Evaluation of sorption capabilities of biopolymeric microspheres by the solid-phase extraction

Abstract

This study presents the sorption capabilities of biopolymeric microspheres with commercial kraft lignin. The suspension-emulsion polymerization method was employed to obtain microspheres in spherical forms. Before copolymerization lignin was modified with methacryloyl chloride to increase its affinity for monomers. Two different types of microspheres (hybrid and non-hybrid) with the increasing quantity of lignin were studied. In the hybrid ones, divinylbenzene (DVB) and methacrylated kraft lignin (L) were used as organic compounds whereas triethoxyvinylsilane (TEVS) was applied as an inorganic one. The second type of microspheres was synthesized without the addition of TEVS. There were also applied two materials without a lignin component for comparison purposes. The hybrid lignin-containing microspheres exhibited a more developed porous structure than the non-hybrid ones. Their specific surface areas were in the range of 454–522 m2/g and 2305 m2/g, respectively. The results of swelling studies of synthesized materials in typical organic solvents and distilled water were presented. Additionally, in acetone and water, tendency to swell depending on time has been determined. The prepared microspheres were tested as sorbents for removal of fluorine containing phenolic compounds from the aqueous solutions using the solid phase extraction (SPE) technique. A mixture of: phenol (Ph), 2-fluorophenol (2-FPh), 2,6-difluorophenol (2,6-DFPh) and 2,4,6-trifluorphenol (2,4,6-TFPh) as testing compounds was applied. The prepared porous polymers possessed good sorption properties towards the testing compounds.