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A new nitrogen-rich hierarchical porous polymer (PCPM) was synthesized via a self-catalyzed polycondensation from hexachlorocyclotriphosphazene and melamine under the solvothermal condition, which presented a high adsorption capacity and a fast adsorption kinetics towards three typical water-soluble micropollutants. [Display omitted] • Novel nitrogen-rich hierarchical porous polyphosphazenes were facilely synthesized. • The adsorbent has rich mesopores and a high specific surface area of 321.1 m2/g. • The adsorbent exhibited a high adsorption capacity and a fast adsorption kinetics. • Q max was 187.5, 336.2, and 320.4 mg g−1 for Cr (VI), CR and DCF, respectively. • The adsorption is the result of synergistic action of multiple adsorption mechanisms. The rapid and highly-efficient uptake of waterbody contaminants by polymer-based adsorbent is still a challenge. Herein, a new nitrogen-rich hierarchical porous polymer (PCPM) was synthesized via a self-catalyzed polycondensation between hexachlorocyclotriphosphazene and melamine. The PCPM possessed hierarchical pore architecture with specific surface area of 321.1 m2/g and pore size distribution from 1.3 to 63.0 nm. Owing to the remarkable porous texture and nitrogen-rich active sites with high electron density, PCPM exhibited a high adsorption capacity of 187.5, 336.2, and 320.4 mg g−1 for Cr (VI), Congo red (CR), and diclofenac sodium (DCF), respectively. Moreover, the adsorption rate of these contaminants onto PCPM was very fast, reaching 90 % of adsorption equilibrium capacity for Cr (VI), CR and DCF within the first 7 min, 45 min and 30 min, respectively. Adsorption data revealed that the adsorption process conformed to pseudo-second-order kinetics and Langmuir isotherm model. The removal process was spontaneous, exothermic for Cr (VI) and endothermic for CR and DCF. FT-IR and XPS analysis demonstrated that electrostatic interaction and hydrogen bonding contributed to the adsorption of CR and DCF onto PCPM, while the removal mechanism of Cr (VI) by PCPM included redox reaction and chelation besides the above two interactions. [ABSTRACT FROM AUTHOR]

An amino-rich hollow polyphosphazene microcapsule with rigid-flexible coupling cationic skeleton (HTCM) was facilely prepared by a one-step precipitation polycondensation of hexachlorocyclotriphosphazene and tetraethylenepentamine at room temperature, which exhibited a highly efficient, rapid and selective adsorption behavior towards anionic dyes. [Display omitted] • HTCM was facilely synthesized by one-step polymerizaiton at room temperature. • HTCM owned hollow structure and rigid-flexible coupling cationic skeleton. • The average adsorption capacity of HTCM for MO reached 1009.66 mg g−1 at 25 °C. • The α values of MO for MB, CV and RhB reached 124.22, 124.87 and 136.35 respectively. • The adsorption mechanism of HTCM involved electrostatic interaction and H-bonding. An amino-rich hollow polyphosphazene microcapsule with rigid-flexible coupling cationic skeleton (HTCM) was facilely prepared by one-step polycondensation from hexachlorocyclotriphosphazene and tetraethylenepentamine. The systematic adsorption studies for six single dye systems and three binary mixed dye systems showed that HTCM possessed a highly-efficient and selective adsorption behavior towards anionic dyes from water. Especially, the adsorption capacity of HTCM towards methyl orange (MO) at equilibrium reached 1009.66 mg g−1 at 25 °C, and the relative separation factors of anionic dye MO for three cationic dyes (methylene blue, Crystal violet and Rhodamine B) was up to 124.22, 124.87 and 136.35, respectively. The adsorption rate of MO onto HTCM was very rapid, attaining 68.6 % of adsorption equilibrium capacity for MO within the first 30 min. The adsorption kinetics, isotherm and thermodynamic analysis revealed that the uptake behavior of HTCM towards MO obeyed pseudo-second-order kinetic model, intraparticle diffusion model and Langmuir model, and the uptake process was spontaneous and endothermic. As verified from FT-IR and XPS analysis for HTCM before and after MO adsorption, the adsorption mechanism of HTCM for MO involved electrostatic interaction and hydrogen bonding. The present study promises the potential of HTCM for highly selective separation of anionic dyes from wastewater. [ABSTRACT FROM AUTHOR]

We proposed a feasible strategy to prepare a rigid-flexible coupled polyphosphazene supported polyurethane foam (PUF-PCP) adsorbent by in situ polycondensation between hexachlorocyclotriphosphazene and polyethyleneimine on the surface of polyurethane foam (PUF) at room temperature. Owing to combination of the open cell porous structure of PUF support and the superior adsorption capacity of PCP coatings, the PUF-PCP composite adsorbent exhibited good adsorption behavior towards anionic dyes. Especially, the experimental adsorption capacity of PUF-PCP for methyl orange (MO) dye was up to 978.56 mg g−1 at 25 ºC. The relative separation factors of MO for methylene blue, crystal violet and rhodamine B were 224.1, 78.1 and 161.8 respectively, exhibiting an excellent adsorption selectivity of PUF-PCP towards MO. Moreover, the used PUF-PCP adsorbent can be easily collected and regenerated. The adsorption test data were best explained by Langmuir model and pseudo-second-order model. The adsorption process of MO onto PUF-PCP was spontaneous and endothermic. XPS and FT-IR analysis confirmed that electrostatic adsorption and hydrogen bonding were the plausible uptake mechanism of PUF-PCP for MO molecules. The present work demonstrated that PUF-PCP has promising potential in removing environmental anionic pollutants from waterbody. [Display omitted] • PUF-PCP was facilely fabricated by in situ polycondensation at room temperature. • The maximum adsorption capacity of PUF-PCP for MO was up to 978.56 mg g−1. • PUF-PCP can selectively adsorb anionic dyes from binary mixed dye system. • The relative separation factor of anionic MO for cationic MB was as high as 224.1. • PUF-PCP absorbent exhibited good reusability for MO removal. [ABSTRACT FROM AUTHOR]