Mohd Yusof, Nor Saadah (2021) The effect of sonication on the ion exchange constant, K-X(Br) of CTABr/chlorobenzoates micellar systems. Ultrasonics Sonochemistry, 71. ISSN 1350-4177, DOI https://doi.org/10.1016/j.ultsonch.2020.105360.
Full text not available from this repository.Abstract
The ion exchange constant, K-X(Br) (for the case of cetyltrimethylammonium bromide, CTABr, in this study) is a method dependant characterization of ion exchange process by counterions, X and Br with different relative binding ratios. In this report, the ion exchange constant, K-X(Br) values for micelle systems irradiated under 2 min of sonication at 120 W power using a probe sonicator with 1 cm tip were determined to be 85.2, 125.6 and 122.4 when X = o-, m- and p-chlorobenzoates, respectively. The values were quantified using a semiempirical kinetic method coupled with Pseudophase Micellar model, and later compared to the same system in the absence of sonication. The sonication was found to amplify the K-X(Br) values by similar to 13-fold for X = o-chlombenzoate and similar to 2.5-fold for X = m- and p-chlombenzoates. This is due to the improvement of ion exchange process by the oscillation of bubbles generated by acoustic cavitation. An active ion exchange process indicates better stabilization of the micelle aggregational structure by the penetration of the introduced counterions, X into the micelle Stern layer leading to the growth of the micelle. This is supported by the remarkable increase in the viscosity of the micelle system by > 7-fold for X = o-chlombenzoate and by > 2-folds for X = m- and p-chlombenzoates. Sonication was also found to induce maximum viscoelasticity at lower concentration ratio of CTABr]: X]. The ability of ultrasound to induce micelle growth and exhibiting viscoelasticity at lower concentration of counterionic additive will be very useful in technologies where viscoelastic solution is desired such as in oil drilling and centralized heating and cooling system.
| Item Type: | Article |
|---|---|
| Funders: | Universiti Malaya [FSUMRG-KIMIA-17], FRGS grant from The Ministry of Higher Education, Malaysia [FP038-2019A] |
| Uncontrolled Keywords: | Ultrasound; Micelle; Ion exchange; Viscoelasticity; Micelle growth |
| Subjects: | Q Science > QD Chemistry Q Science > QP Physiology |
| Divisions: | Faculty of Science > Department of Chemistry |
| Depositing User: | Ms Zaharah Ramly |
| Date Deposited: | 25 Apr 2022 05:39 |
| Last Modified: | 25 Apr 2022 05:39 |
| URI: | http://eprints.um.edu.my/id/eprint/26861 |
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