Abstract

Poly(N,N dimethylaminoethyl methacrylate) hydrogels (PDMAEMA) were optimized by pore-forming and copolymerization with polyethyleneimine (PEI) and the macroporous PDMAEMA together with the composite materials PEI/PDMAEMA were synthesized to remove anionic dyes from aqueous solution for the first time. The physicochemical properties of these materials were investigated by Fourier transform infrared spectroscopy (FT-IR), elemental analysis (E.A), thermogravimetric analysis (TGA) and scanning electron microscope (SEM). The adsorption behaviors of PDMAEMA, macroporous PDMAEMA and PEI/PDMAEMA for sunset yellow FCF and amaranth were compared. The results showed that the adsorption rate of macroporous PDMAEMA was faster than that of PDMAEMA, and the adsorption capacity was nearly unchanged; but for PEI/PDMAEMA, both adsorption rate and adsorption capacity were improved. The maximum adsorption capacity of PEI/PDMAEMA could reach 744.14 mg/g for SY FCF and 757.10 mg/g for amaranth, and the saturation adsorption time were both 1 h. The adsorption isotherms and kinetics were well fitted by Langmuir model and pseudo second-order model, respectively, and the adsorption mechanism was explained by electrical double layer theory. In addition, the desorption ratio of above 92% indicated that these adsorbing materials could be regenerated successfully for recycle and reuse. In a word, ED hydrogels have the excellent adsorption capability and could be employed as a new potential useful adsorbent for the decontamination and analysis of wastewater containing anionic dyes in large scale

Keywords

Polyethyleneimine, Polymers hydrogels, PEI/PDMAEMA, Anionic dyes, Adsorption