A Water-Soluble Epoxy-Based Green Crosslinking System for Stabilizing PVA Nanofibers

Abstract

With the ever-growing concern about environmental conservation, green production and water-based nanofibers have attracted more and more interest from both academic and industrial fields; nevertheless, the stabilization process of water-based nanofibers is primarily relying on the application of organic solvent-based crosslinking agents. In this work, we develop a green approach to fabricate water-resistant polyvinyl alcohol (PVA) nanofibers by using a water-based epoxy compound, N1, N6-bis(oxiran-2-ylmethyl) hexane-1,6-diamine (EH), as the crosslinker. This EH/sodium carbonate/sodium bicarbonate (CBS) solution system can break down large aggregates of PVA molecules into small ones and promote the uniform distribution of EH in the solution, resulting in the improved stability of crosslinked PVA nanofibers. We firstly report that the uniform dispersion of crosslinking agents in the electrospinning solution plays a vital role in improving the stability of spinning solutions and the water resistance of crosslinked PVA nanofibers by comparing crosslinking performances between water-based epoxy and conventional water-based blocked isocyanate (BI). This work could open up a novel strategy and green approach for the stabilization of water-based nanofibers.

Biotechnology of Nanofiber in Water, Energy, and Food Sectors

“…Water-based nanofibers are considered attractive alternatives to organic solvents, which are used during the electrospinning methods [45]. This kind of fiber can be applied to nanofibers such as water-resistant polyvinyl alcohol nanofibers [46], modified cellulose nanofibers [47], and cellulose succinate nanofiber [16]. Such hydrophilic cellulose nanofiber as a separator has a high porosity (60%), and a hydrophilic surface, which can enhance a strong electrostatic repulsion between facilitating ion transportation and fibrils and increase negative surface charges [16].…”

“…The microbial role in water treatment is noteworthy during water/wastewater processing. Many studies indicated this potential approach of applying microbes as immobilized carriers during wastewater treatment (e.g., [46,70,71]). Apart from microbial nanofibers, the microbial immobilization of wastewater treatment has proved its efficiency in removing and biodegradation of many types of wastewater pollutants for a low cost, highly efficient, high surface area, chemically and physically stable carriers, and excellent biological compatibility [72].…”

Physicochemical evaluation of polyvinyl alcohol films crosslinked with saturated and unsaturated dicarboxylic acids: A comparative study

“…2,9,10 Various crosslinkers are commonly utilized for this purpose, including dialdehydes, 11 boric acid, 12 genipin, 13 carboxylic acids, 14 and epoxy compounds. 15 Among them, carboxylic acids have emerged as promising crosslinkers due to their easy availability, environmental friendliness, cost-effectiveness, non-toxicity, biodegradability, and nonaccumulative nature. 16,17 Furthermore, the crosslinking of PVA with carboxylic acids involves an esterification process, with water being the primary by-product.…”

Low-temperature and efficient crosslinking of lyocell knitted fabric with an eco-friendly diepoxy agent for fibrillation resistance

“…Chitosan treated with the epoxy crosslinking agent had good acid resistance and hexavalent chromium absorption (Li and Tang 2016;Vakili et al 2018). Electrospun PVA nano bers were spun from a stable EH/PVA homogeneous viscous spinning solution (Zhang et al 2022). EH can react with the hydroxyl groups on the cellulose molecular chains to form ether bonds.…”