SYNTHESS AND PROPERTIES OF MWCNT-HA COMPOSTE VA SOL-GEL

In the present study, bioceramic composite based hydroxyapatite (HAP) reinforced with carbon nanotubes (CNTs) was synthesized applying sol-gel technique. The dried gels were individually heated at a rate 5°C/min up to 600°C for 2 h in a muffle furnace in order to obtain HA-MWCNTs mixed powder. In this investigation, XRD, FT-IR, SEM, TEM/SAED/EDX and Raman spectroscopy were used. The influences of different dispersing agents (sodium dodecyl sulfate -SDS) as a benchmark for future dispersion experiments and excitation wavelength are discussed and the results are compared.Results showed that the synthesis of HA particles in the MWCNTs sol which was prepared in advance, leads to an excellent dispersion of MWCNTs in HA matrix.The results showed that the apparent average size of crystallites increased with increasing the percentage of CNTs. The average crystallite size of samples (at 600°C), estimated by Scherrer s equation was found to be ~50-60 nm that confirmed by TEM. CNTs kept their cylindrical graphitic structure in composite and pinned and fastened HAP by the formation of hooks and bridges. It is evident from transmission electron microscope (TEM) observations that the CNTs present in the matrix keep their multi-walled cylindergraphite structure.

Keywords:

Ceramic-Matrix composites , Nanostructures , CNT , sol-gel , SEM , TEM