Department of Chemical Engineering, College of Petrochemical Engineering, Lanzhou University of Technology, Lanzhou 730050, PR China.
Department of Chemical Engineering, College of Petrochemical Engineering, Lanzhou University of Technology, Lanzhou 730050, PR China; Key Laboratory of Clay Mineral Applied Research of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, 730000 Lanzhou, PR China.
J Colloid Interface Sci. 2018 Apr 1;515:255-263. doi: 10.1016/j.jcis.2018.01.034. Epub 2018 Jan 10.
The applications of superhydrophobic coatings in daily life are receiving increasing attention. Here, we report a general approach for preparing superhydrophobic coatings with high repellency to daily consumed liquid foods based on food grade waxes. The coatings are prepared by spray-coating the homogeneous wax suspensions in ethanol followed by annealing at 40 °C. The wax suspensions are formed by the heating dissolution-cooling precipitation-ultrasonication process thanks to the unique solubility of the waxes in ethanol. Ultrasonication of the wax suspension is helpful to improve superhydrophobicity by reducing the size of the wax microplatelets. Annealing at 40 °C could enhance mechanical stability of the coatings. The coatings are superhydrophobic with a water contact angle of 158.2° and a sliding angle of 7.3°. The coatings are resistant to intense water jetting and immersion in corrosive aqueous solutions. In addition, the coatings show excellent anti-adhesive properties for various liquid foods including cola, honey, milk and yoghourt. Moreover, the coatings are applicable onto different substrates (e.g., glass slide, PET plate and polyethylene plate) and could be prepared using different waxes (e.g., paraffin wax, beeswax and microcrystalline wax). We believe that the wax superhydrophobic coatings could find applications in various fields such as anti-adhesion of liquid foods, fruit preservation and anti-bioadhesion, etc.
超疏水涂层在日常生活中的应用越来越受到关注。在这里，我们报道了一种基于食品级蜡制备具有高排斥力的疏水性涂层的通用方法，用于日常消耗的液体食品。该涂层通过喷涂乙醇中的均匀蜡悬浮液，然后在 40°C 下退火来制备。蜡悬浮液是通过加热溶解-冷却沉淀-超声处理过程形成的，这得益于蜡在乙醇中的独特溶解度。超声处理蜡悬浮液有助于通过减小蜡微片的尺寸来提高疏水性。在 40°C 下退火可以增强涂层的机械稳定性。该涂层具有超疏水性，水接触角为 158.2°，滑动角为 7.3°。该涂层能够抵抗强烈的水流喷射和浸入腐蚀性水溶液中。此外，该涂层对各种液体食品（如可乐、蜂蜜、牛奶和酸奶）表现出优异的抗粘性。此外，该涂层适用于不同的基底（例如，载玻片、PET 板和聚乙烯板），并且可以使用不同的蜡（例如，石蜡、蜂蜡和微晶蜡）来制备。我们相信蜡超疏水涂层可以在防粘液体食品、水果保鲜和防生物附着等各个领域得到应用。
