Click synthesis and dye extraction properties of novel thiacalix[4]arene derivatives with triazolyl and hydrogen bonding groups

Using a click reaction between alkynylthiacalix[4]arene and ethyl 2-azidoacetate followed by an ammonolysis with ethanolamine,leucinol and hydrazine hydrate,respectively,three novel thiacalix [4]arene derivatives 4,5 and 6 with triazolyl and hydrogen bonding groups（NH and OH） were synthesized in high yields.They exhibited excellent extraction capability for six anionic and cationic dyes.The flexible cavity,π-triazole rings and hydrogen bonding groups all play crucial roles in dye complexation.

Extraction of Dyes from Sunflower Petal and Their Fourier Transform Infrared Characterization

Three solvents of different polarities(water,methanol and 1%NaOH solution)were used to extract dyes that produced different shades from dried sunflower(Helianthus annuus)petal.The extraction procedures using different solvent types were carried out separately.The dye extracts were thereafter subjected to Fourier Transform Infrared Spectrometry(FT-IR)analysis for characterization in terms of functional groups.The intensities of the extracted dyes on the shade of colours obtained on pieces of cotton material varied from yellow in methanolic extract to light yellow in aqueous and black in 1%NaOH solution extracts.The results obtained from the FT-IR analysis revealed the presence of several useful functional groups such as N-H,C=H,O-H and C=O in the extracts.

Efficient removal of naphthalene-2-ol from aqueous solutions by solvent extraction

Naphthalene-2-ol is a typical biologically recalcitrant pollutant in dye wastewater.Solvent extraction of naphthalene-2-ol from aqueous solutions using mixed solvents was investigated.Various extractants and diluents were evaluated,and the effects of volume ratio of extractant to diluent,initial p H,initial concentration of naphthalene-2-ol in aqueous solution,extraction time,temperature,volume ratio of organic phase to aqueous phase（O/A）,stirring rate and extraction stages,on extraction efficiency were examined separately.Regeneration and reuse of the spent extractant were also investigated.Results showed that tributyl phosphate（TBP） achieved 98% extraction efficiency for naphthalene-2-ol in a single stage extraction,the highest among the 12 extractants evaluated.Extraction efficiency was optimized when cyclohexane and n-octane were used as diluents.The solvent combination of 20% TBP,20% n-octanol and 60% cyclohexane（V/V） obtained the maximum extraction efficiency for naphthalene-2-ol,99.3%,within 20 min using three cross-current extraction stages under the following extraction conditions：O/A ratio of 1：1,initial p H of 3,25°C and stirring rate of 150 r/min.Recovery of mixed solvents was achieved by using 15%（W/W） Na OH solution at an O：A ratio of 1：1 and a contact time of 15 min.The mixed solvents achieved an extraction capacity for naphthalene-2-ol stably higher than90% during five cycles after regeneration.