2021 Undergraduate Research Symposium
The Department for Chemical and Biomolecular Engineering held the 2021 Undergraduate Research Symposium on April 9, 2021, via Zoom. This year, nine undergraduates presented research from eight labs.
“Each year, I am impressed by the challenges that our students are tackling,” said department head Paul Kenis, the Elio Eliakim Tarika Endowed Chair in Chemical Engineering. “These posters represent far more than an extra set of hands in the lab. They are pursuing their own projects, employing cutting-edge techniques to address research questions head-on — from water remediation to bone repair and beyond.”
The poster presentations (listed below) were judged by Corey Correnti (BS ’85), former Senior Vice President of Marketing, Sales and Supply at BP, who is currently a senior advisor for Marakon; Jim Morris (BS’ 81), former chief facilities engineer for ExxonMobil, who is currently assisting with the development of ChBE’s Professional Master’s program; and Tom Tulig (BS’ 78), the former vice president of novel processes and new energies technology and the general manager of process development at Shell.
- Rachel Park won first prize with her poster, “Metal Oxide Supports for Molybdenum Carbide Nanocatalysts in the Reverse Water Gas Shift Reaction.” Park is advised by Dr. Hong Yang.
- Maxwell Polanek placed second with his poster, “Incorporating Placental-Derived Membrane Matrix and Soluble Factors in Mineralized Collagen Scaffolds for Improved Bone Repair.” Polanek is advised by Dr. Brendan Harley.
- Devin Schinski took third place with his poster, “Polyethylene Encapsulation of Platinum-Bound Nanoparticles.” Schinski is advised by Dr. Damien Guironnet.
The winning poster presenters were recognized later on April 9 at the Undergraduate Awards Ceremony, which was also held on Zoom.
Thank you to all who joined us for these virtual events. The Zoom recordings are available by request at email@example.com. We look forward to hosting this annual event on campus in 2022.
2021 Symposium Participants:
|“Incorporating Placental-Derived Membrane Matrix and Soluble Factors in Mineralized Collagen Scaffolds for Improved Bone Repair”
|Dr. Brendan Harley
|“Process Intensification Approaches for Improved CO2 Electroreduction”
|Dr. Paul Kenis
|“Fabricating dichroic single crystals through principles of crystal engineering”
|Dr. Ying Diao
|“Computational Insight into Plant Signaling Hormones Principal”
|Dr. Diwakar Shukla
|“Investigation of electrochemical systems for sustainable water purification”
|Dr. Xiao Su
|“Polyethylene Encapsulation of Platinum-Bound Nanoparticles”
|Dr. Damien Guironnet
|“Swelling Thin Layers of Plant Tissue Analogs”
|Dr. Shelby Hutchens
|“Metal Oxide Supports for Molybdenum Carbide Nanocatalysts in the Reverse Water Gas Shift Reaction”
|Dr. Hong Yang
|Yazeed A. Alfawaz
|“Mechanism of Substrate Translocation in Bicarbonate Transporter BicA”
|Dr. Diwakar Shukla
2021 Symposium Abstracts:
“Incorporating Placental-Derived Membrane Matrix and Soluble Factors in Mineralized Collagen Scaffolds for Improved Bone Repair”
Advisor: Dr. Brendan Harley
Craniomaxillofacial (CMF) bone injuries cannot heal naturally, requiring surgical intervention due to their large size and complex topography. Approximately 26% of injured Iraq war veterans sustained CMF injuries in the form of blast wounds, and 0.1% of births involve CMF defects such as cleft palate. The gold standards for treatment are autografts and allografts, which are limited by bone availability and risk of disease transfer, respectively. Our lab has previously developed mineralized collagen scaffolds which enhance osteogenic differentiation and bone formation without exogenous factors, both in vitro and in vivo. These scaffolds are designed to mimic the extracellular matrix of bone, including its porous structure, mineral content, and protein composition. The amnion and chorion membranes of the human placenta have displayed anti-inflammatory, immunogenic, and osteogenic properties in the past, and thus represent promising compositional factors for incorporation in a biomaterial scaffold. The amnion membrane has been used for both bone and soft tissue regeneration in vivo, and our lab has demonstrated that the inclusion of powderized amnion in our non-mineral CG scaffolds enhances osteogenic differentiation under inflammatory conditions. Additionally, the chorion membrane contains soluble factors that upregulate osteogenic behavior in the MG-63 pre-osteoblast cell line. We aim to include either amnion and chorion membrane powder or extracts in our mineralized collagen scaffolds to evaluate their efficacy in inducing osteogenesis in human mesenchymal stem cells (hMSCs) and dampening the inflammatory response. This will ideally elucidate the source of these membranes’ beneficial properties and allow for more directed biomaterial design. The development of a scaffold capable of inducing osteogenic differentiation would be transformative to the field of tissue engineering.
“Process Intensification Approaches for Improved CO2 Electroreduction”
Advisor: Dr. Paul Kenis
Electrochemical reduction of CO2 to CO can be a potential method for utilizing excess CO2 emissions. When coupled with the Fischer-Tropsch reaction, the process could form an alternate way to produce liquid fuels and/or carbon feedstock. However, the activities of the existing CO2 electrolyzers are not suitable from an economical feasibility perspective for scale-up/scale-out and process integration at industrial scales. Conventionally, electroanalysis experiments are performed in a 3-electrode cell or an H-cell which have severe transport limitations. A flow electrolyzer can be used for electroanalysis experiments to overcome the limitations of the conventional 3-electrode cell or H-cell. While the activity levels obtained in a flow electrolyzer are promising, significant improvements in catalyst utilization are still needed for a feasible scale-up/scale-out of the CO2 electroreduction process. This study will focus on the operations of the CO2 flow electrolyzer to obtain optimized process design rules, magneto enhancement effect, and the promising approach of elevated temperatures for achieving better activity, selectivity, and energy efficiency.
“Fabricating dichroic single crystals through principles of crystal engineering”
Advisor: Dr. Ying Diao
The emerging field of optoelectronics utilizes crystalline materials and their ability to modulate light. More specifically, materials that exhibit dichroism (e.g., polymers, nanoparticles) have been used for light polarizing and beamsplitting applications. Because little is known about the design rules for dichroism in molecular crystals, single crystalline dichroic materials are scarce despite their attractive properties (e.g., uniformity, increased thermal resistance). This research aims to report a strategy for enhancing dichroism in single crystals of 4-phenylazopyridine (4PAzP), an asymmetric azo dye, using tris(pentafluorophenyl)borane (BCF) as a molecular shepherd to facilitate a parallel alignment of transition dipole moments through perfluorophenyl embraces and boron coordination.
In this project, dichroic dark red single crystals containing 4PAzP and BCF were formed after slow evaporation. Their composition and geometry were determined by single-crystal X-ray diffraction to be the boron adduct (BCF)•(4PAzP), identifying significant characteristics such as the B←N bonds within each adduct and the π-π interactions between adducts. The adducts pack into stacks of helices in such a way that aligns both the azo chromophores and the transition dipole moments linearly and in parallel, which was determined to be the key feature to obtain single crystal dichroism. The dichroic properties of the single crystals were observed under a polarized optical microscope and UV-Vis spectroscopy.
The results suggest that by employing perfluorophenyl embraces and boron coordination to rearrange azo chromophores in single crystals, the dichroism of analogous chromophores can be enhanced. This discovery can provide insight on how high-performance dichroic crystals can be fabricated for use in advanced optoelectronic applications.
“Computational Insight into Plant Signaling Hormones Principal” Advisor:Dr. Advisor: Dr. Diwakar Shukla
Parasitic activity of witchweed, orâ€¯Strigaâ€¯leads to aâ€¯$10 billion loss per year of staple food crops and affects the livelihood of 100 million farmers.â€¯â€¯Therefore, it is necessary to develop chemical interventions to inhibit the activity of this parasite without â€¯affecting crops. Witchweed senses the presence of host plants via strigolactone molecules exuded from their roots. These molecules are sensed by the strigolactone receptor. The interaction between the strigolactone molecule, DWARF14 (D14) strigolactone receptor, and D3 F-box C-terminal helix (CTH) has been shown to play a critical role in perception. Previously, it was believed that the D3 CTH only interacts with the active form of D14 to inhibit strigolactone binding, but recent experiments have indicated that D3 can interact with the inactivated form as well. To determine the mechanism by which D3 inhibits strigolactone binding activity, molecular dynamics (MD) simulations were performed for D14 with either strigolactone, CTH, or both. The apo system (no ligand present) was used to investigate whether the CTH affected the conformational ensemble, while the holo system (ligand present) with CTH was used to see if helix-ligand binding was responsible for inhibiting strigolactone perception. Our simulations show that strigolactone perception inhibition results from significant interactions between strigolactone and the CTH. Through greater understanding of this mechanism, it may be possible to combatâ€¯Strigaâ€¯parasites by selectively improving strigolactone binding in host crops or selectively inhibiting strigolactone signaling in the parasite.
“Investigation of electrochemical systems for sustainable water purification”
Advisor: Dr. Xiao Su
The focus of the project is on developing new systems for separating ions of concern, either polyfluorinated substances (PFOA (Perfluorooctanoic acid) and GenX (Hexafluoropropylene oxide dimer acid)) or valuable rare earth metals (Cerium and Yttrium) from mining wastewater. The goal of the project is to develop a cost-efficient, low-energy system for separation of toxic micropollutants that are charged in the presence of competing species. Electrochemical platforms allow for the unique control of surface properties based on voltage and current response, without the need for chemical regenerants or extensive physical processing. A key approach will be the molecular-level tuning of electrodes through materials design, synthesis, and processing by creating molecularly selective interfaces that are redox-active, electrochemically responsive, as well as both mechanically and chemically stable. In our lab we have developed new techniques using redox polymers that increase selectivity towards rare earth metal and PFAS. We used CNT (carbon nanotubes) for Yttrium and Cerium adsorption and PTMA for PFAS. CNT was used based on the array of structural, mechanical, and electronicâ€¯properties, such as high aspect ratio, high strength and excellent current carrying capability. PTMA copolymer (poly(4-methacryloyloxy-2,2,6,6- tetramethylpiperidin-1-oxyl) and poly(4-methacryloyloxy2,2,6,6-tetramethylpiperidine)) due to its amine interactions towards PFAS, hydrophobic interactions promoting captures, as well as the electrostatic interactions. Our system was able to capture PFAS – adsorb up to around 110 mg of GenX / g adsorbent – and rare earth metals – adsorb around 110 mg Yttrium / g adsorbent and around 280 mg Cerium / g adsorbent. We were able to compare different adsorption values at different screening currents and potentials and compare adsorption capacity at different pH levels where we saw electrostatic interaction dominant at alkaline conditions compared to open circuit. Finally, we were able to develop new techniques using novel electro sorption methodologies remediation of water from toxic micropollutants.
“Polyethylene Encapsulation of Platinum-Bound Nanoparticles”
Advisor: Dr. Damien Guironnet
The crosslinking of silicon is an important reaction in the process of developing novel elastomers and resins. These materials have shown a range of applications for industrial and consumer products, motivating our interest in their study. The technique we are using, hydrosilylation, crosslinks silanes with olefins and alkynes to form silicones via a platinum catalyst. As desire for silicones grow it would be useful to have shelf stable mixtures that could be quickly and easily activated to allow for greater control and selectivity of reactions. This is difficult to achieve however as our platinum catalyst is still very active at room temperature.
We propose to selectively inhibit catalyst activity through the encapsulation of silica nanoparticles in low molecular weight polyethylene. Our nanoparticles are first functionalized by the addition of norbornene as a linker for platinum. Once the platinum in our Karstedt’s catalyst binds to those linkers, the nanoparticle surface becomes an array of active sites for our reaction to occur. By encapsulating the Pt-bound particle in polyethylene, a non-reactive barrier is formed to halt the hydrosilylation from progressing. When heated this barrier melts, exposing the particle surface and activating our catalyst.
The current technique for our encapsulation is by nano-precipitating a solution of polyethylene and nanoparticles in pentane. Precipitation of the polymer occurs quickly, and it has been shown to successfully coalesce around the outside of our particles. The issue however is that total encapsulation of our nanoparticles is not guaranteed. This means not all the active sites are covered by our current process. Exposed Pt can be removed by washing but this means sacrificing stability for a slower and less controlled reaction. The goal of my project is to improve the degree of particle encapsulation by altering the conditions of our nanoprecipitation. The desired outcome of these changes would be further improving stability at low temperature while also minimizing the loss of Pt in the preparation of our particles.
“Swelling Thin Layers of Plant Tissue Analogs”Advisor: Dr. Shelby Hutchens
Closed-cell plant tissues allow plants to move without the aid of muscle. They do this by driving water across the cell membranes due to an osmotic pressure gradient. As more water builds up inside the cells, the tissues become more rigid because of the buildup of turgor pressure. Plant tissue analogs (PTA) were synthesized as closed-celled, fluid-filled soft composites that mimic the microstructure of plants. The composite was an emulsified mannitol inner phase with PDMS outer phase. PDMS is robust, biocompatible, cost effective, and allows for both mass transport and mechanical deformation. This study focused on the size dependency on the swelling behavior of PTAs. Previous research has shown that PTAs stiffen upon swelling, and equilibrium properties have been described. However, designing active materials utilizing PTA required knowledge of their time dependent responses. The project first studied the maximum swelling ratio of PTAs of varying inner phase mannitol concentrations. The project then investigated the geometry that approximate one-dimensional fluid transport with cylindrical PTAs with varying heights and a constant radius. This was done to determine whether fluid transport would be primarily normal to the circular surface. The PTAs exhibited homogenous swelling for the largest height to radius ratio, but the swelling diverged for smaller height to radius ratios. Thus, the PTA swelling model does not follow the same kinetics as hydrogels, and more analysis should be performed to determine a model that follow swelling kinetics of PTAs.
“Metal Oxide Supports for Molybdenum Carbide Nanocatalysts in the Reverse Water Gas Shift Reaction”
Advisor: Dr. Hong Yang
Elevated global temperatures, rising sea levels, glacial retreating, and the acidification of ocean waters have been linked to increasing emissions of greenhouse gases from the consumption of fossil fuels such as carbon dioxide (CO2). One strategy is the sequestration and catalytic upgrading of CO2 to produce value-added solvents and chemicals (e.g. methanol and synthetic fuels). The electroreduction of CO2 is promising, but the low product selectivity to any one product, low overall throughput, and poor catalyst stability remains unsolved. On another front, the commercially available copper on zinc and aluminum oxide (Cu/ZnO/Al2O3) has been well studied for the thermal reduction of CO2 to carbon monoxide (CO) using hydrogen gas (H2) via the reverse water gas shift reaction (RWGS, CO2 + H2ïƒŸïƒ CO + H2O). The production and subsequent purification of a CO gas stream can then be used for the formation of methanol and aldehydes. Until recently, little progress had been made towards improving the RWGS activity and stability of Cu/ZnO/Al2O3. It was discovered that metal carbides could replace the oxide support, leading to a stabilization of metal single atoms and nanocluster and an enhancement in the overall mass activity for RWGS. The carbide itself also provides active sites for this reaction, thus a “metal-free” catalyst can be realized by the synthesis of supported carbide nanostructures without copper or a noble metal. In this work, we developed a synthesis for the formation of beta molybdenum carbide (β-Mo2C) nanoparticles (~5 nm) using a wet impregnation and carburization process. Phase-purity of this carbide was dependent on the choice of metal oxide support; namely the medium binding energy of Mo atoms with silica (SiO2) was preferred over reducible metal oxides (i.e. ceria and titania) and oxides with weaker interactions (magnesium oxide). During the RWGS performance evaluation, the β-Mo2C/SiO2 outperformed all the materials and bulk β-Mo2C. The optimized β-Mo2C/SiO2 achieved the highest recorded Mo2C mass activity at 600 °C (588 μmolCO2 g-1Mo2C s-1) while maintaining near-complete selectivity to CO and stability for 10h on stream. This work provides progress towards the formation of phase-pure carbide nanomaterials while providing a novel metal-free catalyst towards the synthetic-upgrading of CO2.
Yazeed A. Alfawaz
“Mechanism of Substrate Translocation in Bicarbonate Transporter BicA”
Advisor: Dr. Diwakar Shukla
Cyanobacteria are responsible for 30-80% of aquatic CO2 fixation and have evolved mechanisms to utilize bicarbonate as a carbon source in photosynthesis. In some aquatic plants, evidence suggests that increasing bicarbonate concentration directly enhances photosynthesis rate. The bicarbonate transporter (BicA) from cyanobacteria Synechocystis sp. PCC6803 is a sodium-coupled transporter and a member of the SLC26 family. Despite several biochemical studies and the recent reporting of its crystal structure, the structural understanding of the bicarbonate transport mechanism by BicA remains elusive. In this study, we conducted extensive all-atom molecular dynamics (MD) simulations on BicA to characterize the bicarbonate transport process. Furthermore, we constructed a Markov state model (MSM) to characterize long-timescale protein dynamics and quantify the thermodynamic stability and transition barriers of key conformational states. By presenting a detailed mechanistic understanding of bicarbonate transport in BicA, our results provide invaluable insights to engineer BicA to enhance photosynthetic yield and production.