Rate constants ( q / E values) for laser pulse initiated photopolymerization have been determined for 1200-2700-&diameter bilayer surfactant vesicles prepared from dioctadecylmethyl(2-[ (4-vinylbenzoy1)-oxylethy1)ammonium bromide (31, from mixtures of dioctadecyldimethylammonium bromide (DODAB) and vinylbenzoic acid, from mixtures of 3 and DODAB, and from mixtures of 3 and vinylbenzoic acid. q / E values were 1.35 J-' for 1650-A-diameter 3 vesicles, were 0.059 J-' for mixed vesicles prepared from vinylbenzoic acid and DODAB (0.25:l mole fraction), varied between 0.123 and 1.46 J-' for vesicles prepared from different mixtures of DODAB and 3, and varied between 0.16 and 0.314 J-l for different mixtures of vinylbenzoic acid and DODAB. Plots of polymerization rate constants against the mole fraction of 3 in vesicles prepared by cosonicating 3 + DODAB were found to increase curvilinearly to a plateau value, indicating domain formation. Subsequent to vesicle polymerizations, cumulants, weight-and number-average molecular weights of the separated poly(viny1benzoates) and, hence, the average chain lengths were determined by gel exclusion chromatography. The average chain lengths varied from 10 in laser-polymerized 3 vesicles, through 20 in laser-polymerized vesicles prepared from mixtures of DODAB and vinylbenzoic acid, to 40 in laser-polymerized vesicles prepared from mixtures of 3 and vinylbenzoic acid. These relatively small chain lengths were discussed in terms of the restricted geometries prevailing a t intravesicular surface polymerizations. Fluorescence measurements and a Monte Carlo based computer simulation of the photopolymerization were used to substantiate the proposed mechanism of vesicle polymerization.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.