Majid Habibi Mohraz, Farideh Golbabaei, Il Je Yu, Asghar Sedigh Zadeh, Mohammad Ali Mansournia, Somayeh Farhang Dehghan,
Volume 8, Issue 1 (4-2018)
Abstract
Introduction: Electrospun nanofibers are suitable option to synthesize filtering mats for nanoparticles. This study was aimed to fabricate polyurethane nanofiber mats through electrospinning process and to investigate the effect of different parameters such as packing density, face velocity and particle type on the filtration efficiency and quality factor of electrospun polyurethane nanofiber mats.
Material and Method: The nanofiber mats were produced by electrospinning process. Polyurethane granules were dissolved (15w/w%) in a solvent system consisting of dimethylformamide and tetrahydrofuran (3:2). Then, the filtration performance testing system was made at the Fluid Mechanics Department of Hanyang University of South Korea and the filtration efficiency and pressure drop of prepared nanofiber mats were studied.
Result: Findings showed that by increasing the duration of electrospinning, the basis weight, thickness, packing density, initial pressure drop and filtration efficiency of the mats increased, and the quality factor of the mats decreased due to the increase of the pressure drop. The increase in electrospinning duration from 15 to 45 minutes was led to the increase in pressure drop from 7 to 32 Pa and the average filtration efficiency was increased about 9-10% for KCl and DEHS test particles. The filtration efficiency and quality factor of the prepared polyurethane nanofiber mats were declined with the increase of filtration face velocity from 2 to 5 and 10 cm/s. The reduction in filtration efficiency was more obvious for particles smaller than 425 nm.
Conclusion: The results demonstrated that prepared polyurethan naofiber mats provide acceptable filtration performance. What is more, such nanofiber mats can have other potential benefits such as light basis weight, low thickness and simple production.
Adel Jafari, Farshid Ghorbani Shahna, Abdulrahman Bahrami, Majid Habibi Mohraz,
Volume 13, Issue 2 (6-2023)
Abstract
Introduction: With the spread of the COVID-19 pandemic and the lack of adequate protection by existing protective equipment, many researchers’ attention has turned to developing improved respiratory protection equipment. Considering their special properties and nanoscale dimensions, electrospun nanofibers are a suitable option for improving operational characteristics of substrates used in conventional facemasks. This study aimed to optimize the electrospinning process of polyacrylonitrile nanofibers (PAN) containing ZIF8 and use the optimized substrate in medical facemasks to increase their protective performance.
Material and Methods: This study employed an environmentally friendly method to synthesize ZIF8 in an aqueous environment. Then, PAN/ZIF8 polymer solutions were prepared in dimethylformamide. The effects of electrospinning parameters, including electrospinning voltage, polymer solution concentration, electrospinning distance, and polymer injection flow rate on diameter and uniformity of nanofibers were investigated. Electrospinning conditions were optimized using response surface methodology (RSM) and central composite design (CCD) to obtain desired values for response (dependent) variables. Finally, optimized PAN/ZIF8 and PAN nanofibers were electrospun on spun-bond substrate. Base weight, average diameter of fibers, filtration performance, pressure drop, and quality factor of fabricated substrates were assessed.
Results: According to results, optimal conditions for electrospinning of PAN/ZIF8 polymeric solution for polymer concentration (A), electrospinning voltage (B), electrospinning distance (C), and polymer injection flow rate (D) were respectively 70 w/v%, 20 kV, 18 cm, and 0.4 ml/h. Moreover, despite lower base weight of PAN/ZIF8 nanofiber mask, it displayed higher filtration performance (98.51%), lower pressure drop (31.42 Pa), and higher quality factor (0.140 Pa-1) in comparison to other studied masks.
Conclusion: Experimental models developed in this study provide acceptable values for filtration efficiency and quality factor for filtration applications. Additionally, they serve as a guideline for subsequent experiments to produce uniform and continuous nanofibers with desired diameter for future applications in absorbent media (intermediate absorbent layers) of respirators.