Education
- PhD Chemical Engineering: University of Texas at Austin ( 8 - 2005)
- “Nanocomposite Blends of ABS and Montmorillonite: Compatibilization and Dispersion”
- Thesis Advisor: Dr. Donald R. Paul
- MS Chemistry: Texas State University, San Marcos, TX (12-1996)
- “Rubber-Toughened Blends of Bisphenol A Polycarbonate and Styrene-Maleic Anhydride
Copolymer”
- Thesis Advisor: Dr. Patrick Cassidy
- BS Chemistry: Texas A&M University, College Station, TX (5-1980)
Honors and Awards
- TTU College of Engineering Teacher-Scholar Eminence Award, 2016
- TTU College of Engineering Teacher-Scholar Eminence Award, 2015
- TTU College of Engineering Brown-Henderson Award, honoring teaching and service, 2013.
- ASEE Southeastern Section New Faculty Research Award, 2010.
- TTU Sigma Xi Outstanding Research Award, 2009.
- TTU College of Engineering Kinslow Award, best paper written by a Tennessee Tech engineering
faculty, 2007.
- American Institute of Chemical Engineers Student Chapter Advisor, Tennessee Technological
University, 2005-2006.(First Place, Team National Chem-E-Car Champions, 11-2005.)
Research Statement
Our group is interested in advanced high performance polymer nanocomposites: the processing,
characterization and prediction of properties. ●These materials are often used in
extreme environments including combustion and cryogenics. Materials comprised of polymer
and nanoparticles offer improvement over traditional composites in mechanical, barrier
and thermal properties while maintaining specific gravity and often optical clarity.
To achieve this level of performance, one must achieve high levels of dispersion and
good interfacial compatibility. Current research is in 4 Kelvin dynamical properties
of polymeric thin films. ●Thrust II is to form/synthesize responsive nanoparticles
for medical diagnostics and drug delivery in massively arrayed microfluidics. This
manufacturing environment offers opportunities for intimate customization of the morphology
combined with high throughput● Thrust III is to understand the environmental fate
and transformation of metal nanoparticles in surface waters. This includes utilizing
nanoparticles for antifouling in water purification membranes.
Academic and Professional Experience
a - Academic:
Associate Professor, Tennessee Technological University, Cookeville, TNn2011-present. Research program
in nanocomposite thermal stability, nano-materials for protein separations, nano-stability
of organophotovoltaics, nanoparticle environmental fate and transformation.
Assistant Professor , Tennessee Technological University, Cookeville, TNn2005-2011.
Secondary Teaching – Advanced Placement Chemistry (LBJ Science Academy, Austin, TX. Noblesville High,
Noblesville IN. New Braunfels High, New Braunfels, TX.)n 1986 - 1998. Developed outreach
programs and led award-winning students in advanced and inquiry-based chemistry
b- Professional
Chief Technology Officer, Promethia Labs LLC, Cookeville, TN n 2013-2015. Co-founder of biomedical diagnostics
device company based on research patents.
Project Manager, Texas State University, San Marcos, TX n1998 – 2005. Supervised a staff of 4-5 undergraduate
and 1 graduate researchers. Assisted in writing proposals, developed collaborations,
developed documented quality control program. Proposals won totaled over $1MM, primarily
SBIR.
Process Engineer II , Advanced Micro Devices, Austin TX n 1984 – 1986. Provided production engineering
support in diffusion, CVD, laser repair and implant.
Process Engineer I, Celanese, Bishop, TX n 1983 – 1984. Provided support during scale-up of new plastics
compounding products. Responsibility for inventory, analytical development, and troubleshooting
leading to commercialization.
Plant Chemist, Celanese, Bay City and Bishop, TX n 1980 – 1983. Unit support. Supervised technician
in OSHA and RCRA analytical compliance.
Professional Listings:
Academic Keys “Who’s Who in Engineering Education”
PATENTS:
- “Fluidic System for High Throughput Preparation of Polymeric Microparticles and Nanoparticles,”
WO 20151788792 A1, H. A. Stretz, J. Massingill, T. Betancourt, Tennessee Technological
University, Texas State University, Chemtor, Filed 11-26-2015.
- “Thermoresponsive microparticle composite hydrogels for electrophoresis,” US 8177950,
J. W. Thompson, H. A. Stretz, P. E. Arce, Tennessee Technological University. Filed
11-21-2008, Issued 05-15-2012.
- “Nanocomposite polymer hydrogel with aligned nanoparticles,” PCT/US2012/047380, J.
W. Thompson, H. A. Stretz, P. E. Arce, Tennessee Technological University, Filed 07-19-2012.
Recent Publications:
- Jamkhindikar, S. P., Stretz, H. A., Massingill, J. L. Jr., Betancourt, T., “High
Throughput Fiber Reactor Process for Organic Nanoparticle Production: PNIPAM, Poly(acrylamide)
and Alginate,” Journal of Applied Polymer Science, 134 (2017) 45524
- Esfahani, M. R., Pallem, V. L., Stretz, H. A., Wells, M. J. M., “Core-size regulated
aggregation/disaggregation of citrate-coated gold nanoparticles (5-50 nm) and dissolved
organic matter: Extinction, emission, and scattering evidence,” Spectrochimica Acta, 189 (2018) 415-426.
- Esfahani, M. R. Pallem, V. L., Stretz, H. A., Wells, M.J.M., “Absorption, fluorescence
and scattering spectroscopy of 5-50nm citrate-coated gold nanoparticles: an argument
for radius of curvature effects on aggregation,”Spectrochimica Acta A, 175 (2017) 100-109.
- Esfahani, M., Pallem, V., Stretz, H. A., Wells, M.J.M., “Disaggregation of humic
acid in the presence of gold nanoparticles, effects of nanoparticle size and pH,” Environmental Nanotechnology Monitoring and Management, 6 (2016) 54-63.
- Koutahzadeh, N., Esfahani, M., Stretz, H. A., Arce, P. E., “" Investigation of
UV/H2O2 pretreatment effects on humic acid fouling at PSF/TiO2 and PSF/MWCNT nanocomposite
ultrafiltration membranes,” Environmental Progress and Sustainable Energy, 36 (2017) 27-37.
- Esfahani, M. R., Tyler, J. L., Stretz, H. A., Wells, MJM, “Effects of a dual
nanofiller, nano-TiO2 and MWCNT for polysulfone-based nanocomposite membranes for
water purification,” Desalination, 372 (2015) 47-56.
- Esfahani, M. R., Stretz, H. A., Wells, MJM, “Abiotic reversible self-assembly
of fulvic and humic acids in low electrolytic conductivity solutions by dynamic light
scattering,” Science of the Total Environment, 537 (2015) 81-92.
- Ambuken, P. V., Stretz, H. A., Dadmun, M., Kilbey, S. M., “Gas expanded polymer
process to anneal nanoparticle dispersion in thin films,” Solar Energy Materials and Solar Cells, 140 (2015) 101-107.
- Kaiser, A., Probst, M., Stretz, H. A., Hagelberg, F., “Aggregates of PCBM molecules:
a computational study,” International Journal of Mass Spectrometry, 365-366 (2014) 225-231.
- Ambuken, P.V., Stretz, H.A., Koo, J.H., Messman, J. M., Wong, D., “Effect of
addition of montmorillonite and carbon nanotubes on a thermoplastic polyurethane:
high temperature thermomechanical properties,” Polymer Degradation and Stability, 102 (2014) 160-169.
- Thompson, J. W., Stretz, H. A., Arce, P. E., Gao, H., Ploehn, H., He, J., “Effect
of magnetization on gel structure and protein electrophoresis in polyacrylamide hydrogel
nanocomposites,” Journal of Applied Polymer Science,126 (2012) 1600-1612.