Category Archives: materials chemistry

Cody Busch–Antimicrobial properties of silver nanoparticle-impregnated wheat gluten biofilms

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Abstract: “Wheat gluten (WG) biofilms result in a more affordable and biodegradable alternative for medical first aid bandages. WG biofilms were prepared by denaturing the WG protein with acid and heat, mixing with glycerol, and then drying to remove excess liquid. WG film properties such as density and porosity were measured. Different concentrations of silver nanoparticles (AgNPs) were synthesized and incorporated into the WG films to test their antimicrobial properties using several different pathogens. It was concluded that as the concentration of silver decreases, the diameter of the zone of inhibition also decreases, conveying that higher amounts of silver exhibit stronger antimicrobial properties. Incorporation of silver nanoparticles into WG biofilms had weaker antimicrobial properties than the silver disks alone. Some pathogens such as Klebsiella pneumoniae were more susceptible to the antimicrobial properties of WG with 0% AgNPs than WG with 100% AgNPs.”

ECI Abstract Manuscript

Omar Kazi–Direct Electrochemically Grown Thick Energy Dense Lithium Manganese Oxide Cathodes for Lithium-Ion Batteries

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Abstract: “We demonstrate for the first time an intermediate temperature (250-350°C) molten hydroxide mediated electrodeposition process to grow ternary lithium manganese oxide chemistries (Li2MnO3, LiMnO2, and LiMn2O4). State-of-the-art synthesis routes for such cathodes for lithium-ion batteries involve prolonged high temperature (over 700°C) processing for long reaction times under high oxygen pressure, followed by slurry casting after mixing with binders and additives. Our electrodeposited oxide cathodes are synthesized with the lowest reported temperature and reaction times, yet still retain the key structural and electrochemical performance observed in the high-temperature bulk synthesized analogs. The binder-and-additive- free, tens of microns thick, greater than 80% dense electrodeposits exhibit near theoretical gravimetric capacities and reversible areal capacities up to 1.5 mAh/cm^2.”

Kazi_Omar_ACS_Presentation_Transcript

Ji Seon “Lucy” Shon–Single-Chain Nanoparticle Delivers a Partner Enzyme for Concurrent and Tandem Catalysis in Cells

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Abstract: “In biological environment, enzymes catalyze reactions at extremely high efficiency and selectivity. The polypeptide scaffolds of enzymes selectively bind substrates to the catalytic to increase the efficiency. Single-chain nanoparticles have been developed with Ru(bpy)3 as enzyme mimic photocatalyst. They have been shown to penetrate the cell membrane and perform the reactions inside cells. More importantly, the nanoparticles can co-deliver an exogenous enzyme (beta-galactosidase) into cells and reside in endosomes. The SCNP-enzyme complex preserves their activity and perform concurrent or tandem reactions intracellularly. Therefore, the endosomes are engineered as artificial organelles, which efficiently producing fluorescent compounds or bioactive agents intracellularly.”

Shon_Text transcript

Milena Nutrobkina and Elizabeth Slowik–Plant Inspired Soft Actuators

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Abstract: “Actuators are responsible for moving and controlling other systems. Hydrogel actuators have been developed for therapeutic purposes in surgical applications but lose their mechanical strength under too much swelling. Closed-celled, fluid-filled systems, like plants, however, can swell with an increase in mechanical stiffness. Using this as our motivation, we try to synthesize these closed-celled, fluid-filled soft composites that could be used as actuators. This composite is made of emulsified salt water inner phase and PDMS, a two part polymer formed from intersecting polymeric chains. The plant tissue analog (PTA) allows for semi-permeable fluid motion that is biocompatible, flexible, and robust. Since the material is osmotically active, the composite can swell upon water intake due to a difference in chemical potential while maintaining cellular rigidity. This project first investigated the maximum swelling ratios of PTA of different salt concentrations, glycerol concentrations, mixing speeds, wall thickness, and cavity diameters measured via swelling in deionized water or salt water until the sample ceases to swell or ruptures. Furthermore, actuators were created by combining different PTAs in a variety of geometries. The actuators contained parts that are soft and other parts that are stiff to have a bending or twisting motion. Under swelling, the PTAs mimicked a sphere, twist motion, and time delayed wiggle action.”

Text Transciption_Nutrobkina_Slowik