Lignin grafted hydroxyapatite entrapped in polyacrylamide: Characterization and adsorptive features for Th4+ and bovine serum albumin

• Published in: International journal of biological macromolecules Vol. 204; pp. 333 - 344
• Main Authors: Aslan, Fuat, Baybaş, Demet, Ulusoy, Ulvi
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.04.2022
• Subjects: Adsorption; BSA; Hydroxyapatite; Lignin; Polyacrylamide; Thorium; Lignin; BSA; Hydroxyapatite; Adsorption; Polyacrylamide; Thorium
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2022.01.200

Water-soluble sulfolignin (SL) was grafted onto hydroxyapatite (Hap) by using epichlorohydrin. SLgHap was then entrapped in cross-linked polyacrylamide by in situ polymerizations of acrylamide and N, N′-methylenebisacrylamide to obtain the composite of PSLgHap. The composite was characterized by FT-IR, BET- porosity, XRD, EDXRF, SEM-EDX, TGA-DTG, PZC, CEC, and swelling tests. The adsorptive features of PSLgHAP were investigated for Th4+ and BSA in view of its dependence on pH, ionic intensity, concentration, temperature, and time. The results of characterization tests confirmed the formation of PSLgHap. The grafting efficiency concerning sulfur contents of PSLgHap was 96% by EDXRF. The isotherms were best represented by the Sips model, Langmuir adsorption capacities were 369 and 390 mg gSLgHap−1 for BSA and Th4+. The enthalpy and entropy changes were positive whilst Gibbs energy was negative by entropy controlled. The adsorption kinetics of both species was obeyed to pseudo second-order model, whereas it was first-order for BSA and hybrid-order for Th4+ of Langmuir model. •Sulfolignin grafted hydroxyapatite was entrapped in PAAm by in situ polymerization.•Grafting efficiency was proved to be >95% by EDXRF.•The composite characterized by XRD, SEM-EDX, FTIR, TG/DTG, and swelling features.•Adsorption of Th4+ and BSA was determined by isotherms, kinetics, and thermodynamics.•Monolayer adsorption capacities were 390 mg g−1 for Th4+ and 369 mg g−1 for BSA.