We prepared low-density polyethylene (LDPE) nanofiber, a few hundred nanometers in diameter, using polyvinyl butyral (PVB) and a laser melt-electrospinning (M-ESP) device. We blended PVB with LDPE via an internal melt mixer, removed the PVB after M-ESP by ethanol treatment, and studied the influence of PVB on fiber diameter. A substantial diameter reduction with improved crystallinity of LDPE fiber was observed with increased PVB content in the blend. PVB inclusion also increased the polarity of the LDPE/PVB blend, resulting in better spinnability. The removal of PVB from LDPE/PVB blend fiber caused a massive drop in the LDPE fiber diameter, due to fiber splitting, particularly in PVB-rich samples. Fourier transform infrared (FTIR) spectroscopy of fibers confirmed that the prepared nanofiber was the same as pure LDPE fiber.

The ultimate functionality and applicability of polymeric nanofibers are mainly to subject on its diameter. This study explores the influence of melt flow rates (MFRs) of low-density polyethylene (LDPE) on the diameter of laser melt electrospun nanofibers. Ethylene-vinyl alcohol (EVOH) copolymer was added to the nonpolar LDPE as a spinning aid. After electrospinning, the EVOH was removed from LDPE/EVOH blend fiber by treating with isopropanol/water solution and LDPE nanofiber was obtained with a diameter of only 190 ± 85 nm for the highest MFR. A linear diameter reduction was observed for pure LDPE and EVOH removed LDPE fiber with the increase of MFR. However, a slight diameter increment was reported for the LDPE/EVOH blend fiber with higher MFR due to the improved melt viscosity of the component. A massive diameter decrement was found after EVOH removal from the blended fiber, resulting in the renovation of microfiber to a stable nanoscale dimension.

A fibrous membrane being prepared from nanofiber is of great demand for super‐efficient filtration of industrial wastewater. This study reported a highly efficient noanofibrous membrane made of superfine polypropylene (PP) nanofiber with an average diameter of only 228 nm and that had also demonstrated a direct influence of fiber diameter on its properties and performance for textile wastewater purification. The PP nanofibers were prepared with a varying content of PP/ethylene‐co‐vinyl alcohol (EVOH) blends from which the EVOH matrix was removed after electrospinning. Subsequently, the PP nanofibrous membranes were manufactured using the prepared PP nanofibers via a simple wet‐laid process. The fiber diameter turned out to be an important factor in the surface properties and pore characteristics of the PP nanofibrous membrane. The finer PP nanofiber constructed a compact fibrous mesh structure of the membrane leading to an optimum porosity, a high hydrophobicity, and a smaller mean pore size with a narrower distribution. The filtration performance of the nanofibrous membrane for dyeing wastewater has also evidenced the potentiality of the finer PP nanofiber. Moreover, in comparison with the commercial PP fibrous membrane, the developed PP membrane was found to be more promising.

The image designed by Mohammad Zakaria and colleagues shows the influence of melt flow rates (MFR) of low‐density polyethylene (LDPE) on the diameter of laser melt electrospun nanofibers. A massive reduction of LDPE fiber diameter with increased MFR was revealed for EVOH removal from LDPE/EVOH blend fiber. The cover shows the SEM micrograph of as‐spun fibers prepared from pure LDPE with different MFRs (13, 23, 45, 70 and 145 g / 10 min) and pure EVOH. Pure LDPE also tends to reduce in fiber diameter as MFR increased. Due to the polarity, finer EVOH fibers were obtained despite low MFR. DOI: https://doi.org/10.1002/app.50282

The image created by Mohammad Zakaria and colleagues depicts a super‐efficient nanofibrous membrane made of ultra‐fine polypropylene nanofiber. The membrane's compact fibrous mesh structure was created using PP nanofiber, resulting in optimal porosity, good hydrophobicity, and a smaller mean pore size with a narrower distribution. The nanofibrous membrane's filtration performance for dyeing wastewater has also demonstrated the potential for finer PP nanofiber. The developed nanofibrous membrane, which filtered wastewater very close to drinking water, rejected 99.95 percent of the color. The commercial PP membrane, on the other hand, can only reject 17.38 percent of color from wastewater. DOI: https://doi.org/10.1002/app.52657