Preparation of novel ACMO-AA/PVDF composite membrane by one-step process and its application in removal of heavy metal ions from aqueous solutions

In this study, a simple one-step process was used to fabricate a high-efficiency 4-acryloylmorpholine-acrylic acid/ polyvinylidene fluoride (ACMO-AA/PVDF) composite membrane for the adsorption of heavy metal ions. The initiation phase involved the use of the strong organic base tetramethylammonium hydroxide (TMAH) to facilitate the partial dehydrofluorination of PVDF, thereby yielding a reactive C--C -- C bond. Following this, undesirable residuals and by-products of TMAH were removed through a thermal treatment process. Subsequently, an ACMO and AA, both possessing distinctive functional groups, onto the active C--C -- C bond took place in-situ. The use of a suitable initiator (AIBN) and crosslinking agent (MBA) facilitated the copolymerization process, culminating in the production of the ACMO-AA/PVDF composite membrane with excellent capability for the adsorption of heavy metal ions. Performance evaluations confirmed the membrane high efficiency in Pb2+ 2 + removal with complete removal realized at initial Pb2+ 2 + concentrations of <= 50 mg & sdot;L-1 & sdot; L -1 and presenting a maximum adsorption capacity of 1214.75 mg & sdot;g-1, & sdot; g -1 , as described by the Langmuir model. In complex environments with coexisting metal ions such as Cu2+, 2 + , Hg2+, 2 + , and Cd2+, 2 + , at an each initial concentration of up to 50 mg & sdot;L-1, & sdot; L -1 , the membrane exhibited a Pb2+ 2 + removal rate of 93.81 %, and Hg2+ 2 + and Cu2+ 2 + removal rates of 93.75 % and 92.93 %, respectively. The results of surface morphological and microstructural analyses showed that the principal adsorption mechanism is chemical chelation. Furthermore, the membrane exhibited sustainable usability, retaining its structural integrity and adsorption efficacy over multiple regeneration cycles. This indicates that the ACMO-AA/PVDF composite membrane is a viable candidate for deep decontamination processes involving Pb2+, 2 + , Hg2+, 2 + , and Cu2+ 2 + in environmental remediation applications.