Stephen Beaudoin

Professor of Chemical Engineering
Director, Purdue Energetics Research Center

FRNY 1019
Purdue University
Davidson School of Chemical Engineering
Forney Hall of Chemical Engineering
480 Stadium Mall Drive
West Lafayette, IN 47907-2100
(765) 494-7944 (office)
(765) 494-0805 (fax)
Joined Purdue in 2003
B.S. Chemical Engineering, MIT, 1988
M.S. Chemical Engineering, University of Texas-Austin, 1990
Ph.D. Chemical Engineering, North Carolina State University, 1995

Research Interests

Research Objectives

  • Measure and model the adhesion between residues of explosives compounds and surfaces of interest in Homeland Security environments 
  • Use understanding to develop improved methods for detecting explosives residues


Understanding the adhesion between energetic particles and binders, and between explosive formulations and surfaces, is essentially important to making improved munitions and to detecting and interdicting improvised explosive devices. Poor adhesion within formulated explosives leads to local hot spot formation and can result in deflagration or detonation. Depending on the interaction force between an explosive residue, a surface, and a detection trap, the effectiveness of contact sampling to detect trace explosives in air transportation environments may vary dramatically. We perform basic studies of surface energy, adhesion forces, deformation, removal forces, and responses of explosive surfaces to various insults in order to fully characterize the adhesion in these systems.

Research Objectives

  • Measure the conformation of polymers adsorbed to crystalline drug surfaces using atomic force microscopy (AFM)
  • Relate the polymer conformation to changes in crystal growth and dissolution rates


About 75% of active pharmaceutical ingredients (APIs) in the drug development pipeline demonstrate poor aqueous solubility in crystalline solid form. This poses a problem in oral dosage forms due to low bioavailability. Amorphous solid forms, however, possess much greater free energy and are correspondingly much more soluble. One approach to stabilize the inherently unstable amorphous form and prevent crystallization utilizes adsorbed polymers to occupy growth sites and serve as mechanical barriers to growth. The effectiveness of this method depends critically on the conformation of the polymer once it is adsorbed onto the solid drug. For example, if the polymer chain is extended, a single adsorbed molecule can block multiple sites in addition to its adsorption site; however, a coiled polymer has limited ability to block multiple sites. Using AFM, we are studying the conformation of adsorbed polymers and relate this parameter to crystal growth kinetics. 

Research Objective

  • Develop improved centrifuge-based technique for advanced powder characterization.   


Powder behavior during solids handling, such as in the pharmaceutical, food, and personal care industries, is controlled to a large degree by the adhesion characteristics of the powder's particulate ensemble. Key physical properties of a particulate system, chiefly size, geometry, composition, and surface roughness, generally control the particle adhesion. A classic method for measuring powder adhesion involves coating metal plates with powder, mounting these plates in centrifuge tubes so that their coated surfaces face outward, and then tracking the removal of particles from the plates when the centrifuge is rotated. While the technique is simple to use, it gives low-quality information about the powder adhesion characteristics. Our work pursues the use of rationally-designed plates in the centrifuge method. By tracking the removal of small quantities of powder from these plates, we are able to extract a great deal of high-value added information about the particle adhesion. Specifically, substrates designed with hemispherical indentations of different sizes and roughness allow us to characterize the size, shape, roughness, and composition of the particles in the powder.

This work is supported by the Department of Homeland Security Science and Technology Directorate, and the Department of Education.

Research Group

Graduate Students

  • Caralyn Coultas-McKenney
  • Leonid Miroshnik
  • Andrew Parker (co-advised with Prof. Lynne Taylor)
  • Michael Stevenson (co-advised with Prof. David Corti)
  • Jason Wickham (co-advised with Prof. Steve Son)

Awards and Honors

Outstanding Mentor Award, College of Engineering, 2017
A.A. Potter Best Teacher Award, College of Engineering, 2017
Purdue University Focus Award, 2017
Purdue University Provost Fellow for Student Success, 2009-2010
Purdue University Faculty Scholar, 2007-2012
Omega Chi Epsilon Mentoring Award, Purdue University Student Chapter, 2006-2007
Inaugural recipient of the Excellence in Teaching Award sponsored by the Purdue Student Government and the Office of the Provost, 2005
NSF CAREER Award Recipient, 2000
Outstanding Undergraduate Educator in Chemical Engineering at Arizona State University, 1995-1996

Selected Publications

Hoss, D., Boudouris, B., Beaudoin, S., "Analyzing Adhesion in Microstructured Systems through a Robust Computational Approach", Surface and Interface Analysis , 49, 1165-1170 (2017).

Sweat, M.L., Parker, A.S., Beaudoin, S.P., "Compressive Behavior of High Viscosity Granular Systems: Effect of Particle Size Distribution", Powder Technology, 311, 506-513 (2017).

Fronczak, S., Dong, J., Browne, C., Krenek, E., Franses, E., Beaudoin, S. Corti, D., "A New 'Quasi-Dynamic' Method for Determining the Hamaker Constant of Solids Using an Atomic Force Microscope", Langmuir, 33(3), 714-725 (2017).

Thomas, M., and Beaudoin, S., "An Enhanced Centrifuge-Based Approach to Powder Characterization: Experimental and Theoretical Determination of a Size-Dependent Effective Hamaker Constant", Powder Technology, 306, 96-102 (2017).

Sweat, M.L., Parker, A.S., Beaudoin, S.P., "Compressive Behaviour of Idealized Granules for the Simulation of Composition C-4", Propellants, Explosives, and Pyrotechnics, 41(5), 855-863 (2016) DOI: 10.1002/pr ep.201600036.

Laster, J., Deom, N., Beaudoin, S., and Boudouris, B., "Design of Free-Standing Microstructured Conducting Polymer Films for Enhanced Particle Removal from Non-Uniform Surfaces", Journal of Polymer Science, Part B: Polymer Physics, 54(19), 1968-1974 (2016).

Schram, C., Beaudoin, S., and Taylor, L., "Polymer Inhibition of Crystal Growth by Surface Poisoning", Crystal Growth and Design, 16(4), 2094-2103 (2016).

Sweat, M., Parker, A., and Beaudoin, S., "Compressive Behavior of High Viscosity Granular Systems: Effects of Viscosity and Strain Rate", Powder Technology, 302, 480-487 (2016).

Hoss, D. J., Knepper, R., Hotchkiss, P. J., Tappan, A. S., Boudouris, B. W., and Beaudoin, S. P., "An Evaluation of Complementary Approaches to Elucidate Fundamental Interfacial Phenomena Driving Adhesion of Energetic Materials", Journal of Colloid and Interface Science, 473, 28-33 (2016).

Quesnel, D., Rimai, D., Schaefer, D., Beaudoin, S., Harrison, A., Hoss, D., Sweat, M., and Thomas, M.,"Chapter 4. Aspects of Particle Adhesion and Removal," Developments in Surface Contamination and Cleaning, Volume 1, 2nd Ed., 119 - 147, Kohli, R. and Mittal, K., Eds., Wiley, (2016).

Chaffee-Cipich, M, Hoss, D., Sweat, M., and Beaudoin, S., "Contact between Traps and Surfaces during Contact Sampling of Explosives in Security Settings," Forensic Science International, 260, 85-94 (2016).

Harrison, A., Beaudoin, S., and Corti, D., "Wang-Landau Monte Carlo Simulation of Capillary Forces at Low Relative Humidity in Atomic Force Microscopy," Adhesion Science and Technology, 30(11), 1165-1177 (2016).

Harrison, A., Corti, D., and Beaudoin, S., "Capillary forces in nanoparticle adhesion: A review of AFM methods," Particulate Science and Technology, 33(5), 526-538 (2015).

Beaudoin, S., Jaiswal, P., Harrison, A., Hoss, D., Laster, J., Smith, K., Sweat, M., and Thomas, M., "Fundamental Forces in Particle Adhesion," Particle Adhesion and Removal, 1st Ed., Mittal, K. and Jaiswal, R., Eds., Wiley, 1-80 (2015).

Schram, C., Taylor, L., and Beaudoin, S., "Influence of Polymers on the Crystal Growth Rate of Felodipine – Correlating Adsorbed Polymer Surface Coverage to Solution Crystal Growth Inhibition," Langmuir, 31(41), 11279-11287 (2015).

Thomas, M. and Beaudoin, S., "An Enhanced Centrifuge-Based Approach to Powder Characterization: Particle Size and Hamaker Constant Determination," Powder Technology, 286, 412-419 (2015).

Harrison, A., Otte, A., Carvajal, T., Pinal, R., and Beaudoin, S., "Cohesive Hamaker Constants and Dispersive Surface Energies of RDX, PETN, TNT, and Ammonium Nitrate-based Explosives," Propellants, Explosives, Pyrotechnics, 40(6), 892-897 (2015).

Schram, C., Beaudoin, S., and Taylor, L., "Impact of Polymer Conformation on the Crystal Growth Inhibition of a Poorly Water Soluble Drug in Aqueous Solution," Langmuir, 31(1), 171-179 (2015).