# The Effect of the Fiber Diameter, Epoxy-to-Amine Ratio, and Degree of PVA Saponification on CO2 Adsorption Properties of Amine-Epoxy/PVA Nanofibers

## TL;DR

This paper studies how fiber diameter, chemical ratios, and PVA saponification affect CO2 capture performance of nanofibers for direct air capture.

## Contribution

The study introduces AE/PVA nanofibers with optimized properties for CO2 adsorption through controlled electrospinning and saponification.

## Key findings

- Thinner fibers increase CO2 adsorption kinetics due to higher surface area.
- Secondary amines balance adsorption capacity and desorption efficiency.
- Highly saponified PVA improves thermal durability by reducing side reactions.

## Abstract

Achieving carbon neutrality requires not only reducing CO2 emissions but also capturing atmospheric CO2. Direct air capture (DAC) using amine-based adsorbents has emerged as a promising approach. In this study, we developed amine-epoxy/poly(vinyl alcohol) (AE/PVA) nanofibers via electrospinning and in situ thermal polymerization. PVA was incorporated to enhance spinnability, and B-staging of AE enabled fiber formation without inline heating. We systematically investigated the effects of electrospinning parameters, epoxy-to-amine ratios (E/A), and the degree of PVA saponification on CO2 adsorption performance. Thinner fibers, obtained by adjusting spinning conditions, exhibited faster adsorption kinetics due to increased surface area. Varying the E/A revealed a trade-off between adsorption capacity and low-temperature desorption efficiency, with secondary amines offering a balanced performance. Additionally, highly saponified PVA improved thermal durability by minimizing side reactions with amines. These findings highlight the importance of optimizing fiber morphology, chemical composition, and polymer properties to enhance the performance and stability of AE/PVA nanofibers for DAC applications.