Co-assembly of exfoliated Mg/Al layered double hydroxides nanosheets with sulfobutyl ether-β-cyclodextrin for enantioseparation of racemic propranolol

Co-assembly of exfoliated Mg/Al layered double hydroxide (Mg/Al-NO3-LDH) nanosheets with sulfobutyl ether-β-cyclodextrin (SBE-β-CD) via swelling/restoration method was presented in this paper. SBE-β-CD located in the form of flat-lying intertwined bilayer arrangement in the interlayer region. The structural and characteristic features of the supramolecular products as prepared were studied by XRD, FT-IR, UV–vis DRS and TGA. The as-proposed SBE-β-CD-LDH materials were applied to recognize clinical medicine propranolol enantiomers (R,S-PPL). Series studies were carried out to address various experimental parameters including contact time, pH value and operational temperature, concentrations of R,S-PPL. The experimental results indicated that SBE-β-CD-LDH could tend to adsorb R-PPL and the e.e.% value of single separation was 17.4% under optimal experimental conditions. The special spatial structure of SBE-β-CD-LDH might play a key role to achieve the enantioseparation of racemic PPL. According to the kinetic studies, the separation of PPL enantiomers had been well described by pseudo-second-order kinetic model. The adsorption isotherms indicated that the adsorption data fitted the Freundlich isotherm equation well. The thermodynamic parameters indicated that the adsorption process was a spontaneous and endothermic chemisorption process.