Deposition of cellulose acetate coatings on titanium substrates by electrospraying for biomedical applications

Abstract

Functional coatings have gained interest in the field of metal implants, as they reduce the complications associated with mechanical parameters and promote its integration. Among the other coating production methods electrospraying remains very little researched for this application despite its advantages. This study investigates the feasibility of the electrospraying method for the production of coatings with extended mechanical properties. Six biocompatible cellulose acetate coatings from solutions of (6–16) wt% were fabricated on titanium substrates using electrospraying. The layer thickness varied between the samples from 1.8 to 16.4 μm, while the roughness varied between the samples from 1 to 2 μm. Bending tests showed that the maximum elongation of the coatings between the samples gradually decreased from 40.00 % to 13.33 %. Stretching of detached films revealed decrease in tensile strength and elastic modulus from 58 to 30 MPa and from 2082 MPa to 978 MPa, respectively. Pull-off tests showed coatings adhesion strength of 0.8–1.4 MPa after sandblasting. Investigation of chemical composition and structure of the coatings using X-ray photoelectron spectroscopy, Fourier-transformed infrared and Raman spectroscopy showed results typical of cellulose acetate materials and confirmed that no structural changes took place during electrospraying. X-ray diffraction analysis revealed that the coatings obtained are amorphous. The coatings produced by the fast and cost-effective electrospraying process have competitive overall properties, while the coatings prepared from 10 and 12 wt% solutions are most suitable for use on titanium surfaces due to their mechanical properties and uniformity.