This Scalable Nanomanufacturing project will develop new fundamental understanding and manufacturing science needed to transition vapor-phase fiber surface modification technology from small-batch scale to a fully continuous manufacturing prototype. Textiles, nonwovens and other natural and synthetic fiber-based materials are manufactured world-wide and impact the lives of billions of people every day. While common textiles can be very low cost, the field of high-performance and "smart" nonwovens and textiles is evolving rapidly. For example, new electrospun nanofibers and engineered nonwovens are used for battery separators, highly durable aerosol filtration, bio-medical implants, cell growth scaffolds and geosynthetics. For most of these applications, the nano-scale surface structure is critical to achieve the targeted function and capability. Therefore, new manufacturing processes that modify, adjust and control the surface chemistry of fibrous materials at the nanometer scale will have tremendous impact in many emerging product areas. Lab-scale demonstrations show that vapor-phase atomic layer deposition (ALD) and related molecular layer deposition (MLD) provide new and highly promising nano-scale capability to coat and modify complex fibers with high precision, conformality and uniformity, with potential for significant new products. Continuous ALD process needs for pervious substrate materials (where gases can pass through the item being coated) are distinct from those for ALD on solid or other impermeable surfaces. The project will design, evaluate and iteratively improve a continuous roll-to-roll flow-through ALD tool for fibrous substrate materials. Successful outcome will include new research result in ALD reactor design, utilization and surface reaction analysis. The intellectual merit of this project includes contributing to the demand for new understanding in extending nanoscale materials and fabrication techniques to dimensions and magnitude needed to realize low-cost functional products. Work will also yield lab-scale process demonstrations that could attract interest for process scaling, to create new products for improved health, safety and clean energy generation. Additional broader impacts include the education of PhD students in nanoscale materials, materials processing and reaction scaling. The project will also expand outreach to K-12 students and teachers, and it will seek to provide opportunities for underrepresented groups to participate in research and dissemination activity.
