Master of Science, University of Akron, 2012, Polymer Science

Two of the most commonly employed bioadhesives used for wound closure applications today are fibrin-based and cyanoacrylate-based bioadhesives, both of which have adverse effects. Fibrin-based bioadhesives allow for the possible transmission of viral blood-borne pathogens, while cyanoacrylate-based bioadhesives have toxicity concerns due to their degradation into formaldehyde. To address these drawbacks and many others, it is proposed that a polyisobutylene-based bioadhesive be employed, since polyisobutylene has a long, successful history as a bio-friendly material. Potential polyisobutylene-based bioadhesives first were prepared by the difunctionalization of α-ω-dihydroxy polyisobutylenes with vinyl methacrylate through “green” enzyme catalyzed Candida antarctica lipase B (CALB) transesterification reactions at 50¿¿¿¿¿¿¿ within 24 hours with high yields. Four different compounded crosslinking solution formulations consisting of synthesized α-ω-dimethacrylate polyisobutylenes, 10% or 20% of the trifunctional crosslinker 2-ethyl-2-hydroxymethyl-1-,3-propanediol trimethacrylate (TMP-TMA) and a 20% solution of the ultra-violet (UV) reactive photoinitiator 2,2-dimethoxy-2-phenylacetophenone effectively demonstrated the ability to crosslink terminally functionalized linear polyisobutylenes into continuous film networks under ambient conditions quickly (< 5 min.) by the use of UV light. Various techniques were used to characterize their crosslinking and physical properties, as well as to determine that the molecular weight of α-ω-dimethacrylate polyisobutylenes had a greater effect on the characterizable attributes than the amount of TMP-TMA employed. Techniques used to characterize the continuous polyisobutylene film networks included: the evaluation of polyisobutylene film discontinuities; the measurement and calculation of their physical dimensions; aesthetic evaluation; solvent extraction and swelling assessments; FTIR; TGA; and DSC. These methods characterized th (open full item for complete abstract)

Committee: Judit E. Puskas Dr. (Advisor); Chrys Wesdemiotis Dr. (Committee Member) Subjects: Polymer Chemistry; Polymers

Master of Science, University of Akron, 2009, Biology

Two separate experiments were performed to test the biocompatibility of amphiphilic conetwork polymers for medical applications. In experiment 1, four different types of polymers were tested in the liver and brain of 20 rats to determine which polymer would be best suited for intervertebral disc repair or replacement. The samples used for the brain and liver injections were Monomer: 1-cyanoacryl-2,4,4-trimethylpentane(TMP-CA), Polymer: cyanoacrylate terminated tri-arm star PIB [Ø(PIB-CA)3, Initiator: N,N-diethyl telechelic [Ø(PIB-NEt3)3] PIB, and Monomer + Polymer Combination: cyanoacrylate-telechelic 3-arm star polyisobutylene [Ø(PIB-CA)3] + 2,2,4-trimethylpent-1-cyanoacrylate (pTMP-CA). The solid samples implanted into the liver were Monomer: poly(1-cyanoacryl-2,4,4-trimethylpentane)poly(TMP-CA), Polymer: cross linked [Ø(PIB-CA)3] polymer, and Monomer + Polymer Combination: copolymer of [Ø(PIB-CA)3] + 2,2,4-trimethylpent-1-cyanoacrylate (pTMP-CA).The rats were divided into three groups. Group number one had four different “honey-consistency” gel polymers injected into the liver and a saline injection for control. Group number two was subjected to the same injections, but this time the site of injection was the brain. Group number three had three types of solid polymers surgically implanted into the liver. Tissues were then examined histologically to determine if any damage had occurred. A polymer sample that resulted in little or no significant tissue damage would be a good candidate for intervertebral disc replacement and/or repair. In experiment 2, two types of polymers were used; a polyisobutylene polymer as well as a Bionate sample for a control, (to determine the biocompatibility of the polymer for a potential pacemaker coating). Both were implanted on the peritoneal wall of eight rats. The rats were divided into two groups of four. Group number one had four polyisobutylene polymer strips sutured to the peritoneal wall. Group number two had four Bionate stri (open full item for complete abstract)

Committee: Daniel Ely PhD (Advisor) Subjects: Anatomy and Physiology; Animals; Biology; Biomedical Research; Experiments; Health; Immunology; Materials Science; Polymers; Toxicology

MS, University of Cincinnati, 2013, Engineering and Applied Science: Electrical Engineering

Metamaterials, the artificially engineered left handed materials (LH), demonstrate unusual electromagnetic properties of simultaneous negative permittivity and permeability that are not available from the traditional right-handed (RH) materials. It has emerged as a new cutting edge technology involving physics, material science and engineering. The exceptional properties of metamaterials have attracted a lot of researchers and guided them to the development of a number of applications in various fields which would not have been possible with natural right-handed materials. The goal of this thesis is to design a metamaterial antenna, using Composite Right/left-Handed (CRLH) Transmission Line (TL), which can be used for various medical applications. The CRLH TL is the perfect representation of LH metamaterial which is thoroughly explained and verified by Agilent ADS momentum simulation. In this thesis, an 800 MHz metamaterial antenna is designed using CRLH TL. The various design configurations of the antenna are simulated in Agilent ADS momentum and their characteristics are analyzed to get the most efficient one. The antenna is very compact in size compared to the conventional microstrip rectangular patch antenna. It has been found that the balanced CRLH TL structure antenna characteristics exceed the performance of all other designs. It has the highest gain and radiated power and provides very high radiation efficiency. The metamaterial antennas are fabricated, tested, analyzed and their characteristics are compared with the simulation results.

Committee: Altan Ferendeci Ph.D. (Committee Chair); Marc Cahay Ph.D. (Committee Member); Peter Kosel Ph.D. (Committee Member) Subjects: Electrical Engineering