Molecular insight into COF monolayers for urea sorption in artificial kidneys

Ahmad Miri Jahromi,Nima Rezaei,Mohammad Khedri,Sina Omrani,Reza Maleki,Mehdi Ghasemi

doi:10.1038/s41598-021-91617-1

Abstract

Urea removal from an aqueous solution is considered a challenge in the biological process. The state of complete kidney destruction is known as an end-stage renal disease (ESRD). Kidney transplant and hemodialysis are the most common methods for confronting ESRD. More recently, wearable artificial kidney (WAK) devices have shown a significant improvement in urea removal performance. However, low efficiency in physical adsorbents is a barrier in developing them. For the first time, the urea adsorption capacity of five types of last-generation covalent organic framework (COF) nanosheets (NSs) was investigated in this study by applying molecular dynamics (MD) simulation tools. To this end, different analyses have been performed to evaluate the performance of each nanoparticle. The MD all-atom (AA) results demonstrated that all introduced COF NSs had urea removal capacity. Among the five NSs, TPA-COF was shown to have the best outcomes. Moreover, coarse-grained (CG) and density functional theory (DFT) simulations were conducted, and the results show that the TPA-COF nanoparticle modified with –OH functional group has even better properties for urea adsorption. The present molecular study sheds new light on COF NSs as an adsorbent for urea removal.

Highlights

Urea has a vital role in industrial and biological processes, and it is the main by-product of protein metabolism
wearable artificial kidney (WAK) devices with the urea adsorption process mechanism have been introduced as a promising method to overcome end-stage renal disease (ESRD)
The results of Gibbs free energy, energy interaction, and the number of H-bonds illustrated the strongest attraction of urea molecules with TPA-covalent organic framework (COF), DAAQ-TFP, DAPH-TFP, Tp-PaSO3Li-COF, and PhOS-COF-1, respectively

Summary

Introduction

Urea has a vital role in industrial and biological processes, and it is the main by-product of protein metabolism. The fact is that some of these urea removal techniques are not either efficient or cost-effective[11] Some of these methods are still new and require more research and optimization because of equipment complexity or other industrial inapplicability[12]. The adsorption process can be considered as a cost-effective and straightforward technique among other urea removal methods It would be an attractive method for urea removal for both water purification and human body purposes. Some of the barriers reducing the performance of adsorbents can be eliminated, such as human incompatibility limitation that can be solved by using a semipermeable membrane that separates urea sorbent and blood[7] These drawbacks restrict the use of sorbent materials for urea adsorption, and the search for a new alternative still is a r equirement[11]. Further research should focus on introducing more effective sorbents so as to make WAK device feasible

Methods

Results

Conclusion