Randolph-Macon College Engineering Physics Professor James T. McLeskey Jr. has been awarded a grant from Qatar University and the Qatar National Research Fund. McLeskey will use the $260,625 grant to develop an optimized membrane for saltwater desalination. The grant will run through 2019.

“The current methods of desalination are energy intensive and therefore expensive,” explains McLeskey. “My research aims to lower the cost of desalination by increasing the efficiency of a new low-temperature method known as Direct Contact Membrane Distillation (DCMD). This method has many advantages, the greatest of which is that the heat for the evaporation of the water can come from a variety of sources, including solar energy or waste heat from other industrial processes, making it environmentally friendly.”

The DCMD Process
In the DCMD process, water evaporates from a warm saltwater solution and condenses into a cool fresh-water stream. The two streams are separated by a porous membrane. The real trick to improving DCMD, explains McLeskey, is to improve the membrane.

“It needs to have pores or holes all the way through so that the evaporated water vapor can pass through,” he says. “However, it also needs to be ‘superhydrophobic’—or water repellant (like a lotus leaf or a freshly waxed car) so that the liquid will bead up and not pass through.”

Three-step Process
Balancing these two characteristics (large pore size while retaining the ability to repel water) is the goal of McLeskey’s research. The work will be done in three steps. First, computer simulations will be used to design an optimal membrane. The first part of the project will be led by Professor Hooman Tafreshi from the Department of Mechanical and Nuclear Engineering at Virginia Commonwealth University.

Second, the researchers will fabricate and characterize the newly designed membranes using a technique known as electrospinning. This part will be done in McLeskey’s lab at Randolph-Macon College. Finally, the performance of the membranes in an actual DCMD system will be tested. This part of the project will be led by Professor Majeda Khraisheh at Qatar University. Professor Emeritus Mohamed Gad-el-Hak, from Virginia Commonwealth University, is also advising on the project. Ultimately, the team hopes to reduce the cost of water desalination to less than five percent of its current cost.

Student Research
RMC senior capstone student Chris Presley ’16 and Schapiro Undergraduate Research Fellowship (SURF) student Donovan Sweeney ’18 have been participating in the McLeskey’s preliminary research studies, and McLeskey expects to have additional SURF students involved in future work. SURF participants conduct 10 weeks of full-time, original research during the summer months, under the guidance of a faculty mentor.

Sweeney, an engineering physics and mathematics major, learned firsthand that SURF gives students unique opportunities to work alongside faculty as they conduct research.

“My research involved testing the experimental desalination design with several commercially made membranes,” he explains. “The way the design works is by heating saltwater and pumping it across a membrane with cold fresh water on the other side of the membrane. This allows for the water vapor to travel from the salt side to the fresh side, leaving all contaminates in the salty brine.” Sweeney says that mentorship is central to SURF’s success.

“Working one-on-one with a faculty member was a great experience,” says Sweeney, whose post-RMC plans include graduate school, where he may study hydro engineering.  “Professor McLeskey has a huge amount of real-world engineering knowledge, and he was a terrific mentor.”

Presley is an engineering physics major and mathematics minor. For his capstone project, he is working toward developing a membrane that can be used in the desalination of saltwater.

“What I seek to do is create a membrane that is both strong enough and have the right pore size to work in the desalination process,” he says.

James McLeskey
McLeskey, who joined the RMC faculty in 2015, earned his B.S. from the College of William & Mary, his M.S. from University of Illinois at Urbana-Champaign and his Ph.D. from University of Virginia.

McLeskey’s research is focused largely in the areas of renewable energy and clean water. His lab was the first to report the fabrication of solar cells made using a water-soluble polymer, and his background includes six years in industry working on the design and repair of large turbo-generator rotors. McLeskey has received numerous teaching awards, including the 2006 Outstanding Faculty Award from State Council of Higher Education for Virginia (SCHEV). He has authored more than 35 peer-reviewed journal publications, authored two book chapters and served as Principal Investigator or Co-Investigator on more than $1.5M in funded research.