نوع مقاله : یادداشت فنی
نویسندگان
1 دانشکده مهندسی معدن دانشگاه یزد
2 عضو هیئت علمی/دانشگاه یزد
3 گروه مهندسی پلیمر دانشگاه یزد
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
This study investigates the influence of the hydrophilic characteristics of nonylphenol ethoxylate (NPE) plasticizers on the performance of polymer inclusion membranes (PIMs) used for uranium transfer. Specifically, it examines how the ethoxylation degree of NPE plasticizers affects the kinetics and stability of PIMs containing di-(2-ethylhexyl)phosphoric acid (D2EHPA) as a carrier. PIMs were fabricated using polyvinyl chloride (PVC) as the polymeric support, incorporating NPE plasticizers with varying ethoxylation degrees to manipulate membrane hydrophilicity.
The research focuses on assessing uranium extraction efficiency and membrane longevity under different operational conditions. Results indicate that the hydrophilic/hydrophobic balance of the NPE plasticizer plays a critical role in determining uranium transfer rates and membrane stability. Increasing the ethoxylation degree enhances membrane hydrophilicity, accelerating the complexation of uranium with D2EHPA at the membrane interface. However, this increased hydrophilicity also leads to greater water uptake, causing plasticizer leaching and a decline in membrane mechanical strength and overall lifespan.
Conversely, using NPE plasticizers with lower ethoxylation degrees results in more hydrophobic membranes. These membranes exhibit slower uranium transfer kinetics but demonstrate superior stability, resisting plasticizer loss and maintaining structural integrity for extended periods. The findings suggest that optimizing the ethoxylation degree is essential to achieve a balance between efficient uranium transfer and long-term membrane stability. Spectroscopic analyses and scanning electron microscopy (SEM) were employed to characterize the distribution of the plasticizer within the PVC matrix and to observe morphological changes in the membrane upon exposure to uranium.
Molecular dynamics simulations were conducted to provide a deeper understanding of the interactions between PVC, NPE plasticizers, D2EHPA, and uranium complexes. These simulations offer insights into the mechanisms that govern uranium transfer and influence membrane stability. This study contributes valuable information for designing high-performance PIMs tailored for uranium extraction, highlighting the importance of carefully considering the trade-offs between kinetic efficiency and operational lifespan.
کلیدواژهها [English]
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