Cross-Linked Ionic Liquid Polymer for the Effective Removal of Ionic Dyes from Aqueous Systems: Investigation of Kinetics and Adsorption Isotherms

Abstract

In the current study, we have synthesized an imidazolium based cross-linked polymer, namely, 1-vinyl-3-ethylimidazolium bis(trifluoromethylsulfonyl)imide (poly[veim][Tf2N]-TRIM) using trimethylolpropane trimethacrylate as cross linker, and demonstrated its efficiency for the removal of two extensively used ionic dyes—methylene blue and orange-II—from aqueous systems. The detailed characterization of the synthesized poly[veim][Tf2N]-TRIM was performed with the help of 1H NMR, TGA, FT-IR and FE-SEM analysis. The concentration of dyes in aqueous samples before and after the adsorption process was measured using an UV-vis spectrophotometer. The process parameters were optimised, and highest adsorption was obtained at a solution pH of 7.0, adsorbent dosage of 0.75 g/L, contact time of 7 h and dye concentrations of 100 mg/L and 5.0 mg/L for methylene blue and orange-II, respectively. The adsorption kinetics for orange-II and methylene blue were well described by pseudo-first-order and pseudo–second-order models, respectively. Meanwhile, the process of adsorption was best depicted by Langmuir isotherms for both the dyes. The highest monolayer adsorption capacities for methylene blue and orange-II were found to be 1212 mg/g and 126 mg/g, respectively. Overall, the synthesized cross-linked poly[veim][Tf2N]-TRIM effectively removed the selected ionic dyes from aqueous samples and provided >90% of adsorption efficiency after four cycles of adsorption. A possible adsorption mechanism between the synthesised polymeric adsorbent and proposed dyes is presented. It is further suggested that the proposed ionic liquid polymer adsorbent could effectively remove other ionic dyes and pollutants from contaminated aqueous systems.

Manganese Removal Using Functionalised Thiosalicylate-Based Ionic Liquid: Water Filtration System Application

“…The positive N + atom of the imidazolium ring and negative thiosalicylate anion of [HIMP][TS] enable adsorbates such metal ions to interact electrostatically. Aromatic moieties in adsorbent and adsorbates can lead to an enhanced adsorption by interactions with the metal ions [32].…”

Use of the Box–Behnken Experimental Design for the Optimization of Orange II (Acid Orange 7) Adsorption on Aloe vera

“…The most common isotherm models found in the bibliography [52,[58][59][60] were used to explain the adsorption equilibrium; they can be found in Table 2.…”

Synthesis and Behavior of Hexamethylenetetramine-Based Ionic Liquids as an Active Ingredient in Latent Curing Formulations with Ethylene Glycol for DGEBA

“…On the other hand, anions of ionic liquids can be both organic and inorganic, and their nature significantly affects the properties of the entire compound. The most important feature of this group of compounds is undoubtedly an extremely wide range of applications, in which the following should be distinguished: (i) dissolution and processing of biomass [ 3 , 4 , 5 ], (ii) catalytic reactions [ 6 , 7 , 8 ], (iii) active ingredients in pharmaceutical preparations [ 9 , 10 ] or (iv) design of polymerizable monomers intended for modern material solutions [ 11 , 12 , 13 ]. The wide area of application of ionic liquids is due to their properties, among which the following should be mentioned: high thermal stability [ 14 ], high electrochemical window [ 15 ], low volatility [ 16 ] and flammability [ 17 ].…”