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Faculty > Eduardo D. Glandt Eduardo D. Glandt
Robert D. Bent Professor of Chemical and Biomolecular Engineering
B.S., Chemical Engineering, University of Buenos Aires, 1968 email: Current Focus of Research Molecular Simulations of Gas Adsorption This work applies molecular models and computer simulation techniques to investigate how the microstructure of a porous material affects its physical and chemical properties and, especially, its capacity as an adsorbent. The goal is to offer guidance in the preparation of high-capacity adsorbents. For example, adsorbed natural gas offers attractive features as a potential fuel for urban transportation: the filling pressure is relatively low (300-400 psig) compared with that of compressed gas, while the energy density may be as high as 20% of that for liquefied natural gas. Important practical problems that affect the implementation of adsorption systems can be readily examined by molecular simulation. They include (i) heat effects, which severely limit the feasible rates of adsorption and desorption; (ii) multicomponent separation, which leads to a partial saturation of the saturation of the substrate by traces of heavier components; and (iii) the presence of very active impurities, such as water vapor, which results in capillary condensation and pore blockage. Polymer Adsorption The adsorption of large flexible molecules from a bulk fluid into the interior of a porous solid is of importance in many different technologies including chromatographic separations and petroleum recovery. We are working on statistical mechanical models for such systems. This research is based on PRISM, a state-of-the-art theory of polymer structure, which has been successfully used to calculate the structure of melts and blends. Recent improvements include a tractable self-consistent version applicable to a wide range of systems. This work can also be regarded as generalization of our own thermodynamic treatment for the adsorption of small molecules. In it, the introduction of an adsorbate within a random porous solid is viewed as "mixing" it with the assembly of immobile obstacles constituting the solid. Solutions of the PRISM equations for polymeric solutes adsorbed within a microporous solid indicate a rich dependence of the structure of the adsorbate on matrix density, polymer density and chain length. Barriers to Mass Transfer in Catalysts and Adsorbents Important rate separations are based on the kinetics of mass transfer within materials such as zeolites and carbon molecular sieves. Differences between nuclear magnetic resonance and tracer exchange diffusivity measurements indicate that there is a significant resistance to trans;port att the entrances to the microporous regions. Computer simulation is a useful complement to experimenatl techniques in this regard, as it provides a convenient means of decoupling the various microscopic physical phenomena with contribution to the observed behavior. It is found, for example, that external adsorption and surface diffusion towards the mouth of the pores may play a large role in aiding transport. In such cases, the mass transfer coefficient decreases with increasing temperature, which would not be predicted by a simple activated model. The rate selectivity of carbon molecular sieves towards some gases over others can be explained by the very strong sensitivity of the mass transfer coefficient: it can change by several orders of magnitude over a change of only a few percent in pore size. Current work is focused on multicomponent systems and on the modeling of industrially relevant adsorbents. Honors and Awards:
D.M. Ford and E.D. Glandt, "Molecular Simulation Study of the Surface Barrier Effect. Dilute Gas Limit", J. Phys. Chem. 1995, 99, 11543. D.M. Ford and E.D. Glandt, "A Molecular Simulation Approach to Studying Mass Transfer Across Surface Barriers", in Access in Nanoporous Materials, T.J. Pinnavaia and M. Thorpe (eds.), Plenum 1995. A.P. Thompson and E.D. Glandt, "Partition Coefficients for Chains Confined in Microporous Media", Macromolecules, 29, 1996, 4314. P.A. Gordon and E.D. Glandt, "Liquid-Liquid Equilibrium for Fluids Confined within Random Porous Materials", J. Chem. Phys., 105, 1996, 4257. P.A. Gordon and E.D. Glandt, "Adsorption of Polar Gases on Model Silica Gel, Langmuir, 1997, 13, 4659. P. A. Gordon and E. D. Glandt, "Adsorption and Heats of Immersion of n-alkanes on Model Silica Gel," I&ECR, 1998, 37, 3221. Q. Wang, P. Danwanichakul, and E. D. Glandt, "Sequential Addition of Particles: Integral Equations," J. Chem. Physics, 2000, 112, 6733. P. Danwanichakul and E. D. Glandt, "Sequential Quenching of Square-well Particles," J. Chem. Phys., 2001, 114, 1785. F.P. Schmidt, J. Luther and E.D. Glandt, "Influence of Adsorbent Characteristics on the Performance of an Adsorption Heat Storage Cycle," I&EC Research., 42, 4910 (2003). P. Danwanichakul and E.D. Glandt, "Particle connectedness and cluster formation in sequential depositions of particles: Integral-equation theory," J. Chem. Phys. 121, 9684 (2004). P. Danwanichakul and E.D. Glandt, "Percolation and jamming in structures built through sequential deposition of particles," J. Colloid Int. Sci. 283, 41 (2005). P. Danwanichakul and E.D. Glandt, "Continuity between disorder and order in the sequential deposition of particles," Chem. Eng. Comm. 192, 1405 (2005). P. Danwanichakul and E.D Glandt, "Sub-monolayer growth by sequential deposition of particles," J. Colloid Int. Sci. 294, 38 (2006). .
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