Department of Chemical Science, University of Cagliari, CNBS, and CSGI, ss 554, bivio Sestu, 09042 Monserrato (CA), Italy.
Langmuir. 2012 Jan 17;28(2):1283-9. doi: 10.1021/la203918d. Epub 2011 Dec 27.
Anion binding to nonionic micelles was quantified by self-diffusion. Four anions were probed by multinuclear PGSTE NMR measurements in a Triton X-100 micellar aqueous solution. The salt concentration used was sufficiently low to avoid any micellar growth affecting surface curvature. The micellar aggregates that provide a model surface are uncharged with hydrophilic headgroups so that electrostatic ion surface interactions play little or no role in prescribing specific anion binding. Anionic affinity to the micellar surface followed a Hofmeister series, (CH(3))(2)AsO(2)(-) ≫ CH(3)COO(-) > H(2)PO(4)(-) > F(-). The observed ion specificity is rationalized by calling into play the nonelectrostatic interactions occurring between the anions and the micellar surface.
阴离子与非离子胶束的结合通过自扩散来定量。在 Triton X-100 胶束水溶液中，通过多核 PGSTE NMR 测量来探测四种阴离子。所使用的盐浓度足够低，以避免任何胶束生长影响表面曲率。提供模型表面的胶束聚集体不带亲水基，因此静电离子表面相互作用在规定特定阴离子结合方面作用很小或没有。阴离子对胶束表面的亲和力遵循 Hofmeister 序列，（CH(3))(2)AsO(2)(-) ≫ CH(3)COO(-) > H(2)PO(4)(-) > F(-)。通过调用阴离子与胶束表面之间发生的非静电相互作用，可以合理地解释观察到的离子特异性。
