CAREER: Towards A Paradigm of Sustainable Liquid Repellent Surfaces

该学院早期职业发展计划(Career)奖支持将在表面科学领域贡献与防液体表面(通常称为不粘涂层)相关的新基础知识的研究。通常，防液体表面是用长链氟碳材料制成的。然而，由于人们越来越担心长链氟碳材料对环境和生物的负面影响，它们正迅速被淘汰。这项研究通过开发替代目前使用的有毒生物蓄积材料的表面处理来促进国民健康。新的疏水性和全方位材料的需求日益增加，用于国防和商业应用，如纺织、恶劣或“肮脏”环境中的表面涂层等。这项工作通过提供设计新型防液表面所需的基本知识来推进表面驱避剂的科学研究，这些新型防液表面具有更环保的短链氟碳材料，并具有与长链氟碳材料相同的性能(即拒液程度)。这种创新的防液表面有可能彻底改变民用、工业和国防部门的不粘涂层技术格局。因此，这项研究的结果和见解将对美国经济和社会大有裨益。教育活动与这项研究相结合，制作了STEM教育工具包和DIY(DIY)视频，供K-12科学课程与教师培训工作坊一起使用。由长链氟碳化合物(即具有8个或更多完全氟化碳的线性分子)组成的憎液表面分解为全氟辛酸，这种酸具有生物累积性，被认为是一种新的污染物。因此，必须开发可替代的可持续材料(例如，短链氟碳化合物)，使其具有与长链氟碳化合物一样的拒液性。这项研究是基于这样的假设，即具有高表面结晶度和重入形态的短链氟碳化合物将提供与长链氟碳化合物相当的拒液性。为了验证这一假设，研究小组将系统地研究氟碳表面配体的分子结构和表面修饰反应坐标对表面结晶度和形貌的影响。由此产生的液体排斥性将进行实验研究，并与理论预测进行比较。总体而言，这项研究将提供对设计拒液表面所涉及的分子结构-加工-结构-性质关系的透彻理解，并为可持续拒液表面的范例铺平道路。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This Faculty Early Career Development Program (CAREER) award supports research that will contribute new fundamental knowledge in the field of surface science, related to liquid-repellent surfaces (often called non-stick coatings). Typically, liquid-repellent surfaces are made with long chain fluorocarbon materials. However, long chain fluorocarbon materials are rapidly being phased out because of the growing concerns regarding their negative environmental and biological impacts. This research promotes national health by developing alternative surface treatments to the currently used toxic bio-accumulating materials. New hydro- and omniphobic materials are increasingly in demand for defense and commercial applications in textiles, surface coatings in harsh or "dirty" environments, among others. The work advances the science of surface repellents by providing the basic knowledge needed to design novel liquid-repellent surfaces with the more benign short chain fluorocarbon materials and with performance (i.e., degree of liquid repellency) equivalent to the long chain fluorocarbon materials. Such innovative liquid-repellent surfaces have the potential to drastically alter the non-stick coatings technology landscape in civilian, industrial and defense sectors. Therefore, the results and insights from this research will be significantly beneficial to the U.S. economy and society. The education activities are integrated with this research through the generation of STEM education kits and do-it-yourself (DIY) videos on "Fun with Surface" to be used in K-12 science classes in conjunction with teacher training workshops.Liquid-repellent surfaces consisting of long chain fluorocarbons (i.e., linear molecules with 8 or more fully fluorinated carbons) decompose into perfluorooctanoic acid, which is bio-accumulative and is considered an emerging contaminant. So, it is essential to develop alternative sustainable materials (e.g., short chain fluorocarbons) that can be as liquid-repellent as long chain fluorocarbons. The research is based on the hypothesis that short chain fluorocarbons with high surface crystallinity and re-entrant morphology will offer liquid-repellency equivalent to long chain fluorocarbons. To test this hypothesis, the research team will systematically investigate the influence of molecular architecture of fluorocarbon surface ligands and surface modification reaction coordinates on surface crystallinity and morphology. The resulting liquid-repellency will be investigated experimentally and compared with theoretical predictions. Overall, this research will provide a thorough understanding of molecular architecture-processing-structure-property relationships involved in design of liquid-repellent surfaces and pave the way to a paradigm of sustainable liquid-repellent surfaces.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.