Effective Poly (Cyclotriphosphazene-Co-4,4′-Sulfonyldiphenol)@rGO Sheets for Tetracycline Adsorption: Fabrication, Characterization, Adsorption Kinetics and Thermodynamics

Abstract

The development of excellent drug adsorbents and clarifying the interaction mechanisms between adsorbents and adsorbates are greatly desired for a clean environment. Herein, we report that a reduced graphene oxide modified sheeted polyphosphazene (rGO/poly (cyclotriphosphazene-co-4,4′-sulfonyldiphenol)) defined as PZS on rGO was used to remove the tetracycline (TC) drug from an aqueous solution. Compared to PZS microspheres, the adsorption capacity of sheeted PZS@rGO exhibited a high adsorption capacity of 496 mg/g. The adsorption equilibrium data well obeyed the Langmuir isotherm model, and the kinetics isotherm was fitted to the pseudo-second-order model. Thermodynamic analysis showed that the adsorption of TC was an exothermic, spontaneous process. Furthermore, we highlighted the importance of the surface modification of PZS by the introduction of rGO, which tremendously increased the surface area necessary for high adsorption. Along with high surface area, electrostatic attractions, H-bonding, π-π stacking and Lewis acid-base interactions were involved in the high adsorption capacity of PZS@rGO. Furthermore, we also proposed the mechanism of TC adsorption via PZS@rGO.

Phosphazene Cyclomatrix Network-Based Polymer: Chemistry, Synthesis, and Applications

“… Proposed mechanism of tetracycline decontamination through PZS@rGO involving π–π stacking, electrostatic interactions, H-bonding, and Lewis acid–base interactions. 118 Reprinted with permission from ref ( 118 ). …”

“…Their porous morphology, large surface area hollow in structure, abundant hydroxyl groups, presence of heteroatoms, active −NH 2 groups, and π–π stacking make polyphosphazenes excellent candidates as adsorbents (shown in Figure ). ,, …”

“…Their porous morphology, large surface area hollow in structure, abundant hydroxyl groups, presence of heteroatoms, active −NH 2 groups, and π−π stacking make polyphosphazenes excellent candidates as adsorbents (shown in Figure 11). 101,117,118 Wu et al selected porous carbon nanosheets (PCNs) with a specific area of 1032.1 m 2 g −1 as a carrier to in situ load aminated cyclomatrix polyphosphazene to generate PCNs@PCP composites. For that, low molecular weight polyethylenimine (PEI) and HCCP were utilized as ideal comonomers to conduct polymerization on PCNs.…”

Fabrication of Bimetallic Cu–Ag Nanoparticle-Decorated Poly(cyclotriphosphazene-co-4,4′-sulfonyldiphenol) and Its Enhanced Catalytic Activity for the Reduction of 4-Nitrophenol

“…Polyphosphazenes are the novel genre of polymers with organic–inorganic nature and an inorganic (−P=N−) bone structure with a multiplicity of side functional groups, for example, organometallic, inorganic, or organic groups. 18 These features of polyphosphazene hybrid materials make them promising candidates for the biomedical carriers and immobilizing the metal ions, which leads to the good dispersion of bimetallic NPs. Yan et al reported the Ag–Au NPs impregnated over the PZS [poly(cyclotriphosphazene- co -4,4′-sulfonyldiphenol)] nanotube with rich −OH groups.…”

“…Therefore, achieving a facile method for the fabrication of one-dimensional polymer nanotubes through self-controlled dimensions under environment-friendly conditions is a task for the researcher. Polyphosphazenes are the novel genre of polymers with organic–inorganic nature and an inorganic (−PN−) bone structure with a multiplicity of side functional groups, for example, organometallic, inorganic, or organic groups . These features of polyphosphazene hybrid materials make them promising candidates for the biomedical carriers and immobilizing the metal ions, which leads to the good dispersion of bimetallic NPs.…”