Functionalized cellulose with hydroxyethyl methacrylate and glycidyl methacrylate for metal ions and dye adsorption applications.

Biodegradable functionalized cellulose based graft copolymers, Cell-g-HEMA and Cell-g-HEMA-co-GMA have been synthesized through free radical polymerization. The graft copolymers are used as sorbents for the removal of Ni(II), Cu(II) and Pb(II) ions, cationic (malachite green, crystal violet) and anionic (congo red) dyes as a function of adsorption time, temperature, pH of medium and concentration of metal ions and dyes. The sorption capacities of polymeric adsorbents for all the adsorbates decrease in the order Cell-g-HEMA-co-GMA > Cell-g-HEMA > Pure cellulose.

Extraction of Cellulose Micro-Whiskers from Rice Husk: A Greener Approach.

Herein, we report a greener, total chlorine free, ultrasonic physicochemical process of extraction and purification of cellulose micro-whiskers from rice husk. The initial step involves the treatment of the rice husk with a concentrated aqueous alkali solution for the duration of 6 h at 80 °C in round bottom flask in order to completely dissolve lignin and silica. After alkali pretreatment, the product obtained was thoroughly washed with distilled water, filtered and dried.

Selective sorption of Fe(II) ions over Cu(II) and Cr(VI) ions by cross-linked graft copolymers of chitosan with acrylic acid and binary vinyl monomer mixtures.

Low-cost and environment-friendly polymeric adsorbents for sorption of heavy metal ions were synthesized by simultaneous graft copolymerization and cross-linking of acrylic acid alone and with comonomers glycidyl methacrylate, acrylamide and acrylonitrile onto chitosan using free radical initiator and cross-linker in aqueous medium. Structural aspects of cross-linked graft copolymers have been characterized by FTIR, SEM, TGA/DTA, XRD and swelling behavior at pH 2.2, 7.

Synthesis and characterization of graft copolymers of chitosan with NIPAM and binary monomers for removal of Cr(VI), Cu(II) and Fe(II) metal ions from aqueous solutions.

To develop pH responsive hydrogels, N-isopropylacrylamide (NIPAM) has been grafted on to chitosan by free radical initiation method using azoisobutrylnitrile (AIBN) as an initiator. The optimum grafting conditions were worked out for grafting of NIPAM onto 1g of chitosan by varying one reaction parameter at a time and keeping all other parameters constant. Binary monomers were grafted for five different concentrations of comonomers acrylic acid (AAc), acrylamide (AAm) and acrylonitrile (AN) at optimum grafting conditions evaluated for GMA alone onto chitosan.

Grafting of GMA and some comonomers onto chitosan for controlled release of diclofenac sodium.

In order to develop pH sensitive hydrogels for controlled drug release we have graft copolymerized glycidyl methacrylate (GMA) with comonomers acrylic acid, acrylamide and acrylonitrile, onto chitosan (Ch) by using potassium persulphate (KPS) as free radical initiator in aqueous solution. The optimum percent grafting for GMA was recorded for 1g chitosan at [KPS]=25.00 × 10(-3)mol/L, [GMA]=0.