Funkcionalizacija površine implantne titanijeve legure kalcij-fosfatnim prevlakama

master's thesis

• Title (english): Surface functionalization of titanium implant alloy by calcium-phosphate coatings
• Author: Elizabeta Rajič
• Mentor: Jozefina Katić (mentor)
• Committee member: Jozefina Katić (predsjednik povjerenstva)
• Committee member: Marijana Kraljić Roković (član povjerenstva)
• Committee member: Dajana Kučić Grgić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2021-07-09, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Chemistry

Abstract

Titanij i njegove legure su najčešće korišteni metalni implantni materijali, a odlikuju ih svojstva kao što su biokompatibilnost, korozijska otpornost, osteointegracija i dobra mehanička svojstva. U ovom radu ispitana je komercijalna legura Ti–6Al–7Nb koja je razvijena kao zamjena za komercijalnu leguru Ti–6Al–4V jer je otkriveno kako vanadij ima iznimno loš učinak na neurološki i dišni sustav te je povezan s pojavom Alzheimerove bolesti. Dobra korozijska otpornost legure, jedan od osnovnih preduvjeta biokompatibilnosti, temelji se na spontano formiranom oksidnom filmu titanija na površini legure. Uslijed dugotrajnog izlaganja agresivnom biookolišu ljudskog tijela može doći do degradacije tog zaštitnog filma, a i titanijeve legure pokazuju visoku razinu bioinertnosti. Stoga se, s ciljem poboljšanja korozijske otpornosti, ali i biokompatibilnosti, bioaktivnosti i stupnja osteointegracije, površina titanijevih implantata modificira prevlakama bioaktivnog kalcijeva fosfata (Ca-P) što je i bila tema ovog rada. Funkcionalizacija površine implantne titanijeve legure Ti-6Al-7Nb provedena je elektrokemijskom metodom depozicije potpomognute katodnim potencijalom (elektrodepozicijom). Uvjeti potenciostatske elektrodepozicije određeni su na temelju rezultata cikličke voltametrije (CV). Elektrokemijska in vitro ispitivanja nemodificiranih i modificiranih površina legure Ti-6Al-7Nb provedena su pod realnim uvjetima primjene u simuliranoj fiziološkoj otopini, Hanksova otopina. Korozijski parametri određeni su metodama elektrokemijske impedancijske spektroskopije (EIS), Tafelovom metodom te linearnom polarizacijom (Mansfeldova metoda). Površinska karakterizacija legure provedena je Fourier pretvornom infracrvenom spektroskopijom uz tehniku snimanja prigušenom totalnom refleksijom (ATR-FTIR) i pretražnom elektronskom mikroskopijom (SEM). Na temelju rezultata ispitan je utjecaj modifikacije površine Ca-P depozitom na korozijsko ponašanje legure Ti-6Al-7Nb i provedena je optimizacija uvjeta postupka elektrodepozicije.

Abstract (english)

Titanium and its alloys are the most commonly used metal implant materials due to their favorable characteristics such as biocompatibility, corrosion resistance, osseointegration and good mechanical properties. In this work, a commercial Ti–6Al–7Nb alloy was investigated, developed as alternative for a commercial Ti–6Al–4V alloy since vanadium was found to have an extremely bad effect on the neurological and respiratory body systems and was associated with Alzheimer's disease. Good corrosion resistance of the alloy, one of the basic prerequisites for biocompatibility, is based on the spontaneously formed titanium oxide film on the surface of the alloy. However, prolonged exposure to the aggressive bioenvironment of the human body fluids can lead to degradation of this protective film, and titanium alloys also show a high level of bioinertness. Therefore, in order to improve corrosion resistance, but also biocompatibility, bioactivity and the degree of osseointegration, the surface of titanium implants is modified by bioactive calcium phosphate (Ca-P) coatings, which was the topic of this work. The surface functionalization of the implant titanium alloy Ti-6Al-7Nb was performed by the electrochemical method of cathodic potential assisted deposition (electrodeposition). Potentiostatic electrodeposition conditions were determined based on cyclic voltammetry (CV) results. Electrochemical in vitro tests of unmodified and modified Ti-6Al-7Nb alloy surfaces were performed under real conditions of application in simulated saline, Hanks' solution. Corrosion parameters were determined by electrochemical impedance spectroscopy (EIS), Tafel method and linear polarization (Mansfeld method). Surface characterization of the alloy was performed by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) imaging technique and scanning electron microscopy (SEM). Based on the results, the influence of Ca-P deposit surface modification on the corrosion behavior of Ti-6Al-7Nb alloy was investigated and the conditions of the electrodeposition process were optimized.

• Keywords: biomedicinski metalni implantni materijali; korozijska otpornost; biokompatibilnost; titanij; TiAlNb; TiO2; kalcijevi fosfati; elektrodepozicija; EIS; Tafelova metoda; linearna polarizacija; ATR-FTIR; SEM
• Keywords (english): biomedical metal implant materials; corrosion resistance; biocompatibility; titanium; TiAlNb; TiO2; calcium phosphates; electrodeposition; EIS; Tafel method; linear polarization; ATR-FTIR; SEM
• Language: croatian
• URN:NBN: urn:nbn:hr:149:974879
• Study programme: Title: Applied Chemistry - Graduate study; specializations in: Environmental chemistry and green technologies, Advanced materials and technologies, Applied organic chemistry; Course: Applied organic chemistry; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra primijenjene kemije (magistar/magistra primijenjene kemije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2023-04-06 14:23:56