原子转移自由基聚合在纳米粒子改性方面的研究进展

介绍了原子转移自由基聚合(ATRP)在纳米粒子改性方面的研究进展,综述了基于 ATRP 的多种不同催化体系的衍生技术在纳米粒子表面改性方面的应用,其中主要包括反向原子转移自由基聚合（RATRP）和电子转移活化再生催化剂原子转移自由基聚合(AGET ATRP),并对其特点进行了概述,对纳米粒子表面引发ATRP的发展进行了展望。     

纳米无机氧化物粒子表面接枝改性

本文对纳米无机氧化物粒子表面的接枝改性作了论述,重点介绍了纳米粒子表面官能团引发的接枝聚合(自由基聚合、阴离子集合、阳离子聚合),并对各种接枝方法以及其发展情况进行了评价。同时对树状接枝进行了简要的介绍。     

可控/活性聚合在无机粒子表面接枝研究进展

介绍了一些主要的可控／活性自由基聚合法,包括氮氧调解自由基聚合法（NMRP）、原子转移自由基聚合法（ATRP）、可逆加成断裂链转移聚合法（RAFT）在粒子表面接枝聚合形成无机纳米粒子／聚合物的壳核结构,达到了对粒子改性的目的。并提出了一些目前研究中存在的问题,对可控／活性聚合应用的发展进行了展望。     

纳米纤维素晶须表面接枝及其液晶性能研究进展

作为一种新兴的纳米生物材料,纳米纤维素日益受到各界的广泛关注,对其进行表面接枝改性并开发新的功能是十分必要的。本文综述了纳米纤维素晶须表面接枝的技术及研究进展,主要介绍了传统自由基聚合、离子和开环聚合及活性自由基聚合技术,包括氮氧自由基调控活性聚合、原子转移自由基聚合、可逆加成-断裂链转移聚合、单电子转移活性自由基聚合,讨论了各种接枝聚合方法的适用范围和优缺点。简述了点击化学在纳米纤维素晶须表面接枝的应用。通过各种聚合方法改性得到的纳米纤维素晶须接枝共聚物往往具有一些特殊的功能,某些接枝共聚物在适当的溶剂中可以形成液晶态,本文重点介绍了接枝改性的纳米纤维素晶须的液晶性能及其形成机理和影响因素等。     

通过ATRP法接枝改性无机纳米粒子研究进展

原子转移自由基聚合方法 (ATRP)被广泛的应用在接枝改性无机纳米粒子上等领域。本文介绍了在纳米二氧化钛、二氧化硅等无机纳米粒子上原子转移自由基聚合方法主要的应用,主要可以提高无机纳米粒子的相容性和抗老化性能等特性。但是,最重要的应用是通过原子转移自由基聚合方可以控制接枝物的链的长度及分子量大小,当接枝产物与材料共混时可以更好的改善材料的力学等性能,从而控制并扩大材料的应用范围,同时也使无机纳米的应用领域得到更广泛的应用。本文主要综述了几种原子转移聚合方法对无机粒子的改性应用研究现状。     

纳米二氧化硅颗粒表面接枝改性的研究

本工作选择马来酸酐和苯乙烯单体在纳米二氧化硅粒子表面进行接枝改性,首先对纳米粒子进行烷基化处理,引入双键,然后引发聚合,使得马来酸酐和苯乙烯与纳米粒子之间形成化学键合。详细研究了各种聚合条件(引发剂浓度、单体加入量的比例、反应温度等)对接枝效果的影响,认为烷基化改性后的纳米二氧化硅粒子在聚合体系中充当极性溶剂中心的作用,控制马来酸酐和苯乙烯在粒子表面的接枝。     

纳米粒子表面ATRP修饰及其在生物医学领域中的应用

综述了各种纳米粒子如金属纳米粒子、金属化合物纳米粒子、无机非金属纳米粒子,有机纳米粒子等通过表面修饰引发原子转移自由基聚合而得到各种功能聚合物材料,并对这些杂化材料在生物医学中的应用进行了总结和展望.     

纳米SiO_2表面接枝甲基丙烯酸甲酯的研究

为了提高纳米二氧化硅(SiO2)粒子在阻燃型聚合物基纳米复合材料中的有效利用,需要对粒子的表面进行改性。此实验采用溶液聚合法,使甲基丙烯酸甲酯单体(MMA)在烷基化预处理的纳米SiO2粒子的表面进行接枝聚合,得到以纳米SiO2粒子为核、接枝聚甲基丙烯酸甲酯为壳的复合颗粒(SiO2-g-PMMA)。结果表明,PMMA以化学键成功地接到纳米SiO2的表面,并可通过改变接枝聚合的条件来调节粒子上所接聚甲基丙烯酸甲酯的结构,改性后的纳米SiO2粒子具有良好的热稳定性及分散性。     

丙烯酸丁酯原位悬浮聚合法制备表面改性纳米TiO_2

将悬浮聚合与溶液聚合方法改性纳米TiO2作了对比研究,探讨了介质和单体浓度对结果的影响,并对改性后纳米二氧化钛粒子的分散性能进行了分析。结果表明,在悬浮与溶液聚合条件下,在纳米TiO2粒子表面均能形成聚合物包覆层,当单体浓度为0.25 g/mL时包覆率达最大值。TG表明与以水为介质相比,在乙醇中聚合物包覆率较大,但TEM表明包覆前的纳米粒子在乙醇中更易团聚,因此悬浮聚合条件下更利于聚合物在单个纳米粒子表面的吸附从而促进纳米粒子的分散。     

纳米粒子及其在复合材料改性中的应用

介绍了纳米粒子的一些优异特性和表面改性的方法，并详细阐述了纳米粒子充聚合物聚合材料的主要制备方法，研究进展及其良好性能。     

Synthesis and characterization of PMMA grafted ZnO nanoparticles

ZnO nanoparticles were synthesized by homogeneous precipitation. To reduce the aggregation among ZnO nanoparticles, an effective surface modification method was proposed by grafting polymethyl methacrylate (PMMA) onto the ZnO particles. That is, the surface of ZnO nanoparticles was firstly treated with a KH570 silane coupling agent, which introduces functional double bonds onto the surface of ZnO nanoparticles, followed by radical grafting polymerization in non-aqueous medium. The obtained nanocomposite was characterized by Fourier transform infrared spectroscopy (FT-IR), thermogravimetry (TG), sedimentation test, scanning electron microscopy (SEM), and X-ray powder diffraction (XRD). Results of FT-IR and TG showed that the desired polymer chains have been covalently bonded to the surface of ZnO nanoparticles. It was found that the increasing monomer concentration could increase the grafting percentage and hence promote the dispersibility. The application of some surfactant is also helpful for dispersion. The viscous properties of nano-suspensions were investigated. The ZnO/PS nanocomposite was prepared by adding PMMA-grafted ZnO into styrene monomer, followed by radical grafting polymerization. The resulted nanocomposite was characterized by TG, DSC (differential scanning calorimetry) and XRD, and the testing results indicated that thermal behaviors of PS were obviously changed.     

Synthesis and characterization of end-functional polymers on silica nanoparticles via a combination of atom transfer radical polymerization and click chemistry

This article describes a divergent strategy to prepare grafted polymer chains with functional end groups for surface modification of nanoparticles with other functional groups. This preparation is achieved through a combination of surface-initiated atom transfer radical polymerization (ATRP) and click chemistry. First, the surface of the silica nanoparticles was modified with polystyrene (PSt) brushes via the “grafting from” approach. The terminal bromides of PSt-grafted silica nanoparticles were then substituted with azido groups. These azido-terminated PSt brushes on the nanoparticle surface were reacted with various alkyne-terminated functional end groups via click reactions. In all cases, FTIR and ¹H NMR spectra indicated quantitative transformation of the chain ends of polystyrene brushes on silica nanoparticles into the desired functional group.     

Surface modification of silica nanoparticles with hydrophilic polymers

Silica (SiO₂) nanoparticles grafted with a water-soluble polymer, i.e. nonionic poly(oxyethylene methacrylate) (POEM) and ionic poly(styrene sulfonic acid) (PSSA) were prepared via a three-step synthetic approach: (1) the activation of silanol group (–OH) in the surface of SiO₂ nanoparticles, (2) surface modification to chlorine (–Cl) group and (3) graft polymerization from nanoparticles via atom transfer radical polymerization (ATRP). The successful synthesis and chemical compositions in the modified SiO₂ nanoparticles were confirmed using FT-IR, UV–visible spectroscopy and X-ray photoelectron spectroscopy (XPS). Thermogravimetric analysis (TGA) results indicated that the grafting amounts of polymer in the nanoparticles were 5 and 8 wt% for POEM and PSSA, respectively. X-ray diffraction (XRD) showed that the grafting of polymers did not significantly alter the microstructure of SiO₂ nanoparticles. Grafting of water-soluble polymer improved the dispersion properties of nanoparticles in alcohol, as verified by scanning electron microscopy (SEM).     

聚合物表面光接枝改性研究进展

表面光接枝主要是用芳酮引发有机材料产生自由基，从而引发单体聚合产生表面接枝链。表面光接枝应用领域广泛．可用于聚合材料的表面改性以及表面功能化。综述了紫外光引发接枝改性聚合物表面的研究进展，包括光接枝聚合机理、改性方法、影响因素等，并对其应用前景及研究方向进行了介绍。     

Polymers interfacing with biology

The development of various controlled radical polymerization techniques as well as site- and residue specific strategies to modify peptides/proteins with synthetic polymers have made polymer chemistry a powerful tool to address materials problems at the biology interface. This article will present recent examples for bioactive surface modification and polymer therapeutics; it will highlight the use of controlled radical polymerization techniques and bioconjugation strategies to develop surface coatings for regenerative medicine and diagnostics, respectively, polymer-based nanomedicines.     

电泳显示器用聚合物包覆颗粒的制备及其分散稳定性的紫外透光率表征

采用自由基接枝聚合法,将不同极性的单体修饰在黑色无机颜料颗粒表面,以紫外透光率法为主要表征手段,考察了聚合物包覆层的组成结构对颗粒在电泳体系中分散稳定性的影响. 结果表明,聚合物修饰后颗粒稳定时间至少提高5倍,且随所用包覆单体侧链长度增大而增大. 当单体支链的碳原子数大于4时,颗粒能很好地长时间分散在非水体系中. 所制黑白电泳显示器在5 V电压下,响应时间小于1 s,对比度达(4~5):1. 本结果为提高缺乏理论研究的电泳显示体系的分散稳定性和电泳显示效果及使用寿命提供了研究基础.     

Synthesis and characterization of PMMA/SiO2 organic–inorganic hybrid materials via RAFT‐mediated miniemulsion polymerization

In this article, we first carried out the surface modification of SiO₂ using silane coupling agent KH570, and then prepared PMMA/SiO₂ organic–inorganic hybrid materials by conventional free radical polymerization and RAFT polymerization in miniemulsion, respectively. The kinetics comparisons of these two polymerizations were studied. PMMA/SiO₂ hybrid materials were characterized by gel permeation chromatography, differential scanning calorimetry and thermogravimetric analysis. Experimental results indicated that the polymerization behavior of MMA in miniemulsion showed controlled/living radical polymerization characteristics under the control of RAFT agent. Incorporation of RAFT agent and SiO₂ nanoparticles improved the thermal properties of polymers, the thermal stability of polymers increased with increasing content of SiO₂ nanoparticles. The structures and morphologies of SiO₂, modified SiO₂, and PMMA/SiO₂ hybrid materials were characterized by FT‐IR and TEM. TEM results showed that the addition of modified SiO₂ nanoparticles to miniemulsion polymerization system obtained different morphology latex particles. Most of modified SiO₂ nanoparticles were wrapped by polymer matrix after polymerization. POLYM. COMPOS., 2013. © 2013 Society of Plastics Engineers     

炭黑表面聚合物接枝改性的研究进展

介绍了各种单体通过自由基聚合、阴离子聚合、阳离子聚合等机理在炭黑表面的接技改性及活性聚合物在炭黑表面的接枝反应的研究进展,归纳了改性炭黑的性能及其表征方法。