Method for the measurement of the diffusion coefficient of benzalkonium chloride

Smith, M.J. , Flowers, T.H., Cowling, M.J. and Duncan, H.J. (2002) Method for the measurement of the diffusion coefficient of benzalkonium chloride. Water Research, 36(6), pp. 1423-1428. (doi: 10.1016/S0043-1354(01)00356-6)

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Biofilm formation on the optical ports of cameras and underwater sensors is the primary cause of their reduced useful deployment time. The use of a transparent hydrogel coating containing the cationic surfactant benzalkonium chloride has been shown to extend the deployment times for up to 12 weeks for these instruments. In order to predict the effective lifetime of these coatings it was necessary to obtain the diffusion coefficient of the benzalkonium chloride used in the coatings. Benzalkonium chloride can have different alkyl chain lengths ranging from C8H17 to C18H37 with chain length greatly affecting its chemical properties. The benzalkonium chloride materials investigated here were mixtures of C12H25 and C14H29 as well as C14H29 on its own. These materials were selected for their proven biofilm resistant qualities. The diaphragm diffusion cell technique was investigated for its applicability to the measurement of diffusion coefficients of molecules with surfactant properties and the ability to form micelles. The method was found to be satisfactory for the cationic surfactant benzalkonium chloride. The average value of the membrane cell integral diffusion coefficient (D) over bar was 7.78 x 10(-6)cm(2) s(-1) at 25degreesC and there was no significant effect of alkyl chain length on the measured value of (D) over bar.

Item Type:Articles
Glasgow Author(s) Enlighten ID:Duncan, Dr Henry and Smith, Dr Margaret and Cowling, Professor Michael and Flowers, Dr Hugh
Authors: Smith, M.J., Flowers, T.H., Cowling, M.J., and Duncan, H.J.
Subjects:T Technology > TP Chemical technology
College/School:College of Science and Engineering > School of Engineering > Systems Power and Energy
College of Arts > School of Culture and Creative Arts > History of Art
Journal Name:Water Research

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