Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 10 of 10

Full-Text Articles in Engineering

Carbon Removal And Optoelectronic Property Tuning In Copper Arsenic Sulfide Thin Films Through Ligand Exchange And Alloying, Louis R. Schroeder, Scott Mcclary, Rakesh Agrawal Aug 2017

Carbon Removal And Optoelectronic Property Tuning In Copper Arsenic Sulfide Thin Films Through Ligand Exchange And Alloying, Louis R. Schroeder, Scott Mcclary, Rakesh Agrawal

The Summer Undergraduate Research Fellowship (SURF) Symposium

Solution processed thin film solar cells are attractive alternatives to conventional energy sources due to low waste generation, flexibility in substrate choice, and scalability. The novel semiconductor Cu3AsS4 in the enargite phase has a near ideal band gap of 1.4 eV and has earth abundant constituent elements; yet single-junction solar cells have yielded low efficiencies due to a secondary carbonaceous phase present, among other issues. This carbonaceous phase may be eliminated by exchanging the carbonaceous ligands with molecular metal chalcogenides. To characterize the ligand exchanged particles, UV-Vis-NIR spectroscopy, Raman spectroscopy, X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, and …


Novel Synthesis Of Cigs Nanoparticles For Scalable, Benign Inks For Solution Processed Solar Cells, Jacob Fields, Ryan Ellis, Rakesh Agrawal Aug 2017

Novel Synthesis Of Cigs Nanoparticles For Scalable, Benign Inks For Solution Processed Solar Cells, Jacob Fields, Ryan Ellis, Rakesh Agrawal

The Summer Undergraduate Research Fellowship (SURF) Symposium

One potential production route to high efficiency, low cost, photovoltaics (PVs) which was explored is Copper Indium Gallium Sulfide (CIGS) nanocrystal inks for solution processed PVs. A common CIGS nanocrystal ink synthesis utilizes ligands—molecules attached to the particle surface—for colloidal stability, size control, and shape control. It is desirable to devise a novel synthesis which will incorporate a ligand that allows suspensions in more benign solvents than current methods—a desirable characteristic for large scale production. In order to develop the aforementioned synthesis of CIGS nanoparticles, an optimization study of synthesis parameters was performed. Selection of an appropriate solvent, and sulfur …


Assembly Of Nucleic Acid-Based Nanoparticles By Gas-Liquid Segmented Flow Microfluidics, Matthew L. Capek, Ross Verheul, David H. Thompson Aug 2016

Assembly Of Nucleic Acid-Based Nanoparticles By Gas-Liquid Segmented Flow Microfluidics, Matthew L. Capek, Ross Verheul, David H. Thompson

The Summer Undergraduate Research Fellowship (SURF) Symposium

The development of novel and efficient mixing methods is important for optimizing the efficiency of many biological and chemical processes. Tuning the physical and performance properties of nucleic acid-based nanoparticles is one such example known to be strongly affected by mixing efficiency. The characteristics of DNA nanoparticles (such as size, polydispersity, ζ-potential, and gel shift) are important to ensure their therapeutic potency, and new methods to optimize these characteristics are of significant importance to achieve the highest efficacy. In the present study, a simple segmented flow microfluidics system has been developed to augment mixing of pDNA/bPEI nanoparticles. This DNA and …


Effect Of Aggregation And Particle Size On The Thermal Conductivity Of Nickel-Epoxy Nanocomposites, Jacob M. Faulkner, Xiangyu Li, Xiulin Ruan Dr. Aug 2016

Effect Of Aggregation And Particle Size On The Thermal Conductivity Of Nickel-Epoxy Nanocomposites, Jacob M. Faulkner, Xiangyu Li, Xiulin Ruan Dr.

The Summer Undergraduate Research Fellowship (SURF) Symposium

Microprocessor advancements have been stunted in recent years by inadequate means of heat dissipation as power continues to grow and size continues to shrink. One way to increase thermal conductivity while maintaining electrical insulation is to add metal nanoparticles to a polymer matrix. This cheap material has become a popular thermal interface for this reason. However, optimization of the interface is dependent upon a number of factors including particle size, shape, orientation, and aggregation. Various theoretical models and numerical approximations have been developed to find the effective thermal conductivity of such nanocomposites, but none has been able to fully incorporate …


Dissolution Of Chalcogens In Amine Thiol Solvents For Use In Nanoparticles, Gaurav A. Mittal, Caleb K. Miskin, Rakesh Agrawal Aug 2015

Dissolution Of Chalcogens In Amine Thiol Solvents For Use In Nanoparticles, Gaurav A. Mittal, Caleb K. Miskin, Rakesh Agrawal

The Summer Undergraduate Research Fellowship (SURF) Symposium

Lead chalcogenide quantum dots have been shown to be ideal materials for solar cells due to their tunable band gap. Developing a dissolution procedure for chalcogens will help lower the production cost of the solar cells produced by the associated nanoparticles. Dissolution was performed in both aqueous and nonaqueous solutions. Precursors for sulfur and selnium were dissolved in both the aqueous solution of ammonium thioglycolate and ammonium hydroxide and in combinations of amines and thiols. Precursors for tellurium were dissolved in ethylenediamine and different thiols. Lead telluride forms larger microparticles that can be suitable for thermoelectric devices. The optimum solutions …


Carbon Dioxide Sequestration To Form Calcium Carbonate Nanoparticles, Krista E. Stump, Michael T. Harris Aug 2015

Carbon Dioxide Sequestration To Form Calcium Carbonate Nanoparticles, Krista E. Stump, Michael T. Harris

The Summer Undergraduate Research Fellowship (SURF) Symposium

The emission of carbon dioxide caused by burning fossil fuels is one of the leading sources of global warming. Reducing the amount of CO2 released into the atmosphere through carbon sequestration can mitigate this problem. One method of carbon sequestration is the use of a carbon dioxide scrubber. Once captured, CO2 can be used to create a valuable chemical commodity such as calcium carbonate nanoparticles. To create CaCO3 particles in the 50-100 nanometer range, a chemical additive is necessary to limit particle size. The study used a laboratory scale carbon dioxide scrubber to react CO2 with …


The Kinetics Of A Palladium Precursor – Tobacco Mosaic Virus Reaction, Adi Banerjee, Mayo Adigun, Michael T. Harris Aug 2014

The Kinetics Of A Palladium Precursor – Tobacco Mosaic Virus Reaction, Adi Banerjee, Mayo Adigun, Michael T. Harris

The Summer Undergraduate Research Fellowship (SURF) Symposium

There have been numerous developments in the field of production of metallic nanoparticles using biotemplates such as the Tobacco Mosaic Virus (TMV). Past research has looked at the conditions required to maximise nanoparticle formation. This study of the kinetics of a nanomaterial synthesis reaction using a biotemplate would elucidate the understanding of the controlled growth of nanoparticles, which can be applied in the fabrication of photocatalysts, electrical nanocircuits and solar cells. This study specifically focuses on the reaction between a palladium precursor and the TMV without an external reducing agent, where the palladium ion concentration is measured over time using …


Stability Of Aqueous Dispersions Of Titanium Dioxide Against Sedimentation And Aggregation, Guanrong Bai, Xilan Zhu, Elias I. Franses, David S. Corti, Yung-Jih Yang Aug 2014

Stability Of Aqueous Dispersions Of Titanium Dioxide Against Sedimentation And Aggregation, Guanrong Bai, Xilan Zhu, Elias I. Franses, David S. Corti, Yung-Jih Yang

The Summer Undergraduate Research Fellowship (SURF) Symposium

Particles of titanium dioxide (TiO2) are widely used as white pigments in paints and inks, due to their brightness and high refractive index. Yet, with TiO2 having a high density (4.2 g/cm3), particles with typical sizes of 300 nm sediment rapidly even before significant agglomeration can occur. Thus, increasing the stability of TiO2 dispersions against sedimentation as well as aggregation is important. We studied the effect of sodium dodecyl sulfate (SDS), a commonly used dispersant, on the stability of aqueous dispersions of TiO2 with weight fractions from 0.01 to 40. The sedimentation time of …


Pulsed Laser Coating Of Bioceramic (Hap) And Niti Nanoparticles On Metallic Implants, Aayush Goswami, Gary J. Cheng Oct 2013

Pulsed Laser Coating Of Bioceramic (Hap) And Niti Nanoparticles On Metallic Implants, Aayush Goswami, Gary J. Cheng

The Summer Undergraduate Research Fellowship (SURF) Symposium

This research deals with increasing the biocompatibility of the bio implants which have a global market valued more than $94.1 billion . The surface of the metal alloys used for the bone implants need to be coated with bio compatible materials like HAp(Hydroxyapatite), graphene, etc. in order to promote the growth of cells(osteoblasts) on the surface of the implants. Various techniques like plasma spray coating, ion beam sputter coating, etc. have been used before to coat such materials on a substrate, however these have faced problems of coating quality. In order to perfect this coating, that is make it more …


Electrochemical Sensing With Metal Oxides, Isabella Ramirez, Lia Stanciu, Alexandra Snyder Oct 2013

Electrochemical Sensing With Metal Oxides, Isabella Ramirez, Lia Stanciu, Alexandra Snyder

The Summer Undergraduate Research Fellowship (SURF) Symposium

The effective sensing of hydrogen peroxide is important for a variety of reasons. It can be utilized as a diagnostic tool for diseases like asthma; also, the sensing can be utilized in pharmaceutical and food production for quality control. The use of silver oxide nanoparticles with varying morphologies has not been investigated as a sensing agent for hydrogen peroxide in the past. The particles’ properties and ability to oxidize and reduce hydrogen peroxide suggest that they will be effective to create a sensitive sensor. The silver oxide particles were prepared through chemical reduction using varying molar ratios of reactants. The …