SDS Adsorption and Rhodamine B Dye Removal

Aluminum nitrate (Al (NO₃)₃·9H₂O) and NaOH pellets, which are analytical reagents, are delivered from Samchun (Korea). Sodium dodecyl sulfate (SDS) (>95% of purify, Wako Pure Chemical Industries, Ltd., Japan) was directly used without further purification as a surface modifier. The critical micelle concentration (CMC) of SDS is measured by the conductometry under different NaCl (p. a, Merck, Germany) concentrations at 22°C mentioned in somewhere [31 (link)]. The stock SDS solution of 0.1 M was prepared for adsorption experiments. Rhodamine B (RhB) was purchased from Merck with a molecular weight of 479.02 g/mol, and the purity > 95% is employed as cationic dye. The chemical structures of SDS surfactants and RhB were described elsewhere [29 (link)]. The ionic strength was controlled by adding the suitable volume of 0.1 M NaCl. The salt solution was filtered through a 0.2 μm cellulose membrane before using. The pH solution is adjusted by the addition of HCl and NaOH and measuring by a pH meter (Hanna, Woonsocket city, USA). Ultrapure water with a resistance of 18.2 MΩ.cm used in all experiments was daily produced by an ultrapure water system (Labconco, Kansai, MO, USA).