Synthesis, characterization and swelling behavior of high-performance antimicrobial biocompatible copolymer based on carboxymethyl xanthan

Highly reactive adsorbent based on carboxymethyl xanthan gum‐g‐poly(4‐vinylpyridine) copolymer for the potential removal of Acid Orange 10 dye and Cr(VI) ions for water treatment

“…This finding is consistent with the neat adsorbent copolymer's swelling behavior. The equilibrium water capacity exhibited the highest value at pH = 2.5 (about 7000%) 53 . However, as the pH of the solution increases above 2.5, adsorption of both AO‐10 and Cr(VI) ions was found to be decreased, reaching a minimum removal efficiency at pH 10, with percentages of 19.6% and 6.8% for AO‐10 and Cr(VI) ions, respectively.…”

“…The equilibrium water capacity exhibited the highest value at pH = 2.5 (about 7000%). 53 However, as the pH of the solution increases above 2.5, adsorption of both AO-10 and Cr(VI) ions was found to be decreased, reaching a minimum removal efficiency at pH 10, with percentages of 19.6% and 6.8% for AO-10 and Cr(VI) ions, respectively. This was due to the reduction of the positively charged adsorption sites on the CMX-5 surface, thereby promoting activities of electrostatic repulsion between the negatively charged carboxylate groups in CMX, and the negatively charged adsorbate, since at high pH, AO-10 exists as naphthalene O À and Cr(VI) ions as chromate (CrO 4 2À ).…”

“…Carboxymethyl xanthan gum (CMX) was prepared from the reaction between native xanthan gum and monochloroacetic acid in the presence of sodium hydroxide according to the method described before 54 . CMX‐g‐P(4VP) copolymers (Figure S1) as adsorbents were prepared by grafting 4‐vinyl pyridine onto carboxymethyl xanthan gum by free radical polymerization using K 2 S 2 O 8 (KPS) as an initiator according to the method described before 53 . Briefly, 0.5 g of CMX was dissolved in 35 ml of distilled water under vigorous stirring.…”

“…54 CMX-g-P (4VP) copolymers (Figure S1) as adsorbents were prepared by grafting 4-vinyl pyridine onto carboxymethyl xanthan gum by free radical polymerization using K 2 S 2 O 8 (KPS) as an initiator according to the method described before. 53 Briefly, 0.5 g of CMX was dissolved in 35 ml of distilled water under vigorous stirring. After the formation of a homogeneous solution of CMX, a predetermining amount of KPS dissolved in distilled water was added dropwise, followed by the addition of 4VP under stream bubbling of nitrogen gas at 60 C. The reaction mixture was poured into cold acetone with stirring to precipitate the viscous solution.…”

“…51,52 In our previous work, we reported on the synthesis and characterization of CMX-based graft copolymers via the first etherification of native xanthan gum with monochloroacetic acid and grafting the obtained product with 4-vinyl pyridine. 53 Here, the present work aims to study the feasibility of carboxymethyl xanthan gum-g-poly (4-vinyl pyridine), CMX-g-P(4VP) toward its potential application as high-performance absorbent for removal of Acid Orange 10 dye (acidic azo dye), 7-Hydroxy-8-phenylazo-1,3-naphthalenedisulfonic acid disodium salt (Figure 1) and Cr(VI) ions from aqueous solution. The introduction of pyridine moiety via the grafting technique provides more active sites besides the OH and COOH groups of CMX.…”