Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 66 for “"Molecular orientation"”.
-
Iodine-129 Moessbauer Spectroscopy: Probing the Molecular Orientation in Liquid Crystals
Made available in DSpace on 2015-05-12T22:39:09Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 7500404.PDF: 1207144 bytes, checksum: a052026110bf54f5c5ee1f371c18a01f (MD5) Previous issue date: 1974
-
Molecular orientation and relaxation behavior in flexible water- blown polyurethane foams
… understand the relaxation behavior and the molecular orientation upon deformation in these systems. The two main experimental techniques used in this investigation were stress relaxation in tension and deformation-IR dichroism. The stress relaxation in the foams and their respective plaques …
-
Uncovering molecular orientation and morphology at biotic/abiotic interface for peptide-based graphene sensors
… the dynamics of changes in the bioreceptors’ orientation for a better biointerface design. In this thesis, we aimed to uncover the mechanisms behind the sensing performance of peptide-functionalized carbon-based biosensors developed for sensing volatile organic compounds (VOCs). Using …
-
Novel interphases: Synthesis, molecular orientation and grafting of liquid crystal polymers on carbon fibers
… includes studies in three broad categories: molecular orientation of nematic melts containing dispersed carbon fibers, the chemical grafting of a liquid crystal polymer to these fibers by in-situ polymerization of monomeric melts, and the synthesis and anchoring on fibers of specially …
-
The effect of molecular orientation on the wear of ultra-high molecular weight polyethylene
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1998.
-
Influence of Molecular Orientation and Surface Coverage of w-Functionalized Mercaptans on Surface Acidity
… synthesis to investigate the effect that the orientation of the functional group has on surface acidity. 3-dodeycloxymercaptophenol and 4-dodecyloxymercaptophenol differ in that the hydroxyl group is substituted on different carbons of the benzene ring. The difference in substitution patterns …
-
The effects of molecular orientation on the physical aging behavior of oriented glassy amorphous polymers
… objective of this study was to determine whether molecular orientation has an effect on the rate of physical aging in amorphous glassy polymers. There is already a large body of literature concerning the phenomenon of physical aging, although the vast majority has been directed toward isotropic, …
-
A Study of Molecular Orientation at Neat Liquid-Mica Interface by Sum Frequency Generation (SFG) Spectroscopy
… force microscopy (AFM). In order to compare the orientation of mica-ionic liquids interface, a series of ionic liquids were studied by using sum frequency generation vibrational spectroscopy. Through SFG simulation orientation analysis, it showed that the imidazole ring of ionic liquids, …
-
Electron paramagnetic resonance studies of molecular orientation and nuclear exchange in single crystals of morphine N-oxide.
… by the presence of two magnetically distinct orientations of the N-0 bond within the crystal. As the temperature is raised, the spectra are further complicated by motional effects. Since at -150° the molecule is essentially frozen in the crystal lattice with respect to the time of the EPR …
-
Mold filling characteristics and molecular orientation in injection molding of liquid crystalline copolyesters of poly (ethylene terephthalate)
… fluid pigments into the melt before injection. Molecular orientation of the molded parts was studied by measuring the shrinkage of the microtomed samples at various temperatures, injection speeds, and cavity thicknesses for these two molds. For PET/60 mole % PHB, the viscosity was found to be …
-
Rheological characterizaton, and the development of molecular orientation and texture during flow for a liquid crystalline copolymer of para- hydroxybenzoic acid and polyethylene terephthalate
… materials are due to the high degree of molecular orientation which develops during the processing step. In order to more fully understand and predict such behavior, a constitutive equation describing the flow behavior of these materials would be useful. It has been suggested that in …
-
Structure and Dynamics of Complex Fluids
… of mica to the thickness comparable to the molecular size. Anisotropy in molecular orientation and shear moduli of the confined film, which strongly depended on the relative direction between shear and the initial molecular orientation predetermined by the mica surface structure, was …
-
Electrospinning applications in mechanochemistry and multi-functional hydrogel materials
… to bring self-healing functionality to the molecular level. The mechanically induced reactions can become productive when stress-sensitive molecules, or mechanophores, are incorporated into materials. One mechanophore that has been heavily investigated is spiropyran, a molecule that exhibits …
-
Surface properties of poly(bisphenol-A-carbonate)
… process. <br></br><br></br>A high degree of molecular orientation and residual stress (a major reason for premature mechanical failure) was primarily attributed to cold moulding and poor mould design coupled with inadequate testing of, the finished product. The high birefringence observed in …
-
CRITICAL DYNAMICS OF LIQUID CRYSTAL ABOVE THE ISOTROPIC - NEMATIC PHASE TRANSITION
… point the correlation length (zeta) of molecular orientational order could be comparable to the inverse of a light scattering momentum transfer k. We study the non-linear effects in the dynamics of molecular orientation under such a condition. We first derive the complete quadratic …
-
Investigations of the optoelectronic behaviour of novel phthalocyanine Langmuir-Blodgett films.
… non-peripheral octa-substituted phthalocyanines, molecularly engineered for Langmuir-Blodgett deposition by M. Cook at the University of East Anglia. The Langmuir-Blodgett method is used to deposit the two materials in the Y-form, onto substrates of glass and gold plated glass, and on quartz with …
-
Phase Transitions and the Effect of External Fields in Thermotropic Main Chain Liquid Crystal Systems
… that grooved surfaces can strongly influence the molecular orientation of macromolecular liquid crystals especially when coupled with a magnetic field. Specifically, grooves parallel to a magnetic field were found to increase both the rate and ultimate degree of molecular orientation relative to …
-
Photophysics of Hybrid Perovskites with Electroactive Molecules
… by mediating the interaction between molecular orbitals and the inorganic lattice bands. Whereas conventional perovskites rely on electronically inert organic spacers, this thesis explores systems where electroactive cations actively participate in excited-state processes through …
-
Microfluidic flow of colloidal particles in nematic liquid crystals
… We study the change in structure of defects and molecular orientation around a static particle, particle migration in microfluidic channels, morphology of Saturn ring defects and director structure in ducts of comparable size to the particle, and many particle migration and advection in large …
Page 1 of 4