Selectivity Performance and Antifouling Properties of Modified Chitosan Composites

As a sequel to the quest to enhance membrane performance for various industrial applications, the chemical combinations of chitosan (CS), silver nanoparticles (AgNPs), and graphene oxide (GO) were carefully formulated to study the antifouling and tensile behavior of the modified polymer composites while employing dimethylacetamide (DMAc) as a plasticizer to enhance the polymer's fluidity and thermoplasticity.

According to antifouling tests, the flux recovery rates and antifouling capabilities of CS/AgNP/GO, CS/GO, and CS/AgNP membranes depended on their wettability. An increase in the interaction between bovine serum albumin (BSA) solution and the membranes might explain why the flow recovery rate (FRR) was higher, possibly because there were more -NH₂ groups from the DMAc group and -OH groups from the CS, which helped water molecules stick to the negatively charged BSA through electrostatic and hydrogen bonding. The CS/AgNPs/GO composite sample showed a strong ability to prevent fouling, achieving over 77.5% due to greater interfacial intermolecular bonding than that of CS/AgNPs (68.2%) and CS/GO (65.1%), respectively. Effective collision of the membrane constituents during polymer preparation could also be responsible for higher antifouling performance.

In addition, the tensile strength of the modified CS composite was observed to vary from 42.7 to 49.6 MPa as the concentration of DMAc increased. The membrane's tensile strength was significantly influenced by the chemical interaction between DMAc and CS, as these two substances were the sole modifiable components in the composite in this case.

Therefore, efficient chemical interactions of various components within the polymer matrix significantly influenced the membrane’s flux recovery rate, selectivity performance, tensile strength, and ability to prevent fouling.