Enhanced adsorption of cationic and anionic dyes from aqueous solutions by polyacid doped polyaniline

• Published in: Synthetic metals Vol. 245; pp. 151 - 159
• Main Authors: Shen, Junjie, Shahid, Salman, Amura, Ida, Sarihan, Adem, Tian, Mi, Emanuelsson, Emma AC
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.11.2018; Elsevier BV
• Subjects: Adsorbents; Adsorption; Aniline; Aqueous solutions; Chemical synthesis; Doping; Dye adsorption; Dyes; Endothermic reactions; Field emission microscopy; Fourier transforms; Infrared spectroscopy; Methylene blue; Polyacid; Polyacids; Polyaniline; Polyanilines; Rose bengal; Surface area; Surface chemistry; Thermodynamics; Water treatment; X ray powder diffraction; Zeta potential; MO; PR; CBB; RBBR; AG; Doping; PANI; Rose bengal; Polyaniline; CR; Methylene blue; RB; CSA; CV; MB; TMP; ZSP; Dye adsorption; PTSA; OG; PAMPSA; MG; Polyacid
• ISSN: 0379-6779; 1879-3290
• DOI: 10.1016/j.synthmet.2018.08.015

[Display omitted] •Polyacid doped polyaniline was first investigated as an adsorbent for dye removal.•The polyacid was important for the formation of a well-defined porous structure.•The maximum adsorption capacities for MB and RB were 466.5 mg g−1 and 440.0 mg g−1.•The adsorption mechanisms involved π-π interaction and electrostatic interaction. A new high surface area polyaniline (PANI) adsorbent was synthesized by matrix polymerization of aniline in the presence of a polyacid, poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (PAMPSA). Morphological and physicochemical properties of PANI-PAMPSA were characterized by field emission scanning electron microscope (FESEM), Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), nitrogen adsorption/desorption and zeta potential measurement. Adsorption properties were evaluated using methylene blue (MB) and rose bengal (RB) as model dyes. The results showed that PANI-PAMPSA obtained a well-defined porous structure with a specific surface area (126 m2 g−1) over 10 times larger than that of the emeraldine base PANI (PANI-EB) (12 m2 g−1). The maximum adsorption capacities were 466.5 mg g−1 for MB and 440.0 mg g−1 for RB, higher than any other PANI-based materials reported in the literature. The FTIR analysis and zeta potential measurement revealed that the adsorption mechanisms involved π-π interaction and electrostatic interaction. The adsorption kinetics were best described by a pseudo-second-order model, and the adsorption isotherms followed the Langmuir model. The thermodynamic study indicated that the adsorption was a spontaneous endothermic process. Overall, the convenient synthesis and the high adsorption capacity make PANI-PAMPSA a promising adsorbent material for dye removal.