Plasma surface treatments of Al2O3/ZrO2 nanocomposites and their influence on the formation and adhesion of calcium phosphates

Author(s)

dos Santos, Katia Helena ^[1] ; Ferreira, Julieta Adriana ^[1] ; Osiro, Denise ^[1] ; Andrade da Conceicao, Gelson Jose ^[2] ; Colnago, Luiz Alberto ^[3] ; Alves Junior, Clodomiro ^[4] ; de Jesus Agnolon Pallone, Eliria Maria ^[1]

Affiliation

^[1] Univ Sao Paulo, Dept Biosyst Engn, Av Duque de Caxias Norte 225, BR-13635900 Pirassununga, SP - Brazil

^[2] Univ Sao Paulo, Dept Vet Med, Av Duque de Caxias Norte 225, BR-13635900 Pirassununga, SP - Brazil

^[3] Brazilian Agr Res Corp, EMBRAPA Instrumentat, Rua Quinze de Novembro 1500-1501, BR-13561206 Sao Carlos, SP - Brazil

^[4] Fed Univ Semi Arid Reg, UFERSA, Av Francisco Mota 572, BR-59625900 Mossoro, RN - Brazil

• Document type: Journal article
• Source: Applied Surface Science; v. 456, p. 552-560, OCT 31 2018.
• Web of Science Citations: 0

Abstract

In the present work, Al2O3/ZrO(2 )nanocomposite surfaces were treated with plasma under gaseous atmospheres with different proportions of N-2, H-2, and O-2 to improve the adhesion of biomimetically deposited calcium phosphate layers. Initially, samples of Al2O3/ZrO2 were shaped and sintered at 1500 degrees C for 2 h. Subsequently, the surfaces were treated and coated with calcium phosphate. The treated and untreated surfaces before and after the deposition of the biomimetic coatings were characterised using scanning electron microscopy, confocal microscopy, infrared spectroscopy, X-ray diffraction, and a scratch test. The results showed that pre-treatment increased the amount of calcium phosphates formed on the surface regardless of the gas composition used owing to the increase in polarity on the treated surfaces and formation of oxygenated groups such as Al-OH and Zr-OH. The phases of calcium phosphates formed were: hydroxyapatite (HA), alpha-tricalcium phosphate (alpha-TCP), and beta-tricalcium phosphate (beta-TCP). Although the HA phase was predominant, the alpha-TCP phase was responsible for increasing the adhesion of calcium phosphates onto the surface. Among the gaseous compositions used, the combination of 30% N-2, 50% H-2, and 20% O-2 favoured the highest formation of phosphates on the surface of the nanocomposite. (AU)

• FAPESP's process: 14/11100-9 - Study of adhesion and consistency of calcium phospate coating on alumina-zirconia nanocomposite
• Grantee: Kátia Helena dos Santos
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 15/07319-8 - Study ultra rapid sintering and low energy consumption: flash Sintering
• Grantee: Eliria Maria de Jesus Agnolon Pallone
• Support Opportunities: Regular Research Grants