The Effect of Silver Nanoparticles/Titanium Dioxide in Poly(acrylic acid- co -acrylamide)-Modified, Deproteinized, Natural Rubber Composites on Dye Removal.

This work aims to enhance the dye-removal performance of prepared poly(acrylic acid- co -acrylamide)-modified, deproteinized, natural rubber ((PAA- co -PAM)-DPNR) through incorporation with silver nanoparticles/titanium dioxide. The (PAA- co -PAM)-DPNR was prepared by emulsion-graft copolymerization with a grafting efficiency of 10.20 ± 2.33 to 54.26 ± 1.55%. The composites based on (PAA- co -PAM)-DPNR comprising silver nanoparticles and titanium dioxide ((PAA- co -PAM)-DPNR/Ag-TiO ₂ ) were then prepared by latex compounding using the fixed concentration of AgNO ₃ (0.5 phr) and varying concentrations of TiO ₂ at 1.0, 2.5, and 5.0 phr. The formation of silver nanoparticles was obtained by heat and applied pressure. The composites had a porous morphology as they allowed water to diffuse in their structure, allowing the high specific area to interact with dye molecules. The incorporation of silver nanoparticles/titanium dioxide improved the compressive modulus from 1.015 ± 0.062 to 2.283 ± 0.043 KPa. The (PAA- co -PAM)-DPNR/Ag-TiO ₂ composite with 5.0 phr of TiO ₂ had a maximum adsorption capacity of 206.42 mg/g, which increased by 2.02-fold compared to (PAA- co -PAM)-DPNR. The behavior of dye removal was assessed with the pseudo-second-order kinetic model and Langmuir isotherm adsorption model. These composites can maintain their removal efficiency above 90% for up to five cycles. Thus, these composites could have the potential for dye-removal applications.