Growing concerns over the environmental impact of hydraulic fracturing of oil and gas wells have prompted stringent regulations on wastewater management. Polymeric membranes offer an attractive approach to recover and reuse the wastewater due to high energy efficiency, small footprint, and low cost. However, the membranes are often subjected to surface fouling by the contaminants in the wastewater, severely limiting their wide adoption. It is imperative to develop an energy-efficient membrane nano patterning technology that can effectively control the membrane surface properties to achieve excellent antifouling properties for wastewater recovery and reuse. This award is to develop a laser chips-based nanoscale photolithography approach for flexible and high-throughput membrane surface nano patterning for wastewater treatment. This research involves multiple disciplines of science and engineering including nanomanufacturing, optical design, modeling, fabrication and characterization, polymer science and processing, and membrane development. These disciplines will be integrated into curriculum development and existing outreach educational activities to provide hands-on research opportunities for graduate, undergraduate, and K-12 students, especially for those from underrepresented groups.
Printing nanoscale patterns on membranes with high throughput photolithography is an effective approach to mitigate surface fouling. Nevertheless, the intrinsic inflexibility and requirement of UV light sources lead to high production cost and low energy efficiency for the nanomanufacturing process. The primary focus of this research project is to develop a novel low-cost and energy-efficient nanomanufacturing process by directly using laser chips for photolithography. A single blue-light laser chip consisting of millions of individual micro-laser cavities will be designed and utilized to transfer the nanoscale laser mode patterns to the surface of polymeric membranes. These surface nanopatterns can be flexibly controlled by manipulating the cavity resonant modes to optimize the membrane surface antifouling properties. The interdisciplinary team of engineers brings expertise in optoelectronic devices, nanomanufacturing, polymer processing and membrane antifouling applications to address the various aspects of the technology. The laser chips-based lithography developed in this project will represent an important technological breakthrough in flexible and high throughput nanoscale patterning, creating robust nanoscale-patterned membranes for wastewater treatment and enabling an environmentally responsible way for energy production.
