Enhanced adsorption of methyl violet and congo red by using semi and full IPN of polymethacrylic acid and chitosan

• IPN type hydrogels were synthesized from polymethacrylic acid and chitosan.
• Both semi and full IPNs were synthesized and characterized.
• Adsorption of methyl violet and congo red dyes was studied with these gels.
• Semi IPNs showed high adsorption with good fitting to isotherms and kinetic models.

Semi and full interpenetrating polymer network (IPN) type hydrogels were prepared by free radical in situ polymerization of methacrylic acid in presence of chitosan using N,N′-methylene-bis-acrylamide (MBA) and glutaraldehyde (for full IPN) as crosslinker. Several semi and full IPN type hydrogels were prepared by varying initiator and crosslinker concentration and also monomer to chitosan mass ratio. These hydrogels were characterized and used for removal of methyl violet and congo red dye from water. Isotherms and kinetics of dye adsorption were also evaluated.