Controlled morphology of electrospun nanofibers from waste expanded polystyrene for aerosol filtration

Abstract

This paper reports on the recycling of expanded polystyrene (EPS) waste to be repurposed as EPS nanofibrous mats for air filtration applications. The EPS nanofibrous mats were prepared via electrospinning technique. The EPS solutions for producing the mats were made by dissolving the EPS waste in dimethylformamide (DMF) and d-limonene solvents. The mixing ratio of DMF and d-limonene solvents were varied to obtain EPS solutions with different surface tension and viscosity. As a result, different fiber morphology (smooth fiber, wrinkled fiber, and beaded fiber) and diameter ranging from 314 nm to 3506 nm were obtained. The synthesized EPS nanofibrous mats were characterized by scanning electron microscope, Fourier-transform infrared spectroscopy, x-ray diffraction spectroscopy, differential scanning calorimetry, mechanical strength, porosity, and water contact angle measurement apparatus. The mechanical strength measurement exhibited that the beaded fiber had the highest tensile strength and the lowest elasticity compared to wrinkled and smooth fiber. The water contact angle measurement showed that the EPS nanofibrous mats were classified as ultra-hydrophobic, which was a good criterion for air filter media. Some filtration parameters of the EPS nanofibrous mats were measured, including particle collecting efficiency, pressured drop, and quality factor. The particle collecting efficiency of each EPS nanofibrous mats was measured using monodisperse polystyrene latex (PSL) particles and PM 2.5 from burning incense as the test particles. The EPS nanofibrous mats had a high collecting efficiency (up to 99.99%) and had a low pressure drop (below 70 Pa) for the face velocity of 5.4 cm s −1 . The quality factor of the EPS nanofibrous mats reached 0.10 for PSL filtration and 0.16 for PM 2.5 filtration. Overall, the EPS nanofibrous mats with controlled morphology were suitable to be used as air filtration media with high mechanical strength, ultrahydrophobic surface, and high quality factor.

Circulatory Management of Polymer Waste: Recycling into Fine Fibers and Their Applications

“…Expanded polystyrene (EPS) is one of the plastics most recycled into the form of micro or ultrafine fibers by conventional electrospinning for effective filter media. An air filter was developed by Rajak et al by recycling expanded polystyrene (r-EPS) waste to be repurposed as fine EPS fibrous mats using electrospinning [ 109 ]. The highest capture efficiency was achieved almost 100% by the fiber with the smallest diameter (314 nm), and the lowest efficiency was achieved at 70.4% by fiber with the largest diameter (3500 nm).…”

Advanced Design of Fiber-Based Particulate Filters: Materials, Morphology, and Construction of Fibrous Assembly

“…The ABS membrane was processable with solvents of dimethylacetamide, dimethylformamide, and tetrahydrofuran, and the resulting webs exhibited PM 2.5 filtration efficiency greater than 95%. Polystyrene filter webs were made from the recycled waste of high-impact polystyrene (HIPS) and expanded polystyrene (EPS), and the recycled webs showed the filtration efficiency greater than 99.99%, which was comparable to the commercial high-efficiency particulate air (HEPA) filter [ 98 , 99 ].…”

A superhydrophilic bilayer structure of a nylon 6 nanofiber/cellulose membrane and its characterization as potential water filtration media

“…The wettability of the bilayer membranes was investigated from the water contact angle (WCA) value measured by a contact angle measurement apparatus (Nachriebe 320, Nachriebe, Center for Aerosols and Analytical Instrumentation, Department of Physics, ITB, Bandung, Indonesia). 32,33 The water droplet (volume of 5 mL) images on the bilayer membrane surface were taken using a camera and it was digitally processed by an image processing soware to obtain the WCA values. The WCA measurements were carried out on the NFT1, NFT2, NFT6, NFT9, and NFNWS samples.…”