墨水直写打印网格膜的润湿性研究

Research on Wettability of the Mesh Membrane Made by Direct Ink Writing

墨水直写(Direct Ink Writing,DIW)制备的硅树脂网格膜,利用图案化的亚毫米级结构具有了超疏水性,可用于油水分离、防水透气等领域。但是,网格膜上的亚毫米结构对其润湿性的影响机理尚未得到深入研究。为深入理解其亚毫米结构对润湿性的影响机理,制备润湿性不同的网格膜,在纤维直径一定的情况下,通过调整亚毫米结构的槽宽和槽深2个特征尺寸,分析水滴的润湿状态及其对接触角和滚动角的影响。结果显示,通过调控亚毫米结构可以改变液滴的润湿状态,对网格膜的润湿性起着决定性作用。在槽深足够的情况下,水滴处于Cassie状态,水滴滚动角较小;随着槽深下降,水滴会从Cassie状态过渡到Wenzel状态,液滴无法滚动。在2种状态下,改变槽宽均可以调节接触角的大小。因此,可以通过亚毫米结构的设计,来实现表面润湿状态的调节。

The silicone mesh membrane prepared by Direct Ink Writing(DIW)with the patterned submillimeter scale structure was super hydrophobic and could be used in the fields of oil-water separation and air-breathable waterproofing.However,the influence mechanism of the submillimeter structure on its wettability has not been thoroughly studied.In order to further understand the influence mechanism of submillimeter structure on the wettability of the mesh membrane and prepare them with different wettability,the wetting states of the water droplets and the influence of the submillimeter structure on the contact angle and sliding angle were analyzed by adjusting the groove width and depth of the submillimeter structure under the condition of a certain filament diameter.The results showed that the wetting states of the droplets could be changed by adjusting the submillimeter structure,which played a decisive role in the wettability of the mesh membrane.When the groove depth was enough,the water droplets were in the Cassie state and the sliding angles were small.As the groove depth decreased,the droplets would transform from the Cassie state to the Wenzel state,which made the droplets can not slide.In both states,the contact angle could be adjusted by changing the groove width.Therefore,the wetting states of the mesh membrane could be adjusted through the structural design of the submillimeter.