tel: (610) 758-6834
Our research focuses on rational and directed design of novel inorganic nanomaterials for efficient separation and reaction technologies, with applications spanning energy (e.g., integrated biorefinery) to sensing and imaging. We are broadly interested in engineering functional inorganic nanoparticles and the porosity, morphology, and functionality of a range of inorganic thin films. We integrate materials synthesis and characterization with molecular and multiscale modeling of phenomena spanning molecular transport to device performance.
Rational design of crystalline inorganic membranes for high-selectivity separations
The need for low-energy techniques to separate high-value chemicals from complex process streams (e.g., in the biorefinery) underscores the potential impact of fundamental separations-driven materials research aimed at designing viable membrane technology. While membranes composed of oriented and intergrown microporous zeolite crystals have been investigated for decades, we focus on narrowing the materials gap (i.e., single-crystal vs. polycrystalline selectivity) that has, in part, stifled their rapid commercialization for large-scale separations. We target our fundamental efforts at the materials engineering level, aiming to elucidate molecular transport in grain boundaries and to uncover the chemical nature of such polycrystalline features in order to guide their in situ and post-synthesis engineering.
Porous, nanoparticulate films: Engineering membrane selectivity, functionality, and versatility
As an alternative to polycrystalline and surfactant directed inorganic films, we aim to engineer robust, ordered nanoparticulate films (i.e., on porous supports or as self-supported capsules) and their replicas for applications in high-resolution separations and sensing. Nanoparticle composition, size control, functionality, and assembly are employed as handles for realizing films with finely controlled and/or autonomously actuated (i.e., by the local environment) pore sizes, molecule-specific selectivity, and simultaneous reaction-diffusion capabilities.
Functionalized inorganic nanoparticles for dispersed and assembled applications
Work in our lab depends upon the existence of nanoparticles with tailored composition and functionality (e.g., tethered organic molecules, reactive metal centers, occluded fluorophores). As such, we carry out fundamental research on nanoparticle synthesis (e.g., biomimetic routes) in order to elucidate synthesis-structure-properties relations governing, for example, nanoparticle stability, triggered and controlled assembly, and catalytic activity in assembled (i.e. thin films, nanoparticle clusters) and dispersed nanoparticle applications.
"Hierarchical nanofabrication of microporous crystals with ordered mesoporosity", W. Fan, M. A. Snyder, S. Kumar, P.-S. Lee, W.C. Yoo, A.V. McCormick, R.L. Penn, A. Stein, M. Tsapatsis, Nature Materials, (doi:10.1038/nmat2302) (2008).
"Silica nanoparticle crystals and ordered coatings using Lys-Sil and a novel coating device", M. A. Snyder, J. A. Lee, T. M. Davis, L. E. Scriven & M. Tsapatsis, Langmuir 23, 9924-9928 (2007) (Cover article).
"Hierarchical nano-manufacturing: From shaped zeolite nanoparticles to high performance separation membranes", M. A. Snyder & M. Tsapatsis, Angewandte Chemie 46, 7560-7573 (2007).
"Germania nanoparticles and nanocrystals at room temperature in water and aqueous lysine sols", T. M. Davis, M. A. Snyder & M. Tsapatsis, Langmuir 23, 12469-12472 (2007).
"Quantitative analysis of membrane morphology, microstructure, and polycrystallinity via laser scanning confocal microscopy: Application to NaX zeolite membranes", M. A. Snyder, D. G. Vlachos & V. Nikolakis, Journal of Membrane Science 290, 1-18 (2007).
"Nanoparticles in lysine-silica sols", T. M. Davis, M. A. Snyder, J. E. Krohn & M. Tsapatsis, Chemistry of Materials 18, 5814-5816 (2006).
"The role of molecular interactions and interfaces in diffusion: Permeation through single-crystal and polycrystalline microporous membranes", M. A. Snyder & D. G. Vlachos, Journal of Chemical Physics 123, 184708 (2005).
"Net-event kinetic Monte Carlo for overcoming stiffness in spatially homogeneous and distributed systems", M. A. Snyder, A. Chatterjee & D. G. Vlachos, Computers & Chemical Engineering 29, 701-712 (2005).
"Combining simultaneous reflectance and fluorescence imaging with SEM for conclusive identification of polycrystalline features of MFI membranes", M. A. Snyder, Z. Lai, M. Tsapatsis & D. G. Vlachos, Microporous and Mesoporous Materials 76, 29-33 (2004).
"Mesoscopic modeling of transport and reaction in microporous crystalline membranes", M. A. Snyder, D. G. Vlachos & M. A. Katsoulakis, Chemical Engineering Science 58, 895-901 (2003).