聚合物银纹化的分子机理

本文综述了近年来有关聚合物银纹化分子机理方面研究的进展情况。内容包括银纹的起源、生长、断裂过程以及各种结构关系对银纹的影响，并对几种典型的聚合物银纹形态进行了描述。     

水溶性共轭聚合物分子刷的研究进展

水溶性共轭聚合物研究属于国际前沿研究领域,因其具有水溶性和超级信号放大作用,在生物传感领域展现出良好的应用前景.但由于传统水溶性线型共轭高分子两亲性结构特点,其含有的憎水性刚性共轭链在水溶液中易聚集,水分子对共轭链激发态的影响导致其发光效率低(一般小于30%),严重制约了其应用与拓展.如何方便有效构筑高分子的高支化是获得高荧光效率的关键.在本篇综述中,我们综述了水溶性共轭聚合物分子刷的合成技术,分析了其结构与光学性质的关系,为水溶性共轭聚合物分子刷的设计和制备提供指导.另外,总结了水溶性共轭聚合物分子刷在化学生物传感、生物成像、药物运输、癌症治疗等领域的应用,最后对水溶性共轭聚合物分子刷存在的主要问题以及未来的热点方向进行了分析和展望!     

聚合物刷与生物分子相互作用的研究进展

聚合物刷是由一端紧密接枝在一个曲面或平面的聚合物链组成的大分子结构。近年来,随着聚合物制备方法和表面修饰技术的不断发展,聚合物刷的应用范围也在不断拓宽,相关研究已成为功能高分子材料领域的热点之一。具有特殊结构和功能的聚合物刷在生物分子固定、蛋白质分离、酶催化、药物控释等方面具有广阔的应用前景。本文综述了聚合物刷与生物分子相互作用及应用的最新研究进展,并展望了今后的发展方向。     

聚合物分子刷的合成与应用

本文综述了近年来在线形聚合物、树枝状大分子及树枝化聚合物等不同聚合物的每个重复单元上,高密度地、通过不同联接方式接枝上新的聚合物侧链而形成的刷形接枝共聚物,即聚合物分子刷的研究进展。主要介绍聚合物分子刷的三种合成途径,即“大单体聚合法”,“从主链接枝法”及“接枝到主链法”,并对不同路线的特点进行分析,同时对分子刷在制备纳米杂化材料、纳米导线及智能材料等方面的应用进行了综述。     

聚合物分子刷的合成与应用

本文综述了近年来在线形聚合物、树枝状大分子及树枝化聚合物等不同聚合物的每个重复单元上,高密度地、通过不同联接方式接枝上新的聚合物侧链而形成的刷形接枝共聚物,即聚合物分子刷的研究进展。主要介绍聚合物分子刷的三种合成途径,即“大单体聚合法”,“从主链接枝法”及“接枝到主链法”,并对不同路线的特点进行分析,同时对分子刷在制备纳米杂化材料、纳米导线及智能材料等方面的应用进行了综述。     

聚合物分子刷的合成与应用

本文综述了近年来在线形聚合物、树枝状大分子及树枝化聚合物等不同聚合物的每个重复单元上,高密度地、通过不同联接方式接枝上新的聚合物侧链而形成的刷形接枝共聚物,即聚合物分子刷的研究进展.主要介绍聚合物分子刷的三种合成途径,即“大单体聚合法“,“从主链接枝法“及“接枝到主链法“,并对不同路线的特点进行分析,同时对分子刷在制备纳米杂化材料、纳米导线及智能材料等方面的应用进行了综述.     

用ATRP法构筑核壳型梯度极性的多羟基多臂星状超支化聚合物及聚合物刷——三层聚合物刷的合成与表征

设计并通过原子转移自由基聚合方法 (ATRP)合成了核壳型具有梯度极性的多羟基多臂星状聚合物刷 .端羟基超支化聚 (3 乙基 3 羟甲基氧杂环丁烷 )与 2 溴 异丁基酰溴反应制得大分子引发剂 (HP Br) ,以Cu(I)Br和N ,N ,N′ ,N′ ,N″ 五甲基二乙基三胺 (PMDETA)为催化体系 ,进行甲基丙烯酸甲酯 (MMA)的ATRP反应 ,得到以甲基丙烯酸甲酯为臂的多臂星状超支化聚合物 (HP g PMMA) .又以HP g PMMA为引发剂 ,进行甲基丙烯酸羟乙酯 (HEMA)的ATRP聚合 ,得到核壳型具有梯度极性的多羟基多臂星状超支化聚合物 (HP g PMMA b PHEMA) ,继续将其羟基官能团溴代化 (与 2 溴 异丁基酰溴反应 ) ,引发HEMA的ATRP溶液聚合 ,得到了多臂星状超支化聚合物刷 .产物的结构用1 H NMR、FTIR、GPC等进行了表征和测试 .     

超分子作用介导的瓶刷聚合物构建及组装

瓶刷聚合物(BBPs)具有独特的分子结构和富有前景的应用领域,因此受到学者们日益广泛的关注。通过共价键接枝策略来合成瓶刷聚合物费时、合成困难,难以功能化。而通过非共价键作用,则容易将侧链接枝到共聚物主链上,为构建超分子瓶刷共聚物提供有利条件。超分子作用的引入,不仅带来瓶刷聚合物制备方面的灵活性,同时使材料具备更多的响应性、可逆性等功能。本文介绍了氢键、主客体相互作用、金属配位作用、离子相互作用等多种超分子作用介导的瓶刷聚合物的构建及组装,分析讨论了其各自特点、构筑策略,阐明了超分子作用介导的瓶刷聚合物的巨大应用潜能和重要研究意义,最后对其目前仍面临的问题和未来发展进行了分析和展望。     

含偶氮苯侧链分子刷聚合物的合成及其光响应自组装

分子刷聚合物伸展的高分子主链、高密度的侧链和较低的侧链空间缠结,使其展现出独特的流变学、力学性能和特殊的分子聚集状态,在纳米技术、表面科学等领域有着广泛的应用前景.基于同时含有2-羰基溴与炔基基团的大分子试剂聚2-((2-溴代丙酰氧基)甲基)丙烯酸丙炔酯,引发偶氮苯丙烯酸酯单体的原子转移自由基聚合(ATRP)与叠氮功能...     

超支化聚硅碳烷-g-环糊精聚合物刷的合成与表征

通过硅氢加成反应和核多步法聚合合成出超支化聚硅碳烷(HBP),并对其端基进行了硅氢化、羟基化和酰氯化三步改性得到大分子引发剂HBP-Cl;再用其引发甲基丙烯酸N,N-二甲氨基乙酯(DMA)进行原子转移自由基聚合(ATRP),得到超支化聚硅碳烷-g-聚甲基丙烯酸N,N-二甲氨基乙酯(HBP-g-PDMA),最后将单-6-碘代β-CD通过离子键固载到PDMA链上,得到超支化聚硅碳烷-g-环糊精聚合物刷(HBP-g-PDMA-β-CD).采用FTIR、1H-NMR、13C-NMR、29Si-NMR对其结构进行了表征,利用凝胶渗透色谱/多角度激光光散射(SEC/MALLS)联用仪和激光粒度分析仪研究了其高分子的精细结构,并通过元素分析研究了固载时间对β-CD固载量的影响.     

刺激响应型聚合物刷的研究进展

本文综述了刺激响应型聚合物刷的研究进展,阐述了刺激响应型聚合物刷的分类、与基体表面的连接方式以及常规制备方法,介绍了离子强度、温度、pH值、光、溶剂等刺激响应型聚合物刷及其研究现状,并对相应的刺激响应机理进行了探讨。此外,本文还综述了多重刺激响应型聚合物刷的制备设计思路及其刺激响应特性,概述了聚合物刷在响应外界刺激后对基体的弯曲作用以及利用该作用进行可控三维自组装,并对刺激响应型聚合物刷的应用前景进行了展望。     

毛细管内高分子溶液的浓度分布

采用连续自洽场理论分析了毛细管中发生凝胶化之前的聚合物溶液浓度分布的影响因素及其规律. 结果表明, 体系尺寸有限时, 改变聚合物链段、溶剂与壁面的相互作用参数之差, 聚合物溶液浓度分布会发生贫化/吸附转变; 临界作用参数与聚合物链长的倒数呈线性关系, 且拟合常数与体系尺寸、聚合物溶液平均体积分数有关; 聚合物分子量分布为多分散时, 分子量较低的组分更容易接近容器壁面, 分子量较大的组分则相反. 总之, 增加聚合物溶液浓度、链长, 选择优良溶剂, 减小体系尺寸等都会使浓度分布更加均匀.     

Ultradense Polymer Brushes by Adsorption

Standing room only : Dense polymer brushes can be prepared by adsorbing a diblock copolymer comprising a neutral block and a polyelectrolyte block to an oppositely charged polyelectrolyte brush (see picture). The density of the resulting neutral brush is determined by charge compensation, leading to brush densities well over 1 nm^?2. The diblock copolymer can be desorbed by changing the solution conditions.

     

Polymer Brushes on Planar TiO2 Substrates

A facile and universal method is presented for the preparation of polymer brushes on amorphous TiO₂ film. Homogeneous and stable poly(methyl methacrylate), polystyrene, poly(4‐vinylpyridine), and poly(N‐vinyl imidazole) (PNVI) brushes up to 550 nm are directly created onto TiO₂ via UV‐induced photopolymerization of corresponding monomers. Kinetic studies reveal a linear increase in thickness with the polymerization time. Characterization of the resulting polymer brushes by FTIR spectroscopy, X‐ray photoelectron spectroscopy, contact angle, and atomic force microscopy (AFM) indicates an efficient UV‐grafting reaction. Finally, we have demonstrated the possibility in converting the PNVI brushes to poly(vinyl imidazolium bromide), i.e., poly(ionic liquid) brushes by polymer–analogous reactions.

     

Exploring Actuation and Mechanotransduction Properties of Polymer Brushes

Soft nanotechnology requires new approaches and materials to efficiently convert chemical energy into mechanical motion and vice versa. A number of key design parameters, such as responsiveness to external stimuli, directionality of response through alignment, transduction via surface stresses or changes in ionic conductivity can be found in polymer brushes and several recent examples of actuation and transduction in polymer brushes will be explored.

     

Response of Bi-disperse Polyelectrolyte Brushes to External Electric Fields——A Numerical Self-consistent Field Theory Study

The self-consistent field theory has been employed to numerically study the response of bi-disperse flexible polyelectrolyte (PE) brushes grafted on an electrode to electric fields generated by opposite surface charges on the PE-grafted electrode and a second parallel electrode. The numerical study reveals that, under a positive external electric field, the shorter and negatively charged PE chains are more responsive than the longer PE chains in terms of the relative changes in their respective brush heights. Whereas under a negative external electric field, the opposite was observed. The total electric force on the grafted PE chains was calculated and it was found that, under a positive external electric field, the magnitude of the total electric force acting on one shorter PE chain is larger than that on one longer PE chain, or vice versa. The underlying mechanism was unraveled through analyzing the total electric field across the two oppositely charged electrodes.     

Grafting of Polymer Brushes from Xanthate-Functionalized Silica Particles

Monodisperse silica particles (SiPs) were surface-modified with a newly designed silane coupling agent comprising a triethoxysilane and an alkyl halide, namely, 6-(triethoxysilyl)hexyl 2-bromopropionate, which was further treated with potassium O-ethyl dithiocarbonate (PEX) to immobilize xanthate molecules on the particle surfaces. Surface-initiated macromolecular design via interchange of xanthates (MADIX) polymerization of vinyl acetate (VAc) was conducted with the xanthate-functionalized SiPs. The polymerization was well controlled and produced SiPs coated with poly(vinyl acetate) (PVAc) with a well-defined target molar mass and a graft density of about 0.2 chains nm⁻². Dynamic light scattering and TEM measurements revealed that the hybrid particles were highly dispersible in good solvents without any aggregation. The PVAc brushes were hydrolyzed with hydrochloric acid to produce poly(vinyl alcohol) brushes on the SiP surfaces. In addition, the number of xanthate molecules introduced on the SiP surfaces could be successfully controlled by adjusting the concentration of PEX. Thus, the SiPs have two functionalities: xanthates able to act as a MADIX chain-transfer agent and alkyl bromide initiation sites for atom transfer radical polymerization (ATRP). By using these unique bifunctional particles, mixed polymer brushes were constructed on the SiPs by MADIX of VAc followed by ATRP of styrene or methyl methacrylate.