Utjecaj pH-vrijednosti na kemijsku postojanost čelika za ortopedske pločice

undergraduate thesis

• Title (english): Influence of pH value on the chemical stability of steel for orthopaedic plates
• Author: Sara Šambula
• Mentor: Vera Rede (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2022-03-02, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering

Abstract

U radu je provedena analiza utjecaja pH-vrijednosti simulirane fiziološke otopine na kemijsku postojanost čelika za ortopedske pločice. U teorijskom dijelu rada opisana je povijest biomaterijala, njihova općenita primjena, zahtjevi na svojstva te vrste biomaterijala koji se koriste za ortopedske implantate. U eksperimentalnom dijelu provedena je analiza kemijskog sastava i mikrostrukture te mjerenje mikrotvrdoće HV0,2 ortopedske pločice od nehrđajućeg čelika oznake X2CrNiMo17-2-2. Nakon 44-dnevnog izlaganja uzoraka u fiziološkoj otopini uzorcima je izmjeren gubitak mase, a masenom spektrometrijom ispitan je utjecaj pH-vrijednosti simulirane fiziološke otopine (Hanksove otopine) na koncentraciju otpuštenih iona nekih elemenata. pH-vrijednost fiziološke otopine varirana je od 4,07 do 7,21. Analizirani čelik ima austenitnu mikrostrukturu s malim udjelom delta-ferita (⁓5 %) i mikrotvrdoću oko 410 HV0,2. Nakon 44-dnevnog izlaganja uzoraka u otopinama, utvrđen je gubitak mase kod svih uzoraka. Masenom spektrometrijom uz induktivno spregnutu plazmu (ICP-MS) utvrđen je prirast koncentracije iona svih mjerenih elemenata osim silicija. Visoki stupanj linearne korelacije postoji između pH-vrijednosti otopine i koncentracije iona kroma, nikla, molibdena, mangana, bakra i željeza. pH-vrijednost otopine ne utječe na koncentraciju iona natrija, sumpora, fosfora i vanadija.

Abstract (english)

This paper examines the influence of the pH value of a simulated physiological solution on the chemical resistance of steel for orthopedic plates. The theoretical part of the paper describes the history of biomaterials, their general application, property requirements, and the types of biomaterials used for orthopedic implants. In the experimental part, the analysis of the chemical composition and microstructure as well as the measurement of microhardness HV0,2 of the orthopedic plate made of stainless steel, designated as X2CrNiMo17-2-2, were performed. After the samples were exposed to a physiological solution for 44 days, the mass loss was measured and the effect of the pH of the simulated physiological solution (Hanks solution) on the concentration of some of the ions released from the steel was determined by mass spectrometry. The pH of the physiological solution varied from 4,07 to 7,21. The analysed steel has an austenitic microstructure with a low amount of delta-ferrite (⁓5 %) and a microhardness of about 410 HV0,2. After the samples had been exposed to the solutions for 44 days, mass loss was observed in all samples. Inductively coupled plasma mass spectrometry (ICP-MS) showed an increase in the ion concentration of all measured elements except silicon. There is a high degree of linear correlation between the pH of the solution and the ion concentration of chromium, nickel, molybdenum, manganese, copper and iron. The pH of the solution has no influence on the ion concentration of sodium, sulphur, phosphorus and vanadium.

• Keywords: kemijska postojanost; pH-vrijednost; ortopedska pločica; fiziološka otopina
• Keywords (english): chemical resistance; pH value; orthopedic plate; physiological solution
• Language: croatian
• URN:NBN: urn:nbn:hr:235:728994
• Study programme: Title: Mechanical Engineering; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka strojarstva (sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka strojarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2022-02-24 21:33:11