Ph.D. Position - Fall 2026 / Spring 2027 - Environmental Engineering, Membrane Processes
Job type: Ph.D. student position
Job rank: Graduate Research Assistant
Institution: Department of Civil and Environmental Engineering, George Washington University
Location: Washington, DC, United States
Start date: Fall 2026 or Spring 2027
Support: Full financial support, including salary/stipend, tuition, and benefits
Position description
The Department of Civil and Environmental Engineering at the George Washington University is seeking one motivated Ph.D. student to conduct NSF-funded research on molecular layer-by-layer deposited reverse osmosis membranes. The student will join Prof. Xitong Liu's research group and collaborate with researchers at the University of Maryland and the National Institute of Standards and Technology. Interested students are encouraged to learn more about the group at https://blogs.gwu.edu/xitongliu/ or contact Prof. Liu at xitongliu@gwu.edu.
Project description
Reverse osmosis membranes are central to seawater desalination and industrial water treatment, but conventional interfacial polymerization often produces polyamide films with rough, heterogeneous surfaces and poorly controlled polymer structures. These structural limitations can contribute to fouling, scaling, and incomplete rejection of certain contaminants. This project will develop next-generation polyamide reverse osmosis membranes using a rinse-free molecular layer-by-layer (mLbL) deposition strategy, in collaboration with the University of Maryland and the National Institute of Standards and Technology. By controlling monomer concentration and delivery volume, the project aims to fabricate ultrathin, highly crosslinked membranes with improved salt rejection, enhanced fouling and scaling resistance, and improved rejection of microcontaminants. The work will also explore how surface properties, including charge and hydrophilicity, influence mineral scaling and organic fouling. The broader goal is to establish a scalable and versatile membrane fabrication platform that links high separation performance with fundamental insight into fouling and scaling mechanisms.
Related publications
- Rinse-free mLbL technique: https://doi.org/10.1016/j.memlet.2025.100098
- Functionalization of mLbL polyamide RO membranes: https://doi.org/10.1016/j.memsci.2022.120855
Related NSF Grants:
https://www.nsf.gov/awardsearch/show-award?AWD_ID=2521800
https://www.nsf.gov/awardsearch/show-award?AWD_ID=2232686
What we offer:
- Full financial support, including stipend, tuition, and benefits.
- Collaboration with researchers at the University of Maryland and the National Institute of Standards and Technology.
- Training in advanced membrane fabrication, surface modification, membrane performance testing, and advanced characterization techniques
- Access to state-of-the-art analytical facilities, including the GW Nanofabrication and Imaging Center (https://nic.gwu.edu/), Materials Characterization Labs at UMD (https://matcl.umd.edu/)
- Guest researcher access to world-leading measurement and characterization facilities at NIST (https://www.nist.gov/ctl/facilities)
- Strong mentorship in research, writing, publication, and career support (academia and industry)
- Travel support to present research at national and international conferences.
- Professional development for careers in academia, industry, government laboratories, or technology startups (including the two tech startups founded by the Liu research group alumni)
Candidate qualifications
Self-motivated candidates with a B.S. degree in Environmental Engineering, Chemical Engineering, Chemistry, Materials Science and Engineering, or a closely related field are particularly encouraged to apply. A master's degree with research experience is desirable but not required.
- Research experience in membranes, polymers, water chemistry, colloids and interfaces, or related areas is preferred.
- Strong written and verbal communication skills in English are highly valued.
- The successful candidate should be able to work independently and collaboratively in an interdisciplinary research environment.
Application instructions
Application links and admissions requirements are available through the GW Engineering doctoral admissions page: https://graduate.seas.gwu.edu/doctoral-admissions-requirements. The deadline will be extended for students applying for Fall 2026 entry. Prospective students are strongly encouraged to send the following materials as a single PDF file to Prof. Xitong Liu at xitongliu@gwu.edu with the subject title: GW PhD application-Your Name-Current Institution
- A cover letter describing motivation and past research experience
- A C.V. or resume
- Undergraduate transcripts and, if applicable, master's transcripts
- TOEFL score, if applicable
GRE scores are currently optional for Ph.D. applications to GW.
About George Washington University and Washington, DC
George Washington University is a private R1 research university located in the heart of Washington, DC. The School of Engineering and Applied Science is housed in the 500,000-square-foot Science and Engineering Hall, which includes a Class 100 nanofabrication cleanroom and an advanced microscopy suite. Recent graduates from the GW Environmental Engineering program have pursued careers as faculty members at major research universities, environmental engineers in consulting firms, and co-founders of startup companies.
GW's Foggy Bottom campus is within walking distance of the National Mall, the Washington Monument, and the Smithsonian museums. Washington, DC offers world-class cultural attractions, high-quality performing arts, and numerous parks and gardens for outdoor activities.
About the principal investigator
Xitong Liu is an Associate Professor in the Department of Civil and Environmental Engineering at the George Washington University. He received B.S. and M.S. degrees from Nanjing University, a Ph.D. from Johns Hopkins University, and postdoctoral training at Carnegie Mellon University. His honors include the George Washington University Early Career Inventor of the Year Award (2026), the AAEES 40-under-40 Recognition Program (2025), the GW OVPR Early Career Award (2025), the CAPEES-ESE Early Career Award (2025), the DOE Geothermal Lithium Extraction Prize Award (2023), the inaugural ACS ES&T Engineering Best Paper Award (2022), the ACS PRF Doctoral New Investigator Award (2020), and the ACS C. Ellen Gonter Environmental Chemistry Award (2017). His research has been published in journals including Environmental Science & Technology, Nature Communications, and Journal of Membrane Science, and has been supported by NSF, SERDP, USDA, and ACS. His students have received awards including the ACS C. Ellen Gonter Environmental Chemistry Award (2024), GW New Venture Competition 1st and 3rd prizes and Sustainability Prize (2023 and 2025), and Cleantech Open Northeast Winner (2023). The Liu research group studies environmentally relevant interfacial phenomena and develops durable, selective, and cost-effective separation technologies for water purification and recovery of critical materials. Current research interests include advancing reverse osmosis membranes for water purification, designing colloidal amendments for groundwater remediation, and developing electrochemical separation technologies for direct lithium extraction from water streams. The Liu research group members and alumni have founded two startup companies: Ellexco focusing on direct lithium extraction, and LayerPure Technologies focusing on fouling resistant, high rejection reverse osmosis membrane fabrication.