Capstone Talks 2013

2013 Capstone Celebration Symposium

PLU Chemistry Department

April 29^th to May 3^rd, 2013

Join the Chemistry Department to hear the senior capstone presentations. Student presentations will occur Monday through Friday. The schedule of talks with more details is given below.

[ Monday | Wednesday |  Friday ]

Morken Center, Room 103

1:00 pm - Hyaluronic Acid: Synthesis and Application

Thaddeus Golbeck, Senior Capstone Seminar

Cancer is one of the most deadly diseases in our world with no certain cure found. Studies have found commonalities that many of the tumors show a higher concentration of hyaluronic acid (HA) near the site of the tumor. Various synthetic methods such as a step-by-step reaction, automated solid-phase, and chemoselective combined with a one-pot synthesis have been developed to synthesize hyaluronic acid. Synthesized hyaluronic acid immobilized to superparamagnetic nanoparticles (HA-SPIONs), with an anti-cancer drug attached, can then be added in the vicinity of cancerous cells to test if the hyaluronic receptor CD44 will engulf the SPIONs. The result is that the HA-SPIONs are engulfed and could mean that a target specific cancer treatment can be developed.

1:40 pm - Charge Collection Resistance and Interface Studies in an Inverted Organic Photovoltaic Cell

Laura Murphy, Senior Capstone Seminar

An ITO/ZnO/C60/Al2O3/Al electron-only device was designed for measuring the sum of the charge transport and charge collection efficiencies in an inverted organic photovoltaic device. Upon testing, the device shorted. Tall surface profile features on the ZnO electron injection layer could account for the device shorting.

2:20 pm - Synthesis and Characterization of 3, 4-Dimethylmethcathinone

Jeremy May, Senior Capstone Seminar

In this research we present a synthesis and full chemical characterization of 3, 4-dimethylmethcathinone hydrochloride (3, 4-DMMC). The title compound was synthesized in a three step reaction starting from o-xylene and propionic acid. Ferric chloride was used to catalyze the electrophilic aromatic substitution to form a ketone intermediate, followed by a simple bromination and addition of methylamine to yield the crude product. Product was purified by recrystallization in diethyl ether. The final compound was characterized by 1H NMR, 13C NMR, UV-Vis, GC-MS, FT-IR, and melting point.

3:10 pm - Oxidative DNA Damage in Saccharomyces cerevisiae

Jennifer Reynolds, Senior Capstone Seminar

DNA is susceptible to damage. It is known that this damage can lead to mutations due to replicational mutagenesis; it is thought that mutant RNA may be generated via transcriptional mutagenesis, causing the production of mutant proteins, which may increase replication in a process called retromutagenesis. This lab concentrates on providing significant evidence of this process by analyzing mutation rates and comparing them to DNA damage. Here, we describe a method to isolate genomic DNA from the yeast Saccharomyces cerevisiae and visualize the extent of oxidative DNA damage using Fpg digestion and alkaline gel electrophoresis.

3:50 pm - Arsenic Contamination in Rice and Groundwater of Southeast Asia

Tace Rand, Senior Capstone Seminar

Southeast Asia faces a crisis of arsenic contamination in drinking water and rice. Reducing conditions mobilize arsenic from sediment into groundwater that is consumed or used for irrigation. This review examines the chemical behavior of arsenic species in this system, an ICP-MS method to determine arsenic content in rice, and remediation.

1:00 pm - Benzofulvene Molecules and Flavoprotein Inhibition: Research in Drug Development

John Rubenkonig, Senior Capstone Seminar

Benzofulvene molecules provide a potential new avenue for cancer therapy. This project optimized the reaction conditions of a novel organic pseudo-condensation synthesis by varying the temperature, metal stabilizing group and solvent used. In doing so, yields of above 80% were realized. Further, substrate scope analysis was performed and potential enzymatic inhibition was investigated via computer modeling.

1:40 pm - Effect of Dithiocarbamate Ligands on Cadmium Selenide Nanospheres and Nanobelts

Jenny Stein, Senior Capstone Seminar

We study how ligands bind to different shapes of cadmium selenide nanocrystals. Nanocrystals have important applications in solar cells due to their size-tunable optical and electronic properties. The CdSe nanosphere interface has been thoroughly studied with respect to how different ligands attached to the surface change certain properties. Nanobelts and other 2-dimensional nanostructures are a newer focus for improving the efficiency of solar cells. An important question to ask is whether the same ligands we apply to nanospheres are as effective when bound to nanobelts. We exposed nanobelts and nanospheres to dithiocarbamate ligands to determine whether the crystals experience the same changes.

2:20 pm - N-Acetylcysteine: Effects on Retromutagenesis

Justin Brent Pascual, Senior Capstone Seminar

We demonstrated the effects of the antioxidant N-Acetylcysteine on retromutagenesis, using both the wild-type and ogg1Δ strains of Saccharomyces cerevisiae. While the antioxidant had no observable effect on the wild-type strain, the median mutation frequencies decreased with an increase in antioxidant concentration. We also determined that the survival of the yeast strains was unimpeded by the presence of N-Acetylcysteine.

3:10 pm - Watching Paint Dry: An Evaluation of Formaldehyde Emissions

Alex Lineweaver, Senior Capstone Seminar

Solid-phase microextraction (SPME) is a method of concentrating analyte molecules from dilute sample matrices. The silica fiber of the SPME device allows a wide range of samples to be concentrated with the use of multiple fiber types and derivatization options. Once concentrated on the fiber, analytes can be desorbed directly from the fiber into the analyzing instrument, avoiding any need for dilution. This work investigates the emission of formaldehyde from curing paint using SPME in combination with gas chromatography/mass spectrometry (GC/MS). This methodology is able to detect formaldehyde at concentrations in the low parts per billion (ppb) range. The headspace over paint samples was sampled using 65 μm poly(dimethylsiloxane)/divinylbenzene fibers derivatized with o-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride (PFBHA). PFBHA allows indirect analysis of the highly reactive formaldehyde species by reacting in a 1:1 ratio with formaldehyde to produce a stable oxime compound that is then detected and quantified with GC/MS. The headspace analyses show that formaldehyde emissions from curing paint peak at approximately 100 min of curing and never rise above 25 ppb.

3:50 pm - Metal Deposition on High Surface Area Carbon Electrode & Electrochemical Analyses

Michael Shiu, Senior Capstone Seminar

Two major types energy storage devises, battery and capacitor has a lot of property in common but they behaves in a very different way. It has been a long journey for scientists to try to combine the battery and capacitor into one devise. In our research, we already made capacitor that has a great amount of surface area, which has a higher specific energy. Now we coat iron on the surface because we propose If we can form metallic iron on the pore walls of carbon nanofoams, then those electrodes will electrochemically oxidize faster than iron deposited on nonporous carbons because carbon nanofoams have much larger interfacial surface areas than nonporous carbon does. In addition, if we can chemically reduce the iron oxide on the capacitor, we can generate much more energy.

1:10 pm - Synthesis and Thermal Decomposition of hetero-Diels-Alder Trigger Adducts for Self-Immolating Polymers

Brian Levandowski, Senior Capstone Seminar

The retro-Diels Alder reaction of N-carbamoyl-3,6-dihydro-1,2-oxazine species have the potential as trigger moieties in Self-Immolating Polymers. N-Aryl- and N-alkyl-N′-hydroxyureas were readily converted to heterodienophiles upon oxidation under copper(II) aerobic catalysis. The in situ hetero-Diels-Alder reactions of these carbamoyl nitroso species with acyclic 1,3-butadienes, and alicyclic 1,3-dienes furnished the corresponding N-carbamoyl-3,6-dihydro-1,2-oxazines at room temperature in 61-98% yield. The novel 3,6-dihydro-1,2-oxazines can undergo a retro-Diels-Alder reaction with hydrolytic decomposition when heated (65-130 °C) under aqueous conditions. The dienophile portion thereby releases the N-aryl or N-alkylamine, nitric oxide or nitroxyl, and carbon dioxide. Pro nuclear magnetic resonance (1H NMR) spectrometry was utilized to measure the kinetic parameters for the decomposition. Substitution of the dienes are assessed to determine which steric or electronic factors contribute to the threshold temperatures required for the retro-Diels-Alder decomposition pathway.

1:50 pm - Binding Affinity of 4-Chlorobenzenethiol to CdSe Nanospheres and Nanobelts

Michael Klennert, Senior Capstone Seminar

CdSe nanoparticles have provided many real life applications that have opened the door for economic and social growth. CdSe nanoparticles come various shapes and outer organic layers, ligands. With this, how does the shape of a CdSe nanoparticle affect the interaction of various ligands? We concluded that 4-chlorobenzene thiol (CBT) indicates a strong binding affinity for CdSe nanospheres in comparison to CdSe nanobelts which resulted in no change in diffusion constants. From here we are able to begin to uncover what is going on between the CdSe nanoparticle and ligands and how the shape of the CdSe nanoparticle may change the effect of the ligand.

The Chemistry of Interfaces: Engineering Materials for Biotechnology, Aerospace and Beyond

Dr. Kjersta Larson-Smith (PLU Alumna, 2006), Boeing Research and Technology, The Boeing Company

The chemical interactions that occur at interfaces are often challenging to understand, yet they are critical to the engineering of new materials. This talk will explore the role of interfacial science for two vastly different applications. The first part of the talk will focus on the self-assembly of gold nanoparticles at emulsion interfaces and their use for clot dissolution. Secondly, we will examine the interactions at coating-substrate interfaces for aerospace applications. Lastly, I will attempt to discuss how to translate the skills gained from a PLU chemistry degree into a career in materials research.