In this study, superior carbon nanotubes (CNT) were chemically modified with itaconic acid (IA) and a polyaniline (PANI) composite was formed and used to remove methylene blue (MB) dye from an aqueous solution. The capacity of CNTs modified with IA (IA/CNT) and composited with PANI (PANI/CNT) to remove MB dye from an aqueous solution was compared and investigated. The effects of parameters such as pH (3–10), adsorbent dose (0.8–8 g/L), initial dye concentration (10–100 mg/L), and temperature (25–55 °C) on MB adsorption were investigated. IA/CNT and PANI/CNT adsorbents were characterized by analyzes such as Fourier Transform Infrared Spectroscopy (FT-IR), Field Emission Scanning Electron Microscopy (FE-SEM), transmission electron microscope (TEM), and Brunauer, Emmett and Teller (BET). It was determined that the isotherm data fit the Langmuir isotherm model. The maximum adsorption capacity (qmax) of PANI/CNT and IA/CNT calculated according to this model (at 25 °C) was 12.78 and 32.78 mg g− 1, respectively. Thermodynamic analysis results showed that the adsorption was exothermic, feasible, and spontaneous. It can be said that the possible mechanism of MB on PANI/CNT and IA/CNT adsorbents occurs with the participation of π–π interaction, electrostatic attraction and hydrogen bonding.

Evaluation of adsorption characteristics of new-generation CNT-based adsorbents: characterization, modeling, mechanism, and equilibrium study
    Abstract
        Graphical abstract
    1 Introduction
    2 Experimental
        2.1 Materials
        2.2 Characterizations
        2.3 Preparation of adsorbents
            2.3.1 Itaconic acid modification of CNTs
            2.3.2 PANICNT composites
        2.4 Adsorption of MB by CNT-based adsorbents
    3 Results and discussion
        3.1 Characterization of PANICNT and IACNT adsorbents
        3.2 Dye adsorption properties
            3.2.1 Effect of pH
            3.2.2 Effect of adsorbent dose
            3.2.3 Effect of time and initial dye concentration
            3.2.4 Effect of temperature and thermodynamic parameters
        3.3 Adsorption isotherms
        3.4 Adsorption kinetics
        3.5 Recyclability and regeneration
    4 Conclusion
    References

• Suheyla Kocaman(Department of Chemical Engineering, Faculty of Engineering and Natural Science, Konya Technical University, 42022 Konya, Turkey)