Fabrication of Polymeric Membrane with High Salt Rejection by Embedding Poly(Amidoamine) Dendrimer-Functionalized Halloysite Nanotubes

The fabrication of membranes for water desalination and wastewater treatment is an important strategy to overcome water quality problems worldwide. Herein, the influence of the presence of the poly(amidoamine) dendrimer (PAMAM) on the performance of the cellulose acetate (CA) membrane was investigated. Halloysite nanotube (HNT) was functionalized with the third generation of PAMAM dendrimer and incorporated into the CA membrane by phase inversion process to improve the properties of the membrane. The functionalized HNTs and composite membranes were characterized in detail: Fourier-transform infrared spectroscopy (FTIR), Atomic force microscopy (AFM), contact angle measurements, zeta potential, thermogravimetric (TGA) analyses, and field emission scanning electron microscopy (FE-SEM). A dead-end filtration system examined the performance of the incorporated cellulose acetate membrane. Based on the results, the membrane permeability, salt rejection, and antifouling properties were improved due to the addition of hydrophilic HNTs- PAMAM nanocomposite in the membrane casting solution. The loading of 1wt% of HNTs/PAMAM was optimized as filler composition. It showed salt rejection of 91% and 75.6% for sodium sulfate and magnesium chloride respectively along with the maximum porosity (82%), antifouling performance (85%), reversible fouling ratio (45%), and the lowest contact angle (~ 32).