复合粒子涂膜表面疏水性能分形评价

采用接枝法和非均相乳液聚合与溶胶-凝胶法相结合技术,制备了不同形状的复合粒子,经低表面能的物质修饰后,其涂膜表面具有超疏水性。采用分形理论对涂膜表面疏水性进行评价,用分形维数表征涂膜表面微观形貌与疏水性能之间的关系,结果表明对于粗糙结构表面,分形维数较粗糙度因子能更好地反映表面形貌对水接触角的影响。     

多层自组装硫脲和纳米金电流型萘免疫传感器的研究

建立了基于硫脲和纳米金层层自组装技术的无标记、高灵敏电流型免疫传感器,用于萘的检测。利用循环伏安法研究了修饰电极表面的电化学特性以及测试溶液的pH值、孵育时间和温度对免疫传感器性能的影响。实验表明,此免疫传感器在含不同浓度萘抗原的PBS溶液(pH7.4)中37℃下孵育30 min后,在pH7.4的测试底液中测定,响应电流与萘浓度在0.5～100μg/L范围内有良好的线性关系,r=0.9986,检出限为0.08μg/L。此传感器制备简单,灵敏度高,稳定性好,可以重复使用。应用于实际水样中萘的测定,回收率为94.3%～107.0%。     

Geometric Model Describing the Banded Morphology of Particle Films Formed by Convective Assembly

Nanoparticle films coated on smooth substrates by convective assembly from dilute suspensions in dip‐coating configuration are known to have discrete film morphologies. Specifically, the film morphology is characterized by alternating bands of densely packed particles and bands of bare substrate. Convective assembly is a frontal film‐growth process that occurs at the three‐phase contact line formed by the substrate, the suspension in which it is submersed, and the surrounding air. The bands are parallel to this contact line and can be either monolayered or multilayered. Monolayered bands result whenever the substrate is withdrawn from the suspension at a rate too high for particles to assemble into a continuous film. We report a new insight to the mechanism behind this banding phenomenon, namely, that inter‐band spacing is strongly influenced by the constituent particle size. We therefore propose a geometric model relating the inter‐band spacing to the particle size. By making banded films with systematically varied particle sizes (silica/zeolite, 20 to 500 nm), we are able to quantitatively validate our model. Furthermore, the model correctly predicts that multilayered banded films have higher inter‐band spacings than monolayered banded films comprising the same particles.     

卵磷脂有序体中碳酸钙超微颗粒的研究

近些年来，国内外对超微颗粒的研究正处方兴未艾，由于纳米级材料与大块物质的特性截然不同，引起了国内外科学工作者的关注，试图用各种方法制备各种超微颗粒．在有序体中制备铂、佬、金、银、锅等超微颗粒已有文献介绍山，在表面活性剂AOT与水形成的有序体中制各碳酸钙超细颗粒也有报导问，用脂质体合成某些超微颗粒的工作也有文章发表［3］．但是由卵磷脂（PC）与水组成人。膜体系制备碳酸钙超微颗粒尚未见到报导．我们根据分子有序组合体具有”隔室化”作用，形成纳米级空间的思路，采用PC－H。0有序体系作为生成碳酸钙的反应场所．…     

磁性粒子在蛋白质分离纯化中的应用

磁性粒子与磁性分离技术结合用于生物分子和生物微粒的分离近年来受到了广泛关注。磁性粒子经过适当的表面修饰,可高度选择性地结合目标蛋白,在解决蛋白质的快速分离及高特异性的选择性分离方面具有优势。随着蛋白质组学研究的发展,磁性粒子用于蛋白质分离纯化的研究日渐增多。本文介绍了磁性粒子和磁性分离的基本特点,综述了近5年国内外有关磁性粒子在蛋白质分离纯化中的应用和发展现状。     

The morphology of isomorphous substituted hectorites

Small-angle scattering (SAS) is used to investigate geometric structure parameters of isomorphically substituted hectorites. The aluminum content, the layer charge, and the purity of the substituted hectorites are related to the Al supply. The structural information contained in the scattering curves I(h) about the morphology of the samples in four different range orders from 1 nm to 300 nm is analyzed using the theory of the chord length distribution. The geometric structure parameters obtained are compared with results from XRD (L ₀-parameter), N₂-adsorption (L ₁ and mesopore size) and photon-correlation spectroscopy (largest dimension L ₃ and characteristic dimension of the secondary particles). Accepted after revision: 13 November 2001 Electronic Publication     

α-Fe粉体浓悬浮体系的制备及磁流变效应

报道使用价格低廉的还原铁粉制备磁性粒子浓悬浮体系,对体系磁流变效应进行研究,并研究了磁性颗粒尺寸和氧化物对悬浮体系力学性质及沉降稳定性的影响.     

DYNAMIC RHEOLOGICAL BEHAVIOR OF POLYPROPYLENE FILLED WITH ULTRA-FINE POWDERED RUBBER PARTICLES

Dynamic rheological characteristics of polypropylene (PP) filled with ultra-fine full-vulcanized powdered rubber (UFPR) composed of styrene-butadiene copolymer were studied through dynamic rheological measurements on an Advanced Rheometric Expansion System (ARES). A specific viscoelastic phenomenon, i.e. “the second plateau“, appeared at low frequencies, and exhibits a certain dependence on the amount of rubber particles and the dispersion state in the matrix. This phenomenon is attributed to the formation of aggregation structure of rubber particles. The analyses of Cole-Cole diagrams of the dynamic viscoelastic functions suggest that the heterogeneity of the composites is enhanced on increasing both particle content and temperature.