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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
Access: Restricted to the UNT Community Members at a UNT Libraries Location.
Date: December 2004
Creator: Ranade, Ajit
open access

Determination of Wear in Polymers Using Multiple Scratch Test.

Description: Wear is an important phenomenon that occurs in all the polymer applications in one form or the other. However, important links between materials properties and wear remain illusive. Thus optimization of material properties requires proper understanding of polymer properties. Studies to date have typically lacked systematic approach to all polymers and wear test developed are specific to some polymer classes. In this thesis, different classes of polymers are selected and an attempt is made to us… more
Date: August 2004
Creator: Damarla, Gowrisankar

Development of a Novel Grease Resistant Functional Coatings for Paper-based Packaging and Assessment of Application by Flexographic Press

Description: Recent commercial developments have created a need for alternative materials and methods for imparting oil/grease resistance to paper and/or paperboard used in packaging. The performance of a novel grease resistant functional coating comprised of polyvinyl alcohol (PVA), sodium tetraborate pentahydrate (borate) and acetonedicarboxylic acid (ACDA) and the application of said coating by means of flexographic press is presented herein. Application criteria is developed, testing procedures describe… more
Access: Restricted to UNT Community Members. Login required if off-campus.
Date: August 2004
Creator: Brown, Robert W.
open access

Hydrophobic, fluorinated silica xerogel for low-k applications.

Description: A new hydrophobic hybrid silica film was synthesized by introducing one silicon precursor (as modifiers) into another precursor (network former). Hybrid films have improved properties. Hydrolysis and condensation of dimethyldiethoxysilane (DMDES) (solvent (EtOH) to DMDES molar ratio R = 4, water to DMDES molar ratio r = 4, 0.01 N HCl catalyst) was analyzed using high-resolution liquid 29Si NMR. It was found that after several hours, DMDES hydrolyzed and condensed into linear and cyclic species.… more
Date: May 2004
Creator: Zhang, Zhengping
open access

Investigation of growth kinetics of self-assembling monolayers by means of contact angle, optical ellipsometry, angle-resolved XPS and IR spectroscopy.

Description: Absorption of octadecanethiol and p-nitrobenzenethiol onto gold surfaces from ethanol solutions has been studied by means of contact angle, optical ellipsometry, angle-resolved XPS (ARXPS), and with grazing angle total reflection FTIR. Growth of the monolayers from dilute solutions has been monitored and Langmuir isotherm adsorption curves were fitted to experimental data. A saturated film is formed within approximately 5h after immersion in solutions of concentrations ranging from 0.0005mM to … more
Date: August 2004
Creator: Jakubowicz, Agnieszka

Study of Conductance Quantization by Cross-Wire Junction

Description: The thesis studied quantized conductance in nanocontacts formed between two thin gold wires with one of the wires coated by alkainthiol self assembly monolayers (SAM), by using the cross-wire junction. Using the Lorenz force as the driving force, we can bring the two wires in contact in a controlled manner. We observed conductance with steps of 2e2 / h. The conductance plateaus last several seconds. The stability of the junction is attributed to the fact that the coating of SAM improves the st… more
Access: Restricted to the UNT Community Members at a UNT Libraries Location.
Date: May 2004
Creator: Zheng, Tao
open access

Synthesis and characterization of crystalline assembly of poly Nisopropylacry-lamide)-co-acrylic acid nanoparticles.

Description: In this study, crystalline poly(N-isopropylacrylamide-co-acrylic acid) (PNIPAm-co-AAc) nanoparticle network in organic solvents was obtained by self assembling precursor particles in acetone/epichlorohydrin mixture at room temperature followed by inter-sphere crosslinking at ~98 °C. The crystals thus formed can endure solvent exchanges or large distortions under a temporary compressing force with the reoccurrence of crystalline structures. In acetone, the crystals were stable, independent of te… more
Date: December 2004
Creator: Zhou, Bo
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