材料表面润湿性的影响因素及预测模型

目的预测不同材料表面和液体之间的润湿性能。方法选取9种不同板材以及14种实验液体,采用60—1200目砂纸打磨所有平板,得到具有不同粗糙度和表面能的实验材料。利用控制变量法,分别研究了液体表面张力、固体粗糙度和固体表面能对接触角的影响。然后进行了三因素十水平的均匀设计实验,并应用SPSS软件对实验结果进行了线性分析。结果在不同液体的作用下,随着表面张力的增加,接触角不断增大,其中蒸馏水的表面张力最大,为70.13 m N/m,其在三种材料中的接触角也最大。在具有相同粗糙度的材料表面,随着表面能的增加,接触角减小,固体表面能最大(67.72 m J/m2)时,接触角达到最小值,为25.1°。在具有相同表面能的材料表面,随着粗糙度的增加,接触角呈现两种相反的趋势:当θ90°时,随着粗糙度的增加,接触角不断增大;θ90°时,随着粗糙度的增加,接触角不断减小。通过均匀设计得到了接触角的预测模型,发现液体表面张力对接触角影响的权重最大,固体表面能次之,粗糙度最小。结论通过SPSS软件拟合得到了真实材料表面接触角与其影响因素的定量关系式,针对现场管材和液体的选型进行了理论指导,从而有效降低了输送过程中的阻力损失。

Influencing Factors and Prediction Model of Material Surface Wettability

The work aims to predict wettability of surfaces between different liquids and materials. Nine different panels and fourteen kinds of experimental liquids were selected, experimental materials of different roughness and surface energy were ob-tained by sanding all panels with 60—1200 pieces of sandpaper. Effects of liquid surface tension, solid roughness and solid sur-face energy were studied in control variable method, based on which uniform design experiment involving three factors at ten levels was carried out, and the experimental results were linearly analyzed with SPSS software. Under the effect of different kinds of liquids, contact angle increased along with the increase of liquid tension in the same liquid, and the surface tension of distilled water was the maximum (70.13 mN/m), its contact angle in the three materials was the maximum as well. When roughness of the material surfaces was the same, the contact angle decreased as surface energy increased, and the solid surface energy reached peak value (67.72 mJ/m2) when the contact angle was the minimum (25.1°). Obviously, the roughness played a contrary role on contact angle as the roughness increased on the material surface of the same surface energy, that is, the contact angle increased continuously with the increase of roughness when θ>90° and decreased with the increase of roughness when θ<90°.The predication model of contact angle was obtained based upon uniform design.The theoretical model showed that the liquid surface tension was the most important factor, followed by solid surface, and roughness the last. Quantitative relation be-tween contact angle and its influencing factors is obtained by fitting with SPSS software, which can provide theoretical guidance on model selection of tubing and liquid on site, and further reduce resistance loss during delivery process effectively.