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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.
1

Thermal transitions in a random copolyester of 1,4 - hydroxybenzoic and 2,6 - hydroxynaphthoic acids

Golombok, Ruth January 1990 (has links)
No description available.
2

Diffraction measurements of crystalline morphology in thermotropic random copolyesters

Wilson, David James January 1992 (has links)
No description available.
3

NMR studies of flexible molecules in the nematic mesophase

Horne, Timothy James January 1990 (has links)
No description available.
4

Structure and properties of oriented thermotropic liquid crystalline polyesters and polyamides

Zhang, Heping January 1992 (has links)
No description available.
5

The synthesis and evaluation of poly- and mono-domain elastomers based on polysiloxanes

Beattie, Helen Naomi January 1994 (has links)
No description available.
6

An X-ray diffraction study of methyl siloxane liquid crystal side chain polymers and crystalline derivatives of biphenyl and 1-benzothiophene

Adib, Z. A. January 1987 (has links)
No description available.
7

Picosecond studies of optical nonlinearities

Darzi, Ayad K. R. January 1991 (has links)
No description available.
8

Synthesis and characterisation of novel poly(estersulphonate)s and poly(esteramide)s

McDonald, Lynn January 1994 (has links)
No description available.
9

Plastic deformation and associated structural changes of some liquid crystalline aromatic copolyesters

Salahshoor-Kordestani, Sorosh January 1991 (has links)
No description available.
10

Single molecule study on the conformation, orientation and diffusion anisotropy of conjugated polymer chains in a liquid crystal matrix

Chang, Wei-Shun, 1973- 28 August 2008 (has links)
The nature of the solvent plays an important role in the conformation and orientation of polymers in solution. A particularly interesting case is when the solvent itself possesses order, such as when dissolving the polymer in a LC. In this dissertation, the morphology and diffusion behavior of the conjugated, stiff polymer MEH-PPV, (poly[2-methoxy-5((2-ethylhexyl)oxy)-1,4-phenylenevinylene]), in liquid crystal (LC) solvents have been investigated. Using polarization sensitive fluorescence correlation spectroscopy, it was found that in a nematic LC the polymer molecules are extended and highly aligned parallel with the nematic director. The conformation and orientational order of MEH-PPV increase with chain stiffness as a result of an interplay among the conformational entropy, solvation anisotropy, and bending energy of the polymer chains. In the smectic phase, about 10% of the MEH-PPV molecules are aligned perpendicular to the director in between the smectice layers, an effect not previously observed for a polymer solute. When applying an external electric field across the LC cell, the LC director changes orientation from a planar to a homeotropic alignment. The MEH-PPV chains remain aligned parallel with the LC director with applied field in the bulk of the LC device. However, the local structure near the LC-substrate interface is more complex. Single molecule polarization distributions measured as a function of distance from the LC device interface allow us to use MEH-PPV as sensitive local probe to explore complex structures in anisotropic media. Furthermore, diffusion anisotropy of the polymer solute in a LC solvent was studied by a novel two-beam cross-correlation technique. The diffusion anisotropy was observed to be about 2. This value is comparable to the diffusion anisotropy of the solvent and suggests that, despite the high degree of alignment, the solute diffusion is governed by the solvent and not the solute.

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