Physical Sciences and Mathematics Commons^™

New Approaches To Cyclopentadienyl-Fused Thiophene Complexes Of Iron And Synthesis And Characterization Of Carbonic Anhydrase Active-Site Mimics For Co2 Hydration, Deepshikha Gupta

Theses and Dissertations--Chemistry

Polyheterocycles such as polythiophene and its derivatives comprise an important class of conducting polymers used for electronic applications. They have been of great interest for use in electronic materials due to their increased environmental stability as well as novel electronic properties in their polymer states. We have been interested in exploring the electronic properties of organometallic analogues of the low-band-gap polymer poly(benzo[3,4-c]thiophene) (polyisothianaphthene) that incorporates η⁵-cyclopenta[c]thienyl monomers such as ferroceno[c]thiophene. First chapter of this dissertation involved synthetic attempts to ferroceno[c]thiophene. Exploring a shorter synthetic route to starting material, 1,2-di(hydroxymethyl)ferrocene was …

Polythiophene Nanocomposites For Photodegradation Applications: Past, Present And Future, Mohammad Mansoob Khan Dr, M. O. Ansari, S. A. Ansari, M. H. Cho

Dr. Mohammad Mansoob Khan

Polythiophene (PTh) has been the subject of considerable interest because of its good environmental stability, unique redox electrical behavior, stability in doped and neutral states, ease of synthesis, and wide range of applications in many fields. Apart from its applications in the electrical or electronic field, PTh has shown promising applications in photocatalytic degradation. The fabrication of a catalyst, metal oxides with PTh, extends the absorption range of the modified composite system, thereby enhancing the photocatalytic activity under UV or visible light irradiation. Substituted PTh, such as alkyl substitution, modifies the electronic properties of the polymer, thereby enlarging the potential …

Development Of Transition Metal-Catalyzed Polymerization Reactions And Their Applications For The Preparation Of Well-Defined Conjugated Polymer Architectures, Carlos Anthony Chavez

LSU Doctoral Dissertations

The synthesis of conjugated polymers and design of complex materials based on them have become increasingly popular as the demand for low-cost efficient and processible optoelectronic and semiconducting devices escalates. While advanced applications of polymeric materials require some degree of sophistication, success can be achieved through careful consideration of polymerization techniques and methodologies. Controlling critical aspects of the polymerization process allows for synthesis of complex macromolecular architectures possessing unique and novel properties that may be worth of further comprehensive investigation. This dissertation primarily focuses on the development and preparation of well-defined hierarchical macromolecular architectures. The foundation of this work encompasses …

The Synthesis, Characterization, And Application Of Carborane-Cluster Based Macrocycles And Boron Nitride Nanosheets In Photovoltaics, Christopher Robert Petrelli

Dissertations - ALL

Chapter 1: Dye-sensitized solar cell (DSSC) efficiencies have not significantly improved in recent years, primarily because of their single band gap design, limitations in dye absorption energies, and the Shockley-Queisser (SQ) limit. DSSCs require incident photon energy in the visible spectrum for the cell to produce a usable current. While the possibility of absorbing two

near-infrared photons is a known concept for surmounting the SQ limit, the opportunities presented by mesoporous systems for creating such a sensitizer do not appear to have been studied. By incorporating carborane cluster-based macrocyclic compounds as "electron reservoirs," a number of the inherent limitations in …

Application Of Scanning Probe Microscopy To Characterize Physical Properties Of Polymer Brushes, Photoactive Polymers And Rare Earth Oxide Nanostructures, Susan Denise Verberne-Sutton

LSU Doctoral Dissertations

A sample stage for characterizing photoactive materials was developed for studies with scanning probe microscopy (SPM). A sample stage was designed that directs light from a solar simulator via a fiber optic cable to illuminate the sample. Current-sensing and photocurrent measurements can be acquired with a conductive tip. The designed photocurrent stage can be used for SPM systems with a tip-mounted scanner. Current-sensing measurements can be taken with or without illumination to measure the current produced from organic photovoltaic (OPV) or photoconductive samples. Topography, lateral force and current-sensing images are acquired simultaneously, providing information of how nanoscale morphology affects the …

Electrochemical Actuation Properties Of A Novel Solution-Processable Polythiophene, Yanzhe Wu, Amy M. Ballantyne, Pawel Wagner, Dezhi Zhou, Geoffrey M. Spinks, David Officer, Gordon G. Wallace

Gordon Wallace

No abstract provided.

Technology Platform For Sampling Water With Electrolyte-Gated Organic Transistors Sensitised With Langmuiur-Deposited Calixarene Surface Layers., Delia Puzzovio, Abdullah Al Naim, Lee Hague, Mary Deasy, James P. Ward, Tim Richardson, Martin Grell

Articles

We demonstrate a technology platform that enables the development of new, surface-sensitised organic transistor sensors. We show that an organic semiconductor can still be gated by an electric double layer within the electrochemical window of water after the deposition of up to four Langmuir- Schäfer calixarene layers onto its surface. Since many calixarenes are known to selectively bind waterborne cations, this facilitates sensitising a conventional organic semiconductor with a physically deposited layer for specific cation recognition. When at least two Langmuir-Schäfer layers are deposited, these also block the electrochemical doping of the organic semiconductor, which otherwise competes with the field …

Synthesis And Characterization Of Acceptor: Donor Block Copolymers For Organic Photovoltaics, Brandon Cory Achord

Dissertations

Mankind needs sources of clean power. Photovoltaic (PV) cells, in use since 1839, have proven reliable and practical for certain applications. PV cell efficiency has changed over the years from 1-2% to ultra-high efficiency cells operating at efficiencies greater than 40%. Organic photovoltaics are a potential transformative technology platform. The potential for cell use, efficiency and cost are all parts of the research and development focus at the time this document was written. This research was initiated with a focus on the synthesis and understanding of the variables effecting acceptor-donor block copolymer. The self-assembled morphology resulting from varying volume ratios …

Hyperthermal H2 Induced C–H Bond Cleavage: A Novel Approach To Cross-Linking Of Organic Molecules, Tomas Trebicky

Electronic Thesis and Dissertation Repository

The development of simple and effective methods of incorporating molecular moieties with desirable properties into new functional materials is one of the ultimate goals of material scientists. The work presented in this thesis demonstrates an easy way to accomplish this using a beam of gaseous H₂, which we call hyperthermal hydrogen induced cross-linking (HHIC). We prove theoretically and experimentally that when the kinetic energy of H₂ is raised to ~20 eV, it becomes a light-mass projectile which is energetic enough to knock hydrogen atoms off of organic molecules, but not other heavier atoms. By developing a reactor …

Electrochemical And Photovoltaic Properties Of Electropolymerized Poly(Thienyl-Silole)S, Joshua C. Byers, Paul M. Dicarmine, Mahmoud M. A. R. Moustafa, Xin Wang, Brian Pagenkopf, Oleg A. Semenikhin

Chemistry Publications

Electrochemical and photoelectrochemical properties were studied of a series of donor−acceptor materials based on polythiophene modified with silole moieties. The materials were prepared by electrochemical anodic polymerization of 2,5-bis([2,2′-bithiophen]-5-yl)-1,1-dimethyl-3,4-diphenylsilole and 2,5-bis([2,2′-terthiophen]-5-yl)-1,1-dimethyl-3,4-diphenylsilole, as well as copolymerization of these monomers with 2,2′-bithiophene. Photocurrent measurements showed that introduction of silole resulted in a considerable enhancement of the photovoltaic properties of silole-containing materials and especially the fill factor. However, as demonstrated by Mott−Schottky measurements, electropolymerized silole-containing materials showed a substantial degree of disorder and high density of states in the midgap, which negatively affected their photovoltaic properties. Atomic force microscopy (AFM) and phase imaging …

Preparation And Characterization Of Conducting Polybutadiene/ Polythiophene Composites, Senem Kiralp, Zuhal Küçükyavuz, Atef F. Qasrawi

Turkish Journal of Chemistry

Conductive composite films of cis-1,4-polybutadiene (PBD) with polythiophene (PTh) were prepared electrochemically. Thiophene was polymerized on PBD-coated platinium electrodes. The composites with different PTh percentages showed conductivity in the order of 10^{-3} (\Omega cm)^{-1}. The characterization of the films was performed using FTIR, scanning electron microscope and differential scanning calorimetry techniques. In order to understand the dominant transport mechanism, the temperature dependence of conductivity was investigated.