Application of sodium dodecyl sulfate intercalated Co[sbnd]Al LDH composite materials (RGO/PDA/SDS-LDH) in membrane separation.

Layered double hydroxides (LDHs) is a typical type of anionic clay minerals. In this study, an SDS-LDH with sodium dodecyl sulfate (SDS) intercalation was prepared by the ion exchange method, and the modified SDS-LDH was successfully combined with graphene oxide (GO). In the presence of dopamine, partial reduction of GO to reduced graphene oxide (RGO). RGO/PDA/SDS-LDH (RPS) composite material was prepared successfully and used in the field of membrane separation. The RPS-2 composite membrane combines the advantages of GO and SDS-LDH, which can increase GO flux while maintaining a high rejection rate. The flux was increased from 10.21 L·m−2h−1bar−1 of GO to 79.24 L·m−2h−1bar−1 of RPS-2, and the rejection rate of various dyes was above 97%. The rejection rate of methylene blue (MB) 97.34% was maintained after 10 cycles, and its flux loss rate is only 45.32%. The composite membrane had good stability under different pH conditions, which provides a basis for the practical application of the membrane. [Display omitted] • The ion exchange method was used to successfully insert SDS into LDH and increase the interlayer spacing of LDH. • RPS-2 composite material was prepared by cross-linking with dopamine. • RPS-2 composite membrane can keep stable and filter the dye 10 times. [ABSTRACT FROM AUTHOR]