Modified Calix[4] Resorcinarenes Oligomer as Adsorbent in Dye Adsorption: Investigation of Optimal Adsorption Conditions

Calix [4] resorcinarene belongs to the calixarenes group. Calix is synthesized via a condensation reaction of resorcinol and aldehydes in acidic conditions. These compounds can be suitable hosts for cations, anions, or neutral molecules. Selective absorption can be created in them by modifying and creating side groups. This research decided to study the optimal conditions for the absorption of cationic blue 41 dye by modified calix[4] resorcinarene oligomer. The optimal conditions were determined using the response surface methodology with three variables: adsorbent amount, time, and pH. The results showed that in the adsorption of dye by modified calix[4], resorcinarene oligomer is the most positive linear effect related to the adsorbent, followed by the time of adsorption process; however, pH has little effect. Also, for more than 61 % absorption, 3.9 % by weight of the adsorbent is required in 180 minutes or 5 % by weight in 127 minutes. Also, with the obtained contour diagram, the adsorption efficiency can be predicted with the amount of adsorbent and time.