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Quantitative correlation of counterion (x) affinity to ionic micelles and x- and temperature-induced micellar growth (spherical - wormlike micelles - vesicles) for x = 5-methyl- and 5-methoxysalicylate ions

The semiempirical kinetic method has been used to determine the ratio of cetyltrimethylammonium bromide, CTABr, micellar binding constants of counterions X (K(X)) and Br (K(Br)), i.e., K(X)/K(Br) (= R(X)(Br)) for X = dianionic 5-methyl- and 5-methoxysalicylate ions. The values of K(X) and K(Br) have...

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Main Authors: Yusof, N.S., Khan, M.N.
Format: Article
Published: 2012
Subjects:
QD Chemistry
R Medicine
Online Access:http://eprints.um.edu.my/2963/
http://www.ncbi.nlm.nih.gov/pubmed/22272582
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spelling my.um.eprints.29632014-12-11T09:18:23Z http://eprints.um.edu.my/2963/ Quantitative correlation of counterion (x) affinity to ionic micelles and x- and temperature-induced micellar growth (spherical - wormlike micelles - vesicles) for x = 5-methyl- and 5-methoxysalicylate ions Yusof, N.S. Khan, M.N. QD Chemistry R Medicine The semiempirical kinetic method has been used to determine the ratio of cetyltrimethylammonium bromide, CTABr, micellar binding constants of counterions X (K(X)) and Br (K(Br)), i.e., K(X)/K(Br) (= R(X)(Br)) for X = dianionic 5-methyl- and 5-methoxysalicylate ions. The values of K(X) and K(Br) have been derived from the kinetic parameters obtained in the presence of spherical/nonspherical and spherical micelles, respectively. The values of R(X)(Br) remain essentially independent of [CTABr] within its range 0.005-0.015 M for both dianionic 5-methyl- and 5-methoxysalicylate ions. The increase in temperature from 35 to 55 °C decreases the values of R(X)(Br) from 796 to 53 for 5-methylsalicylate ions and from 89 to 7.0 for 5-methoxysalicylate ions. Rheological properties of 0.015 M CTABr solutions containing ≥0.01 M counterionic salt, M(2)X, show indirectly the presence of unilamellar vesicles, ULV, and long linear, entangled, and branched wormlike micelles, WM, at, respectively, 35 and 55 °C for X = dianionic 5-methylsalicylate ion. However, such studies show WM and probable spherical micelles, SM, at, respectively, 35 and 55 °C for X = dianionic 5-methoxysalicylate ions. It has been shown that, at a constant [CTABr], the micellar structural transitions from SM-to-WM-to-vesicles may be correlated quantitatively with the values of R(X)(Br) regardless of whether such micellar structural transitions occur due to variation in the values of [M(2)X] at a constant temperature or due to variation in temperature at a constant [M(2)X]. 2012-02-13 Article PeerReviewed Yusof, N.S. and Khan, M.N. (2012) Quantitative correlation of counterion (x) affinity to ionic micelles and x- and temperature-induced micellar growth (spherical - wormlike micelles - vesicles) for x = 5-methyl- and 5-methoxysalicylate ions. Journal of Physical Chemistry B, 116 (7). ISSN 1520-6106 http://www.ncbi.nlm.nih.gov/pubmed/22272582 PMID: 22272582
institution Universiti Malaya
building UM Library
collection Institutional Repository
continent Asia
country Malaysia
content_provider Universiti Malaya
content_source UM Research Repository
url_provider http://eprints.um.edu.my/
topic QD Chemistry
R Medicine
spellingShingle QD Chemistry
R Medicine
Yusof, N.S.
Khan, M.N.
Quantitative correlation of counterion (x) affinity to ionic micelles and x- and temperature-induced micellar growth (spherical - wormlike micelles - vesicles) for x = 5-methyl- and 5-methoxysalicylate ions
description The semiempirical kinetic method has been used to determine the ratio of cetyltrimethylammonium bromide, CTABr, micellar binding constants of counterions X (K(X)) and Br (K(Br)), i.e., K(X)/K(Br) (= R(X)(Br)) for X = dianionic 5-methyl- and 5-methoxysalicylate ions. The values of K(X) and K(Br) have been derived from the kinetic parameters obtained in the presence of spherical/nonspherical and spherical micelles, respectively. The values of R(X)(Br) remain essentially independent of [CTABr] within its range 0.005-0.015 M for both dianionic 5-methyl- and 5-methoxysalicylate ions. The increase in temperature from 35 to 55 °C decreases the values of R(X)(Br) from 796 to 53 for 5-methylsalicylate ions and from 89 to 7.0 for 5-methoxysalicylate ions. Rheological properties of 0.015 M CTABr solutions containing ≥0.01 M counterionic salt, M(2)X, show indirectly the presence of unilamellar vesicles, ULV, and long linear, entangled, and branched wormlike micelles, WM, at, respectively, 35 and 55 °C for X = dianionic 5-methylsalicylate ion. However, such studies show WM and probable spherical micelles, SM, at, respectively, 35 and 55 °C for X = dianionic 5-methoxysalicylate ions. It has been shown that, at a constant [CTABr], the micellar structural transitions from SM-to-WM-to-vesicles may be correlated quantitatively with the values of R(X)(Br) regardless of whether such micellar structural transitions occur due to variation in the values of [M(2)X] at a constant temperature or due to variation in temperature at a constant [M(2)X].
format Article
author Yusof, N.S.
Khan, M.N.
author_facet Yusof, N.S.
Khan, M.N.
author_sort Yusof, N.S.
title Quantitative correlation of counterion (x) affinity to ionic micelles and x- and temperature-induced micellar growth (spherical - wormlike micelles - vesicles) for x = 5-methyl- and 5-methoxysalicylate ions
title_short Quantitative correlation of counterion (x) affinity to ionic micelles and x- and temperature-induced micellar growth (spherical - wormlike micelles - vesicles) for x = 5-methyl- and 5-methoxysalicylate ions
title_full Quantitative correlation of counterion (x) affinity to ionic micelles and x- and temperature-induced micellar growth (spherical - wormlike micelles - vesicles) for x = 5-methyl- and 5-methoxysalicylate ions
title_fullStr Quantitative correlation of counterion (x) affinity to ionic micelles and x- and temperature-induced micellar growth (spherical - wormlike micelles - vesicles) for x = 5-methyl- and 5-methoxysalicylate ions
title_full_unstemmed Quantitative correlation of counterion (x) affinity to ionic micelles and x- and temperature-induced micellar growth (spherical - wormlike micelles - vesicles) for x = 5-methyl- and 5-methoxysalicylate ions
title_sort quantitative correlation of counterion (x) affinity to ionic micelles and x- and temperature-induced micellar growth (spherical - wormlike micelles - vesicles) for x = 5-methyl- and 5-methoxysalicylate ions
publishDate 2012
url http://eprints.um.edu.my/2963/
http://www.ncbi.nlm.nih.gov/pubmed/22272582
_version_ 1643687016669380608
score 13.244404

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