Steve Beaudoin

Center Director, Professor of Chemical Engineering

Telephone: (765) 494-7944
Email: sbeaudoi@purdue.edu
More about Steve Beaudoin

 

Graduate Students

Patrick Bowers
School: Chemical Engineering
Expected Graduation: May, 2021
Project/Thesis: Effects of Binder Mechanical and Interfacial Properties on Additively Manufactured Energetics
Co-Advisor: Jeff Rhoads

Caralyn Coultas-Mckenney
School: Chemical Engineering
Expected Graduation: December, 2022
Project/Thesis: The Enhanced Centrifuge Method for Evaluating Topographical Effects on Adhesion of Explosives Powders

Andrew Parker
School: Chemical Engineering
Expected Graduation: December, 2020
Project/Thesis: Effects of Polymers on Crystallization of Pharmacological Active Ingredients from the Melt

Sydney Scheirey
School: Chemical Engineering
Expected Graduation: May, 2023
Project/Thesis: Effects of Crosslinking Agents and Adhesion Modifiers on Additively Manufactured Thermite
Co-Advisor: Jeff Rhoads

Michael Stevenson
School: Chemical Engineering
Expected Graduation: December, 2022
Project/Thesis: Measuring van der Waals Adhesion Forces of Compounded Energetics Using Non-Contact Atomic Force Microscopy
Co-Advisor: David Corti

Jason Wickham
School: Chemical Engineering
Expected Graduation: December, 2020
Project/Thesis: Effects of Interfacial and Mechanical Properties of Compounded Explosives on Their Sensitivity
Co-Advisor: Steve Son

Aaron Woeppel
School: Chemical Engineering
Expected Graduation: May, 2023
Project/Thesis: Engineered Macromolecules for Detection of Trace Explosives Residues Co-Advisor: Bryan Boudouris

 

Recent Publications

Compressive behavior of high viscosity granular systems: Effect of particle size distribution

Sweat, Melissa L ; Parker, Andrew S ; Beaudoin, Stephen P
Powder Technology, 15 April 2017, Vol.311, pp.506-513

Abstract

Granular compressive behavior has been evaluated with respect to particle size distribution. All granules were prepared with a polydimethylsiloxane (PDMS) binder with viscosity ranging from 12 to 2413 Pa·s. All granules were prepared with 90% particulates and 10% binder by mass. Granules were prepared using two unimodal particle size distributions (420–595 μm silica and 105–420 μm silica) and two bimodal particle size distributions. The bimodal size distributions were comprised of 420–595 μm silica and 0–63 μm silica in 75%/25% and 50%/50% mass fractions, where the first percentage refers to the amount of 420–595 μm silica particles included. The granules were compressed with 1, 10, and 100 mm/s velocities. The granules prepared with 420–595 μm silica particles were found to exhibit greater granular strength than those prepared with 105–420 μm particles. These results are uniquely different from those of previous studies which indicate that a smaller size fraction of particles will result in a stronger granule. The addition of a secondary particle size distribution in conjunction with the 420–595 μm silica particles results in a granule with significantly increased strength over the granule prepared with a unimodal distribution. It is suggested that the bimodal size distribution allows an increased number of interparticle contacts per unit volume to increase the granular strength.

 

Impact of surface chemistry on the adhesion of an energetic small molecule to a conducting polymer surface

Laster, Jennifer S ; Ezeamaku, Chibuzor D ; Beaudoin, Stephen P ; Boudouris, Bryan W
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 20 August 2018, Vol.551, pp.74-80

Abstract

The modification of the surface chemistry of a film is a key strategy to enhance the binding of molecules of interest in various sensing and detection applications. For example, the adhesion of explosive residues to a swab is critical for the detection of trace explosives in air transportation environments, and it can be enhanced by increasing the affinity of the swab to target molecules through favored chemical interactions. Here, the surface chemistries of polypyrrole (PPy) films were systematically tuned through the electropolymerization of thin layers of N-substituted pyrrole monomers to evaluate their interactions with a model explosive compound, trinitrotoluene (TNT). The surface groups examined included carboxylic acid, methyl, and amino-phenyl groups, in order to address a wide range of chemical functionalities. The interaction between the functionalized PPy films with TNT was compared with the interactions between TNT and commercial swabbing materials in a vapor deposition process. The amount of TNT deposited from the vapor phase on each of the different films was quantified by the ultraviolet–visible (UV–vis) light absorbance of the Meisenheimer complex formed from the interaction of TNT with a basic solution. The PPy films with surface functionalities that allowed for hydrogen bonding displayed the highest deposition of TNT, while Teflon-coated commercial materials had the lowest interaction with TNT. Thus, this work provides insight into the surface groups of interest for the enhanced collection of trace explosives as well as the critical design criteria for the next generation of swabbing materials.

 

Energetic Microparticle Adhesion to Functionalized Surfaces

Hoss, Darby J. ; Mukherjee, Sanjoy ; Boudouris, Bryan W. ; Beaudoin, Stephen P.
Propellants, Explosives, Pyrotechnics, September 2018, Vol.43(9), pp.862-868

Abstract

Surface chemistry influences interfacial interactions, and while these interactions have been evaluated in many synthetic and biological systems, they have important but unexplored implications in trace explosives detection. Specifically, the detection of energetic materials is a challenging, urgent goal, and one of the most common means by which this effort is implemented at air transportation checkpoints is using methods based on contact sampling. Elucidating the molecular and interfacial interactions of energetic materials with functionalized surfaces provides fundamental knowledge and also advances the goal of improved materials for trace detection. Here, in order to evaluate the effects of specific functional groups on adhesion, atomic force microscopy (AFM) pull‐off force measurements were performed using nitrate‐based energetic (and non‐energetic) particles against self‐assembled monolayers (SAMs) of representative chemical functionalities. These SAMs‐on‐gold substrates were selected to evaluate surface chemistry effects due to their reproducibility, facile production, and versatile tunability. In addition to the experimental results, stabilization energies for the optimized most‐stable configurations for a coupled receptor‐analyte system were determined using density functional theory (DFT). From these combined experimental and computational efforts, it is established that the adhesion between detection surfaces and common energetic materials at the macroscopic scales is correlated to the interaction energies at the molecular level. Moreover, the electron deficient nature of nitro‐rich energetic compounds results in stronger interactions with surfaces functionalized with electron‐donating units. Ultimately, these results will facilitate the rational design of energetic particle collection materials through chemical tailoring in order to enhance the detection and defeat of explosive materials.

 

Towards an Improved Method for Determining the Hamaker Constant of Solid Materials Using Atomic Force Microscopy. I. Quasi-Static Analysis for Arbitrary Surface Roughness

Stevenson, Michael C. ; Beaudoin, Stephen P. ; Corti, David S.
The Journal of Physical Chemistry C, 2020, 124, 5, 3014-3027
Publication Date: January 10, 2020

Abstract

The initial development and preliminary validation of improvements to an existing approach-to-contact atomic force microscopy (AFM) method for determining the Hamaker constant, A, of solid materials is presented. The updated method explicitly accounts for the surface topography of the given substrate, which will lead to improved estimates of A and extend the range of the types of the surfaces to which the method can be applied. After deriving a general van der Waals (vdW) force expression between the AFM cantilever tip, treated as an effective sphere, and a surface with arbitrary roughness, the deflection of the cantilever tip at first contact with the surface, d_c, is then obtained for all tip locations. Since the vdW force varies locally along the surface, a distribution of d_c-values is obtained for a given value of A. For various model surfaces, we discuss the effect of surface roughness on the resulting d_c-distributions, which indicates that surface roughness cannot be accounted for in an approximate way. We also present preliminary experimental validation of the updated method, whereby the predicted d_c-distribution of a simplified version of an amorphous silica surface is found to compare favorably with the d_c-distribution obtained from AFM experiments.