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:

1. “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.
2. “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.
3. “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:

1.      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
2.      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.
3.      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.
4.      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.
5.      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.
6.      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.
7.      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.
8.      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.
9.      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.
10.      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.
11.      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.