Synthesis and characterization of colloidal surfaces with grafted polymer layers /
This work focusses on the chemical grafting of high molecular weight polymers onto colloidal surfaces. The primary objective of this research involves the development of procedures for controlling the grafted amount and molecular structure of polymer chains bound at the particle-water interface. Th...
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
1995.
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| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=742145131&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | This work focusses on the chemical grafting of high molecular weight polymers onto colloidal surfaces. The primary objective of this research involves the development of procedures for controlling the grafted amount and molecular structure of polymer chains bound at the particle-water interface. The colloidal particles used in this study were synthesized by a surfactant-free emulsion polymerization process. These particles possessed a variety of surface groups. Two homopolymers were produced from styrene and glycidyl methacrylate (GMA). Three copolymer systems were studied: styrene-GMA, styrene-allyl glycidyl ether (AGE), and styrene-chloromethyl styrene (CMS). A series of core-shell polymers were prepared by copolymerizing GMA and methyl methacrylate shells around existing polystyrene (PS) seeds. Two titration methods were developed to quantify epoxy content after polymerization. The core-shell particles had high epoxy surface densities with more than 60% of the initial epoxy groups surviving the synthesis process while greater than 80% of the epoxy groups survived in the copolymer particles. We measured the adsorption behavior of poly(ethylene oxide) (PEO) onto the colloidal particles to determine the feasibility of using the particles as anchoring moieties for polymer grafting. The core-shell particles had small adsorbed amounts that mitigated against their use in grafting experiments. The styrene-AGE particles adsorbed the most PEO of any of our epoxy functional systems. The adsorption of PEO onto the styrene-CMS particles was approximately equivalent to the adsorption on PS particles. The styrene-AGE and styrene-CMS copolymer particles were used in the grafting study. Grafting experiments were carried out at two different temperatures and at a wide range of pH values. Hydroxyl- and amineterminated PEO were used. The parameters which had the greatest effect on the grafting of PEO onto the colloidal particles were the temperature and functionality of the polymer's terminal group. A procedure was developed to displace adsorbed PEO from the particle surfaces by adding surfactant, leaving the grafted PEO on the particle surface. This process was then used to develop a methodology to quantify the grafted amounts by measuring the residual PEO and surfactant in solution. |
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| Item Description: | Vita. "Major Subject: Chemical Engineering". |
| Physical Description: | xx, 187 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilms Inc. |
| Bibliography: | Includes bibliographical references. |