Adsorption of Methylene Blue Dye by Cetyltrimethylammonium Bromide Intercalated Polyaniline-Functionalized Montmorillonite Clay Nanocomposite: Kinetics, Isotherms, and Mechanism Study

Abstract

In this study, new adsorbents were prepared by modifying a montmorillonite clay (Mt) with cethyltrimethyl ammonium bromide (CTAB) to form CTAB-Mt, followed by a second modification process with polyaniline (PAni) to form PAni@CTAB-Mt by in situ polymerization of aniline. X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), transmission electron microscopy (TEM), cyclic voltammetry (CV) and the Brunauer–Emmett–Teller (BET) technique were used to characterize the samples. These adsorbents were used in a batch process to remove methylene blue (MB) from aqueous solution. Factors investigated included initial pH of the solution, contact time and temperature. The adsorption data fit the Freundlich isotherm better than the Langmuir and Temkin isotherms. The maximum adsorption capacities (qeq) obtained were 108.82 mg·g−1, 71.20 mg·g−1 and 57.36 mg·g−1 for PAni@CTAB-Mt, CTAB-Mt and Mt, respectively. The enhanced adsorption capability of the hybrid material is due to increase in surface area and pore volume of the PAni@CTAB-Mt adsorbent. The adsorption results were found to fit well with the pseudo-second-order kinetics model, with highest correlation coefficient (R2) values of 0.954, 0.942 and 0.958 for Mt, CTAB-Mt and PAni@CTAB-Mt adsorbents, respectively. The pH and temperature had a significant effect on the adsorption process, and the negative values of ΔG suggest that the adsorption process was spontaneous and feasible. The desorption and reusability experiment indicated that PAni@CTAB-Mt has the potential to be a reusable adsorbent for MB removal.

Bimetallic Organic Gel for Effective Methyl Orange Dye Adsorption

“…And negative values of Δ G θ signify that the adsorption process is spontaneous and feasible. Additionally, as shown in Table 3 , the trend of Δ G θ is positively correlated with the temperature change, indicating that the adsorption process is more favorable at room temperature than at high temperature [ 39 ]. Therefore, the adsorption of MO by MOG-Fe/Al is a spontaneous exothermic entropy reduction process.…”

Optimization Conditions of Malachite Green Adsorption onto Almond Shell Carbon Waste Using Process Design

“…The first mass loss (2.82 wt %) between 30 °C and 120 °C is due to the removal of moisture from the structure. The second mass loss (21.26 wt %) between 190 and 450 °C can be attributed to the degradation of cellulose, hemicellulose, and lignin in the structure and the removal of gaseous products and volatile components from the structure during decomposition [ 41 ] and the total mass loss is 24.92 wt %.…”

“…Molecules 2023, 28, x FOR PEER REVIEW 4 o hemicellulose, and lignin in the structure and the removal of gaseous products and vo tile components from the structure during decomposition [41] and the total mass los 24.92 wt %. The microstructure of carbon-based almond shell presents an amorphous struct that gives a highly porous surface; this result showed a good agreement with textu characterization obtained by the BET method.…”

Shrinkage Reduction in Nanopore-Rich Cement Paste Based on Facile Organic Modification of Montmorillonite

“…The peak of Si-O-Si was observed at 790 cm −1 [40]. The weak absorption band at 912 cm −1 is related to the Al-OH in the vibration [41]. The bands at 445 cm −1 and 526 cm −1 might be coupling vibrations of OH and Si-OH [38,42].…”