Removal of basic dyes from aqueous solutions using calix[4]resorcinarene carboxylic acid derivatives

Water-insoluble calix[4]resorcinarenes derivative 1 and 2 were synthesized and used as sorbents to extract selected basic dyes rhodamine b (rb),methylen blue (mb) and methyl violet (mv). the isolated complex: calix[4]resorcinarene 1-dye were characterized by fourier transform infrared spectroscopy,fluorescence spectroscopy,pdrx and differential scanning calorimetric analysis. the dye adsorption experiments were carried out from an aqueous solution in a batch reactor. the effect of several parameters has been determined to obtain the best experimental conditions. the equilibrium adsorption data were interpreted using langmuir and freundlich isotherms models (best correlation: r2 > 0.997). the calculated maximum adsorption capacity (qmax) for the rb at 25 °c were 29.49 mg/g at ph=8.3. the mechanism of adsorption onto the calix[4]resorcinarene is considered to be due to a host-guest interaction between the dye and azo-calix[4]resorcinarene molecular cavity. the results showed that calix[4]resorcinarene (1) can be considered as potential adsorbents for basic dye from dilute aqueous solution.