Effective intercalation of sodium dodecylsulfate (SDS) into hydrocalumite: Mechanism discussion via near-infrared and mid-infrared investigations

The intercalation approach for hydrocalumite (CaAl-LDH-Cl) with sodium dodecylsulfate (SDS) was investigated by XRD, SEM analysis combining with MIR and NIR spectroscopic methods. The XRD patterns revealed that SDS could be intercalated into the interlayer spacing of CaAl-LDH-Cl, with the d-value expanded to 3.25 nm. To compare to the results of MIR and NIR spectra for Ca-SDS which was synthesized by CaCl2 and SDS, it was found that the main reaction behavior was self-dissolution of CaAl-LDH-Cl followed by re-precipitation coexist with SDS concentration increasing, and the resulting product was composed by Ca-SDS and CaAl-LDH-SDS.