أستخلاص وفصل البلاديوم (II)الشبه كمي بواسطة بوليمر الأيثر التاجي "متعدد ثنائي بنزو-18-كراون-6"

Abstract

Abstract: This study included the extraction and separation of palladium(II) from its aqueous solutions, by using swelled polymer crown ether (PDB18C6), and included the following: After studying the factors that affect the extraction process for palladium ion in order to find the ideal conditions, it was found that; the palladium ion (II) is extracted when (pH=7), and the extraction percentage reaches its highest value (E%=91). It was noticed that, the extraction of palladium ion was impossible from high concentration [0.5M-3.0M] of the acidic medium (HCl , H2SO4 , HNO3), but gave extraction percentage (E%=63-64) at the concentration [0.01M] of the same acid. The percentage extraction of palladium from the alkaline medium (KOH , NaOH) was very low at [1.0M-3.0M], and it became (E%=51-48) at the concentration [0.01M]. It was found from experiments that the best shaking time was (60) minutes. It was also found that when adding ethanol, the best extraction percentage for palladium II was (E%=92), when the volume of ethanol in the aqueous phase was (40%V/V) at a temperature The extraction of palladium from natural medium salts (KCl , NaCl) and medium salt (NH4Cl) has reached highest (E%-69), (E%=80), at the (1.5M) concentration of both NaCl and KCl, respectively, and (E%=80) at the (0.01M) concentration of NH4Cl. The selectivity of saturated solid crown ether polymer towards the extraction of palladium(II) ion, in the present of positive ions and presence negative ions , was also studied. The effect of temperature and thermodynamics functions on the process of extraction of palladium(II) ions was studied, and it appeared that the extraction enthalpy , has a positive value, which means that the extraction process is endothermic. The free energy for extraction showed a negative value while its entropy showed a positive value at all temperature degrees, which means that the reaction is instantaneous. The separation of copper from palladium ions was carried out on a chromatographic column filled with the substance (Polydibenzo-18crown-6), which was treated previously with (2.0M) KOH solution, and using the same solution as a mobile phase to elute Pd (II) first. The process was performed on eight batches, each batch contained (10ml) from the mobile phase, copper was recovered from the column, using (1.0M) HCl in five batches, each (10ml) flow-rate was 1ml/min.