Membrane Materials and Transport Studies for Sustainable Water, Energy and Life Sciences

Membrane Materials and Transport Studies for Sustainable Water, Energy and Life Sciences

Ngoc Bui, Lawrence Livermore National Laboratory, Livermore, CA

2^nd Year Postdoctoral Fellow

Research Interests and Future Direction:

Overcoming the emerging global scarcity of water, energy, and other natural resources (e.g., nutrients, metals, minerals, etc.) are grand challenges faced by humanity today. These critical resources are inextricably linked, and therefore, must be considered together as new technologies are developed. Membrane-based processes promise to provide more efficient and economical separation solutions which are then applicable at large scale for sustainable water and energy production. Recent advances in controlled fabrication and characterization of materials at nanoscale allow for creative designs of functional membranes with effective nanostructure and chemistry. Furthermore, they provide effective tools to unravel transport mechanisms of various molecules across different membrane nanostructures which are crucially important for the development of next-generation membranes with enhanced permselective performance at lower energetic and environmental costs.

In a big picture, my research interests lie in tackling the energy - water nexus by seeking a robust and cost-effective solution to produce water sustainably using renewable energy. Forward osmosis (FO) is a unique and emerging platform technology that may ultimately help address water, resource, and energy scarcity by enabling the harvesting of salinity gradients for electricity generation (pressure retarded osmosis), concentrating high-value dissolved solids for recovery and beneficial reuse (direct osmotic concentration), and converting saline waters to fresh water (FO). Such a versatile technology platform has inspired an increasing number of imaginative uses for both broad and niche applications. Challenges remain, however, as widespread adoption of this platform technology is hindered by the lack of an appropriately designed membrane. Therefore, I would like to spend efforts on innovating new membrane structures by interdisciplinarily bridging nanotechnology and membrane science for the next generation of membrane with high permselectivity, mechanical integrity, anti-fouling and scalability. Also, I am interested in leveraging the advanced characterization tools to study the correlations between membrane nanostructure and chemistry with the transport properties of chemical species across membranes which, in turn, offer opportunities for better predictive models and system designs with precise control to be proposed. I would like to unite the gathered knowledge from my master degree (synthesizing activated/porous carbon nanofibers as efficient electrodes for energy storage devices), my Ph.D. (synthesizing thin-film composite membranes supported on nanofiber-related materials for sustainable water and energy production via forward osmosis; and developing osmotic transport model across the semipermeable membrane) and my postdoc (developing robust vertically-aligned carbon nanotube membranes for breathable and protective fabrics; and unraveling the transport mechanisms through nanoconfinement) as a toolkit in further exploring my direction. Furthermore, I am also interested in learning and exploring more niche applications (in drug delivery, protective fabrics, wound dressings, biomolecule separation devices, adsorption, bio-inspired materials and so on) for functionalized nanomaterials (nanofibers, nanotubes) and their composites. Based on the proposals that I have assembled, I foresee myself collaborating with other experimentalists, the simulation teams and industry.

 

Proposals:  LDRD-Labwide

Postdoctoral Project:  “Breathable and Protective Fabrics based on Vertically-aligned Carbon Nanotube Membrane”. Under supervision of Dr. Kuang Jen Wu and Dr. Francesco Fornasiero, Physical and Life Sciences, Lawrence Livermore National Laboratory, Livermore, CA.

 

PhD Dissertation:  “Nanofiber-supported Thin-film Composite Membrane Synthesis and Transport Study for Forward Osmosis”. Under supervision of Professor Jeffrey R. McCutcheon, Chemical and Biomolecular Engineering Department, University of Connecticut, Storrs, CT.

 

Research Experience:

·         Pioneered in the development of a new and effective generation of nanofiber-supported thin-film composite membrane platform for sustainable water and energy production by harnessing salinity-gradient energy via engineered osmosis (forward osmosis and pressure-retarded osmosis).

-          Synthesized submicron-thick polyamide film onto highly porous nanofibrous web.

-          Studied the correlation between membrane structures and properties (e.g. functionalized nanofiber structure, interconnected porous structure, pore size distribution) with their performances (e.g. water permeability, osmotic water flux, water/salt selectivity, power density harnessed from salinity-gradient energy).

-          Characterization/testing techniques: FE-SEM, TEM, thermal analyses, tensile strength, contact angle, FT-IR, BET specific surface area, reverse osmosis, microfiltration, forward osmosis, pressure-retarded osmosis.

·         Expertise in electrospun nanofiber

-          Developed various nanofibrous support platforms for thin-film composite membrane from different polymers, solvents and nanocomposite.

-          Controlled nanofibers structures and properties (e.g. mechanical properties, fiber surface porosity/roughness via electrospinning process control).

·         Integrated expertise in (activated) carbon nanofiber synthesis with their potential in water treatment and sustainable energy production.

-          Introduced concept and skillset learnt from South Korea to the new laboratory at UCONN, indirectly leading to several funding awards from National Science Foundation and others in which carbon nanofiber is the core material.

-          Developed synthesis procedure and preliminary results as well as trained lab-members on fabricating activated carbon nanofiber (received student proposal award for Multidisciplinary Environmental Research Proposal by UCONN Center for Environmental Sciences and Engineering (CESE), PI: Dr. Jeffrey McCutcheon, Co-PI: Dr. Baikun Li).

·         Developed a new mathematical osmotic transport model.

·         Systems design

-          Designed and custom-built electrospinning systems and trained lab-members on nanofibers fabrication.

-          Custom-built cross-flow forward osmosis system (working with another lab member).

Master Dissertation:  “Activated Carbon Nanofibers as Electrodes for Supercapacitors”

Chonnam National University, Gwangju, S. Korea.

Research Experience:

·         Developed high specific surface area activated carbon nanofibrous electrode for supercapacitor (aim is to increase energy density and specific capacitance of supercapacitors by controlling the porous structure and specific surface area of carbon nanofiber electrode derived from decorated polymeric nanofibers).

·    Studied electrochemical performance of porous carbon fiber-based electrodes.

·    Characterization/Testing techniques: FE-SEM, TEM, BET specific surface area, Nitrogen adsorption, thermal analyses, impedance spectroscopy, cyclic voltammogram, charge - discharge behaviors.

 

Teaching Experience:

Guest Lecturer – University of Connecticut Storrs, CT

CHEG 5395 – Investigation of Special Topics – Membrane Separations Winter 2011, Winter 2012, Fall 2013

Teaching Assistant – University of Connecticut Storrs, CT ENGR 1166, Foundations of Engineering Spring 2009

Teaching Assistant – University of Connecticut Storrs, CT CHEG 4147, Introduction to Process Dynamics and Control Fall 2008

Teaching Assistant – University of Connecticut Storrs, CT CHEG 3123, Transfer Operations I Fall 2008

Selected Publications:

 

PATENTS

1. McCutcheon, J.R., Bui, N.N, Hoek, E.M.V., Lind, M.L, Nano-Structured Membranes for Engineered Osmosis Applications, WO 2011/060202 A1, Application Number PCT/US2010/056426.

2. Kim C., Balathanigaimani M.S., Bui, N.N., Moon H., Yang K.S., Lee J.W., Activated carbon with ultra-high specific surface area from corn and Production method thereof, KO 10-2008-0085605, application number 10-2007-0027360.

 

BOOK CHAPTER(S)

McCutcheon, J.R., Bui, N.N: Forward Osmosis, in “Desalination: Water from Water”, Ed. Jane Kucera.

JOURNAL PUBLICATIONS (H-Index: 10, Total citations: 548)

1.       Bui N.N., McCutcheon J.R., Nanoparticle-Embedded Nanofibers in High Permselectivity Thin-film Composite Membranes for Forward Osmosis, ACS Applied Materials & Interfaces, under revision.

2.       Bui N.N., Arena J., McCutcheon J.R., Proper Accounting of Mass Transfer Resistances in Forward and Pressure Retarded Osmosis: Improving the Accuracy of Model Predictions of Structural Parameter, Journal of Membrane Science, in press.

3.       Bui N.N., McCutcheon J.R., Impacts of Nanofiber Size on Osmotic Flux Performance of Thin-film Composite Membrane for Engineered Osmosis (in preparation).

4.       Bui N.N., McCutcheon J.R., Nanofiber Supported Thin-film Composite Membrane for Pressure Retarded Osmosis, Environmental Science & Technology, 48, 2014, 4129-36.

5.       Bui N.N., McCutcheon J.R., Hydrophilic Nanofibers as New Supports for Thin Film Composite Membranes for Engineered Osmosis, Environmental Science & Technology, 47, 2013, 1761-9.

6.       Bui N.N., Lind M.L., Hoek E.M.V., McCutcheon J.R., Electrospun Nanofiber Supported Thin Film Composite Membranes for Engineered Osmosis, Journal of Membrane Science, 385-386, 2011, 10-19.

7.       Huang L., Bui N.N., Meyering M.T., Hamlin T.J., McCutcheon J.R., Novel Hydrophilic Nylon 6,6 Microfiltration Membrane Supported Thin Film Composite Membranes for Engineered Osmosis, Journal of Membrane Science, 437, 2013, 141-9.

8.       Huang L., Bui N.N., Manickam S.S., McCutcheon J.R., Controlling Electrospun Nanofiber Morphology and Mechanical Properties using Humidity, Journal of Polymer Science Part B: Polymer Physics, 49, 2011, 1734-44.

9.       Manickam S.S., Karra U., Huang L., Bui N.N., Li B., McCutcheon J.R., Activated Carbon Nanofiber Anodes for Microbial Fuel Cells, Carbon, 53, 2013, 19-28.

10.   Bui N.N., Kim B.H., Yang K.S., Dela Cruz M.E., Ferraris J.P., Activated Carbon Fibers from Electrospinning of Polyacrylonitrile/Pitch Blends, Carbon, 47, 2009, 2538-9.

11.   Kim B.H., Bui N.N., Yang K.S., Dela Cruz M.E., Ferraris J.P., Electrochemical Properties of Activated Polyacrylonitrile/Pitch Carbon Fibers Produced Using Electrospinning, Bull. Korean Chem. Soc., 30, 2009, 1967-72.

12.   Kim C., Bui N.N., Yang K.S., Kojima M., Kim Y.A., Kim Y.J., Endo M., Yang S.C., Self-Sustained Thin Webs Consisting of Porous Carbon Nanofibers for Supercapacitors via the Electrospinning of Polyacrylonitrile Solutions Containing Zinc Chloride, Advanced Materials, 19, 2007, 2341-6.

13.   Kim C., Jeong Y.I., Bui N.N., Yang K.S., Kojima M., Kim Y.A., Endo M., Lee J.W., Synthesis and Characterization of Porous Carbon Nanofibers with Hollow Cores through the Thermal Treatment of Electrospun Copolymeric Nanofiber Webs, Small, 3, 2007, 91-95.

14.   Kim C., Cho Y.J., Yun W.Y., Bui N.N. , Yang K.S. , Chang D.R., Lee J.W., Kojima M., Kim Y.A., Endo M., Fabrications and structural characterization of ultra-fine carbon fibres by electrospinning of polymer blends, Solid State Communications, 142, 2007, 20-23.

15.   Cho Y.J., Kim C., Bui N.N., Yun W.Y., Yang K.S., Fabrication of Electrospun Carbon Nanocomposite Fibers from PAN and PAA Blended Solutions, Carbon Science, 8, 2007, 49-51.