(2jd) Surface Nano-Structuring for Membranes Synthesis and Sustainable Separation Processes Development

I am seeking to apply for a faculty position in the Chemical Engineering Department, beginning Fall 2024. I am currently a postdoctoral researcher working with Dr. Gregg Beckham in the Renewable Resources and Enabling Sciences Center at National Renewable Energy Laboratory (NREL). I got my Ph.D. in Chemical Engineering from the University of California, Los Angeles (UCLA) under the guidance of Prof. Yoram Cohen.

Past and Current Research:

During my Ph.D., my research application mainly focused on membrane-based water treatment, purification, and desalination. I worked on the synthesis of surface nano-structured reverse osmosis (RO) and ultrafiltration (UF) membranes, membrane performance characterization, process analysis and optimization of membrane-based water purification systems. My membrane synthesis work led to the development of an approach for fine-tuning the separations performance of UF membranes [JMS, 629, 119180 (2021); Separation. Purification. Technol., 120490 (2022)], low fouling ceramic membranes [Water, 13, 2021 (2021)], low scaling RO membranes [Membranes, 12. 12 (2022): 1287], and synthesis and fabrication of low fouling spiral-wound RO membranes [Desalination, 536, August 15, 2022, 115762]. My work on highly selective RO for contaminants removal has been recently submitted to JMS Letters and work on stimuli-responsive smart polysulfone UF and polyamide RO membranes is expected to be submitted by end of 2023. I am also a co-author of a chapter on Surface Restructuring of RO Membranes [Chapter 10, Water Desalination: Current Status and New Developments, World scientific Publishing Company, 2022]. In addition to the above, I am also contributed to the development of unique wellhead water treatment (for nitrate removal) for deployment in a number of remote and disadvantaged communities in the agricultural region of Salinas Valley, California [J. Env. Management, 250, Nov. 2019, 109487]. My Ph.D. dissertation contains the above work that received the First Place Nation Academic Achievement Award from AWWA.

My current research at NREL mainly focuses on developing and investigating the technical efficiency, economic, and sustainability of membrane-based processes in water and biofuel industries. I am working on several major research projects aimed to produce sustainable aviation fuels from various upstream biological fermentation routes, and my role is mainly in the downstream separation and purification process for in-situ volatile fatty acids recovery. I enhanced the efficiency of the downstream separation process by integrating membrane-based emulsion separator for organic solvent extraction and demonstrated 34% and 55% reduced butyric acid extraction cost and greenhouse gas (GHG) emissions, respectively. I am also working on the downstream separation process scale-up and commissioning of the pilot-scale system, which has the capacity of processing up to 300 L of fermentation broth per hour. I developed membrane processes for oilfield produced water pretreatment, which exhibited 96.5-99.3% reduction in area footprint, 93.3-98.7% reduction in volume footprint of capacity, and up to 60% lower produced water treatment cost compared to the commercial pretreatment processes. In addition, I technically reviewed and evaluated the economic and sustainability of the indirect ocean CO₂ removal processes, and assessed the mutual benefits of its co-location with a seawater desalination plant. The above three studies are expected to be published by end of 2024.

Research Interests:

The work comprising my previous lines of research ranges all the way from nano-scale material synthesis, surface and structural characterization, bench-scale process development and optimization, to pilot-scale process scale up and field demonstration. This exceptional experience has positioned me well to work on the following research directions:

Nano-structured membrane material synthesis for water treatment and desalination

I am interested in developing functionalized membrane through surface nano-structuring. Membrane surface functionalization can be achieved through developing long-lasting, cost-efficient, and convenient post-fabrication membrane modification techniques with nanomaterials, including polyelectrolyte chains, nanoparticles, metal ions, and organic additives. I am particularly interest in using these types of fine property modifications for optimizing and improving membrane selective transport performance, and thus can lead to: (i) reduced membrane’s propensity for organic, inorganic and biological fouling; (ii) enhanced membrane selective separation for specific solutes; and (iii) overcome the typical membrane permeability-selectivity tradeoff. I am also interested in understanding the fundamental impacts of membrane surface modification nano-scale architecture and morphology on solute transport phenomena.

Functionalized surface development for biomedical applications

One of the membrane biomedical applications is pathogen removal and antimicrobial treatment. I am interested in the physiochemical phenomena that govern interactions between pathogens and membrane surfaces modified by biomacromolecules (such as antibodies, lipid bilayers, and other biopolymer assemblies), biocide-releasing nanomaterials (i.e., silver, copper, polymer particles), and abiotic 2D nanomaterials including GO and MoS₂. I seek to identify biological and abiotic material functionalities that trap, immobilize, and destroy (TID) pathogens on the membrane surfaces, and understand molecular mechanisms of bacterial deactivation and deconstruction, interfacial surface phenomena and binding affinities, and transport of pathogens throughout membrane hierarchical material systems. I am also interested in how membrane surface properties and above fundamental interactions respond to environmental variables and stimuli, such as pH, salinity, temperature, humidity, and irradiation to provide scientific principles to extend functionalized membrane lifetimes and improve durability.

Energy- and environmental-efficient membrane-based processes and scale-up

Membrane-based processes have become an increasingly popular separation method due to their numerous attractive advantages including low energy consumption, competitive operating cost, mild operating condition, unique separation principles, transport selectivity, and high separation efficiency. As of today, most of the research efforts regarding membrane applications are into wastewater treatment, water purification, decontamination, and desalination. Other applications of membrane-based processes in carbon removal, membrane reactors, medical applications, pharmaceuticals and biotechnology, food and beverage, oil and gas, and chemical industries are still in their early stages. In the biofuel industry, for example, there is potential to use membrane processes for biomaterials (i.e., lignin, volatile fatty acids, ethers, ethanol, oligomers and monomers) extraction, concentration, fractionation, and purification. Consequently, I am interested in membrane processes engineering and development in specific applications, and compare side by side with the industrial processes in terms of energy consumption, process economics (TEA), and carbon intensity (LCA). The resultant analysis data will be further used to support process scale-up and pilot demonstration.

Funding opportunities:

During my postdoc period, I have extensive experience in seeking research funding opportunities and collaborating with PIs and co-workers at NREL, UCLA, U.S. EPA, and other university and industrial partners. I was involved in writing 5 proposals to US Department of Energy (DOE) with research interests ranging from waste-to-energy, lignin extraction and valorization, wastewater treatment and resource recovery, to effective pathogen removal filter material development. Among the 5 proposals, one was awarded ($3,000,000, Co-PI, 2024-2026) and the rest are still pending final results. With the gained knowledge and experience, I plan to apply as both Principal Investigator (PI) and co-PI for DOE Office of Science (OS), Bioenergy Technologies Office (BETO), Office of Energy Efficiency & Renewable Energy (EERE), and Office of Fossil Energy and Carbon Management (FCEM), National Alliance for Water Innovation (NAWI), Department of Water Resources, US Bureau of Reclamation, and National Science Foundation (NSF) in 1-3 years from starting faculty position.

Teaching Interests:

I have experience mentoring multiple undergraduate and graduate students and serving as a teaching assistant for courses including Thermodynamics, Transport Phenomena, Membrane Science and Technology, and Polymer Processes. I am interested in teaching Fundamentals of Chemical and Biomolecular Engineering, Mass Transfer, Separation Processes, Chemical Engineering Laboratories, and Membrane Science and Technology. I value diversity, equity and inclusion, and take very seriously the responsibility of educating students. I will continue learning and applying best practices of education and assessment to ensure students’ success in the academic environment.