Preparation of Chitosan Poly(methacrylate) Composites for Adsorption of Bromocresol Green

Abstract

In the present study, chitosan poly(methacrylate) composites were prepared and applied for adsorption of bromocresol green from aqueous solutions. The synthesized composites were characterized with scanning electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The bromocresol green removal by the developed adsorbent was investigated, and the effects of experimental parameters, including sample pH and adsorption time, were also examined. Furthermore, the adsorption characteristics of the synthesized adsorbent, including kinetics, adsorption isotherms, and thermodynamics, were comprehensively studied. The adsorption isotherm was well described by the Freundlich model, and the maximum adsorption capacity was 39.84 μg mg –1 by shaking for 40 min at pH 2.0. Bromocresol green adsorption kinetics followed a pseudo-second-order kinetic model, indicating that adsorption was the rate-limiting step. Thermodynamic parameters and the negative values of Gibbs free energy change (Δ G °) showed that adsorption was a spontaneous process. The positive values of entropy change (Δ S °) implied that the adsorption of bromocresol green on chitosan poly(methacrylate) composites was an increasing random process. In addition, enthalpy change (Δ H °) values were positive, suggesting that the adsorption of bromocresol green was endothermic. The adsorption percentage of bromocresol green with chitosan poly(methacrylate) composites remained above 97% after three times of recycling test.

Mesoporous chitosan/activated charcoal powder and bead modified in 1‐butyl‐3‐methylimidazolium acetate for the adsorption of acid blue 25 from an aqueous solution

“…7. It is observed that 0.1 mol L −1 NaOH is the most effective regenerating solvent for the spent ChA and ChB adsorbents, 8,62 while low desorption was recorded in 0.1 mol L −1 HCl. Furthermore, 0.1 mol L −1 NaOH desorbed about 97% and 94% of the dye in the first cycle for ChA and ChB, respectively.…”

Azo-functionalized superparamagnetic Fe3O4 nanoparticles: an efficient adsorbent for the removal of bromocresol green from contaminated water

“…This variation in the removal efficiency can be explained in terms of the pK a value of BCG (p K a = 4.7). 38 In addition, the point of zero charge (PZC) of ADFS (pH = 3) was calculated experimentally by adding a constant amount of ADFS solid material to solutions of different pH values (without using a buffer solution) and measuring the final pH of the solution after a certain time of stirring. A plot of ΔpH versus the final solution pH can help in determining the PZC.…”

“…The bands observed at 2989 and bands at 1400 and 1382 cm À1 are assigned to the asymmetric vibration of -N]N-, indicating that the coupling reaction occurred and the framework of ADFS was successfully formed. 38 The absorption bands appearing at 1240 and 1058 cm À1 stand for the stretching vibrations of C-N. Moreover, the bands at 891 and 544 cm À1 correspond to -C]Cbond bending and Fe-O bond stretching, respectively.…”

Acrylate and Methacrylate Polymers’ Applications: Second Life with Inexpensive and Sustainable Recycling Approaches

“…Liu et al have prepared chitosan poly(methacrylate) composites, containing methacrylic acid fragments, to adsorb bromocresol green (BCG) from aqueous solutions [ 93 ]. Bromocresol is used as a pH indicator and as a tracking dye for DNA agarose gel electrophoresis.…”

“…The best performance was observed at pH 2; at this value a decrease of positive charge of BCG is expected, favouring electrostatic attraction and absorption of BCG onto the chitosan poly(methacrylate) surface. At pH > 2.0 a decrease of absorption efficiency was observed due to an electrostatic repulsion between BCG and anionic surface of absorbent composite [ 93 ].…”