Novel membrane materials for CO₂ capture from flue gas and syngas; antifouling membranes for water purification; understanding of polymer structure/property correlations in thin films
Dr. Lin’s research group focuses on the study of advanced polymer-based membrane materials and processes for gas and vapor separation and water purification. As an energy efficient separation technology, membrane is an attractive alternative to conventional thermally driven and energy intensive separations in addressing critical challenges in the area of energy and sustainability. Our research projects are often composed of design and synthesis of new materials and characterization of material structure and transport properties, with an end goal of solving practical problems and advancing fundamental understanding of structure-property correlation. A selection of current projects is shown below.
Growing evidence indicates that man-made emissions of greenhouse gases, principally CO₂, are contributing to global climate change. The bulk of these CO₂ emissions are caused by the combustion of fossil fuels for power production. One approach to controlling CO₂ emissions to the atmosphere is to capture the CO₂ from the postcombustion flue gas or the precombustion syngas at the power plants for utilization or sequestration. The key to enabling the sustainable power production is a technology that can capture CO₂ from the mixtures with N₂ and H₂ at a low-cost and energy-efficient manner. We propose to molecularly design and engineer polymers with high CO₂ permeability and high CO₂/N₂ and CO₂/H₂ selectivity or polymers with high H₂ permeability and high H₂/CO₂ selectivity.
Polymeric membranes for wastewater reuse are often fouled by suspended solids and dissolved organic matters, resulting in dramatic decrease in water flux. We are pursuing two approaches to mitigate the fouling . First, we aim to develop a facile approach to graft zwitterions (with superior hydrophilicity) to avoid favorable interactions between the membranes and foulants. Second, we aim to introduce micro/nano-patterns on the membrane surface to enhance the hydrodynamic force of the flow.
Development of high performance polymer materials for energy efficient membrane separation is often hampered by their deteriorated separation performance when made into industrial thin film composite membranes operating in the presence of strongly plasticizing components such as heavy hydrocarbons. Recently, perfluoropolymers attract significant interests, because of their superior stability against aging and plasticization. The objective of this program is to develop a fundamental, molecular-based mechanistic understanding of the effect of fluorination on the polymer thin film stability against aging and hydrocarbon-induced plasticization, and apply the guidelines to design a new generation of high performance membrane polymers for practical CO₂/CH₄ and C₃H₆/C₃H₈ separations.