Investigating the effect of the hydrophilic property of NPE modifier on the kinetics and stability of the PIM containing D۲EHPA in Uranium transferring

In the present work, the extraction and separation of uranium from acidic phosphoric solutions using a polymer inclusion membrane (PIM) containing di(۲-ethylhexyl) phosphoric acid (D۲EHPA) as the carrier and polyvinyl chloride (PVC) as the polymer were studied. Different nonylphenol ethoxylates (NPE) were introduced as modifiers used in PIMs. Physicochemical properties of the resulting membranes were analyzed and correlated with their structure. The infrared analysis revealed the presence of intermolecular interactions between the base polymer and NPE, sustaining their good compatibility. The cross-section SEM images showed a dense structure for all studied membranes. However, the surface structure and hydrophilic/hydrophobic balance of the PIMs strongly depend on the NPE. The contact angle measurements indicated that the addition of NPE to the PVC membrane decreases the contact angle, indicating improved membrane wettability. The results of transport measurements showed that PIMs containing NPE are more efficient for uranium extraction than those with only D۲EHPA/PVC due to the plasticizing effect of the NPE. After investigating the best mathematical kinetics models for transport, the highest uranium transport flux (۰.۸۱×۱۰−۶ mol⋅m⁻²⋅s⁻¹) was measured for the PIM containing ۵ wt% of NPE۱۰. Moreover, the membrane with only ۵ wt.% of NPE۱۰ had improved reuse stability compared to the PVC-based membrane due to the hydration effect provided by the water molecules interacting with the polar hydroxyl groups of NPE.

کلیدواژه ها:

Polymer inclusion membrane ، D۲EHPA ، Nonylphenol ethoxylate ، plasticizer ، Flux