Synthesis and performance evaluation of the aerogel-filled PET nanofiber assemblies prepared by electro-spinning

Abstract

This paper focuses on the potential use of sodium silicate based aerogels, instead of small precursor molecules, as a filler in the PET nanofibers (PNFs). For the first time, the aerogel micro-granules (AMG) were added to the electro-spinning solution of PET with successful embedding of them into the PET nanofibers. The evaluation of the samples was carried out by measuring 3M water repellency, sliding angle (SA), water contact angle (WCA), transmission spectroscopy, sound absorption, heat transfer, FTIR, BET, SEM, and AFM. The results indicate a successful synthesis of the AMG with a porosity of 91.8% and a surface area of 815 m² g⁻¹. By addition of the AMG to the electro-spinning solution of PET, the bead-on-string aerogel-filled nanofibers were produced. This was accompanied by a significant improvement in hydrophobicity, dye-ability, and insulation properties. The most hydrophobic sample was prepared with the addition of 2% AMG. After the fluorocarbon treatment of this sample, the WCA was increased from 130.1 to 147.2°, the 3M water repellency was changed from 1 to 10, and the SA was reduced from 90 to 5°. In comparison with the primary PNF, the addition of AMG to the PNF increased the dyeing rate and dye adsorption at equilibrium from 30% to 70% for Disperse Blue 56. This can be introduced as a low-temperature method for dyeing of PET fibers. Also, a decreasing trend in the heat transfer was observed from 21% (for the pure PNF) to 16.4% and 8.3% for 0.5AMG/PNF and 4AMG/PNF, respectively. The investigation of the acoustic properties showed a direct relationship between the amount of AMG in the pure PNF and the sound absorption coefficient (NAC). The comparison of the porous silica aerogel with a non-porous one has clearly shown a significant effect of the porosity on the different properties of the samples.