Synthesis of spherical SBA-15 by poly (vinyl alcohol)/ Hydroxyl-terminated polybutadiene supermicelles as co-surfactant and its application for removal of diazinon from aqueous solution

Abstract

A low-cost and facile strategy was successfully developed to produce spherical micrometer-sized SBA-15 with cylindrical pores arranged in a hexagonal order using pluronic triblock-copolymer P123 as template and poly (vinyl alcohol) (PVA)/hydroxyl-terminated polybutadiene (HTPB) supermicelles as co-surfactant. Herein, a solvent evaporation induced aggregating assembly (EIAA) method was reported for the preparation of SBA-15 microspheres. The materials were characterized by Scanning electron microscopy (SEM), High resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and Brunauer–Emmet–Teller (BET) method. The diazinon adsorption properties of spherical SBA-15 were studied to find out the effect of various experimental factors. Results exhibited that the highest diazinon removal efficiency (95.2%) was achieved at pH 6, initial concentration of 50 mg L −1 , temperature of 318 K, and the adsorbent dosage of 0.1 g L −1 for 60 min. The adsorption behavior of diazinon was described by the Langmuir isotherm and pseudo-second-order model (R 2 > 0.99). Maximum adsorption capacity obtained 526.3 mg g −1 . The apparent activation energy for spherical SBA-15 was 16.69 kJ mol −1 . Thermodynamic studies illustrated that the adsorption process was exothermic with spontaneous nature. The efficiency of diazinon removal was not considerably affected by the presence of the lindane. Moreover, the spherical SBA-15 retained its adsorbing properties after sixteen cycles. • Spheres obtained using P123–PVA/HTPB as a template in the THF/H 2 O/ethanol mixture. • Spherical SBA-15 adsorbent was highly effective to diazinon removal. • The adsorption process was described by the Langmuir isotherm. • The pseudo-second-order model is the best to adsorption kinetic.