Dr. Worthen’s expertise is in the design and engineering of mixtures containing surfactants, polymers, and nanomaterials, sometimes known as colloids, for applications in surface coatings, dispersants, adhesives, inks, medical devices, personal care products, and oilfield chemicals. He has applied his expertise in colloid science to technical challenges in the energy and environmental industries, such as enhanced oil recovery, hydraulic fracturing, and oil spill cleanup. His current research interests include filtration and separation technologies, and the characterization and development of complex fluids for use in the energy, environmental, and commercial fields.
Dr. Worthen’s background in complex fluids was developed during his doctoral research in chemical engineering where he examined the impact of molecular-scale interactions on bulk properties of dispersions, emulsions, and foams. In addition to investigations at ambient conditions, he developed methods to determine interfacial and rheological properties of formulations at elevated temperatures and pressures. He has extensive experience with characterization techniques for suspensions, emulsions, gels, aerosols, interfaces, and charged polymers, including dynamic light scattering (DLS), static light scattering (SLS), electrophoretic mobility/zeta potential determination, interfacial tensiometry, contact angle goniometry, and rheometry.
Prior to joining Exponent, Dr. Worthen worked in the downstream oil industry in both environmental and technical services capacities. His experience includes equipment inspections, development of energy monitoring and minimization programs, and emissions calculations at an oil refinery. He also has experience with synthesis of surfactant-biopolymer conjugates and with characterization tools such as Fourier transform infrared (FTIR) spectroscopy and small-angle X-ray scattering (SAXS).
CREDENTIALS & PROFESSIONAL HONORS
- Ph.D., Chemical Engineering, University of Texas, Austin, 2015
- B.S., Chemical Engineering, University of Toledo, 2010,
magna cum laude
LICENSES & CERTIFICATIONS
Licensed Professional Chemical Engineer, California, #6872
Worthen AJ, Tran V, Cornell KA, Truskett TM, Johnston KP. Steric stabilization of nanoparticles with grafted low molecular weight ligands in highly concentrated brines including divalent ions. Soft Matter 2016; Advance Article.
Xue Z, Worthen AJ, Qajar A, Robert I, Bryant SL, Huh C, Prodanović M, Johnston KP. Viscosity and stability of ultra-high internal phase CO2-in-water foams stabilized with surfactants and nanoparticles with or without polyelectrolytes. Journal of Colloid and Interface Science 2016; 461:383–395.
Xue Z, Worthen AJ, Da C, Qajar A, Ketchum IR, Alzobaidi S, Huh C, Prodanović M, Johnston KP. Ultra-dry carbon dioxide-in-water foams with viscoelastic aqueous phases. Langmuir 2016; 32(1):28–37.
Chen Y, Elhag AS, Cui L, Worthen AJ, Reddy PP, Noguera JA, Ou AM, Ma K, Puerto M, Hirasaki GJ, Nguyen QP, Biswal SL, Johnston KP. CO2-in-water foam at elevated temperature and salinity stabilized with a nonionic surfactant with a high degree of ethoxylation. Industrial & Engineering Chemistry Research 2015; 54(16):4252–4263.
Prigiobbe V, Worthen AJ, Johnston KP, Huh C, Bryant SL. Transport of nanoparticle-stabilized CO2-foam in porous media. Transport in Porous Media 2015; 111(1):265–285.
Foster LM*, Worthen AJ*, Foster EL, Dong J, Roach CM, Metaxas AE, Hardy CD, Larsen ES, Bollinger JA, Truskett TM, Bielawski CW, Johnston KP. High interfacial activity of polymers “grafted through” functionalized iron oxide nanoparticle clusters. Langmuir 2014; 30(34):10188–10196. (Note: * denotes equal author contribution).
Dong J, Worthen AJ, Foster LM, Chen Y, Cornell KA, Bryant SL, Truskett TM, Bielawski CW, Johnston KP. Modified montmorillonite clay microparticles for stable oil-in-seawater emulsions. ACS Applied Materials & Interfaces 2014; 6(14):11502–11513.
Yu H, Yoon KY, Neilson BM, Bagaria HG, Worthen AJ, Lee JH, Cheng V, Bielawski CW, Johnston KP, Bryant SL, Huh C. Transport and retention of aqueous dispersions of superparamagnetic nanoparticles in sandstone. Journal of Petroleum Science and Engineering 2014; 116:115–123.
Chen Y, Elhag AS, Poon BM, Cui L, Ma K, Liao SY, Reddy PP, Worthen AJ, Hirasaki GJ, Nguyen QP, Biswal SL, Johnston KP. Switchable nonionic to cationic ethoxylated amine surfactants for CO2 Enhanced Oil Recovery in high-temperature, high-salinity carbonate reservoirs. SPE Journal 2014; 19(02):249–259.
Worthen AJ, Foster LM, Dong J, Bollinger JA, Peterman AH, Pastora LE, Bryant SL, Truskett TM, Bielawski CW, Johnston KP. Synergistic formation and stabilization of oil-in-water emulsions by a weakly interacting mixture of zwitterionic surfactant and silica nanoparticles. Langmuir 2014; 30(4):984–994.
Worthen AJ, Bryant SL, Huh C, Johnston KP. Carbon dioxide‐in‐water foams stabilized with nanoparticles and surfactant acting in synergy. AIChE Journal 2013; 59(9):3490–3501.
Bagaria HG, Neilson BM, Worthen AJ, Xue Z, Yoon KY, Cheng V, Lee JH, Velagala S, Huh C, Bryant SL, Bielawski CW, Johnston KP. Adsorption of iron oxide nanoclusters stabilized with sulfonated copolymers on silica in concentrated NaCl and CaCl2 brine. Journal of Colloid and Interface Science 2013; 398:217–226.
Bagaria HG, Yoon KY, Neilson BM, Cheng V, Lee JH, Worthen AJ, Xue Z, Huh C, Bryant SL, Bielawski CW, Johnston KP. Stabilization of iron oxide nanoparticles in high sodium and calcium brine at high temperatures with adsorbed sulfonated copolymers. Langmuir 2013; 29(10):3195–3206.
Worthen AJ, Bagaria HG, Chen Y, Bryant SL, Huh C, Johnston KP. Nanoparticle-stabilized carbon dioxide-in-water foams with fine texture. Journal of Colloid and Interface Science 2013; 391:142–151.
Bagaria HG, Xue Z, Neilson BM, Worthen AJ, Yoon KY, Nayak S, Cheng V, Lee JH, Bielawski CW, Johnston KP. Iron oxide nanoparticles grafted with sulfonated copolymers are stable in concentrated brine at elevated temperatures and weakly adsorb on silica. ACS Applied Materials & Interfaces 2013; 5(8):3329–3339.
Worthen AJ, Lapitsky Y. Stabilization of bioderived surfactant/polyelectrolyte complexes through surfactant conjugation to the biopolymer. Colloid and Polymer Science 2011; 289(14):1589–1596.
Worthen AJ, Taghavy A, Aroonsri A, Kim I, Johnston KP, Huh C, Bryant SL, DiCarlo DA. SPE 175065, Multi-scale evaluation of nanoparticle-stabilized CO2-in-water foams: From the benchtop to the field. SPE Annual Tech. Conf. and Expo., Houston, TX, September 28–30, 2015.
Worthen AJ, Xue Z, Parikh PS, Dickey TR, Cornell KA, Quintanilla H, Huh C, Bryant SL, Johnston KP. Salt-tolerant and interfacially active nanoparticles which generate viscous and stable CO2-in-brine foams. 5th International Colloids Conf., Amsterdam, Netherlands, June 21–24, 2015.
Worthen AJ, Foster LM, Dong J, Yu G, Bollinger JA, Truskett TM, Bryant SL, Bielawski CW, Johnston KP. Emulsions of oil in seawater stabilized with particles and surfactants. American Institute of Chemical Engineers Annual Meeting, Atlanta, GA, November 16–21, 2014.
Worthen AJ, Parikh PS, Chen Y, Bryant SL, Huh C, Johnston KP. Carbon dioxide-in-water foams stabilized with a mixture of nanoparticles and surfactant for CO2 storage and utilization applications. GHGT-12, Austin, TX, October 5–9, 2014.
Worthen AJ, Johnston KP, Hirasaki GJ, Nguyen QP, Bryant SL, Huh C, Chen Y, Elhag AS. Design of surfactants and nanoparticles for CO2 sequestration, Enhanced Oil Recovery, and electromagnetic imaging. 247th American Chemical Society National Meeting & Expo, Dallas, TX, March 16–20, 2014.
Worthen AJ, Bagaria HG, Chen Y, Bryant SL, Huh C, Johston KP. Carbon dioxide-in-water foams stabilized with nanoparticle and surfactant amphiphiles. 245th American Chemical Society National Meeting & Expo, New Orleans, LA, April 7–11, 2013.
Worthen AJ, Bagaria HG, Chen Y, Bryant SL, Huh C, Johnston KP. SPE 154285, Nanoparticle stabilized carbon dioxide in water foams for Enhanced Oil Recovery. SPE Improved Oil Recovery Symposium, Tulsa, OK, April 14–18, 2012.
Undergraduate Research Assistant, University of Toledo, 2009–2010
Technical Services Department Co-op, Marathon Petroleum Company, Spring 2010
Environmental Department Co-op, Marathon Petroleum Company, Spring 2008, Fall 2008, Summer 2009
American Institute of Chemical Engineers (member)
American Chemical Society (member)
Society of Petroleum Engineers (member)
News & Events