非对称金纳米粒子(Janus金纳米粒子)。在Janus金纳米粒子表面修饰偶氮苯和环糊精,借助偶氮苯与环糊精之间的光响应超分子作用,精确可逆诱导Janus金纳米粒子自组装形成低聚体;调整粒子表面二氧化硅覆盖区域与裸露金表面的比例,调节特定数目的金纳米粒子进行自组装,可以精确调控自组装体中金纳米粒子数目。     

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。     

含炔键单元的寡聚噻吩类化合物的研究进展

寡聚噻吩类衍生物作为一个富电子体系通常表现出优越的电子传输性和光电性能,炔键作为一个直线型的富电子单元,引入到噻吩体系中可以增长体系的共轭度,增大体系中的刚硬核长度,同时还可以提高整个分子的平面规整度。含炔键单元的噻吩类化合物所具备的分子自组装性能和优异电子传输性已引起人们极大的关注。介绍了炔键在主链上,侧链上及含噻吩炔单元的环形、星形、X形与树枝形的寡聚噻吩类化合物的研究进展。阐述了它们的分子结构与液晶相态结构、光电性能、器件性能、自组装结构之间的关系。所有的研究表明该类化合物在有机分子器件方面有着重要的应用前景。     

分子自组装技术的研究现状

综述了分子自组装技术目前的研究进展,并对接枝、旋涂、化学吸附、分子沉积、慢蒸发溶剂等成膜方法作以介绍,简介了分子自组装技术在液晶、非线性光学材料、聚合物表面改性等材料领域的应用,并对其今后的发展作出预测。     

Gemini表面活性剂在不同状态下的自组装行为研究进展

自Gemini表面活性剂报道以来,受到了研究者和工业界的广泛关注。对于其结构设计、性能研究、工业应用的报道层出不穷。本文综述了Gemini表面活性剂在不同状态下的自组装行为,主要包括水溶液中的自组装、气液界面上的Langmuir单分子膜、离子液晶及气液界面上的晶体生长。分析和展望了今后Gemini表面活性剂自组装体系的研究方向。     

Ferrocenyl-terminated Dendrimers: Design for Applications in Molecular Electronics, Molecular Recognition and Catalysis

This micro-review shows how a simple but powerful organometallic C–H activation could be made very useful for the construction of a large variety of stars, dendritic cores, dendrons and dendrimers of variable sizes including giant dendrimers and gold-nanoparticle-cored dendrimers. The synthesis of ferrocenyl-terminated dendrimers was then achieved by reactions of chlorocarbonylferrocene with polyamino dendrimers, ferrocenylsilylation of polyolefin dendrons and dendrimers and “click” reactions of ferrocenyl acetylene with azido-terminated dendrimers. The functions of these metallodendrimers include molecular electronics (molecular batteries), molecular redox recognition and sensing and catalysis using dendritic stabilization of nanoparticle catalysts.     

Mathematical simulation of lysine dendrimers: Temperature dependences

The mathematical simulation of second- and fourth-generation lysine dendrimers is performed via the molecular-dynamics method. Temperature dependences of primary structural characteristics are obtained. It is shown that the sizes and atomic distributions of these dendrimers are weakly temperature-dependent. Together with the structural properties, the local mobility of CH₂ groups in the dendrimers is investigated via the molecular-dynamics method and NMR spectroscopy. It is shown that the orientational mobility of internal groups of the lysine dendrimers is lower than that of terminal groups, in agreement with the data available for flexible-chain dendrimers. Changes in correlation times with temperature are well described by the Arrhenius dependence. At the same time, the orientational mobility of internal groups in the lysine dendrimers depends on the generation number. This behavior is different from that of flexible-chain dendrimers, in which the mobility of internal groups is the same for dendrimers of different generations.     

树形分子的制备及对量子点荧光性能的影响

采用发散法合成了以乙醇胺为初始核的扇形树枝状化合物PAMAM,用核磁共振法（^1H NMR和^13C NMR）对G1．0—NH2,G1．0-SH进行了表征,证实了其结构;并用荧光分光光度计检测了PAMAM对CdTe量子点水溶液的荧光性质的影响。发现PAMAM树形分子可增强CdTe—TGA量子点的荧光,不同浓度的PAMAM对量子点荧光性能的影响不同。     

Interaction of Cationic Carbosilane Dendrimers and Their siRNA Complexes with MCF-7 Cells

The application of siRNA in gene therapy is mainly limited because of the problems with its transport into cells. Utilization of cationic dendrimers as siRNA carriers seems to be a promising solution in overcoming these issues, due to their positive charge and ability to penetrate cell membranes. The following two types of carbosilane dendrimers were examined: CBD-1 and CBD-2. Dendrimers were complexed with pro-apoptotic siRNA (Mcl-1 and Bcl-2) and the complexes were characterized by measuring their zeta potential, circular dichroism and fluorescence of ethidium bromide associated with dendrimers. CBD-2/siRNA complexes were also examined by agarose gel electrophoresis. Both dendrimers form complexes with siRNA. Moreover, the cellular uptake and influence on the cell viability of the dendrimers and dendriplexes were evaluated using microscopic methods and XTT assay on MCF-7 cells. Microscopy showed that both dendrimers can transport siRNA into cells; however, a cytotoxicity assay showed differences in the toxicity of these dendrimers.     

Preparation of poly(ethylene glycol)-modified poly(amidoamine) dendrimers with a shell of hydrophobic amino acid residues and their function as a nanocontainer

We studied the use of poly(ethylene glycol) (PEG)-modified dendrimers as a nanocapsule with a biocompatible surface. We designed PEG-modified dendrimers having a shell of hydrophobic amino acid residues in the peripheral moiety of the dendrimer to increase their encapsulation ability. Subsequently, l-phenylalanine or γ-benzyl-l-glutamate residues were introduced to all chain ends of the poly(amidoamine) G4 dendrimers. Furthermore, PEG (MW 2000) chains were attached to the amino acid residues. These hydrophobic amino acid residues rendered the PEG-modified dendrimers as more compact. After binding of Rose Bengal (RB) guest molecules to dendrimers, an assay using the Klotz plot showed that the hydrophobic amino acid layer slightly affected the guest site number, but significantly increased intrinsic binding of the dendrimers to guest molecules. The PEG-modified dendrimers with the hydrophobic amino acid layer were better able to retain guest molecules than the dendrimer without the layer: they are therefore useful for drug delivery.     

PAMAM树状大分子负载和释放阿霉素的耗散粒子动力学模拟

采用耗散粒子动力学模拟方法研究了药物输送载体聚酰胺-胺（PAMAM）树状大分子对抗癌药物阿霉素（DOX）的负载和释放行为。构建了PAMAM树状大分子的粗粒化模型,该模型能准确地重现树状大分子的构象性质。考察了PAMAM树状大分子代数（G）对DOX负载以及pH环境对DOX释放的影响。模拟结果表明,PAMAM树状大分子主要通过疏水作用将DOX包封于内部空腔,G6和G7 PAMAM树状大分子的负载能力较强,因为其孔隙率较高,内部有更多的疏水空腔。在低pH环境下,PAMAM树状大分子结构发生变化,DOX分子能快速地从其中释放,主要原因是PAMAM的伯胺、叔胺和DOX伯胺发生质子化,质子化基团间的静电排斥作用使得PAMAM树状大分子发生溶胀,导致其内部空腔暴露,促进了DOX的释放。本工作可以为基于树状大分子的药物输送体系的设计和优化提供参考。     

Engineered Smart Textiles and Janus Microparticles for Diverse Functional Industrial Applications

Janus materials are biomimetically inspired systems with two or more functional properties arising as paramount materials for utilization in different fields like Medical, Protective clothing etc. Janus particles can be in different forms like capsule, fiber, nano cage, disc, nano film etc. which are amalgamated with fabric by different processes. Based on the fabrication and constituent elements, Janus materials can be fabricated by incorporating multiple properties like fire-retardancy, catalytic property, thermal regulation etc. This review article enumerates the numerous industrial applications of the Janus fabrics and simultaneously outlines the extensive methodologies utilized for engineering of the Janus fabrics.     

3D numerical study of induced-charge electrokinetic motion of heterogeneous particle in a microchannel

The transient induced-charge electrophoretic (ICEP) motion of a Janus particle in a microchannel is numerically simulated with a complete 3D multi-physics model in this paper. A half of the Janus particle is an ideally polarizable material, the other half is a dielectric material. The distribution of induced surface charge varies on the ideally polarizable hemisphere of the Janus particle. Under an externally applied electric field, these surface charges generate micro vortices in the liquid. The numerical results illustrate that the orientation of Janus particle determines the direction of particle's motion and affects the velocity of the particle. The vortices on the polarizable side of the Janus particle act like an engine and push the particle to move faster in comparison with non-polarizable particles or fully polarizable particles. The bigger Janus particles move faster than the smaller ones. In the current paper, effects of the applied electric field, size of the particle, zeta potential of the non-polarizable part on the motion of Janus particle are also studied.     

Demulsification of Crude Oil Emulsion Using Polyamidoamine Dendrimers

Abstract

Six dendrimers with the same polyamidoamine (PAMAM) basic structure but different terminals/generations were synthesized by divergent method. The dendrimers were studied by surface tension measurement at the air‐water interface. The demulsification performance for oil/water (O/W) simulated crude oil emulsion and crude oil extract directly from field was investigated. The experimental results indicate that the three dendrimers terminated with ester groups were insufficient demulsifiers for crude oil emulsion. However, the three dendrimers terminated with amine groups exhibited excellent demulsification performance for O/W emulsions. As demulisifers, amine based dendrimers were superior to the commercial polyether ones (SP‐169 and BP‐169). The possible mechanisms for the nanocontainer effects of the dendrimers, through either surface adsorption or internal encapsulation, were discussed.     

Synthesis and luminescent properties of perylene bisimide-cored dendrimers with carbazole surface groups

A group of perylene bisimide (PBI) cored dendrimers were designed and synthesized. The polyphenylene dendrons containing carbazole functional groups at periphery were attached to the PBI core with expectation to control the intermolecular interaction and to tune the charge transporting ability of dendrimers. Their photophysical, electrochemical and thermal properties were investigated. The spectral data showed that energy transfer and photoinduced charge transfer coexist between the carbazole peripheries and the PBI core, competing to influence the luminescent properties of these dendrimers. The red OLEDs were fabricated with these dendrimers as non-doped emitting layer by solution method. The dendrimers bearing carbazoles exhibited improved EL performance than those model compounds. The improved charge balance state caused by these carbazole units is suggested to be responsible for the EL performance.