Polymer and Organic Materials Commons^™

Electrical And Structural Studies Of Polyacrylonitrile (Pan) Complexed With Inorganic Salts., Khairul Bahiyah Md Isa

Student Works (2010-2019)

In the present study, polymer electrolyte films composed of polyacrylonitrile (PAN) as a host polymer, ethylene carbonate (EC) as the plasticizer and lithium triflate (LiCF3SO3) and sodium triflate (NaCF3SO3) as dopant salts were prepared by the solution cast technique. Five systems of polymer electrolytes films have been prepared; these systems are the plasticized-PAN system i.e. PAN-EC system, two salted-PAN systems i.e. PAN-LiCF3SO3 and PAN-NaCF3SO3, and two plasticized-salted PAN systems i.e. PAN-EC-LiCF3SO3 and PAN-EC-NaCF3SO3. The pure PAN film was prepared as a reference. The ionic conductivity for each system is characterized using impedance spectroscopy. The room temperature conductivity of the pure …

Modeling Of Metal-Ferroelectric-Insulator-Semiconductor Structures Based On Langmuir–Blodgett Copolymer Films, Timothy J. Reece, Stephen Ducharme

Stephen Ducharme Publications

Among the ferroelectric thin films used in field-effect transistor devices; the ferroelectric copolymer of polyvinylidene fluoride PVDF –CH2–CF2–, with trifluoroethylene TrFE –CHF–CF2–, has distinct advantages, including low dielectric constant, low processing temperature, low cost, and compatibility with organic semiconductors. The operation of a metal-ferroelectric insulatorsemiconductor structure with PVDF-TrFE as the ferroelectric layer was analyzed and optimized by numerical solution of the Miller and McWhorter model. A model device consisting of 20 nm PVDF/TrFE on a 10-nm-thick high-k dielectric buffer exhibits a memory window of 5 V with an operating voltage of 15 V. The operating voltage can be reduced to …

Dielectric Nanocomposites: An Inside-Out Approach To Storing Electrostatic Energy, Stephen Ducharme

Stephen Ducharme Publications

The ability to achieve high-energy densities is the central challenge in energy storage and recovery. A promising strategy for increasing energy storage is to use highperformance dielectric materials, such as highly polarizable nanoparticles or polymers, or nanocomposites of the two. In this issue, Kim et al. use a molecular coating and clever chemistry to combine oxide nanoparticles with a polymer matrix, thereby producing an improved nanocomposite dielectric. Some advantages and challenges of using nanocomposites as improved dielectric materials are presented in this Perspective.

Polarization Switching Kinetics Of Ferroelectric Nanomesas Of Vinylidene Fluoride-Trifluoroethylene Copolymer, R. V. Gaynutdinov, O. A. Lysova, S. G. Yudin, A. L. Tolstikhina, A. L. Kholkin, V. M. Fridkin, Stephen Ducharme

Stephen Ducharme Publications

The polarization switching kinetics of ferroelectric polymer nanomesas was investigated using piezoresponse force microscopy. The nanomesas were made by self-organization from Langmuir–Blodgett films of a 70% vinylidene fluoride and 30% trifluoroethylene copolymer. The polarization switching time exhibits an exponential dependence on reciprocal voltage that is consistent with nucleation-type switching dynamics.

Raman Studies Of 1,3,5,7 Cyclooctatetraene At High Pressure, Martin Galley, Ed Romano, Sergey Tkachev, Michael Pravica

Undergraduate Research Opportunities Program (UROP)

We performed Raman spectroscopic studies of 1,3,5,7-cyclooctatetraene at elevated pressures up to 10 GPa with the aim of examining possible planarization of the molecule and further studying two prior-discovered phases of the solid with pressure. The Raman excitation source was a Krypton-ion laser operating at 674.1 nm (give wavelength).

1,3,5,7 Cyclooctatetraene has an octagonal formation however it is not aromatic or anti-aromatic (not a subject to the 4n+2 Huckel’s rule) [1]. As a result, its adopts a somewhat reactive tub shape. Upon the addition or removal of one to two electrons under ambient conditions, the molecule planarizes and becomes aromatic …

Impact Of A Microwave Curing Process On Tensile Strength Of Selected Carbon Fiber Composites, Brian B. Balzer

All-Inclusive List of Electronic Theses and Dissertations

The traditional process for curing carbon fiber (CF) composites has been the autoclave system. A review of recent research indicates curing CF composites in a microwave oven has the potential for reducing processing time. The problem statement of the experimental study was that the impact of a microwave curing process on tensile strength of selected CF composite specimens was unknown. The research study describes the statistical procedure and analysis of data to answer the specific question for the experimental trials: What is the effect on the tensile strength of cured CF composite samples due to the relationship of the autoclave …

An Evaluation Of Supercritical Drying And Peg/Freeze Drying Of Waterlogged Archaeological Wood, Eric Schindelholz, Robert Blanchette, Desmond C. Cook, Michael Drews, Steve Hand, Benjamin Held, Joel Jurgens, Betty Seifert

Physics Faculty Publications

This study was undertaken to evaluate the physical effects of drying waterlogged archaeological wood using supercritical carbon dioxide as compared to air drying and the popular polyethylene glycol (PEG)/freeze drying method. Previous studies have shown supercritical drying to be a potentially advantageous alternative to current methods of drying waterlogged wood through reduced processing time, minimal shrinkage, and increased success for reversibility. Samples in the form of blocks and planks of a few centimeters in size were prepared from two archaeological waterlogged wood sources and grouped into three treatment sets: one for air drying, one for PEG/freeze drying, and the other …

The Effects Of Humidity On The Dielectric Response In Ferroelectric Polymer Films Made By Langmuir-Blodgett Deposition, Kristin L. Kraemer, Alexander V. Sorokin, Christina M. Othon, Stephen Ducharme, Vladimir M. Fridkin

Stephen Ducharme Publications

No abstract provided.

Investigation Of Ferroelectricity In Newly Synthesized Nitrile Polymer Systems, Matt Poulsen, Stephen Ducharme, Alexander V. Sorokin, Sahadeva Reddy, James M. Takacs, Y. Wen, Jihee Kim, Shireen Adenwalla

Stephen Ducharme Publications

The ferroelectric and piezoelectric properties of newly synthesized polymer systems have been studied. To date PVDF and its copolymers P(VDF-TrFE) have provided the bulk of the knowledge pertaining to ferroelectricity in polymers. Recently, ultrathin ferroelectric films of P(VDF-TrFE) 70:30 have been fabricated using the Langmuir-Blodgett technique [4]. In this study, various new polymers have been synthesized by chemically altering the PVDF structure. This alteration was performed in order to enhance the amphiphilic nature of the polymer and thus improve the LB film quality and control. Various chemical groups have been used to replace the electropositive hydrogen and electronegative fluorine found …

Mapping Surface Polarization In Thin Films Of The Ferroelectric Polymer P(Vdf-Trfe)., Bradley W. Peterson, Stephen Ducharme, Vladimir M. Fridkin, Timothy J. Reece

Stephen Ducharme Publications

Pyroelectric Scanning Microscopy (PSM) has been developed to enable mapping of surface polarization in ferroelectric thin films, in particular the copolymer polyvinylidene fluoride trifluororethylene, or P(VDF-TrFE). The Chynoweth method for dynamically measuring pyroelectric current is employed in conjunction with a micropositioning system to construct two-dimensional images of the film polarization. These images have revealed enhancement of the polarization near the edges of the film below the average coercive field, with the center's polarization increasing thereafter to meet the edge value at saturation.

Ferroelectricity At Molecular Level, L. M. Blinov, A. V. Bune, Peter A. Dowben, Stephen Ducharme, Vladimir M. Fridkin, S. P. Palto, K. A. Verkhovskaya, G. V. Vizdrik, S. G. Yudin

Stephen Ducharme Publications

he synthesis of ultrathin ferroelectric nanostructures by the Langmuir-Blodgett method and their properties are reviewed. It is shown that ferroelectricity exists in one monolayer of the ferroelectric P(VDF-TrFE) copolymer, i.e., at the molecular level. The specific characteristics of switching of ultrathin ferroelectric films are established.

Electron Irradiation Effects On Ferroelectric Copolymer Langmuir-Blodgett Films, Christina M. Othon, Stephen Ducharme

Stephen Ducharme Publications

The effect of irradiation on the ferroelectric properties of Langmuir-Blodgett films of the copolymer poly(vinylidene fluoride-trifluorethelene) is investigating using 1.26 MeV electrons with dosages from 16 to 110 Mrad. Irradiation causes a systematic decrease in the phase transition temperature, coercive field and polarization of these thin films.

Dielectric Properties Of A Ferroelectric Copolymer Langmuir–Blodgett Film, Mahantappa S. Jogad, Stephen Ducharme

Stephen Ducharme Publications

We report measurements of the real (epsilon prime) and imaginary (epsilon double-prime) parts of the relative complex permittivity of a Langmuir–Blodgett film of ferroelectric copolymer of vinylidene fluoride (70%) with trifluoroethylene (30%). The measurements were made in the temperature range of 35 to 125° C, and frequency range of 19 Hz to 5 MHz. The results indicate low frequency loss due to conduction and dielectric loss peak near the ferroelectric–paraelectric phase transition.

Analysis Of Plastics In The Tyre Industry Using Fourier Transform Infrared Techniques, Differential Scanning Calorimetry And Softening Point Apparatus, Ching Ching Loh

Student Works (2000-2009)

The plastics in a tyre factory were investigated. The plastics were analysed by FTlR-transmission, FTI.R-ATR, softening point apparatus as well as a Differential Scanning Calorimeter. All the plastics were detected to be polyethene based with melting point range of 107 to 125°C. It was also observed that The FTIR transmission spectrum can be different from the FTIR-ATR spectrum. The FTIR-ATR spectrum gives a higher band intensity at longer wavelengths compared to the FTIR-Transmission spectrum. Interference fringes can be present in the FTlR transmission spectrum. In addition to the above, it was also found that the melting point of plastics obtained …

Sorption Of Chlorinated Organic Compounds By Sedimentary Rocks, Paul M. Mcginley, S. Kesaraju, Ronald D. Gruzesky

KWRRI Research Reports

The sorption of dichlorobenzene and trichlorobenzene on carbonate and shale rocks collected in Kentucky demonstrate that rock organic matter content is a good indicator of sorptive reactivity in rock systems. Although this is similar to soil systems, significant differences between sorption in rock and soil systems exist. Sorption isotherms on these rocks are nonlinear and sorption can be an order of magnitude higher than predicted using correlations from soils and their organic matter content. This sorption reaction could lead to significant concentration tailing during contaminant cleanup. Experimental elution of trichloroethylene from rock filled columns verified that cleanup times might be …

Use Of High-Energy Radiation For Degradation Of Environmental Pollutants, Robert D. Guthrie, Manjiri Patwardhan

KWRRI Research Reports

The purpose of this project was to explore the advantages and/or limitations of high-energy radiation treatment as a method for degrading organic pollutants, particularly aryl halides, in an aqueous medium. We have done analyses of ⁶⁰Co-irradiated samples and kinetic studies using pulsed electron beams. For aryl halides containing no more than two fused rings, the main products detected are those of simple halogen replacement by hydrogen, although the amount of aryl halide destroyed was always greater than the total amount of products detected. To accomplish halogen replacement by H, the reaction solvent may not be pure water but must …

Chemistry Of The Oxidant, Ferrate, Its Interaction With Specific Organics Found In Waste Water, Donald H. Williams, J. T. Riley

KWRRI Research Reports

It became obvious during this investigation that while much work has been done with ferrate (VI) chemistry, discrepancies existed in the literature and very little attention had been given possible engineering uses. This work attempted to fulfill these two needs in an exploratory manner.

The preparative techniques were reviewed and mechanical improvements made in one which allowed improved yields. Essentially what was done was to enlarge and improve the filtering technique of the product and use cooler temperatures throughout the preparation. This greatly shortened the time required. Then it was learned that the addition of ethyl alcohol to the final …