Professors David Ford, Wei Fan, and Peter Monson of the Chemical Engineering (ChE) Department are involved in new collaborative research grants totaling $866,522 awarded to UMass Amherst from the National Science Foundation (NSF). The first grant of $327,038, involving Ford, Fan, and Monson, started on July 1 and is entitled “Developing New Theoretical Tools and Materials to Improve the Separation Performance of Inorganic Mesoporous Membranes.”
The second NSF grant awards $539,484 to UMass Amherst, involving Ford and Monson, in addition to $260,744 going to Professor Michael Bevan of Johns Hopkins University as a co-investigator. That grant took effect on September 1 and is entitled “Synthesis of Colloidal Crystals Guided by Particle-Based Theory and Simulation.”
Ford explains that “The first project combines theoretical development, computer simulation, materials synthesis, and separation experiments to guide the manufacture of new high-performance membranes that will be used in the removal of carbon dioxide from flue gases and the recovery of ethanol from fermentation broths, among other energy-related applications.”
As the abstract for this $327,038 grant explains, “Mesoporous inorganic membranes, composed of materials such as silica and alumina and having pore sizes on the order of 2 to 50 nanometers, have significant potential for performing separations of mixtures of small molecules. Chemists and materials scientists now have an amazing amount of control over the geometry and surface chemistry of the pores when synthesizing mesoporous inorganic membranes. However, actually knowing what pore geometry and chemistry to choose for a given separation remains an outstanding problem, partially due to the lack of appropriate models that connect detailed material structure to membrane flow rates.”
In this project, as the abstract notes, the researchers propose a new modeling approach to capture the complex adsorption and flow mechanisms that take place inside the membrane pores during separation operations.
“The modeling - based on dynamic mean field theory (DMFT),” notes the abstract, “retains molecular-level detail while predicting membrane performance at the laboratory or industrial scale. A combined program of theoretical development, computer simulation, materials synthesis, and permeation measurement will develop DMFT into a tool that chemists and materials scientists can use to guide the manufacture of new membranes, and engineers can use to model the performance of industrial membrane units. A novel class of mesoporous membrane materials will also be developed as a key part of the project.”
According to Ford, “The second project combines theory, simulation, and experiment to design systems of colloidal particles that assemble into desired crystalline structures. The resulting structures will serve as metamaterials, which are synthetic materials with periodic structures designed to manipulate electromagnetic or mechanical energy; potential applications include novel photonic and acoustic devices, as well as improved antenna and sensor technology. This grant was funded by NSF’s Designing Materials to Revolutionize and Engineer our Future (DMREF) program, which is an element of the White House’s Materials Genome Initiative.”
The abstract adds that this route to metamaterials is especially flexible, because many kinds of interactions among the particles can be exploited to form new crystalline materials. In addition, it allows better control over the formation process, which can reduce defects in the resulting crystalline structures. The results of the project will provide scientists and engineers with improved tools for identifying colloidal systems of interest, predicting stable crystalline structures, and guiding synthesis of the new materials.
“Theory, simulation, and experiments will be integrated into a program to design systems of colloidal particles that assemble into desired crystalline structures,” the abstract continues. “New theoretical and simulation methods will be developed to predict stable and metastable crystal structures in colloidal systems, with a focus on enhancing capabilities of classical density functional theory and applying hyper-parallel tempering simulation methods. Experimental tools for measuring and designing colloidal potentials and analyzing crystal structures will be extended to binary mixtures. The focus will be on developing and measuring suitable potentials for binary systems through the use of different particle sizes and materials, doublets/dumbbells, and Janus configurations, and on characterizing crystal structures using advanced confocal microscopy techniques. The results will be used to design colloidal systems that assemble into desired crystalline structures.” (November 2014)