神奇的表面化学——油水分离膜的制备及应用

Magical Surface Chemistry:Fabrication and Application of Oil-Water Separation Membranes

日常生活中的表面化学应用无处不在,从“荷叶效应”的自然现象,到特种工业制品的防水、防冻,抗污等性能,这看似生活化、简单的现象背后却蕴含着鲜为人知的表面原理。本实验通过在熔喷布膜表面层层自组装沉积植物多酚——单宁酸(TA)和铁离子Fe(Ⅲ)配位化合物使其形成亲水涂层,再利用高碘酸钠(NaIO_(4))氧化儿茶酚基团促进多酚-金属网络在熔喷布膜表面的固定,进而实现织物从疏水到亲水的改性,最后利用油水分离装置展示膜的分离效果。实验通过展示材料的改性过程及材料改性前后性能差异,层层解析其背后蕴含的物理化学本质。此科普实验所用试剂绿色、操作简单、观赏性及互动性强、改性后的膜具有可循环利用的优势。在面向不同阶段的科普对象时我们采用梯度科普,深入浅出地讲解现象背后蕴含的原理和本质,让公众在获得知识的同时感受到表面化学的神奇和化学之美。该实验不仅可以用于科普实验也可以用于课堂教学,并且具有优异的应用前景。

Surface chemistry permeates various aspects of our daily lives,from the natural phenomenon of the“lotus leaf effect”to the functionalities of specialized industrial products like waterproofing,anti-freezing,and anti-fouling coatings.While these phenomena may seem commonplace and straightforward,they harbor intricate principles of interfacial science.In this experiment,we employ a layer-by-layer self-assembly technique to deposit a hydrophilic coating composed of plant polyphenol tannic acid(TA)and iron(Fe(III))coordination complex onto the surface of a melt-blown fabric membrane.Subsequent oxidation of catechol groups using sodium periodate(NaIO_(4))facilitates the fixation of the polyphenol-metal coordination complex network at the fabric interface,thereby achieving a transition from hydrophobic to hydrophilic modification.Finally,we demonstrate the efficacy of the modified melt-blown fabric membrane in oil-water separation processes.Through this endeavor,we not only showcase the modification process of materials and the resulting property alterations but also delve into the underlying physical and chemical principles layer by layer.The reagents utilized in this educational experiment are environmentally friendly,facilitating simple operation,offering aesthetic appeal,and encouraging interaction.Moreover,the modified membrane boasts recyclability advantages.Employing a gradient approach to science communication,we elucidate the principles and essence behind these phenomena in a comprehensible manner,enabling the public to appreciate the magic and beauty of surface chemistry while acquiring knowledge.This experiment holds promise not only for popular science dissemination and classroom teaching but also for its excellent application prospects.