Polyacrylamide Grafted Activated Carbon by Surface-Initiated AGET ATRP for the Flocculation of MFT

Polyacrylamide (PAM) is grafted from the surface of activated carbon (AC) by surface-initiated activators generated by electron transfer atom transfer radical polymerization (SI-AGET ATRP). This is accomplished by pre-functionalizing the surface of activated carbon by oxidation, followed by the attachment of an ATRP initiator. From this surface, SI-AGET ATRP of acrylamide monomers is performed. The resulting AC-PAM is characterized by FTIR, XPS, TGA, and BET analysis. Additionally, the grafted polymer is cleaved from the surface of AC and its molecular weight distribution is measured by SEC. This material is designed to explore the effect that grafting a polymer flocculant onto AC will have on the polymer's flocculating abilities. This is evaluated by measuring the flocculation and dewatering of mature fine tailings (MFT) when dosed with the AC-PAM compared to PAM. In all, this work demonstrates the successful grafting of PAM onto AC, as well as potential wastewater applications for this composite material. A novel polyacrylamide functionalized activated carbon is synthesized using surface-initiated atom transfer radical polymerization with demonstrated efficacy for flocculation of mature fine tailings in environmental remediation of oil sands tailings. Composed of 11% polymer, this hybrid flocculant uses less polyacrylamide than a pure polymer flocculant.image