Electrospun Nanofibers: Preparation, Characterization and Atmospheric Fog Capturing Capabilities

This study was aimed at enhancing the capability of electrospun nanofiber mats to convert atmospheric fog into fresh water effectively. The demand for clean water has been increasing worldwide, and this problem can be addressed economically by utilizing new technologies. It is known that atmospheric fresh water found on the earth is about 0.03 % of the total global fresh water, which is more than enough to meet the demand for fresh water in many locations. Although desalination may produce a significant quantity of fresh water, it is a fairly costly, energy-intensive, and time-consuming process. In this research, the electrospinning method was used to fabricate superhydrophilic polyacrylonitrile (PAN) and polyvinyl chloride (PVC) nanofiber mats incorporated with hydrophilic polymers of polyvinylpyrrolidone (PVP), polyethylene glycol (PEG), and chitosan at various direct current (DC) voltages, pump speeds, and tip-to-collector distances, in order to evaluate their capability of capturing fresh water from atmospheric fog. Fourier transform infrared (FTIR) and Raman spectroscopy were used to characterize the chemical structures of the nanofibers, while scanning electron microscopy (SEM) and water contact angle measurement methods were used to determine the morphology and surface hydrophobicity, respectively, of the produced nanofibers. At higher concentrations of PVP, PEG, and chitosan (e.g., 16 and 32 wt%), most of the electrospun nanofibers were superhydrophilic, with water contact angle values less than 5 degrees in 0.5 seconds. Humidifier and humidity test chamber results indicated that superhydrophilic nanofibers could absorb up to 69 % of their weight in a shorter period of time. This scalable process can be extended to capturing a larger quantity of fresh water from the atmosphere.