Bioinspired Nanomanufacturing of Graphene-embedded Superhydrophobic Surfaces with Mechanical and Chemical Robustness

超疏水表面具有优异的憎水性能，可应用于各种领域。然而，许多现有的超疏水表面无法承受机械磨损或化学污染。此外，静水压力、蒸发、外力和表面缺陷也会导致超疏水性的丧失。挑战是制造稳定的超疏水表面，可以抵抗化学和机械磨损。该奖项的灵感来自与荷叶相关的超疏水性的稳健性，该奖项支持基础研究，以产生简单且廉价的制造工艺知识，该工艺将多层石墨烯的激光划线与软光刻相结合，以创建坚固耐用的超疏水表面。耐用的超疏水表面的可用性将影响几个行业，如国防、能源、医疗保健、生物医学、航空航天、电子和汽车，这些行业需要防水、防污和类似的性能，这将使美国经济和社会受益。该项目的重点是扩大妇女和代表性不足的少数群体的参与，并为他们提供通向与研究相关的职业的桥梁。它为本科生、研究生和高中生提供超疏水表面和纳米制造方面的教育和实践培训。该项目解决了超疏水表面的一个核心问题，即缺乏耐用性。制造过程包括使用多层石墨烯激光划线来模拟莲花蜡，并通过软光刻结合纳米结构来模拟莲花乳头，从而创造出一种全新的合成超疏水材料，在各种具有挑战性的曝光条件下具有非凡的稳定性。然而，多层石墨烯厚度与机械和化学耐久性之间的基本关系以及热力学稳定性和表面拓扑之间的基本关系仍然知之甚少。该项目旨在培养激光划线多层石墨烯的基础知识，以提高热力学、化学和机械稳定性。激光刻划过程将氧化石墨烯还原为石墨烯，从而捕捉到关键的荷叶特征，这些特征将使荷叶表面在机械上坚固耐用，同时保持超疏水性。此外，通过测量失去超疏水性的临界拉普拉斯压力和临界磨损周期来研究热力学和机械耐久性的量化，使人们能够系统和彻底地了解石墨烯层特性、图案拓扑和增强耐久性之间的潜在关系。由于多层石墨烯厚度和表面拓扑是设计参数，一旦了解，它可以为耐用的超疏水表面的合理设计奠定坚实的基础。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。

Super-hydrophobic surfaces with excellent water-repellent properties can find applications in various fields. However, many existing super-hydrophobic surfaces cannot endure mechanical wear nor chemical contamination. In addition, the hydrostatic pressure, evaporation, external force, and surface defects can also result in the loss of super-hydrophobicity. The challenge is to manufacture stable super-hydrophobic surfaces that can resist chemical and mechanical wear. Inspired by the robustness of the super-hydrophobicity associated with the lotus leaf, this award supports fundamental research to generate knowledge for a simple and inexpensive manufacturing process that integrates laser-scribing of multilayer graphene with soft lithography to create robust and durable super-hydrophobic surfaces. The availability of durable super-hydrophobic surfaces would impact several industries such as defense, energy, healthcare, biomedical, aerospace, electronics, and automotive, where water-repellent, antifouling and similar properties are needed, which would benefit the U.S. economy and society. The project focuses on broadening participation from women and underrepresented minority groups and provides them with a bridge toward research-related careers. It provides education and hands-on training in super-hydrophobic surfaces and nanomanufacturing to undergraduate, graduate, and high school students. This project addresses a central concern of super-hydrophobic surfaces, which is the lack of durability. The manufacturing process involves the use of laser-scribing of multilayer graphene to mimic lotus wax in combination with nanostructures by soft lithography to mimic the lotus papillae, thus creating an entirely new class of synthetic super-hydrophobic materials with exceptional stability under various challenging exposure conditions. However, the fundamental relationships between multilayer graphene thickness and mechanical and chemical durability and between the thermodynamic stability and the surface topology are still poorly understood. This project aims to cultivate fundamental knowledge of laser-scribing the multilayer graphene to enhance thermodynamic, chemical, and mechanical stability. The laser-scribing process reduces graphene oxide to graphene, thus capturing key lotus leaf features that would make the surface mechanically robust, while maintaining super-hydrophobicity. Moreover, the researched quantification of the thermodynamic and mechanical durability by measuring the critical Laplace pressure and the critical abrasion cycle at which the super-hydrophobicity is lost enables a systematic and thorough understanding of the underlying relationships among the characteristics of the graphene layer, pattern topology, and enhanced durability. Because multilayer graphene thickness and surface topology are design parameters, once understood, it can lay a solid foundation for the rational design of durable super-hydrophobic 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.