Highly efficient removal of methyl orange from aqueous media by amine functional cyclotriphosphazene submicrospheres as reusable column packing material

Abstract

Polyphosphazenes have an important place in material science because they allow functional diversity to be realized easily. In this study, for the first time, synthesis of cyclomatrix-type poly-(cyclotriphosphazene-co-4-(aminomethyl)-1,8-octanediamine) (Phz-AO) particles including different surface features and dimensions have been reported using different stoichiometric ratios of hexachlorocyclotriphosphazene and 4-(aminomethyl)-1,8-octanediamine. The use of Phz-AO (1:2) submicroparticles with spherical form and average dimension of 647.82 ± 22.23 nm as an adsorbent was researched for methyl orange (MO) anionic azo dye. Submicrospheres had significant potential for adsorption of negative charged MO and maximum adsorption capacity of 1244.7 mg.g − 1. The submicrospheres displayed high adsorption potential at pH ≤6 conditions thanks to their surface amine groups. The maximum adsorption capacity in synthetic textile wastewater was 912.75 mg.g−1 as experimental. While the adsorption kinetics had the pseudo second order model, the most suitable model for adsorption was the Langmuir isotherm. The thermodynamic parameters for MO adsorption with submicrospheres were 10.02 ± 1.81 kj.mol−1 for ΔH°, 61.08 ± 5.74 j.mol−1.K−1 for ΔS° and ΔG° (kj.mol−1)<0. In light of all data obtained, the Phz-AO (1:2) submicrospheres which can be easily prepared with a single-step reaction are expected to be a remarkable member of the super adsorbent material family.