Amylomaize starch-modified polymeric adsorbents: synthesis, thermal characterization, and adsorption performance for C.I. Basic Yellow 40

This study aimed at the synthesis of new polymeric microspheres based on triethylene glycol dimethacrylate, vinyl acetate, N-vinyl-2-pyrrolidone, and 2-hydroxyethyl methacrylate (Mic1), as well as triethylene glycol dimethacrylate, vinyl acetate, and triethoxyvinylsilane (Mic2). The suspension–polymerization method was used to obtain the adsorptive materials in spherical form with the addition of 20 mass% of amylomaize starch (AMS) as Mic1/AMS and Mic2/AMS. The spectroscopic (ATR/FT-IR) and thermal (DSC, TGA) properties of the new adsorbents were evaluated. The obtained materials were applied as an adsorbent for the C.I. Basic Yellow 40 (BY40) dye removal from aqueous media. The sorption capacities of the polymeric adsorbents with the addition of AMS toward BY40 were determined. The sorption equilibrium parameters according to the Freundlich, Langmuir, Temkin, and Dubinin–Radushkevich isotherm models were also calculated. Starch incorporation reduced the Freundlich constant values ( k F ) from 2.061 to 1.235 and from 0.709 to 0.237 mg 1−1/n L 1/n g −1 for Mic1 and Mic2, respectively, while adsorption remained favorable (1/ n <1). The influence of the cationic (CTAB) and anionic (SDS) surfactants on the sorption efficiency for BY40 was evaluated. BY40 adsorption dropped from 2.8 to 0.1 mg g −1 for Mic1/AMS in the presence of 0.5 g L −1 CTAB and from 2.1 to 0.4 mg g −1 for Mic2/AMS with increasing SDS concentration.