Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Rua Santa Adélia, 166, 09210-170 Santo André, Brazil.
J Colloid Interface Sci. 2012 Feb 1;367(1):370-7. doi: 10.1016/j.jcis.2011.10.032. Epub 2011 Oct 21.
The adsorption of SPADNS (trisodium salt of 2-(p-sulfophenylazo)-1,8-dihydroxynaphthalene-3,6-disulfonic acid) onto resins XAD 2, XAD 7 and silica gel was studied in the presence and in the absence of the cationic surfactant CTAB (cetyl trimethylammonium bromide). At a ratio of 2.5 CTAB to 1 SPADNS, the surfactant caused a marked increase in SPADNS adsorption. The experimental results for adsorption versus time were applied on the basis of three kinetic models (pseudo-first-order Lagergren, pseudo-second-order, and intraparticle diffusion). The interaction between CTAB and SPADNS was investigated using spectrophotometric, conductometric, and computational techniques. Theoretical results point to the formation of an ion pair between CTAB and SPADNS that influences the solution spectra, in agreement with conductometric and spectrophotometric data.
吸附 SPADNS（2-（对磺基苯偶氮）-1,8-二羟基萘-3,6-二磺酸的三钠盐）到树脂 XAD2、XAD7 和硅胶上的研究是在阳离子表面活性剂 CTAB（十六烷基三甲基溴化铵）存在和不存在的情况下进行的。在 2.5 CTAB 与 1 SPADNS 的比例下，表面活性剂导致 SPADNS 吸附显著增加。吸附与时间的实验结果基于三个动力学模型（准一级 Lagergren、准二级和内扩散）进行了应用。使用分光光度法、电导率法和计算技术研究了 CTAB 和 SPADNS 之间的相互作用。理论结果表明 CTAB 和 SPADNS 之间形成离子对，影响溶液光谱，与电导率和分光光度数据一致。
