Interaction between effects of ambient parameters and those of other important parameters on electrospinning of PEI/NMP solution

Abstract

By electrospinning method, fibers are produced with diameters ranging from hundred nanometers up to a few micrometers. In this study, the influence of ambient temperature and relative humidity on the morphology of electrospun polyetherimide (PEI) fibers at varying electrospinning parameters such as solution concentration, applied voltage, and tip-to-collector distance was investigated. 1-methyl-2-pyrrolidinone was used as a solvent for PEI. Morphology and diameter of electrospun PEI fibers were examined by field-emission scanning electron microscopy. It was seen that 20 wt% of the PEI solution shows the most increase in average diameters from 30 to 70% RH at 15, 25, and 35°C. It was also seen that 20 wt% of the PEI solution shows the most decrease in average diameters from 15 to 35°C at each of the RH values. An interesting result was observed for 12 cm of tip-to-collector distance. The average fiber diameters firstly decreased from 15 to 25°C, and then increased from 25 to 35°C for all of the RH values.

Optimizing the electrospun parameters which affect the preparation of nanofibers

“…The electrospun solution was cellulose acetate (CA) dissolved in in acetone/dimethylformamide/ethanol (2:2:1) [82].Huang et al, reported that with increasing the relative humidity the average diameter fibers of electrospun poly(acrylonitrile) (PAN) solution witch dissolved in DMF increased, at conditions (concentration = 10% w/w, voltage = 28 KV, flow rate = 1mL/h and needle to collector distance =18 cm). Also they electrospunpolysulfone (PSU) with concentration 28% w/w and the same process conditions, found that average diameter of produced fiber increased with increasing relative humidity and fiber size distributions became broader [83].Oğulata and İçoğlu studied effect of relative humidity on morphology of electrospunpolyetherimide (PEI) solutions dissolved in 1-methyl-2 pyrrolidinone at conditions (concentration = 18% w/w, voltage = 20KV and needle to collector distance = 15cm). They observed that the average diameter of produced fiber increased by 103% with increasing relative humidity from 30% to 70%.…”

Effect of humidity on melt electrospun polycaprolactone scaffolds

“…In general, the results of this study suggests no significant difference in fibre thickness for scaffolds produced at either low or elevated humidities. This contrasts with the case of the effects of humidity on solution electrospinning, where numerous studies reported significant variations in fibre size and morphology Pelipenko et al [7]; Ogulata and Icoglu [8]; Bisht et al [9]; Lu and Xia [10]; Medeiros et al [11]; Casper et al [12]; Nezarati et al [13]. As solution electrospinning relies on solvent evaporation for fibre solidification, the effect of humidity could be expected to be more pronounced compared with melt electrospinning, where fibre solidification is due to polymer cooling.…”

“…Electrospinning is sensitive to environmental conditions such as temperature and humidity. This sensitivity has been well documented in several studies investigating the effect of humidity on solution electrospinning [7][8][9][10][11][12][13][14]. As the formation of fibres in solution electrospinning is through solvent evaporation following extrusion, the process is highly susceptible to the humidity [15].…”

“…However, when Medeiros et al [11] used polystyrene, poly(vinyl chloride), poly(methyl methacrylate), and poly(lactic acid) an increase in fibre size was observed with increases in RH. Ogulata and Icoglu [8] found increases in fibre size with increasing RH when polyetherimide was investigated between 30% and 70% RH. As RH increased further, droplets started to form with poly(vinyl alcohol), poly(ethylene oxide), poly(vinyl alcohol)/hyaluronic acid, poly(ethylene oxide)/chitosan and polystyrene as evaporation rates lowered [7,9,10].…”

A review of recent progress in polymeric electrospun nanofiber membranes in addressing safe water global issues

“…They found maximum increase in fiber diameter for 20% PEI solution at the range of relative humidity (RH) 30–70% and temperature at 15–35 °C and lowest diameter at 15–35 °C for all the humidity levels used. 38 Hence, both the optimum relative humidity and temperature are necessary to obtain defect free nanofibers.…”