仿生沉积法制备水下低气体黏附透明材料

Transparent Materials with Low Underwater Bubble Adhesion via Bio-inspired Co-deposition

透明材料常用于水下设备中,而聚合物透明材料多较为疏水,在水下易黏附气泡,影响其光学性能.利用多巴胺(DA)和聚乙烯亚胺(PEI)共沉积技术,在多种透明聚合物材料表面构建了亲水/水下超疏气涂层.结果表明,聚多巴胺(PDA)与PEI可通过Michael加成或Schiff碱反应在此类材料表面形成亲水交联网络,显著提高其表面亲水性.表现为水接触角显著降低,而水下气接触角显著提高(>140?),气泡在材料表面的黏附力显著下降.沉积时间在6 h以下时,XPS和椭圆偏振测试的结果表明,虽然所选用的透明材料表面沉积量和沉积厚度随时间有所上升,但其透光性不会受到显著影响.该方法具有较强的普适性,可用于多种水下气体黏附性较强的透明高分子材料,如聚苯乙烯(PS)、聚对苯二甲酸乙二醇酯(PET)、聚甲基丙烯酸甲酯(PMMA)、聚丙烯(PP)和聚酰亚胺(PI)等.同时,该方法形成的涂层的长期稳定性也较好,材料在水中浸泡振荡10天之后仍能保持较好的抗气泡黏附能力.该方法适用于如潜水艇舷窗、护目镜、水下光学镜头及其防护罩等水下设备中.

To fabricate hydrophilic/underwater superaerophobic coatings on various transparent materials, such as polystyrene（PS）, polypropylene（PP）, polymethylmethacrylate（PMMA）, polyimide（PI） and polyethylene terephthalate（PET）, a co-deposition method of polydopamine（PDA） and polyethyleneimine（PEI） is developed in this work. This method enables one to overcome the obstacle of the bubble adhesion phenomenon in the transparent materials used in underwater devices such as swim goggles and submarine windows. By adding PDA and PEI, a hydrophilic cross-linking network is formed on the material surface via Michael addition or Schiff-base reaction. The modified surface demonstrates improved hydrophilicity, and the water contact angle decreases from 80？ to 66？ while the submerged gas contact angle increases from 100？ to 146？, exhibiting extremely low gas adhesion under water. All these materials are immersed into water during a continuous bubbling process, the PDA/PEI modified surfaces show great gas repellent ability in water on which no obvious bubbles are observed. XPS results and ellipsometer tests show that, with extended deposition time, the amount of the PDA/PEI coating and the thickness of the PDA/PEI coating grow. Meanwhile, the absorption of substrates increases slightly in the visible region with a deposition time below 6 h, which meets the requirements in high transparency and light transmittance. At the same time, the stability of the PDA/PEI coating is measured. After 10 days of submerging and shaking under water, the transparent materials maintain their hydrophilicity and underwater superaerophobicity after deposition, and the sheets exhibit extremely low gas adhesion during underwater bubbling process. Such coating can be applied on various transparent polymer materials such as PP, PMMA, PI and PET（all the submerged gas contact angles are above 140？）, which are promising to be used in many submerged devices such as swim goggles, submarine windows, underwater optical lens and transparent shields.