الفهرس 
Title : Modification of xanthan gum for various applications
AbstractOnly 14 pages are availabe for public view
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Abstract
Magnetic responsive hydrogels (CMX-cl-P4VP/M-NPs) were successfully synthesized through an in-situ co-precipitation procedure. The base copolymer hydrogels were constructed from the grafting of 4-vinyl pyridine (4VP) onto carboxymethyl xanthan (CMX) in the presence of N, N′-methylene bisacrylamide (MBA) as a chemical cross-linker. The prepared CMX-cl-P4VP hydrogels were loaded with different amounts of M-NPs and used to remove AO-10 dye and Cr(VI) ions from the aqueous solution. The physicochemical properties of the nanocomposite were investigated using FTIR, XRD, SEM/EDX, TEM, and TGA techniques. The effects of different parameters were studied systematically. The outcomes of the batch adsorption demonstrated that the adsorbent hydrogel incorporated with a low percentage (10%) of magnetite nanoparticles had a strong affinity for the removal of AO-10 dye and Cr(VI) ions at optimum pH = 3, and the removal percentage reached 99.3 and 97.4% for 500 mg L-1 and 300 mg L-1 of AO-10 dye and Cr(VI) within 90, 50 min, respectively. The adsorption kinetics data was well described by pseudo-first-order kinetics. The maximum adsorption capacities of AO-10 dye and Cr(VI) ions onto adsorbent were found to be 2449 and 575 mg g−1 at 298 K, calculated from the Langmuir model. The calculated thermodynamics parameters evidenced an exothermic nature and spontaneous adsorption process, ascribed to the negative values of ΔHo and ΔGo. The reusability of the nanocomposite was studied for up to five cycles using dilute NaOH as eluent, with a slight decrease in adsorbent efficiency.