Background: There are many patents on design of a material surface with special wetting property, however, theoretical methods are lacked. The wetting property of a nanofiber member has attracted much attention. A material with different sizes or with different structures possesses different wetting properties. No theory can explain the phenomenon.

Methods: The contact angle, fiber fineness, pore size and layer of the nanofiber membrane were tested. The contact angles were measured for membranes with different thicknesses. The geometrical potential is used to explain the experimental phenomenon.

Results: The wetting property of a nanofiber membrane mainly depends on fiber diameter and thickness.

Conclusion: Wetting property of a PVA nanofiber membrane depends upon not only the hydrophilic groups, but also the geometrical structure of its surface, the latter prevails when the porous size of the membrane tends to a nanoscale, and the wetting property can be inverted from hydrophilicity to hydrophobicity.

背景：具有特殊润湿性的材料表面设计有许多专利，但是缺少理论方法。纳米纤维构件的润湿性引起了很多关注。具有不同尺寸或结构的材料具有不同的润湿特性。没有理论可以解释这种现象。

方法：测试了纳米纤维膜的接触角，纤维细度，孔径和层数。测量具有不同厚度的膜的接触角。几何势用于解释实验现象。

结果：纳米纤维膜的润湿性主要取决于纤维直径和厚度。

结论：PVA纳米纤维膜的润湿性不仅取决于其亲水基团，还取决于其表面的几何结构，当膜的孔径趋于纳米级时，后者就占主导地位，并且润湿性可以从亲水性反转疏水性。