Bicontinuous Structures of Polymerized Microemulsions: 1H NMR Self

Bicontinuous Structures of Polymerized Microemulsions: 1H NMR .... Thus, the echo attenuation I/I0 is given as where I0 is the echo amplitude in the ...
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Langmuir 1997, 13, 2917-2921

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Bicontinuous Structures of Polymerized Microemulsions: 1 H NMR Self-Diffusion and Conductivity Studies C. H. Chew,*,† L. M. Gan,† L. H. Ong,† K. Zhang,‡ T. D. Li,† T. P. Loh,† and P. M. MacDonald‡ Department of Chemistry, National University of Singapore, Republic of Singapore, and Chemistry Department, Erindale College, University of Toronto, Toronto, Ontario, Canada Received August 12, 1996. In Final Form: January 9, 1997X The bicontinuous microemulsions consisting of methyl methacrylate (MMA), 2-hydroxyethyl methacrylate (HEMA), water, and acryloyloxyundecyldimethylammonio acetate (AUDMAA) were polymerized using 2,2-dimethoxy-2-phenylacetophenone as a photoinitiator. They were characterized by 1H NMR self-diffusion and conductivity measurements before and after polymerization. It is believed that bicontinuous microporous structures existed in these resulting transparent polymeric materials. Some of these microstructures may closely resemble those of bicontinuous microemulsions prior to polymerization. This is especially so for those transparent polymer samples prepared from bicontinuous microemulsions containing higher water content (>45 wt %) and lower HEMA content (55 wt %). The conductivity retention (κf/κi) is generally increased with the increase of the water content in bicontinuous microemulsions. From the appropriate formulation of bicontinuous microemulsions, transparent polymers with a conductivity retention of up to 90% have been obtained. For such systems, the final bicontinuous microstructures in polymeric materials may be least modified during the polymerization of their precursor microemulsions. Acknowledgment. The authors are grateful to the National University of Singapore for financial support under Grants RP950605 and RP950606. LA9607971