Research Groups

The Abrams group uses molecular simulations to address questions in biological and materials sciences primarily centered on structure/function relationships. The group has made efforts to develop and implement new molecular simulation methods for statistically accurate prediction of energetics and rates of molecular-level processes. Current research in the Abrams group (2013) focuses on understanding the structure/function relationships underlying HIV entry and the design of entry inhibitors and microbicides against AIDS, on predicting transport rates of small molecules through proteins, such as CO in myoglobin, and on understanding how control of void growth in epoxies under tension can lead to better toughening mechanisms, which would be advantageous in military protective applications.

Cameron Abrams: Research Group Website

The Alvarez Research Group focuses on a unique blend of soft matter physics, polymer dynamics, molecular rheology, and interfacial transport/mechanics. Their efforts concentrate on making key connections between fundamental parameters measured on lab-scale equipment and the more crude real world processing conditions required to manufacture materials with engineered properties on global supply scales. Expertise lies in developing novel instruments that take advantage of key physics in order to capture/measure fundamentally relevant phenomena/parameters. They are highly motivated by recent connections made by the group that will inform material development for the present and future of nanomaterials, composites, structured polymers, and "smart" materials.

Nicolas Alvarez: Research Group Website

The Baxter research group focuses on materials, interfaces, processing, and physical and chemical phenomena related to photovoltaics (PV). This group has developed new materials with improved properties as PV absorbers and buffer layers, designed nanostructured architectures and investigated their benefits and limitations, and used ultrafast pump – probe spectroscopy to identify performance-limiting photophysical processes in PV materials. Materials of particular interest include perovskite thin films, kesterite single crystals, and nanocrystal arrays.

Jason Baxter: Research Group Website

The Cairncross research group is working on topics related to renewable polymers and renewable fuels. In addition, Professor Cairncross teaches courses on renewable energy, sustainable engineering and design, and is involved with several groups on campus promoting sustainability.

Bio-fuels are a small but growing part of the U.S. energy portfolio. However, availability of renewable feedstocks that can be efficiently converted into fuels is a major limitation on the potential for bio-fuels. The Cairncross research group has developed a novel bubble column reactor for the conversion of waste greases into biodiesel. The bubble column reactor is more robust to impurities than other process alternatives. The research involves a combination of reaction experiments, using transport principles to improve reactor design, evaluation of process design, and estimation of environmental impacts. Current projects are evaluating the life cycle environmental impacts of producing biodiesel from waste greases, improving processes for separating lipids from waste sources, improved purification techniques for crude biodiesel, and growing algae to produce biofuels.

Plastics are a ubiquitous part of modern life. The Cairncross group has been researching the transport of small molecules within polymers and polymer composites to understand and improve the performance of polymers for commodity and infrastructure applications. Current projects include evaluating factors that affect moisture transport through polylactide – a bio-based polymer that is produced from corn – and developing mathematical models of antioxidant diffusion and degradation in polyethylene nanocomposites that are used for water infrastructure.

Richard Cairncross: Research Group Website

The Fafarman lab is developing new chemistries and new processes for the fabrication of high-performance optoelectronic materials from colloidal nanocrystalline building blocks. The group introduced a class of compact, inorganic capping groups (or ligands) for the nanocrystal surface that promote the dispersibility of semiconducting and metallic particles in polar solvents. This allows us to assemble all-inorganic nanocrystal-solids with exceptionally short interparticle spacing, directly from solution. These colloids exhibit highly charged surfaces, a phenomenon we are currently exploiting by using electric fields to direct their assembly in to solid-state materials, allowing for a dramatic increase in the atom economy of the process. The sparse surface coverage of these compact ligands allows us to manipulate and measure the chemical composition at the nanocrystal surface, in order to optimize the electrical and optical properties of the solid, particularly for photovoltaics. To understand the interplay between the chemical processes the group develops and the photophysics and electrical behavior of the resulting all-inorganic nanocrystal arrays, the group uses spectroscopy and electrical measurement, often in tandem. Measuring the absorption spectrum of a compact array of semiconducting nanocrystals under an applied field (Stark spectroscopy) helps the group understand the electronic coupling between nanocrystals. Vibrational spectroscopy provides a handle for understanding the composition of the nanocrystal surface, and the action of charge carriers under illumination or under bias. Steady-state spectroscopies are performed in the lab, while time-resolved experiments are done in collaboration with groups at Drexel and Brookhaven National Lab.

Aaron Fafarman: Research Group Website

The Kalra group combines experiments and meso-scale simulations to study structure-property-performance correlation in nanofiber-based novel materials for energy storage and conversion devices, including fuel cells, super-capacitors, batteries and solar cells. The key focus is on tailoring material architecture from sub-nanometer to macroscopic length scales for synergistic effects of properties and performances in energy devices. Nanofibers are fabricated via a process called electrospinning, where a droplet of polymer, organic/inorganic hybrid or ceramic sol-gel precursor liquid is elongated by the action of a strong electrical field. The resulting nanofibers with diameters in the range of 50-500 nm are collected as non-woven mats. These mats provide a flexible, light-weight, free-standing platform with an interconnected pore structure (for efficient mass transport) and high surface area, necessary to develop efficient electrodes for various energy devices. Depending on the specific target application, Kalra lab synthesizes nanofibers composed of one or more of the following class of materials; polymers, organic/inorganic hybrids, carbon and ceramics. Nanofiber synthesis is accompanied by a comprehensive set of structural and electrochemical characterization techniques including scanning/transmission electron microscopy, x-ray diffraction, x-ray scattering, x-ray photoelectron spectroscopy, nitrogen physisorption, cyclic voltammetry, impedance spectroscopy, and charge-discharge measurements. In addition, to fundamentally understand process-structure correlation, Kalra lab conducts molecular and meso-scale simulations using molecular dynamics and dissipative particle dynamics approaches. Within the scope of these overall research interests, the current active research projects include 1) Understanding the self assembly of rod-rod block copolymers within nanofibers for organic solar cells; 2) Understanding the structure-property-performance correlation in nanofiber-based electrodes for lithium-air batteries; 3) highly-ordered electrode/catalyst assembly in proton exchange membrane fuel cells for enhanced catalyst utilization; 4) Superporous electrospun carbon nanofibers for supercapacitors. In addition to energy applications, the ongoing research in Kalra lab on nanofibers can potentially impact several other fields including sensing, catalysis, smart textiles, drug delivery and tissue engineering.

Vibha Kalra: Research Group Website

The Snyder group strives to fully understand the nature of the electrocatalytic site and how its properties may be adjusted to optimize interaction with reactants/intermediates yielding improved catalyst activity and selectivity. Through the use of fundamental investigations of idealized, single crystal metal/alloy electrodes we can gain insight into reaction mechanisms and how they may be influenced by structural, compositional and electronic properties. These insights will provide the basis for development of unique nanostructured catalysts that are more suited for integration into real-world electrochemical devices. The group’s focus is divided into four areas: (1) Dealloying/nanoporous metals and the kinetics of electrochemical reactions within nanoconfined environments, emphasis on organic synthesis of nanoporous nanoparticles for aqueous electrochemical reactions, such as oxygen reduction with relevance to fuel cells, nitrate reduction for water purification and water splitting for hydrogen/oxygen evolution; (2) Nonaqueous electrochemistry, understanding the kinetic advantages of organic and ionic liquid electrolytes for the oxygen reduction and carbon dioxide reduction/fuel conversion reactions; (3) Electrochemistry in unique/extreme environments, developing testing apparatuses and procedures for studying the effects of extreme reaction conditions, such as high temperature and pressure, and how they may be used to tailor kinetics and selectivity; (4) Gas phase catalysis, understanding the influence of catalyst nanostructure and the interaction of metal/metal oxide interfaces on reaction mechanisms of the water-gas-shift and methanol production reactions (the group is also interested in finding the link between gas phase methanol production and electrochemical carbon dioxide reduction where a mechanistic understanding of the gas phase reaction may help to improve the methanol selectivity of the electrochemical reaction).

Joshua Snyder: Research Group Website

The Soroush group is currently conducting research in Polymer Reaction Engineering, Process Risk Assessment and Fault Detection, and Solar Cell Modeling and Optimization.

In Polymer Reaction Engineering, the Soroush group conducts experimental and theoretical/computational studies to understand mechanisms of high-temperature polymerization reactions of acrylates and methacrylates. Reactions are modeled and simulated at quantum level, and then the knowledge gained on the reaction mechanisms is used in macroscopic modeling of polymerization reactors. Their ultimate aim is to design novel processes for the production of higher quality, environmentally friendlier resins and coatings at lower operating costs. In this area, the Soroush group collaborates with University of Pennsylvania’s Department of Chemistry and DuPont.

In Process Risk Assessment and Fault Detection, the group uses historical process data to probabilistically assess risks and identify faults. Their methods provide online estimates that alert operators about potentially serious safety problems. The methods identify the root cause(s) of triggered alarms in a short period of time so that the process personnel with help from control and safety systems can return the process operation to normal, or steer the process to safer conditions. The group has tested their methods on a plant at Air Liquide. In this area, the group collaborates with University of Pennsylvania’s Department of Chemical Engineering and Wharton School of Business, and Air Liquide.

In Solar Cell Modeling and Optimization, the group employs an integrated research strategy involving first-principles mathematical modeling and simulation, synthesis and characterization to design solid-state dye sensitized solar cells with optimal performance, and optimally operate and integrate the cells. Central to this research is the hypothesis that higher power conversion efficiencies will be obtained by reducing major losses in electrical conduction within the photoanode and electrolyte of the cell. In this project the group collaborates with Dr. Ken Lau and University of Pennsylvania’s Department of Chemical Engineering.

Masoud Soroush: Research Group Website

The Tang lab's research mission is to advance the fundamental understanding of physical and chemical phenomena in ways that improve the lifetime, performance, and cost of electrochemical energy systems. Broadly, we improve device performance by first diagnosing and understanding fundamental obstacles, then developing new materials, architectures, and system-level solutions to these problems. To this end, we employ a variety of theoretical and experimental methods to integrate materials development with diagnostics and theory at the molecular and system level. Current topics of interest in the group are: a) understanding and controlling the decomposition reactions of nonaqueous electrolytes, with an emphasis on corrosion and passivation; b) alloy electrocatalysts for hydrogen fuel cells and electrolysis; and c) hydrogen peroxide electrochemistry.

Maureen Tang: Research Group Website