Syntheses and characterization of novel nonlinear optical and electroresponsive polymers.
Item
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Title
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Syntheses and characterization of novel nonlinear optical and electroresponsive polymers.
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Identifier
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AAI9510747
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identifier
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9510747
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Creator
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Zou, Wan Kang.
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Contributor
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Adviser: Nan-Loh Yang
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Date
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1994
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Language
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English
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Publisher
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City University of New York.
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Subject
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Chemistry, Polymer | Chemistry, Organic
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Abstract
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The first synthesis and detailed characterization of a novel linear, high molecular weight and electroresponsive polymer--polystannane--were accomplished. The structure of this polymer was established using {dollar}\sp{lcub}119{rcub}{dollar}Sn, {dollar}\sp{13}{dollar}C and {dollar}\sp1{dollar}H NMR. Its molecular weight, {dollar}\rm \overline{lcub}M{rcub}n,{dollar} was found to be ca. {dollar}1\times10\sp4{dollar} based on {dollar}\sp{lcub}119{rcub}{dollar}Sn NMR end group analysis and Vapor Pressure Osmometer. This polymer is highly photoactive, air sensitive, and its bleaching behaviors with photoscission are similar to polysilanes and polygermanes.;In addition to {dollar}\sigma{dollar}-electron conjugated polystannane, the synthesis and characterization of {dollar}\sigma{dollar}-electron conjugated silicon-based polysilane polymers was also conducted, including study of their nonlinear optical properties. Polysilanes with four different combinations substituents were synthesized. The value of the third order optical nonlinearity {dollar}\chi\sp{lcub}(3){rcub}{dollar} was measured to be on the order of {dollar}2.0\pm0.6\times10\sp{lcub}-12{rcub}{dollar} esu from the poly(phenylmethylsilane) thin films using OKG experiment. The response time of the nonlinear optical process associated with the electronic mechanism is found to be faster than 3 ps.;The sign of {dollar}\chi\sp{lcub}(3){rcub}{dollar} of the poly(phenylmethylsilane) solution was determined to be negative at 532 nm and positive at 1064 nm from Z-scan measurements. The value of {dollar}\chi\sp{lcub}(3){rcub}{dollar} at 532 nm is {dollar}{lcub}-7.0{rcub}\times10\sp{lcub}-12{rcub}{dollar} esu, while {dollar}\chi\sp{lcub}(3){rcub}{dollar} at 1064 nm is relatively small, {dollar}{lcub}+5.0{rcub}\times10\sp{lcub}-13{rcub}{dollar} esu. The near infrared (1064 nm) third order optical nonlinearity {dollar}\chi\sp{lcub}(3){rcub}\sb{lcub}1064{rcub}{dollar} nm is about {dollar}1.3\times10\sp{12}{dollar} esu using DFWM technique. No significant third order optical nonlinearity difference was observed with different side-chain substituents for polysilanes.;The syntheses and characterization of three {dollar}\pi{dollar}-electron conjugated polymers were completed: poly(4-butoxycarbonyl-methylurethane); poly-bis(p-toluenesulfonate); and a soluble ladder polymer. Poly-4BCMU in PMMA matrix films with high optical transparency were prepared. The resonant third order optical nonlinearity {dollar}\chi\sp{lcub}(3){rcub}{dollar} of poly-4BCMU in PMMA matrix film was found to be about {dollar}3\times10\sp{lcub}-10{rcub}{dollar} esu with a subpicosecond ({dollar}\sim{dollar}12 ps) response time. The non-resonant {dollar}\chi\sp{lcub}(3){rcub}{dollar} term was found to be {dollar}3\times10\sp{lcub}-11{rcub}{dollar} esu with a faster than 1 ps response time. The relaxation time of the transient degenerate four-wave mixing grating in poly-4BCMU PMMA matrix films has been found to be laser energy fluency dependent.
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Type
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dissertation
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Source
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PQT Legacy CUNY.xlsx
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degree
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Ph.D.
