Mechanically stable membranes of polyacrylic acid-grafted chitosan-functionalized carbon nanotubes with remarkable water storage capacity in sandy soils

Polyacrylic acid (PAA) is one of the most exciting hydrophilic polymers for water control and conservation; however, it suffers from poor mechanical properties during the agricultural applications. For that purpose a series of PAA-based multiwalled carbon nanotubes (MWCNTs) membranes have syn- thesized via a grafting process of MWCNTs using chitosan (CS) polymer as a binder. The fabricated membranes have spectroscopically characterized by dif- ferent techniques to confirm the composite structure. The MWCNTs content into the PAA membranes has played a pronounced effect on water absorptiv- ity, swelling behavior, and mechanical properties. PAA membrane has showed a fourfold increase in yield-stress by the addition of 3 wt% PAA/CS/MWCNTs, while preserving a 91% of water absorptivity of PAA membrane. The soil appli- cations of the PAA/CS/MWCNTs membranes have showed remarkable improvements in soil moisture content compared to the PAA membrane. This study provides a promising pathway for future field applications, especially in arid lands.