电子转移活化再生催化剂原子转移自由基聚合(ARGET ATRP)的研究进展

ARGET ATRP可将反应中催化剂用量降至ppm级,是目前最具工业化应用前景的原子转移自由基聚合(ATRP)之一。综述了ARGET ATRP的反应机理、引发剂、催化体系、还原剂、反应条件及其在污水处理、纤维素改性、燃料电池方面的应用,并对ARGET ATRP技术的前景进行了展望。     

原子转移自由基聚合可控制备聚合物刷及其最新应用进展

刷状聚合物是一类独特的聚合物分子,具有低粘度、高流变性、良好的溶解性及大量末端官能团等特性,在生物医学及先进材料设计等领域潜力巨大。原子转移自由基聚合(ATRP)作为一种温和、通用、强大的活性可控聚合技术,在合成聚合物刷中得到了非常广泛的应用。因此,通过ATRP技术对聚合物的分子结构进行设计,制备出结构明确、性能新颖的聚合物刷对于探索新型功能材料方面日益重要。综述了ATRP技术制备聚合物刷的最新研究进展及其在设计与制备结构可控的各种先进材料方面的应用,并对ATRP法制备聚合物刷的方法、聚合物刷的性能及应用做出了重点介绍。     

原子转移自由基聚合及催化剂负载化研究进展

原子转移自由基聚合(ATRP)具有可控聚合的典型特征,自1995年来受到高分子界的广泛关注。介绍了ATRP在应用方面的研究进展;传统ATRP由于存在催化剂脱除困难等问题,制约了其工业化进程。介绍了易分离的负载型催化剂的近期研究进展。     

原子转移自由基聚合反应改性氧化石墨烯研究进展

原子转移自由基聚合(ATRP)是一种具有潜在应用价值的可控活性自由基聚合方法,通过ATRP反应对氧化石墨烯(GO)进行改性,可以有效控制各种接枝聚合物分子链的长度和接枝密度,赋予GO不同的功能性,如良好的溶剂分散性、环境敏感刺激响应性、生物相容性等。文中分别从GO表面固定引发剂直接引发ATRP反应和GO表面非共价键结合ATRP聚合物分子链2种途径,对ATRP反应改性GO进行综述,总结了ATRP改性反应的过程条件和研究方法,并指出了GO功能化复合材料的功能特性和应用前景。     

ATRP表面接枝在功能膜制备中的应用

ATRP表面引发接枝聚合是功能膜制备中一个重要而有效的方法.近年来,随着原子转移自由基聚合(ATRP)研究的快速发展,将ATRP应用于功能膜制备的研究已取得了显著的进展.详细介绍了在膜表面固定ATRP引发剂的方法及将ATRP表面接枝法应用于制备抗污染能力强,抗菌性好,环境响应迅速等多种功能性膜方面的研究进展情况.     

PolyHIPE块体中甲基丙烯酸甲酯的ATRP溶液聚合

将用高内相比乳液(HIPE)聚合法得到的多孔聚合物块体(poly HIPE)作为聚合的反应器,在其内部进行甲基丙烯酸甲酯(MMA)的原子转移自由基聚合反应(ATRP),通过扫描电镜、凝胶渗透色谱、红外光谱、热重分析、核磁共振和差示扫描量热等测试手段对块体内聚合的PMMA进行了分析测试。研究表明,MMA在poly HIPE块体内部按照ATRP聚合机理发生聚合;poly HIPE块体对MMA的ATRP溶液聚合影响不同于受限空间内部进行的传统自由基聚合及反向原子转移自由基聚合(RATRP);相较于普通的ATRP溶液聚合,块体内部ATRP聚合所得PMMA的数均相对分子质量有所降低,相对分子质量分布变窄,热稳定性有所提高,间同立构比例有所下降,但全同立构比例明显增加,玻璃化转变温度有所下降。     

Progress in Application of Atom Transfer Radical Polymerization in Hydrogel Preparation

原子转移自由基聚合(ATRP)是一种可控自由基合成技术,与普通的自由基技术相比,ATRP技术使凝胶聚合物网链的均匀性提高,更为重要的是通过引发剂的结构设计可以得到不同结构与性能的水凝胶.综述了线形、支化、无机等不同结构ATRP引发剂在水凝胶研究中的进展,并分析了ATRP技术提高凝胶网络均匀性的机理.     

原子转移自由基聚合法在改性碳纳米管中的应用

原子转移自由基聚合(ATRP)以其适用单体范围广、反应条件温和、分子设计能力强等优点受到各领域科学家的普遍关注。在介绍ATRP原理及特点的基础上,综述了ATRP在改性碳纳米管方面的研究进展,主要包括通过ATRP对碳纳米管进行非共价改性、共价改性以及ATRP与其他技术共同作用的改性方法,对应用ATRP改性碳纳米管的研究方向进行了分析。     

ATRP法制备水凝胶的研究进展

原子转移自由基聚合(ATRP)是一种可控自由基合成技术,与普通的自由基技术相比,ATRP技术使凝胶聚合物网链的均匀性提高,更为重要的是通过引发剂的结构设计可以得到不同结构与性能的水凝胶.综述了线形、支化、无机等不同结构ATRP引发剂在水凝胶研究中的进展,并分析了ATRP技术提高凝胶网络均匀性的机理.     

ATRP法制备水凝胶的研究进展

原子转移自由基聚合(ATRP)是一种可控自由基合成技术,与普通的自由基技术相比,ATRP技术使凝胶聚合物网链的均匀性提高,更为重要的是通过引发剂的结构设计可以得到不同结构与性能的水凝胶.综述了线.形、支化、无机等不同结构ATRP引发剂在水凝胶研究中的进展,并分析了ATRP技术提高凝胶网络均匀性的机理.     

原子转移自由基聚合法制备聚合物刷

介绍了原子转移自由基聚合法(ATRP)制备聚合物刷(平面刷、球形刷和分子刷)的研究进展及应用前景.聚合物刷子的奇异构象使其具有许多新奇的性质和潜在的应用前景.ATRP是制备具有可控结构的聚合物以及有机/无机杂化材料的一种较好的方法.通过ATRP制备聚合物刷,可以有效地改变聚合物刷的组成和聚合度,从而改变聚合物刷的表面性质,设计出具有新型结构及性能的材料.     

Advanced Materials by Atom Transfer Radical Polymerization

Atom transfer radical polymerization (ATRP) has been successfully employed for the preparation of various advanced materials with controlled architecture. New catalysts with strongly enhanced activity permit more environmentally benign ATRP procedures using ppm levels of catalyst. Precise control over polymer composition, topology, and incorporation of site specific functionality enables synthesis of well‐defined gradient, block, comb copolymers, polymers with (hyper)branched structures including stars, densely grafted molecular brushes or networks, as well as inorganic–organic hybrid materials and bioconjugates. Examples of specific applications of functional materials include thermoplastic elastomers, nanostructured carbons, surfactants, dispersants, functionalized surfaces, and biorelated materials.     

Plasmon-triggered living photopolymerization for elaboration of hybrid polymer/metal nanoparticles

Surface plasmon resonance can be used to manipulate light at the nanoscale. It was used here to trigger photopolymerization of an atom transfer radical polymerization (ATRP) molecular system, leading to a thin polymer shell at the surface of the metal nanostructure. The polymerization can be reactivated from the first polymer shell to covalently graft a second monomer layer with precise control over the thickness at the nanometric scale, depending on the photonic parameters. This route can be applied to different nanoobjects and allows an anisotropic surface modification in agreement with the spatial localization of the enhanced electromagnetic field near the nanostructure. This new route opens the door towards the preparation of multifunctional hybrid metal/polymer nanostructures.     

Microscopic laser desorption/postionization fourier transform mass spectrometry

A microscopic laser desorption/postionization Fourier transform mass spectrometer (LD/FTMS) is described. The lateral resolution can be <1 μm with the inherent FTMS high mass resolution intact. Laser postionization allows a certain selectivity and an increase in sensitivity. This capability should allow materials characterization in a wide variety of cases. We demonstrate microscopic desorption and postionization for atoms and molecules.     

Development of ion beam sputtering techniques for actinide target preparation

Ion beam sputtering is a routine method for the preparation of thin films used as targets because it allows the use of a minimum quantity of starting material, and losses are much lower than most other vacuum deposition techniques. Work is underway in the Isotope Research Materials Laboratory (IRML) at ORNL to develop the techniques that will make the preparation of actinide targets up to 100 μg/cm² by ion beam sputtering a routinely available service from IRML. The preparation of the actinide material in a form suitable for sputtering is a key to this technique, as is designing a sputtering system that allows the flexibility required for custom-ordered target production. At present, development work is being conducted on low-activity actinides in a bench-top system. The system will then be installed in a hood or glove box approved for radioactive materials handling where processing of radium, actinium, and plutonium isotopes among others will be performed.     

Signatures of clustering in superparamagnetic colloidal nanocomposites of an inorganic and hybrid nature

The individual and co-operative properties of inorganic and hybrid superparamagnetic colloidal nanocomposites that satisfy all the requirements of magnetic carriers in the biosciences and/or catalysis fields are been studied. Essential to the success of this study is the selection of suitable synthetic routes (aerosol and nanocasting) that allow the preparation of materials with different matrix characteristics (carbon, silica, and polymers with controlled porosity). These materials present magnetic properties that depend on the average particle size and the degree of polydispersity. Finally, the analysis of the co-operative behavior of samples allows for the detection of signatures of clustering, which are closely related to the textural characteristics of samples and the methodology used to produce the magnetic carriers.     

低温MH/Ni电池负极材料的研究方法

制约MH/Ni电池低温性能的主要因素是贮氢合金负极材料.综述了低温贮氢合金负极材料的研究进展,分析了影响电极材料低温性能的各方面因素,给出了提高其低温性能的具体方法,其中包括元素替代、结构设计及制备工艺等的运用.这些将有益于今后研制和生产适用于宽温度范围的MH/Ni电池负极材料.     

Arrayed time-of-flight mass spectrometry for time-critical detection of hazardous agents

The design and operation of an arrayed time-of-flight (TOF) mass spectrometer for simultaneous data acquisition from multiple samples is described. Versions of the instrument employ sets of two or four linear or reflectron mass analyzers. They are housed in the same vacuum chamber and utilize the same laser for ion desorption. Instrument performance is illustrated in the example of a two-linear-mass-analyzer array using MALDI-MS for mixtures of commercially available proteins as well as intact microorganisms. We also describe the properties of a novel short delay time (<170 ns) pulsed extraction method for linear TOF analyzers. This configuration allows uniform resolution improvements to be achieved in a wide m/z range. In addition, we present multiplexed sample preparation methods, using different reagents prior to mass analysis in the arrayed system, to increase the overall sensitivity of the MS method and to allow wider and more efficient detection across the entire range of potentially hazardous agents. In addition to the multifold increase in data collection rates, arrayed TOF-MS configurations provide a high degree of redundancy, critical for rapid, high confidence agent identification as well as for reduction in false alarm rates.     

Quantitative Element-Sensitive Analysis of Individual Nanoobjects

A reliable and quantitative material analysis is crucial for assessing new technological processes, especially to facilitate a quantitative understanding of advanced material properties at the nanoscale. To this end, X-ray fluorescence microscopy techniques can offer an element-sensitive and non-destructive tool for the investigation of a wide range of nanotechnological materials. Since X-ray radiation provides information depths of up to the microscale, even stratified or buried arrangements are easily accessible without invasive sample preparation. However, in terms of the quantification capabilities, these approaches are usually restricted to a qualitative or semi-quantitative analysis at the nanoscale. Relying on comparable reference nanomaterials is often not straightforward or impossible because the development of innovative nanomaterials has proven to be more fast-paced than any development process for appropriate reference materials. The present work corroborates that a traceable quantification of individual nanoobjects can be realized by means of an X-ray fluorescence microscope when utilizing rather conventional but well-calibrated instrumentation instead of reference materials. As a proof of concept, the total number of atoms forming a germanium nanoobject is quantified using soft X-ray radiation. Furthermore, complementary dimensional parameters of such objects are reconstructed.