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Deposition and Characterization of Pentacene Film.

Description: Many organic materials have been studied to be used as semiconductors, few of them being pentacene and polythiophene. Organic semiconductors have been investigated to make organic thin film transistors. Pentacene has been used in the active region of the transistors. Transistors fabricated with pentacene do not have very high mobility. But in some applications, high mobility is not needed. In such application other properties of organic transistors are used, such as, ease of production and flex… more
Date: December 2003
Creator: Singh, Nidhi
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries

The Effects of Color Concentrate in Polyolefins.

Description: Throughout history consumer products were generally manufactured from wood and metal. They either had to hold their natural color or become subject to painting. When plastics entered the industry, it was recognized for its ease of shaping, re-usability, physical properties and its low cost. One of plastics' greatest benefits is its ability to hold a given color from within allowing it to avoid use of paint. This paper will give a brief overview on the effects of pigments when incorporated in a … more
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Date: December 2001
Creator: Flora, Paul
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Techniques Utilized in the Characterization of Existing Materials for Improved Material Development

Description: It has become increasingly important to remain on the cutting edge of technology for a company to remain competitive and survive in today's high-tech industries. To do this, a company needs various resources dedicated to this cause. One of these resources is the use of existing materials, as starting points, for which improved materials can be based. For this, a company must rely on the characterization of existing materials to bring that base technology into their company. Through this evaluat… more
Date: December 2001
Creator: Withaeger, Gary
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries

Mineral-filled polypropylene: Improvement of scratch resistance

Description: A potential alternative to acrylonitrile-butadiene-styrene (ABS) and polycarbonate+ABS (PC+ABS), pigmented mineral-filled polypropylene (PP) finds an opening in automotive interior components such as instrument panels, knee bolsters, consoles, etc. Because of the lack of surface aesthetics, pigmented mineral-filled PP is experiencing a limitation to its acceptance in many applications. This study focuses on exploring various mineral fillers and additives in polypropylene to provide a material w… more
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Date: December 2001
Creator: Khatib, Jamal F.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Stability of Field Emitter Arrays to Oxygen Exposures

Description: The purpose of these experiments was to determine the degradation mechanisms of molybdenum based field emitter arrays to oxygen exposures and to improve the overall reliability. In addition, we also evaluated the emission current stability of gold-coated field emitter arrays to oxygen exposures. oxygen at 1x10-6 torr was introduced into the chamber through a leak valve for different lengths of time and duty cycles. To ensure identical oxygen exposure and experimental measurement conditions, ti… more
Date: December 2002
Creator: Godbole, Soumitra Kumar
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries

Characterizaton of Triethoxyfluorosilane and Tetraethoxysilane Based Aerogels

Description: Aerogels are highly porous, low dielectric constant (low k) materials being considered by the semiconductor industry as an interlayer dielectric. Low k materials are needed to overcome capacitance problems that limit device feature sizes. Precursors triethoxyfluorosilane (TEFS) and tetraethoxysilane (TEOS) were used to prepare bulk aerogels. Samples were prepared by sol-gel methods, and then carbon dioxide supercritically-dried. Effects of varying the water to precursor ratio were studied with … more
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Date: December 2001
Creator: Roepsch, Jodi Ann
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Synthesis and study of crystalline hydrogels, guided by a phase diagram.

Description: Monodispersed nanoparticles of poly-N-isopropylacrylamide-co-allylamine (PNIPAM-co-allylamine) and PNIPAM-co-acrylic acid (AA) have been synthesized and used as building blocks for creating three-dimensional networks. The close-packed PNIPAM-co-allylamine and PNIPAM-co-AA nanoparticles were stabilized by covalently bonding neighboring particles at room temperature and at neutral pH; factors which make these networks amicable for drug loading and release. Controlled release studies have been pe… more
Date: December 2004
Creator: Huang, Gang
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries

Cure Kinetics and Processing Parameters of Neat and Reinforced High Performance Epoxy Resins: Evaluation of Techniques

Description: Kinetic equation parameters for the curing reaction of a commercial glass fiber reinforced high performance epoxy prepreg composed of the tetrafunctional epoxy tetraglycidyl 4,4-diaminodiphenyl methane (TGDDM), the tetrafunctional amine curing agent 4,4’-diaminodiphenylsulfone (DDS) and an ionic initiator/accelerator, are determined by various thermal analysis techniques and the results compared. The reaction is monitored by heat generated determined by differential scanning calorimetry (DSC). … more
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Date: December 1999
Creator: Bilyeu, Bryan
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries

Barrier and Long Term Creep Properties of Polymer Nanocomposites.

Description: The barrier properties and long term strength retention of polymers are of significant importance in a number of applications. Enhanced lifetime food packaging, substrates for OLED based flexible displays and long duration scientific balloons are among them. Higher material requirements in these applications drive the need for an accurate measurement system. Therefore, a new system was engineered with enhanced sensitivity and accuracy. Permeability of polymers is affected by permeant solubility… more
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Date: December 2004
Creator: Ranade, Ajit
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Rational Design of Metal-organic Electronic Devices: a Computational Perspective

Description: Organic and organometallic electronic materials continue to attract considerable attention among researchers due to their cost effectiveness, high flexibility, low temperature processing conditions and the continuous emergence of new semiconducting materials with tailored electronic properties. In addition, organic semiconductors can be used in a variety of important technological devices such as solar cells, field-effect transistors (FETs), flash memory, radio frequency identification (RFID) t… more
Date: December 2012
Creator: Chilukuri, Bhaskar
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Preparation and Characterization of a Treated Montmorillonite Clay and Epoxy Nanocomposite

Description: Montmorillonite reinforced polymers are a new development in the area of nanocomposite materials. Since reinforcement of epoxy is important to the development of high strength adhesives and composite matrices, the introduction of montmorillonite to epoxy is of interest. Compositional effects on epoxy reactivity, on molecular relaxation, and on mechanical properties were investigated. Change in reactivity was determined by Differential Scanning Calorimetry. Tensile properties at room temperature… more
Date: December 2000
Creator: Butzloff, Peter Robert
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Epoxy + Liquid Crystalline Epoxy Coreacted Networks

Description: Molecular reinforcement through in-situ polymerization of liquid crystalline epoxies (LCEs) and a non-liquid crystalline epoxy has been investigated. Three LCEs: diglycidyl ether of 4,4'-dihydroxybiphenol (DGE-DHBP) and digylcidyl ether of 4-hydroxyphenyl-4"-hydroxybiphenyl-4'-carboxylate (DGE-HHC), were synthesized and blended with diglycidyl ether of bisphenol F (DGEBP-F) and subsequently cured with anhydride and amine curing agents. Curing kinetics were determined using differential scanning… more
Date: December 2000
Creator: Punchaipetch, Prakaipetch
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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