Calcium Phosphate Layers Deposited On Thermal Sensitive Polymer Substrates In Radio Frequency Magnetron Plasma Discharge

Calcium phosphate coatings were deposited on thermally sensitive polyprophylene substrates in radio frequency (rf) magnetron sputtering discharge. The steady state of the deposition plasma and its components were identified by deposition rate measurements and mass spectrometry. Low rf powers and deposition rates, with a 10 min plasma on/off temporal deposition scheme, were established as suitable experimental conditions for the deposition of calcium phosphate layers on the thermoplastic polymers. By scanning electron microscopy and atomic force microscopy, the influence of the polymer substrate heating to the surface coating topography was studied. The results showed that the thermal patterning of the polymers during the plasma deposition process favors the embedding of the calcium phosphate into the substrate, the increase of the coating surface roughness, and a good adherence of the layers. The layers generated in the 10 min plasma on/10 min plasma off deposition conditions were not cracked or exfoliated. The Fourier Transform Infrared spectra of the polyprophylene substrates presented similar molecular bands before and after the depositions of calcium phosphate layers.