Superhydrophobic Veneers: Surface Coatings Inspired by Nature

超疏水表面结合了固有的疏水性和微尺度的粗糙度，在自清洁表面，耐腐蚀性，拒水性和减少阻力方面具有广泛的潜在应用。通过开发更简单、成本更低的方法，从最初光滑的基材制备这些材料，以及开发保持所谓“Cassie”状态的稳定表面，超疏水表面的应用可以大大扩展到涂层领域，在这种状态下，大部分涂层/水界面上存在一层空气，并赋予表面显著的性能。虽然超疏水表面在自然界中非常丰富，但真正复制自然表面的方法通常是生产手持弹性体材料，而不是表面涂层。在基板上复制高度进化和功能性自然表面的能力可能会彻底改变超疏水涂层的制造，从而产生融合自然和合成世界最佳的独特材料结构和成分。智力优势：该项目引入了一种新的方法，通过表面引发聚合，将大自然的工程、微观粗糙和高功能表面复制到固体基材上。在这种方法中，从自然表面制备的模具的微尺度特征充满了单体。当填充单体的模具被压在初始基底上时，模具的微尺度特征限制了表面引发的聚合，因此生长的、束缚的聚合物链填充了模具的微特征，从而复制了自然表面。这种方法通过自然提供了无限的涂层地形，并通过合成化学（远远超出自然）提供了近乎无限的材料组合，以产生具有新颖结构和结构的超疏水涂层。该项目还通过表面引发聚合引入了新的材料成分和结构，包括在最初光滑的聚合物薄膜上使用超疏水贴面，以提供多功能涂层。该项目的主要目标如下：研究SH聚合物薄膜的生长，作为光滑聚合物薄膜的贴面，以提供独特的分层涂层。开发一种新的表面激发方法，将自然界中的SH涂层复制到固体基材上。更广泛的影响：该项目将开发具有不同成分和独特仿生结构的新型表面涂层，复制高度进化的自然表面，以影响自清洁窗户，腐蚀和磨损保护以及干燥环境中的集水等应用。该项目将通过PI的课堂活动和他对本科生的指导，以及他对K-12学生的大力宣传，将研究和教育结合起来。对于本科生研究人员来说，这个项目将实验室扩展到外部世界，因为大自然独特的表面被识别、收集和复制为涂层。PI将继续通过范德比尔特夏季学院为有天赋的八年级学生提供为期一周的纳米技术强化课程，其中包括一个特殊的实验室组件，用于自然表面的复制。PI将继续通过校园nsf资助的教师研究经验（RET）项目在他的实验室接待一位高中教师。

1134509JenningsSuperhydrophobic surfaces combine intrinsic hydrophobicity with microscale roughness and have a broad array of potential applications in self-cleaning surfaces, corrosion resistance, water repellency, and reduced drag. Applications of superhydrophobic surfaces could be greatly expanded into the area of coatings by the development of simpler, less costly methods to prepare these materials from initially smooth substrates and the development of stable surfaces that maintain the so-called "Cassie" state where an interlayer of air exists over most of the coating/aqueous interface and imparts remarkable properties to the surface. While superhydrophobic surfaces are abundant in Nature, approaches to truly replicate natural surfaces have generally produced hand-held elastomeric materials but not surface coatings. The ability to replicate highly evolved and functional natural surfaces onto a substrate could revolutionize the fabrication of superhydrophobic coatings, leading to unique materials architectures and compositions that fuse the best of the natural and synthetic worlds.Intellectual Merit: This project introduces a new approach to replicate Nature's engineered, microscopically rough, and highly functional surfaces onto a solid substrate through surface initiated polymerization. In this approach, the microscale features of a mold prepared from a natural surface are filled with monomer. When the monomer-filled mold is pressed against an initiated substrate, the microscale features of the mold function to confine a surface-initiated polymerization so that the growing, tethered polymer chains fill the microfeatures of the mold,thereby replicating the natural surface. This approach offers a limitless supply of coating topographies through Nature and a near-boundless array of materials compositions through synthetic chemistry (well beyond those in Nature) to generate superhydrophobic coatings with novel architectures and structures. The project also introduces new materials compositions and structures through surface-initiated polymerization, including the use of superhydrophobic veneers atop initially smooth polymer films to provide multi-functional coatings. The broad objectives of the project are as follows:1. Investigate the growth of SH polymer films as veneers atop smooth polymer films to provide uniquely layered coatings.2. Develop a novel surface-initiated method to replicate SH coatings in Nature onto solid substrates.Broader Impacts: This project will develop new surface coatings with varied compositions and unique biomimetic architectures that replicate those of highly evolved natural surfaces to impact such applications as self-cleaning windows, corrosion and wear protection, and water collection in dry environments. The project will integrate research and education through the PI's classroom activities and his mentoring of undergraduate research students, as well as his strong commitment to outreach for K-12 students. For undergraduate researchers, this project extends the lab into the outside world, as Nature's unique surfaces are identified, collected, and replicated as coatings. The PI will continue to offer an intensive week-long course on nanotechnology to gifted rising eighth graders through the Vanderbilt Summer Academy with a special laboratory component on the replication of natural surfaces. The PI will continue to host a high school teacher in his laboratory through an on-campus NSF-funded Research Experiences for Teachers (RET) program.