No abstract

Cellulose (Cel) was first chemically modified with thionyl chloride to increase its reactivity. In the next step CelCl was reacted with ethylenediamine (CelEn) and subsequently reacted with ethylene sulfide to obtain a solid substance, CelEnEs. The modification reactions were confirmed by elemental analysis, TG, XRD, (13)C NMR and FTIR. The chemically modified biopolymer CelEnEs had an order of divalent metal sorption of Pb(2+)>Cd(2+)>Ni(2+)>Co(2+)>Cu(2+)>Zn(2+), and the maximum adsorption capacities were found to be 6.282±0.023, 5.783±0.015, 5.561±0.017, 4.694±0.013, 1.944±0.062 and 1.733±0.020 mmol g(-1), respectively. The equilibrium data were fitted to Langmuir, Freundlich and Temkin models, and in general, the experimental data best fit the Freundlich model. This newly synthesized biopolymer proved to be a chemically useful material for cations removal from aqueous solution.

Hybrid pigments based on organo-saponite (cetyltrimethyl ammonium bromide (CTAB-Sap) and a commercial anthocyanin (ACN) dye, Crystal Red Grape, were prepared. The interactions between organic dye guest and hosts (including saponite and organo-saponite) were investigated by X-ray diffraction, transmission electron microscopy and Fourier transform infrared spectroscopy. The pigments exhibit different colors function of their host-guest interactions. The blue color of organo-clay-anthocyanin indicates the stabilization of quinoidal base form of the dye. The hybrids have good stability against visible light irradiation and basic pH conditions. These dyed materials are environmentally friendly and can be promising candidates in different application fields.