Synthesis, Rheological Profiling, and Adsorptive Features of Sodium Alginate Grafted Polyacrylamide Composite Hydrogels

International Journal of Chemistry | Vol. 5, No. 11, November 2014 | pp. 81–88

DOI: 10.46882/2014/IJC/000074

Article Type: Original Research Paper

Title: Synthesis, Rheological Profiling, and Adsorptive Features of Sodium Alginate Grafted Polyacrylamide Composite Hydrogels

Names of Authors: J. K. Mensah¹, R. P. Sharma²*

Authors’ Affiliations:
¹Department of Chemistry, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
²Department of Chemistry, Indian Institute of Technology, Bombay, India.

Abstract: The development of durable biopolymeric hydrogel networks is essential for industrial wastewater treatment due to the requirement for specific structural coordination sites. This study describes the chemical synthesis and rheological optimization of a hybrid hydrogel fabricated via the free-radical graft copolymerization of acrylamide onto a high-viscosity sodium alginate backbone. The grafting reaction was initiated using potassium persulfate (KPS) and crosslinked via N,N'-methylenebisacrylamide (MBA) under optimized gas environments. Structural networks and morphology features were characterized using FT-IR spectroscopy, thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). Swelling kinetics were evaluated as a function of time, pH, and saline concentration. The hydrogel showed highly responsive pH-dependent swelling profiles, achieving a maximum water absorption capacity of 380 g/g at pH 8.0 due to structural carboxylate ionizations causing intermolecular chain repulsions. Rheological analysis confirmed strong non-Newtonian shear-thinning characteristics with a storage modulus (G') that remained constant up to 75°C. Batch adsorption tests showed high affinity for divalent nickel and zinc ions, matching the Langmuir isotherm with monolayer capacities of 64.2 mg/g and 78.4 mg/g at 298 K, confirming high remediation potential.

Keywords: Sodium alginate; Acrylamide; Graft copolymerization; Hydrogel; Rheological profiling; Heavy metal adsorption

Manuscript Timeline: Received: March 04, 2014; Revised: April 15, 2014; Accepted: May 20, 2014; Published: November 02, 2014.

Citation: Mensah, J. K., & Sharma, R. P. (2014). Synthesis, Rheological Profiling, and Adsorptive Features of Sodium Alginate Grafted Polyacrylamide Composite Hydrogels. International Journal of Chemistry, 5(11), 81–88.

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