V. Uluslararası Seramik, Cam, Emaye, Sır ve Boya Kongresi (SERES'21), Eskişehir, Turkey, 13 - 15 October 2021, vol.1, no.1, pp.63-64
In the present study, B4C-BN composite nanoparticles were synthesized via
sol-gel technique. Preceramic polymeric gels were prepared by condensation and
dehydration reaction of glycerin and boric acid. To investigate the effects of polymeric gel network on phase content and final morphology of synthesized particles,
different amounts of ammonium polyacrylate were used as a gel dispersing agent.
The thermal behaviour of condensed gel products was analysed by using DTA/TG.
The chemical structure of the gels was inspected with fourier-transform infrared
spectroscopy in the 400–4000 cm-1 wavenumber region. The precursors were
obtained by the preceramic polymeric gels in a muffle furnace at 675◦C for 2 hours.
Then, the grounded precursors were subjected to a final heat treatment at 1500◦C
for 5h in argon flow. Morphology and phase content of as-synthesized powders were
characterized by using SEM and XRD techniques, respectively.
The results indicate that borate ester bonds (B-O-C) were successfully formed during the polymerization of glycerin and boric acid-based gel. In addition to borate
esters, (B-N-O) bonds were seen in the FT-IR results of ammonium polyacrylatecontaining gels network. Highly crystalline, polyhedral-equiaxed boron carbide
nanoparticles were produced from the polymeric gel without ammonium polyacrylate addition. As a result of the preliminary formation of (B-N-O) bonds,
B4C-BN composite nanoparticles were obtained from compositions containing
ammonium polyacrylate. It is also observed that the particle size of as-synthesized
particles is reduced by increasing the amount of ammonium polyacrylate. So,
controlling the particle size and phase content of synthesized powders by sol-gel
technique could be possible by tailoring the molecular structure of the condensed gel.