Microstructure formation in dip-coated particulate films.
Microstructure formation in dip-coated particulate films.
复制标题
浸涂颗粒薄膜中微结构的形成。
DOI：
10.1016/j.jcis.2005.07.049
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发表时间：
2006
影响因子：
9.9
通讯作者：
N. Dingenouts
中科院分区：
文献类型：
--
作者：
L. Günther;W. Peukert;G. Goerigk;N. Dingenouts
研究了浸涂微粒薄膜的微观结构对用作涂覆浴的水性硅溶胶的稳定性的依赖性。通过改变电解质浓度和pH值，调节溶胶中不同的稳定条件。在涂覆过程之前小心避免颗粒的明显聚集。稳定性行为的表征明确证明了在低pH值下归因于水合力的非DLVO贡献。采用透析累积法研究了成膜过程中颗粒网络的结构演化。累积的溶胶的粘度作为剪切速率的函数进行测量，并与涂布过程的干燥特性相关。原子力显微镜（AFM），小角X射线散射（SAXS）和N2吸附被用来获得信息的表面和体积结构的浸涂膜。涂层的结构被发现明显不同的稳定性参数。这归因于在第一干燥阶段期间变化的相互作用。最后，确定了涂层结构对光透射性能的影响。未涂覆的和涂覆的基底的消光之间的比较揭示了取决于微观结构的高达±50%的差异。
The microstructure-dependence of dip-coated particulate thin films on the stability of an aqueous silica sol used as coating bath is studied. Different stability conditions are adjusted in the sol by changing electrolyte concentration and pH value. Care was taken to avoid pronounced aggregation of the particles before the coating process. The characterization of the stability behavior gives clear evidence of a non-DLVO contribution at low pH values that is attributed to hydration forces. Structural evolution of the particulate network during film formation is studied using a dialysis accumulation procedure. The viscosity of the accumulated sol is measured as a function of shear rate and related to the drying characteristic of the coating process. Atomic force microscopy (AFM), small-angle X-ray scattering (SAXS) and N2sorption are used to obtain information on the surface and volume structure of the dip-coated films. The structure of coatings is found to distinctly vary with stability parameters. This is attributed to changing interactions during the first drying stage. Finally, the influence of coating structures on the light transmission properties is determined. A comparison between the extinction of the uncoated and the coated substrate revealed a difference of up to ±50% in dependence on the microstructure.