表面活性剂对乙烯-醋酸乙烯酯聚合物胶膜润湿性影响的分子动力学模拟

乙烯-醋酸乙烯酯聚合物(ethylene-vinyl acetate, EVA)胶膜是太阳能光伏板的重要组成部分，影响着光伏组件的发电效率、可靠性等性能，但火灾危险性较大。为提高水对EVA胶膜的灭火效果，采用分子动力学模拟的方法，建立14种常见的表面活性剂模型，研究不同种类表面活性剂对于EVA胶膜润湿性的影响，并通过接触角实验验证模拟结果。计算了体系的相互作用能，分析了相对浓度分布、径向分布函数和静电势等参数，从分子尺度揭示润湿机理。结果表明：阴离子表面活性剂作用效果最好，其中十二烷基二苯醚二磺酸钠(sodium dodecyl diphenyl ether disalfonate, SLDED)的亲水基团与水分子的相互作用较强，效能最为突出。在水系灭火剂中添加此类表面活性剂，能够增强水分子在材料表面的附着，达到高效灭火的目的。

Effect of surfactants on the wettability of EVA adhesive film: A molecular dynamics investigation

As an important part of photovoltaic panel, EVA film has an impact on photovoltaic modules such as power generation efficiency and reliability but it has a high fire hazard. In order to improve the fire-extinguishing performance of water on EVA adhesive film, using molecular dynamics simulation methods, fourteen commonly used surfactants were selected to study their effects on the wettability of EVA. Contact angle experiment was been done to verify the simulation results. The interaction energy of the surfactant-EVA adsorption system were calculated. The relative concentration distribution and radial distribution function of the water-surfactant-EVA system and electrostatic potential of surfactants were analyzed to reveal the wetting mechanism at molecular scale. The results show that anionic surfactants have the best effect, among which SLEDE is the most effective, for its hydrophilic group has a strong interaction with water molecules. Adding such surfactants in water system fire extinguishing agents can enhance the attachment of water molecules on EVA to achieve the purpose of efficient fire extinguishing.