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Deuterium (2H) and Nitrogen 14 (14N) NMR spectroscopy were used to investigate the molecular dynamics in one thermotropic and one lyotropic liquid crystal. Quantitative analyses of deuterium spectral densities of motion for three deuteron sites (ring and C[alpha]) at two different Larmor frequencies (46 and 61.4MHz) are reported in the smectic A and C* phases of (S)-[4-(2-methylbutyl)phenyl]-4’-octylbiphenyl carboxylate (8BEF5-d15), a partially deuterated smectogen. 2H spectral densities for two deuteron sites on the chain (C1 and C2/C3) at Larmor frequency 61.4MHz and 14N spectral densities for the head group (NH4+) of the molecule decylammonium chloride (DACl) at 28.9MHz are reported in the lamellar phase of a partially deuterated sample, DACl-d11/H2O binary system. The motional model is the small step rotational diffusion for reorientations plus internal rotations in the strong collision limit. In the chiral C* phase of the first molecule, 8BEF5-d15, the helical axes are aligned along the external magnetic field and the deuteron spins appear to relax in a macroscopically uniaxial environment. After including the molecular tilt, the reorientation processes in the SmC* phase are found to have higher activation energies than those in the smectic A phase. Applying the same motional models to the lyotropic molecule DACl-d11, the tumbling motion of the long axis of the molecule in the aggregates is more rigorous in comparison to the molecular spinning motion. The similarity of deuterium spectral densities from the C1 and C2/C3 sites may indicate a relatively rigid unit of C1-C2-C3-C4 in the backbone.

A thermotropic cholesteric polymer, (acetoxypropyl)cellulose (APC) is synthesized by reacting (hydroxypropyl)cellulose and acetic anhydride. The molar etherification and esterification values, determined by chromic acid oxidation and saponification are 3.1 (+OR-) 0.3 and 1.9 (+OR-) 0.1, respectively. Fractions ranging in molar mass from 2.2 x 10('4) to 6.5 x 10('5) g mol('-1), and of the same chemical composition, are obtained by addition of n-heptane to a dilute alcoholic solution. / The phase separation behaviour of APC in dibutyl phthalate (DBP) is adequately explained by the modified lattice theories for freely-jointed chains, even when orientational interactions are neglected. The volume fraction of APC needed for anisotropic phase separation is 0.52 (+OR-) 0.02 in DBP at 25(DEGREES)C, while the isotropic phase is stable below a polymer volume fraction of 0.69 (+OR-) 0.04. Between these concentrations, the ordered phase coexists with a more dilute isotropic phase. The concentration of both phases increases with that of the solution. The molar mass of APC in the mesophase exceeds that in the isotropic phase. The critical concentration determined by optical microscopy and differential scanning calorimetry increases markedly with temperature from 25(DEGREES) to 150(DEGREES)C. This increase is attributed to a decrease in the stiffness of the chain; the axial ratio of the Kuhn segment decreases from 10.8 (+OR-) 0.8 to 5.6 (+OR-) 0.4 over the same temperature range. The axial ratio of the Kuhn segment is calculated from the limiting viscosity numbers of the APC fractions in dimethyl phthalate. / Variations in cholesteric pitch of APC with temperature and with diluent concentration are determined from the spectrophotometrically measured changes in the wavelength of light reflected by thin layers of the mesophase. The pitch increases with both DBP content and temperature for all the samples. As predicted by Kimura (1982), the temperature dependence of the pitch decreases with increasing DBP concentration. Quantitative agreement with Kimura's theory requires the use of physically reasonable dimensions for the optically active APC chain. / Analysis of the refractometric data indicate that shearing of the cholesteric mesophase transforms it into a nematic-like arrangement. The birefringence of the undiluted nematic APC is 0.013 at 26(DEGREES)C, from which a nematic layer order parameter of 0.73 (+OR-) 0.3 is calculated. The order parameter appears to be concentration independent.

Controlling the assembly of amphiphilic molecules and micron-sized, disk-shaped particles at different length scales into ordered structures enables bottom-up organization which is of great interest to emerging technologies based on structured materials. The primary object of this work is the investigation of structure forming components - Zirconium phosphate (ZrP) discotic particles and polymersomes/ amphiphiles on their self-assembly and interactions. The effect of bilayer architecture of polymersomes on surface reactivity was investigated via fluorescent probing method. Established through complementary experiments, correlation between reactivity and molecule diffusivity in polymer-rich environment revealed the mechanism of reduced reactivity when tethered reactive groups are located deeper within the hydrophilic polymer layer. The phase diagram of charged nanoplatelets was constructed as a function of particle concentration, surface cation moiety, and ionic strength. Influence of surface cation on the isotropic-nematic transition was done by measuring the transition boundaries of discotic suspensions prepared by acid-base exfoliation reaction with a series of exfoliating agents. Furthermore, a novel phase transition was found, where platelet-platelet interaction was influenced synergistically by ionic strength and ion exchange. At low pH, directional inter-platelet attractions lead to the formation of low volume fraction colloidal gels. Alternative surface modification approaches, including biomolecule deposition and alkyl chain grafting were explored. Finally, self-assembly of platelets in emulsions and oil-water interface was examined. Surface modification was applied to link surface properties to stable emulsion-forming ability in mixed surfactant-particle system. Emulsion uniformity was achieved by microfluidic flow focusing method. Surface engineering and interaction control was demonstrated throughout this work to be viable approaches to the fundamental understanding of collective behaviors of individual building blocks.

Thesis (Ph. D.)--University of Nevada, Reno, 2006. / "August of 2006." Includes bibliographical references. Online version available on the World Wide Web.

Thesis (Ph. D.)--McMaster University (Canada), 1990. / Source: Dissertation Abstracts International, Volume: 53-01, Section: B, page: 0285. Supervisor: W.J. Leigh.

Thesis (Ph.D.)--McMaster University (Canada), 1993. / Source: Dissertation Abstracts International, Volume: 54-12, Section: B, page: 6174. Adviser: William J. Leigh.

Thesis (M.S.)--West Virginia University, 2008. / Title from document title page. Document formatted into pages; contains viii, 71 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 63-67).

Thesis (M.S.)--Ohio University, March, 1987. / Title from PDF t.p.

Thesis (Ph.D.)--Kent State University, 2007. / Title from PDF t.p. (viewed Mar. 4, 2009). Advisor: John West. Keywords: liquid crystal, polymer, shear, structure, application Includes bibliographical references (p. 252-267).