SBIR Phase II: Ultra Permeable Carbon Nanotube Membranes for Forward Osmosis

This Small Business Innovation Research (SBIR) Phase II project will take advantage of the unique properties of carbon-nanotube (CNT) pores to develop membranes that are specifically tailored for forward osmosis (FO) applications. FO processes have a number of advantages over evaporation and pressure-driven membrane processes: low energy cost, low mechanical stresses, and high product concentration. The main problem impeding the widespread use of FO remains the lack of robust optimized FO membranes. CNT membranes are ideal for FO applications as they offer improvements in all relevant membrane characteristics: (1) improved structural integrity; (2) high permeability; (3) robust chemical stability; and (4) low fouling propensity. Most importantly, CNT membranes can be fabricated with sufficient structural support in the active layer to operate with only minimal external reinforcement, which minimizes concentration polarization losses. This project builds on the fabrication and functionalization approaches developed in Phase I, and applies them on a larger scale to achieve the objective of developing membranes with fast flow and high selectivity at reasonable production costs. Performance of the membranes will be benchmarked using laboratory tests that simulate real-world applications. This project will deliver an innovative FO membrane platform that exhibits superior performance and stability in FO applications. The broader impact/commercial potential of this project will be to enable a variety of green technologies such as renewable power generation, wastewater reuse, and energy-efficient desalination. Although FO-based processes are extremely energy efficient, their commercial use has been hampered by the lack of high performance FO membranes. This project should produce two main outcomes. First, it would deliver a solid technical foundation for developing a novel FO membrane platform that would provide a superior commercial alternative to existing FO membrane architectures. Second, the performance advantages of the CNT membranes would open up several applications for commercial development.