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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.
71

Liquid crystal-gold nanoparticle composites

QI, HAO 20 August 2009 (has links)
Studies of liquid crystal (LC) /Au nanoparticle (NP) composites have been pursued in columnar and in nematic phases of thermotropic LCs. Using LCs forming a columnar phase, we found that different functionalities on the corona of the Au NPs (hydrophobic vs. hydrophilic) display unique effects on the stability and ordering of the columnar LC phase. Doping nematic LCs with non-chiral or chiral Au NPs causes the formation of textures commonly observed for chiral nematic LCs, i.e., the formation of somewhat uniform stripe textures or patterns separated by areas of homeotropic alignment of LC molecules. Two scenarios are proposed. In the first scenario, the Au NPs form topological chain-like defects and the remaining Au NPs reside at the interface inducing vertical alignment of the LC molecules. In the second scenario, chiral Au NPs transfer chirality to the nematic LC host. Further, induced circular dichroism studies proved the second scenario. Using the same chiral Au NP systems, the origin of chirality of Au NPs has also been studied, and a powerful methodology has been proposed to unravel the puzzle of chirality of chiral ligand-protected Au NPs. Further investigations of these texture phenomena led to the discovery of using metal NPs to control the orientation and alignment of LCs. In due course, a dual alignment and electro-optical switching behaviour was found using alkylthiol-capped Au NPs doped into a nematic LC with positive dielectric anisotropy in planar namatic LC cells. This study was also expanded to Ag and CdTe NPs, which showed the same phenomenon, and all investigated NPs significantly reduced the voltage needed to re-orient the LCs in an electric field (threshold voltage). Starting from basic and moving on to more application-oriented research, we finally also initiated structure-property relationship studies of LC/NP composites.
72

An experimental and theoretical comparison of the swarm, continuum, and molecular-statistical theories of nematic liquid crystals.

Kuhn, William Lawrence. January 1974 (has links)
Thesis (Ph. D.)--University of Washington. / Includes bibliographical references.
73

The rheology and structure of thermotropic liquid crystalline polymers in extensional flow /

Wilson, Thomas Stephen, January 1991 (has links)
Thesis (Ph. D.)--Virginia Polytechnic Institute and State University, 1991. / Vita. Abstract. Includes bibliographical references (leaves 264-269). Also available via the Internet
74

AC-calorimetry and dielectric spectroscopy on anisotropic liquid crystal and aerosil dispersions

Cruceanu, Florentin I. January 2008 (has links)
Dissertation (Ph.D.)--Worcester Polytechnic Institute. / Keywords: phase transitions; quenched random disorder; liquid crystals; dielectric spectroscopy; calorimetry. Includes bibliographical references (leaves 78-83).
75

Phase behaviors in mesomorphic systems of - substituted-trans-P- N- alkoxycinnamic acids and 6-N-alkoxy-2-naphthoic acids /

O-pa Bangcharoenpaurpong. January 1978 (has links) (PDF)
Thesis (M.Sc. in Physical Chemistry) -- Faculty of Graduate Studies, Mahidol University, 1978. / Supported by the University Development Commission and the National Research Council.
76

Effect of molecular order on photopolymerization behavior and polymer properties of liquid crystal monomers a dissertation /

Wang, Qian. January 2008 (has links)
Dissertation (Ph.D.).--University of Texas Graduate School of Biomedical Sciences at San Antonio, 2008. / Vita. Includes bibliographical references.
77

Orientationally ordered particles characterization and applications /

Neal, Jeremy R. January 2010 (has links)
Thesis (Ph.D.)--Kent State University, 2010. / Title from PDF t.p. (viewed May 26, 2010). Advisor: Peter Palffy-Muhoray. Keywords: orientational order; strain alignment; rubber; stretching; elastomer synthesis; liquid crystal elastomer, gold nanoparticle. Includes bibliographical references (p. 183-186).
78

Rheology and mesoscale morphology of flows of cholesteric and nematic liquid crystal polymers

Cui, Zhenlu. Wang, Qi. January 2005 (has links)
Thesis (Ph. D.)--Florida State University, 2005. / Advisor: Dr. Qi Wang, Florida State University, College of Arts and Sciences, Dept. of Mathematics. Title and description from dissertation home page (viewed Sept. 14, 2005). Document formatted into pages; contains xvi,139 pages. Includes bibliographical references.
79

Microparticles as a new analytical method to study liquid crystal colloids

Zhang, Ke. January 2006 (has links)
Thesis (Ph.D.)--Kent State University, 2006. / Title from PDF t.p. (viewed Sept. 19, 2006). Advisor: John L. West. Keywords: nematic isotropic interface, liquid crystal colloids, dielectrophoresis, microparticle, drag effect, Raman mapping, IR imaging. Includes bibliographical references (p. 152-164).
80

Nuclear resonance in dispersed systems

Yang, Koahsiung, January 1977 (has links)
Thesis--University of Florida. / Description based on print version record. Typescript. Vita. Includes bibliographical references (leaves 164-166).

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