Needle-like forms with a few tens of nanometer in diameter and more than a few tens of micrometer length, and specific oxygen state during In-flight glass melting

The special oxygen gas burner for the in-flight-melting method can produce glass within one second. The nature and the theoretical bases of this glass were not studied well. Then we observed this glass using a Raman spectra method, a soft X-ray absorption fine structure (XAFS) method, and a scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) method. We found the specific oxygen chemical states with a large pre-edge structure at around 533 similar to 534 eV in oxygen K-edge X-ray Absorption Near Edge Structure (XANES) spectra which were made in the 1000 kcal/kg-glass specific energy making process and collected at the most upper-stream in the in-flight path. This pre-edge shape of oxygen was much different from the soda-lime glass made with the crucible/tank furnace nor natural silicate glass (tectosilicates, phyllosilicates, nesosilicates). We also found the needle-like fibers with from a few tens of nanometer to sub-micron in diameter and with more than a few tens of micrometer length which were produced in the 1000 or 1200 kcal/kg-glass specific energy making process and collected at the most upper-stream in the in-flight path. (c) 2022 The Ceramic Society of Japan. All rights reserved.

Automated summary

This study observed and analyzed the glass produced by the in-flight-melting method using multiple techniques. It discovered specific oxygen chemical states and unique fiber structures that differ from traditional glass and natural silicate glass.