Chemiluminescence as a Novel Indicator for Interactions of Surfactant-Polymer Mixtures at the Surface of Layered Double Hydroxides

Chemiluminescence (CL) has been employed as a novel technique to monitor the interactions between poly(ethylene glycol) (PEG) and sodium dodecyl benzenesulfonate (SDBS) at the surface of CO3-layered double hydroxides (LDHs). The CL data demonstrated that the interactions of PEG and SDBS at the LDH surfaces were dependent on the SDBS concentration, the PEG molecular weight, and the PEG concentration. Furthermore, powder X-ray diffraction (XRD), zeta-potential measurements, thermogravimetric analysis (TGA), CL spectrum, and radical scavenging methods clarified the relationship between the CL intensity and the interactions of PEG with SDBS at the LDH surfaces. At low concentrations of SDBS, few interactions between PEG and SDBS took place. The aggregation of the LDH colloidal solution occurred as a result of SDBS hydrophobic tails pointed to the aqueous environment. As the concentration of SDBS increased, the PEG chains were bound onto the SDBS bilayers to reduce the electrostatic repulsion between anionic head groups of SDBS due to the structural transformation of SDBS at the surface of LDHs from monolayers to bilayers. This work would provide an attractive route to manipulate the adsorption and composition of polymer-surfactant mixtures at the particle surface by tuning the CL signals.