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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
291

Processing And Study Of Carbon Nanotube / Polymer Nanocomposites And Polymer Electrolyte Materials

Harish, Muthuraman 01 January 2007 (has links)
The first part of the study deals with the preparation of carbon nanotube/polymer nanocomposite materials. The dispersion of multi-walled carbon nanotubes (MWNTs) using trifluoroacetic acid (TFA) as a co-solvent and its subsequent use in polymer nanocomposite fabrication is reported. The use of carbon nanotube/ polymer nanocomposite system for the fabrication of organic solar cells is also studied. TFA is a strong but volatile acid which is miscible with many commonly used organic solvents. Our study demonstrates that MWNTs can be effectively purified and readily dispersed in a range of organic solvents including dimethyl formamide (DMF), tetrahydrofuran (THF), and dichloromethane when mixed with 10 vol% trifluoroacetic acid (TFA). X-ray photoelectron spectroscopic analysis revealed that the chemical structure of the TFA-treated MWNTs remained intact without oxidation. The dispersed carbon nanotubes in TFA/THF solution were mixed with poly(methyl methacrylate) (PMMA) to fabricate polymer nanocomposites. A good dispersion of nanotubes in solution and in polymer matrices was observed and confirmed by SEM and optical microscopy study. Low percolation thresholds of electrical conductivity were observed from the fabricated MWNT/PMMA composite films. A carbon nanotube/ polymer nanocomposites system was also used for the fabrication of organic solar cells. A blend of single-wall carbon nanotubes (SWNTs) and poly3-hexylthiophene (P3HT) was used as the active layer in the device. The device characteristics showed that the fabrication of the solar cells was successful without any shorts in the circuit. The second part of the study deals with the preparation and characterization of electrode and electrolyte materials for lithium ion batteries. A system of lithium trifluoroacetate/ PMMA was used for its study as the electrolyte in lithium battery. A variety of different processing conditions were used to prepare the polymer electrolyte system. The conductivity of the electrolyte plays a critical role in the high power output of a battery. A high power output requires fast transport of lithium ions for which the conductivity of the electrolyte must be at least 3 x 10^-4 S/cm. Electrochemical Impedance Spectroscopy (EIS) was used to determine the conductivity of the polymer electrolyte films. Among the different processing conditions used to prepare the polymer electrolyte material, wet films of PMMA/salt system prepared by using 10vol% of TFA in THF showed the best results. At about 70wt% loading of the salt in the polymer, the conductivity obtained was about 1.1 x 10^-2 S/cm. Recently, the use of vanadium oxide material as intercalation host for lithium has gained widespread attention. Sol-gel derived vanadium oxide films were prepared and its use as a cathode material for lithium ion battery was studied. The application of carbon nanotubes in lithium ion battery was explored. A carbon nanotube /block copolymer (P3HT-b-PS) composite was prepared and its potential as an anode material was evaluated.
292

Les probabilités de traversée sur les plages de spins identiques pour le modèle d'Ising bidimensionnel

Lapalme, Ervig January 1999 (has links)
Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.
293

Dynamics and subcritical transition focusing on spatially-localized turbulence in two-dimensional Kolmogorov flow / 二次元コルモゴロフ流れの局在乱流に着目した動力学及び亜臨界遷移

Hiruta, Yoshiki 25 March 2019 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第21552号 / 理博第4459号 / 新制||理||1640(附属図書館) / 京都大学大学院理学研究科物理学・宇宙物理学専攻 / (主査)准教授 藤 定義, 教授 佐々 真一, 教授 早川 尚男 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM
294

ATMOSPHERIC-PRESSURE in situ PLASMA REDUCTION AND PATTERNING OF METAL-ION CONTAINING POLYMERS

Ghosh, Souvik 02 June 2017 (has links)
No description available.
295

Bulk Synchronous Parallel Implementation of Percolation Centrality for Large Scale Graphs

Saad, Kristen M. 30 August 2017 (has links)
No description available.
296

Towards a Prediction of Landscape Evolution from Chemical Weathering and Soil Production

Jackson, Eric Alan January 2017 (has links)
No description available.
297

Enhanced Percolative Properties from Controlled Filler Dispersion in Conducting Polymer Composites (CPCs)

Balogun, Yunusa A. 02 November 2009 (has links)
No description available.
298

Models of Disordered Media and Predictions of Associated Hydraulic Conductivity

Blank, L. Aaron, Jr. 08 December 2006 (has links)
No description available.
299

The Continuity of High-Permeability Zones in Sedimentary Deposits

Guin, Arijit 08 May 2009 (has links)
No description available.
300

The Kozeny-Carman Equation Considered With a Percolation Threshold

Porter, Lee Brenson, II 14 July 2011 (has links)
No description available.

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