Synthesis, characterization, and metal uptake capacity of a new polyaniline and poly(acrylic acid) grafted sodium alginate/gelatin adsorbent

Abstract

A B S T R A C TThe present work reports the development of new (sodium alginate-gelatin (SAG))-g-poly (acrylic acid)/polyaniline (SAPAPN) from sodium alginate/gelatin blend by cross-linking with glutaraldehyde, followed by grafting with poly(acrylic acid) and polyaniline by free radical polymerization using ammonium persulfate. The structure, thermal stability, and morphology of SAPAPN adsorbent was characterized by Fourier transform infrared spectroscopy, thermo gravimetric analysis, and scanning electron microscopy, and results were consistent with the expected structures. The influence of various experimental conditions like pH, time, and initial feed concentrations on the uptake of metal ions like Cu 2+ , Ni 2+ by SAPAPN adsorbent was tested. It was seen that the adsorption equilibrium data could be fitted to the Langmuir isotherm. Desorption studies were performed in acid media and EDTA, to examine whether the SAPAPN adsorbent can be recycled for the metal ion removal. The results showed that with SAPAPN adsorbent, the maximum metal ion uptake achieved is 0.8386 mMg À1 for Cu 2+ and 2.2026 mMg À1 for Ni 2+ , respectively. Metal ion sorption studies showed that the adsorbent can be used for the removal of hazardous metal ions from aqueous solutions. The copper and nickel uptake achieved suggests the potential use of the adsorbent to extract divalent toxic metals from industrial aqueous streams.

Fabrication of Eco-Friendly Polyelectrolyte Membranes Based on Sulfonate Grafted Sodium Alginate for Drug Delivery, Toxic Metal Ion Removal and Fuel Cell Applications

“…The Q e values are reported to be 43.51 (Cu(II)) and 240.64 (Ni(II)). Moreover, the development of membranes from polyaniline and poly(acrylic acid)-g-sodium alginate/gelatin was also reported [ 31 ]. The Q e values of this study were reported as 53.29 for Cu(II) and 129.28 for Ni(II).…”

“…reported to be 43.51 (Cu(II)) and 240.64 (Ni(II)). Moreover, the development of membranes from polyaniline and poly(acrylic acid)-g-sodium alginate/gelatin was also reported [31].…”

“…The required concentrations (400-1100 ppm) of metal ions were prepared by dilution of stock solution with DD water, and pH was adjusted to 5.5 with 0.01 M NaOH and HCl. Sorpton studies of Cu(II) ions were conducted by batch experiment [30,31]. Briefly, 40 mg of membrane was weighed and placed in Cu(II) ion aqueous solution; the samples were shaken at 30 • C with 200 rpm for 4 h. The concentrations of Cu(II) ion solutions were measured with atomic absorption spectroscopy (SHIMADZU, AA-6880).…”

“…Compared to the spectra of pristine PEMs before and after adsorption of the Cu(II) ion, the adsorption peaks at 3465,1715, 1655, 1475 and 1061/1079/1040 cm −1 corresponding to -OH stretching, C=O stretching, C-N stretching, C=C stretching and S=O stretching either decreased in intensity or shifted the peaks from their respective adsorption. Hence, the presence of nitrogen, oxygen and sulphur atoms in the amide, carboxyl/hydroxyl and sulfone groups are responsible for the sorption of Cu(II) ions attachment [30,31].…”

“…Having functional group (-OH, -COO − , -CONH, SO 3 − , -NH 2 and -C-O-C-) polymeric membranes can be used for the removal of toxic metals and organic pollutant from waste water. PEMs have been fabricated either by blending biopolymers or incorporating inorganic fillers into the biopolymer matrix [4,[23][24][25][26][27]31]. To remove copper from aqueous media, various materials have been developed, i.e., PEG functionalized chitosan and poly(vinyl alcohol), PVA, blend membranes [32], PVA/SiO 2 composite [33] and poly(vinyl pyrrolidone)/Fe 2 O 3 -Al 2 O 3 nanocomposites [34].…”