共查询到4条相似文献,搜索用时 0 毫秒
1.
Gu Xiaohong Nguyen Tinh Sung Li-Piin VanLandingham Mark R. Fasolka Michael J. Martin Jonathan W. Jean Y. C. Nguyen Diep Chang Nei-Kai Wu Tsun-Yen 《Journal of Coatings Technology and Research》2004,1(3):191-200
Surface properties of a polymeric coating system have a strong influence on its performance and service life. However, the
surface of a polymer coating may have different chemical, physical, and mechanical properties from the bulk. In order to monitor
the coating property changes with environmental exposures from the early stages of degradation, nondestructive techniques
with the ability to characterize surface properties with micro- to nanoscale spatial resolution are required. In this article,
atomic force microscopy has been applied to study surface microstructure and morphological changes during degradation in polymer
coatings. Additionally, the use of AFM with a controlled tip-sample environment to study nanochemical heterogeneity and the
application of nanoindentation to characterize mechanical properties of coatings surfaces are demonstrated. The results obtained
from these nanometer characterization techniques will provide a better understanding of the degradation mechanisms and a fundamental
basis for predicting the service life of polymer coatings.
Presented at the 81st Annual Meeting of the Federation of Societies for Coatings Technology on November 12–14, 2003, in Philadelphia,
PA. 相似文献
2.
Yang-Kook Sun Dong-Won Kim Sung-Ho Jin Yoo-Eup Hyung Sung-In Moon Dong-Kyu Park 《Korean Journal of Chemical Engineering》1998,15(1):64-70
Spinel-type LiMn2O4 powders having submicron, narrow particle-size distribution and excellent phasepure particles have been synthesized at low temperatures from metal acetate aqueous solution containing glycine as a chelating agent by a sol-gel method. The dependence of the physicochemical properties and cycling characteristics of the spinel LiMn2O4 powders on the various calcination temperatures has been extensively studied. It was found that the physicochemical properties of the LiMn2O4 powders could be controlled by simply varying the calcination temperature. Glycine-assisted LiMn2O4 powders have shown excellent rechargeability and delivered discharge capacity of 119 mAh/g for more than 150th cycles in Li/polymer electrolyte/liMn2O4 cells. 相似文献
3.
Suzana ŠegotaLidija ?urkovi? Davor LjubasVesna Svetli?i? Ivona Fiamengo HouraNenad Tomaši? 《Ceramics International》2011,37(4):1153-1160
The application of heterogeneous photocatalysis is described as an advanced oxidation process (AOP) for the degradation of the diazo reactive dye using immobilized TiO2 as a photocatalyst. Starting TiO2 solutions were prepared with and without the addition of polyethylene glycol (PEG) and TiO2 films were directly deposited on a borosilicate glass substrate using the sol-gel dip-coating method. The surface morphology and the nanoscale roughness of TiO2 films were studied by means of atomic force microscopy (AFM). Structural properties of TiO2 were identified by X-ray diffraction (XRD). The decomposition behaviour of organic compounds from the gels was investigated using thermal gravimetry (TG) and differential scanning calorimetry (DSC). Photocatalytic activities of TiO2 films in the process of degradation of the commercial diazo textile dye Congo red (CR), used as a model pollutant, were monitored by means of UV/vis spectrophotometry. The kinetics of the degradation of the CR dye was described with the Langmuir-Hinshelwood (L-H) kinetic model.The addition of PEG to the TiO2 solution resulted in the changes in the film surface morphology, and affected the ratio of anatase-rutile crystal phases and the photocatalytic activity of TiO2. The TiO2 film prepared with PEG is characterized by higher roughness parameters (Ra, Rmax, Rq, Rz and Zmax), a lower amount of the rutile phase of TiO2, a higher amount of the anatase phase of TiO2 and a better photocatalytic activity compared to the TiO2 film without the addition of PEG. 相似文献
4.
Changsheng Zhao Shengqiang Nie Min Tang Shudong Sun 《Progress in Polymer Science》2011,36(11):1499-1520
Significant progress has been achieved in recent years in the field of pH-sensitive membranes. In many cases, pH-sensitive membranes are systems for which the flux, membrane pore size, and solute rejection ratio may be manipulated by changing the pH. This review summarizes recent developments covering the preparation, pH-responsive properties, and applications in various disciplines. The pH-sensitive groups and the evaluation parameters for pH-sensitive membranes are reviewed and discussed. A variety of preparation methodologies, including blending, pore-filling, surface-grafting, and surface-coating techniques are described, and some of their salient features are highlighted. The flat-sheet form and hollow-fiber form pH-sensitive membranes are reviewed. Membrane pore size change and electroviscous effect are discussed. Furthermore, future perspectives of pH-sensitive membranes are discussed. 相似文献