Study on superabsorbent composites. XXI. Synthesis, characterization and swelling behaviors of chitosan-g-poly(acrylic acid)/organo-rectorite nanocomposite superabsorbents

Investigation on the Effect of Poly(butylmethacrylate)/attapulgite Nanocomposites for Oil Absorption

  In this work, a series of novel polybutylmethacrylate (PBMA)/attapulgite (APT) were synthesized by suspended emulsion polymerization, using ethylene glycol dimethacrylate (EGDMA) as crosslinker. The nanocomposites were characterized by means of Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). The effects of polymerization variables including amount of initiator, amount of crosslinker, and APT content on oil absorbency were investigated, and the swelling kinetics in toluene and chloroform was also systematically evaluated. The results indicated that incorporating 7 wt% APT into PBMA polymeric network could enhance the oil absorbency and oil absorption rate of the oil-absorbing resin. Furthermore, the developed nanocomposites also exhibited good reusability and oil-retention capabilities. The nanocomposites are expected to find practical applications in the recovery of spilled oils and the treatment of wastewater.

Evaluation of ammonium removal using a chitosan-g-poly (acrylic acid)/rectorite hydrogel composite

This paper concerns the removal of ammonium ions (NH(4)(+)) from aqueous solution using a hydrogel composite chitosan grafted poly (acrylic acid)/rectorite prepared from in situ copolymerization. The effects of rectorite content, contact time, pH, NH(4)(+) concentration and temperature on the adsorption capacity were discussed. Langmuir, Freundlich, Tempkin and Redlich-Peterson isotherms were used to describe the experimental data. The results indicate that the adsorption equilibrium can be achieved within 3-5 min and, the hydrogel composite has a higher adsorption capacity for NH(4)(+) in a wide pH levels ranged from 4.0 to 9.0. No significant changes in the adsorption capacity are found over the temperature range studied. The adsorption mechanism of NH(4)(+) onto hydrogel composite was proposed, and the reusable ability of this hydrogel adsorbent was evaluated.