Below is a summary of each of the current and planned projects that comprise our research program. We recommend that you start by reading the "Background" section, and then returning to the list of projects. You can then jump to any particular project of interest by clicking on the title of that project.
PORE SIZE CONTROL IN MEMBRANE FORMATION
PERFORMANCE ENHANCEMENT VIA MEMBRANE STRETCHING
BIODEGRADABLE MEMBRANES AND DEPTH FILTERS
BACKGROUND
The primary focus of our research is on the materials science aspects of membranes for liquid separation processes such as reverse osmosis, nano-, ultra- and micro-filtration, and dialysis. Specifically, the goal of our research is to control the nano-, micro-, and macro-structure of membranes for improved liquid separations. Three approaches are taken to reach the stated goal: (i) control of the phase separation process and manufacturing steps that determine the structure of the membrane, (ii) physical modification of the membrane, and (iii) incorporating nano-porous inorganic materials in polymeric membranes.
Membrane Formation
Most commercial membranes for liquid separation applications are made by preparing a homogeneous polymer solution, forming the solution into the desired shape (typically, flat sheet or hollow fiber), inducing phase separation to yield polymer-lean domains dispersed in a polymer-rich matrix phase, solidifying the polymer-rich phase, and removing the polymer-lean phase, and drying the membrane to yield a micro- or nano-porous structure. If the phase separation is induced by exchange of a non-solvent for the solvent used to prepare the polymer solution, the process is alternatively referred to as phase inversion, diffusion-induced phase separation, or nonsolvent-induced phase separation. If the phase separation is induced by cooling the polymer solution, the process is referred to as thermally induced phase separation (TIPS). Our research group investigates both of these phase separation processes for membrane formation.
Membrane Modification
During the manufacturing process, the membrane can be stretched to modify the pore structure or it can be chemical treated to create or alter functional groups. As outlined in the "performance enhancement via membrane stretching" link above, our research effort includes an investigation of the effects of membrane stretching on membrane structure and membrane performance.