端基功能化聚合物的表面性能

综述了端基功能化聚合物表面结构与性能的最新研究进展.聚合物端基功能化是实现聚合物表面改性的一种有效技术.通过端基功能化可以精确控制聚合物表面功能基团的种类和数量,从而影响聚合物表面的化学结构与性能.重点论述了功能化端基在聚合物表面的离析现象和产生这一现象的原因,以及功能化端基对聚合物表面分子运动能力的影响.本文还介绍了近年来用于研究端基功能化聚合物表面的表征新技术,如SFG、NR、SSIMS等.对端基功能化聚合物表面的环境响应性也进行了阐述.指出了利用不同功能化端基可以有效地控制聚合物表面的亲疏水性.并对端基功能化聚合物的应用进行了展望.     

高分子表面活性剂的分子设计

简要讨论高分子表面活性剂的俣成和表征方法，分析了在水溶液中两亲性聚合分子形态与表面活性的关系，单分子／多分子胶束多的形成是导致聚合物表面活性变差的主要因素，提出了高分子表面活性剂的分子设计原则，设计了多种在高分子量下将能够优质优良表面活性的高分子表面活性剂分子结构模型。     

Confinement effects on the morphology of photopatterned porous polymer monoliths for capillary and microchip electrophoresis of proteins

We find that the morphology of porous polymer monoliths photopatterned within capillaries and microchannels is substantially influenced by the dimensions of confinement. Porous polymer monoliths were prepared by UV-initiated free-radical polymerization using either the hydrophilic or hydrophobic monomers 2-hydroxyethyl methacrylate or butyl methacrylate, cross-linker ethylene dimethacrylate and different porogenic solvents to produce bulk pore diameters between 3.2 and 0.4 microm. The extent of deformation from the bulk porous structure under confinement strongly depends on the ratio of characteristic length of the confined space to the monolith pore size. The effects are similar in cylindrical capillaries and D-shaped microfluidic channels. Bulk-like porosity is observed for a confinement dimension to pore size ratio >10, and significant deviation is observed for a ratio <5. At the extreme limit of deformation a smooth polymer layer 300 nm thick is formed on the surface of the capillary or microchannel. Surface tension or wetting also plays a role, with greater wetting enhancing deformation of the bulk structure. The films created by extreme deformation provide a rapid and effective strategy to create robust wall coatings, with the ability to photograft various surface chemistries onto the coating. This approach is demonstrated through cationic films used for electroosmotic flow control and neutral hydrophilic coatings for electrophoresis of proteins.     

Surface dilational moduli of polymer and blended polymer monolayers spread at air-water interfaces

Surface dilational moduli of polymer monolayers, blended polymer monolayers, and polymer particle monolayers spread at air–water interfaces are reviewed, focusing on measurements using surface pressure isotherm, surface pressure relaxation, and oscillating barrier methods. Differences between the surface dilational moduli of condensed polymer monolayers and expanded polymer monolayers are explored. Moreover, the features of the surface dilational moduli in blended polymer monolayers are discussed in terms of their miscibility.     

高分子共混体系界面张力的研究

<正> 在高分子多相体系中,相间界面张力(γ_(12))是微区的重要控制因素,无论是Donatelli,Sperling等提出的IPN体系微区尺寸关系式,还是Tokita提出的共混体系中分散相粒径表达式,都含有界面张力因子。 然而,由于高分子体系中界面张力测定的诸多实际困难,当前在国内外非常多的研究工作中,广泛地采用了一些替代的办法,应用较多的有以表面张力差来代替界面张力的Antonow原则延伸及一些近似的计算方法,如Wu及Girifalco和Good提出的由表     

Study of polymer-surfactant interactions via surface tension measurements

Interactions between a polymer and a surfactant were studied via surface tension measurements. Poly(ethylene glycol) and sodium dodecyl sulfate were used as a polymer and a surfactant, respectively. The addition of polymer affected the CMC value of the surfactant. The interpretations of the data and theoretical plots of polymer-surfactant interactions are discussed using a theoretical model. Received: 28 September 2000 Accepted: 3 October 2000     

Monte Carlo Calculations of Polymer Adsorption at the Entrance of Cylindrical Pores in Flat Adsorbing Surfaces

The influence of surface interactions on the conformation of flexible polymers partially confined inside narrow cylindrical pores in a flat surface is studied above the critical adsorption energy in a good solvent. We use a static configurational bias computational sampling method to calculate the adsorption free energy and the radius of gyration components parallel and perpendicular to the pore axis as a function of the polymer center of mass position at different degrees of confinement. We find strong free‐energy minima just in front of the pore entry for all degrees of confinement studied. At the location of the free‐energy minimum, polymers are partially adsorbed inside the pore and on the outer solid surface and adopt “drawing pin”‐like conformations. A distinct maximum in the average loop length at the pore entry indicates that the polymer bridges the pore entry of small pores.     

表面等离子体共振传感技术在高分子研究中的应用

介绍了表面等离子体共振 (SPR)的基本原理和SPR传感器技术的应用现状 ,综述了SPR传感器在高分子科学研究中的应用和发展前景。     

促进组织生长的聚合物骨架工程材料

对组织工程中影响细胞生长规律的两个主要因素：材料的表面性质和表面形貌进行了讨论，指出材料的生物相容性应同时包括表面相容性和结构相容性。对于可促进组织生长的聚合物骨架材料的结构设计，必须同时兼顾材料的表面工程和结构２工程，二者必不可少且不可分割。     

高分子表面微纳米结构的构筑及应用

近年来,纳米科技在高分子材料上的应用给高分子科学和材料的发展注入了新的活力.高分子材料表面微纳米结构与材料的性能密切相关,其微纳米结构结合高分子材料本身丰富多彩的特性,在材料科学、微电子学以及细胞生物学等方面都有重要的科学意义和应用价值.目前关于高分子材料表面微纳米结构的构筑已有大量报道,涉及的实验方法和材料非常广泛,大体上可以分为模板法和非模版法.在运用中往往需要综合利用高分子的各种特性和多种实验方法.本文以构筑方法分类,综述了近十几年来在高分子表面构筑微纳米结构的研究进展,对其应用前景做了简要介绍.     

Selective Immobilization of Gold Nanoparticles on the Surface of a Photoreactive Polymer

Summary. A photoreactive polymer containing thiocyanate (SCN) groups was employed for the immobilization of gold nanoparticles (AuNP). Upon UV illumination, isothiocyanate (NCS) groups are generated at the surface by photoisomerization. The illuminated areas of the polymer layer containing NCS were selectively modified with 2-aminoethanethiol to give SH terminated thiourea units at the surface. Gold nanoparticles were selectively immobilized in these areas by immersing the polymer surface in a colloidal solution of gold nanoparticles stabilized by citric acid. Depending on the time of immersion, different amounts of gold were deposited on the illuminated areas, while no immobilization of AuNP was observed in the non-illuminated areas. By using photolithographic masks, patterned gold structures (μm scale) were produced on the polymer surface.     

A new approach to the design of surface treatments for reinforcing agents

A new approach for design of improved interfacial bonding between carbon fibers and polymeric matrices is described. In this method the affinity of surface-treated carbon fibers to various polymer matrices is simulated by analyzing the adsorption characteristics of model compounds, typical of the polymer units, onto very high surface area carbon fibers. The affinity can be evaluated by the use of Thermogravimetric Analysis (TGA) to measure adsorption–desorption characteristics. Since high surface area, activated carbon fibers (ACF) can be chemically treated to obtain acidic, basic, nonpolar or highly polar surfaces, it should be possible to assess the interactions of chemically modified surfaces with model compounds such as methanol (MeOH), acetone, dimethylformamide (DMF), dimethylether, tetrahydrofuran (THF) and water. Some preliminary results are presented, indicating that surface treatments for carbon fibers other than oxidation may lead to enhanced bonding with polymeric matrices.     

两性离子在高分子膜表面功能化改性中的研究进展

两性离子的合成工艺简单,官能团适用性强,且在水溶液中具有较强的水合能力与抑制蛋白质吸附性,因此两性离子在高分子膜表面的功能化改性中显示出很大的优势。将两性离子接枝于高分子膜表面可得到抗污染性强,血液相容性好,环境刺激响应性迅速的功能化膜。两性离子功能化改性高分子膜不仅能广泛应用于水处理和医务治疗中的人工器官材料、血浆分离等领域,在生物医药工业中的蛋白质浓缩、净化与分离等方面同样显示出巨大的应用空间。     

新型成膜法的SAW气体传感器聚合物膜的粘弹性分析

An analysis of the response of surface acoustic wave sensors coated with polymer film based on new coating deposition (self-assemble and molecularly imprinted technology) is described and the response formulas are hence deduced. Using the real part of shear modulus, the polymer can be classified into three types: glassy film, glassy-rubbery film and rubbery film. Experimental results show that the attenuation response is in better consistence with the simulation than in Martin's theory, but the velocity response does not accord with the calculation exactly. Maybe it is influenced by the experimental methods and environment. In addition, simulations of gas sorption for polymer films are performed. As for glassy film, the SAW sensor response increases with increasing film thickness, and the relationship between the sensor response and the concentration of gas is pretty linear, while as for glassy-rubbery film and rubbery film, the relationship between the sensor sensitivity and concentration of gas is very complicated. The ultimately calculated results indicate that the relationship between the sensor response and frequency is not always linear due to the viscoelastic properties of the polymer.     

SURFACE DYNAMIC FRICTION OF POLYMER GELS

The sliding friction of various kinds of hydrogels has been studied and it was found that the frictional behaviors ofthe hydrogels do not conform to Amonton's law F=μW which well describes the friction of solids. The frictional force andits dependence on the load are quite different depending on the chemical structures of the gels, surface properties of theopposing substrates, and the measurement condition. The gel friction is explained in terms of interracial interaction, eitherattractive or repulsive, between the polymer chain and the solid surface. According to this model, the friction is ascribed tothe viscous flow of solvent at the interface in the repulsive case. In the attractive case, the force to detach the adsorbing chainfrom the substrate appears as friction. The surface adhesion between glass particles and gels measured by AFM showed agood correlation with the friction, which supported the repulsion-adsorption model proposed by the authors.     

Interactions between surfactant-coated surfaces in hydrocarbon liquids containing functionalized polymer dispersant

The forces and viscosity between calcium benzene sulfonate surfactant-coated mica surfaces in various hydrocarbon liquids containing a polyamine-functionalized hydrocarbon polymer (M _W≈8000) have been measured using the surface forces apparatus technique. The polymer is found to adsorb to the substrate surfaces by displacing the surfactant layer, and to produce forces that are monotonically repulsive. The forces have a maximum range of 50–100 nm (>3R _H), indicating that tails play a particularly important role in the interaction of this relatively low molecular weight polymer. The forces become steeply repulsive below about 10 nm (∼0.6R _H), at which point a “hard-wall” repulsion comes in that can sustain pressures greater than 100 atm. Thin-film viscosity measurements indicate that the far-field positions of the slipping planes Δ_H depend on the shear rate, showing that significant shear thinning/thickening effects occur within the outermost tail regions of the adsorbed layers during shear. The position of the slipping plane, or hydrodynamic layer thickness Δ_H, varies from 0.6R _H to 2R _H away from each surface (mica and surfactant-coated mica surfaces). Beyond the hydrodynamic layer the far-field fluid viscosity is the same as that of the bulk polymer solution. At separations below D = 2Δ_H the viscosity increases as each polymer layer is compressed. The static forces exhibited various time- and history-dependent effects, which further indicate that a number of different relaxation/equilibration processes are operating simultaneously in this complex multicomponent system. The results reveal that the interactions of tails of functionally adsorbed polymers play a more important role than previously thought. This is especially true in this study where the adsorbed polymers are of low molecular weight and where the tails may represent the largest fraction of interacting segments. Received: 22 September 1998 Accepted: 11 January 1999     

Effect of oxygen plasma treatment on the surface properties of tin-doped indium oxide substrates for polymer LEDs

The effect of oxygen plasma treatment on the surface properties of tin-doped indium oxide (ITO) substrates and the changes in surface properties of treated ITO substrates with ageing time were investigated by X-ray photoelectron spectroscopy (XPS), contact angle and surface free energy measurements. Experimental results show that oxygen plasma treatment increases the oxygen concentration, decreases the carbon concentration, and enhances the surface free energy and polarity, and thereby improves the surface properties of ITO substrates. However, the improved ITO surface properties tended to decay and the surface free energy decreased, with ageing time. In addition, the ageing effect of treated ITO substrates on the performance of polymer light-emitting diodes (LEDs) was studied with respect to the driving voltage, electroluminescent luminance and efficiency. We observe that the ITO substrates aged for various times result in significant differences in optical and electrical characteristics which become worse as the ageing time increases. The optical and electrical performance of polymer LEDs is closely related to the surface properties of ITO substrate and the interface characteristics of ITO/polymer.     

Surface diffusion of metal atoms on polymer substrates during physical vapour deposition

 The surface diffusion of physical-vapour-deposited metal atoms on thermoplastic polymer substrates was investigated. In accordance with the hypothesis of the “classical” atomistic diffusion model, diffusion coefficients are derived from a Monte Carlo simulation. Because the “classical” atomistic diffusion model neglects the desorption of the metal atoms, the absolute diffusion data obtained in our investigations should only be considered as rough estimates. It is more the intention of our work to present relative values in order to correlate the metal surface diffusion on polymer substrates with their physical states (morphologies and surface dynamics). As expected, the diffusivity of metal atoms is strongly influenced by the chemical affinity (“reactivity”) between the metal atoms and the polymer substrate. Furthermore, the diffusivity strongly depends on the physical state of the polymer substrate. On polymer surfaces above the glass-transition temperature the surface diffusivity of metal atoms is 1 order of magnitude higher than the diffusivity below the glass-transition temperature. Received: 9 April 1999/Accepted in revised form: 21 October 1999     

非晶固体高分子表面的低温流动特性

高分子低温加工是材料领域重大挑战。相较于本体分子,位于材料表面高分子链的玻璃化转变温度降低、黏度减小、塑性增强,为高分子材料低温加工提供了可能途径。本文总结了近年来对非晶固体高分子表面分子运动的研究成果,从表面分子动力学的角度阐述了高分子表面低温流动性的起源及其影响因素,举例介绍了表面低温流动特性在高分子材料低温粘结、自愈合以及加工成型等方面的应用,并对未来研究及前景进行了展望。希望通过本文加深对高分子表面低温流动行为的认识和理解,促进高分子材料加工和成型新方法和新概念的发展。     

抗植入式高分子医用材料感染的研究进展

植入式高分子医用材料表面会粘附细菌形成生物膜引发生物材料相关的感染(BRI),给高分子医用材料的广泛应用提出了重大挑战.本文从BRI发生的机制入手,综述了通过高分子医用材料表面改性减少细菌粘附与使用抗菌素-生物材料体系两个方面来抵抗BRI发生的研究进展,重点阐述了局部抗菌药物缓释体系及纳米技术在抗菌药物缓释体系中的应用,并指出高分子前药控释体系的研究和应用是抗高分子医用材料感染的发展趋势.