Low-temperature, chemical vapor deposition of thin-layer pyrolytic carbon coatings derived from camphor as a green precursor

• Published in: Journal of materials science 2018, Vol.53 (2), p.959-976
• Main Authors: Sheikholeslami, Zeinab Sadat, Yousefi, Mohammad, Imani, Mohammad, Joupari, Morteza Daliri
• Format: Article
• Language: English
• Subjects: Biocompatibility; Biomaterials; Blood cells; Camphor; Carbon; Characterization and Evaluation of Materials; Chemical vapor deposition; Chemistry and Materials Science; Classical Mechanics; Coated electrodes; Coatings; Coefficient of friction; Contact angle; Crystallography and Scattering Methods; Free energy; Industrial applications; Low temperature; Materials Science; Modulus of elasticity; Nanoindentation; Organic chemistry; Polymer Sciences; Precursors; Pressure; Raman spectroscopy; Solid Mechanics; Temperature; Thickness; Thin films
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-017-1590-8

Camphor, C 10 H 16 O, as a natural and renewable carbon precursor, can be pyrolyzed to pyrolytic carbon (PyC; pyrocarbon) with significant industrial applications from conducting electrodes to biomedical implant coatings. Here, a simple but controllable chemical vapor deposition setup, operating at low temperatures (650–800 °C) in nitrogen atmosphere at ambient pressure in the absence of catalyst, was used. According to XRD and Raman spectroscopy, nanocrystalline thin PyC films were obtained at this temperature range without a significant change in L c and d 002 values. When the deposition temperature increased from 700 to 800 °C, L a and crystallinity percentage values were increased from 2.40 nm and 73.16% to 4.15 nm to 87.58%, respectively. SEM and AFM analyses showed smooth ( Ra  ≈ 1 nm) and shiny surface for the thin films with 10–500-nm range thickness. The films were hydrophilic on surface (water contact angle ≈ 72.45°) with surface free energy of ≈ 41 mN/m. Young’s modulus, hardness and friction coefficient of the thin PyC coatings were calculated using nanoindentation technique as ≈ 29.9, 3.5 GPa and 0.09, respectively. Resistivity of the films was 2.21 × 10 −5  Ωm, so it can be anticipated to repel the blood cells. Cytocompatibility screening in direct contact mode and in vitro biocompatibility findings supported cyto- and hemocompatible properties for the PyC specimens synthesized from camphor.