Chitosan/PEO nanofibers electrospun on metallized track-etched membranes: fabrication and characterization

Abstract

The development of next-generation adsorption, separation, and filtration materials is growing with an increased research focus on polymer composites. In this study, a novel blend of chitosan (CS) and polyethylene oxide (PEO) nanofiber mats was electrospun on titanium (Ti)-coated polyethylene terephthalate (PET) track-etched membranes (TMs) with after-treatment by glutaraldehyde in the vapor phase for enhancing the nanofiber stability by crosslinking. The prepared composite, titanium-coated track-etched nanofiber membrane (TTM-CPnf) was characterized by Fourier transform infra-red (FTIR), water contact angle, and scanning electron microscopy (SEM) analyses. Smooth and uniform CS nanofibers with an average fiber diameter of 156.55 nm were produced from a 70/30 CS/PEO blend solution prepared from 92 wt. % acetic acid and electrospun at 15 cm needle to collector distance with 0.5 mL/h flow rate and an applied voltage of 30 kV on the TTM-CPnf. Short (15 min) and long (72 h)-term solubility tests showed that after 3 h, crosslinked nanofibers were stable in acidic (pH ¼ 3), basic (pH ¼ 13), and neutral (pH ¼ 7) solutions. The crosslinked TTM-CPnf material was biocompatible based on the low mortality of freshwater crustaceans Daphnia magna. The composite membranes comprised of electrospun nanofiber and TMs proved to be biocompatible and may thus be suitable for diverse applications such as dual adsorptionefiltration systems in water treatment.

The Investigation of the Production of Salt-Added Polyethylene Oxide/Chitosan Nanofibers

“…Certainly, the decrease in conductivity can be attributed to the inherent properties of PEO, considering it is a non-ionogenic polymer. PEO typically lacks ionizable groups along its molecular structure, which results in a lower ability to facilitate the movement of ions, consequently leading to reduced electrical conductivity in solution [ 11 ]. It is known from previous research [ 12 ] and literature reviews [ 8 , 9 ] that solutions of chitosan (CS) tend to exhibit higher conductivity compared to PEO due to the polyelectrolytic nature of chitosan.…”

“…Additionally, the substitution of a positively charged molecule (CS) by a neutral one (PEO) contributed to this decrease in electrical conductivity. These alterations facilitated the creation of a stable needle jet during the electrospinning process, preventing splaying of the jet in the stretching region [ 8 , 9 , 11 ].…”

“…When combined, these polymers interact without establishing any covalent bond formation between their molecular structures. The interaction between CS and PEO is primarily governed by non-covalent forces such as hydrogen bonding, electrostatic interactions, and van der Waals forces, enabling them to blend and intermingle without undergoing chemical bonding [ 11 ]. The interaction between chitosan (CS) and polyethylene oxide (PEO) can involve the formation of two distinct types of hydrogen bonds: the first type of hydrogen bond can occur between the ether oxygen atoms present in PEO and the hydrogen atoms associated with the quaternary ammonium group of chitosan; the second type of hydrogen bond involves interactions between the hydrogen atoms within the hydroxyl groups of chitosan and the ether oxygen atoms in PEO.…”

“…Numerous researchers are currently exploring the production methods of nanofibers derived from chitosan (CS) and its combinations, particularly with high molecular weight polyethylene oxide (PEO) [ 4 , 6 , 8 , 9 , 10 , 11 , 12 , 13 ]. However, despite these efforts, accurately anticipating the specific traits of these polymers and their behavior during the nanofiber manufacturing process remains a challenging task.…”

Development of Environment-Friendly Membrane for Oily Industrial Wastewater Filtration

“…There are plenty of reported methods in the literature to produce polymer-based membranes. For instance, stretching [ 22 ], sintering [ 23 , 24 ], phase inversion [ 25 , 26 ], and tracking etching [ 27 , 28 ]. However, all these techniques are time consuming, involve many steps, yield poor dispersion of GO, and might include large usage of non-environmentally friendly solvents, such as methyl ether ketone (MEK), tetrahydrofuran (THF), and chlorobenzene [ 29 , 30 , 31 ].…”