Termodinamika procesa na međupovršini inertna tvar/vodena otopina elektrolita

doctoral thesis

• Title (english): Thermodynamics of processes at inert matter – aqueous electrolyte solution interface
• Author: Antun Barišić
• Mentor: Tajana Begović (mentor)
• Committee member: Davor Kovačević (predsjednik povjerenstva)
• Committee member: Snežana Miljanić (član povjerenstva)
• Committee member: Mario Vazdar (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Chemistry); Zagreb
• Defense date and country: 2020-11-12, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Chemistry
• Universal decimal classification (UDC): 54 - Chemistry. Crystallography. Mineralogy

Abstract

U sklopu disertacije ispitivane su različite kemijski inertne površine (politetrafluoreten, dijamant, grafit, grafen, ugljikove nanocijevi i staklasti ugljik) u dodiru s vodenom otopinom NaCl. Na temelju distribucijskog modela razvijen je termodinamički model koji opisuje procese koji dovode do nabijanja međupovršinskog sloja vode te su eksperimentalno određeni termodinamički parametri za proces izmjene hidronijevih i hidroksidnih iona između međupovršinskog sloja vode i ostatka vodene otopine. Termodinamički parametri su određeni preko temperaturne ovisnosti točke nul-naboja i izoelektrične točke. Istražene su koloidne čestice i kristalne plohe istih materijala te su rezultati međusobno uspoređeni. Točka nul-naboja inertnih čestica određena je potenciometrijskom masenom titracijom i kiselinsko-baznom titracijom guste suspenzije. Izoelektrična točka inertnih čestica određena je elektroforezom dok je izoelektrična točka kristalnih ploha određena mjerenjem potencijala strujanja. Konstruirane su monokristalne elektrode te je određena ovisnost površinskog potencijala o pH vodene otopine elektrolita. Mjerenjem elektrokinetičkog i površinskog potencijala pri različitim ionskim jakostima promatran je utjecaj protuiona na procese unutar međupovršinskog sloja vode. Računalnim simulacijama klasične molekulske dinamike simulirani su odabrani međupovršinski sustavi te je određena raspodjela molekula vode i iona uz izučavane inertne površine.

Abstract (english)

In the frame of this doctoral thesis various chemically inert surfaces (polytetrafluoroethylene, diamond, graphite, graphene, carbon nanotubes and glassy carbon) were investigated in contact with the aqueous NaCl solution. Based on the distribution model, a thermodynamic model was developed that describes processes which lead to charging of interfacial water layer. Thermodynamic parameters for the distribution of hydronium and hydroxide ions between inner layer and bulk of the solution have been experimentally calculated. These parameters were determined via the temperature dependence of the point of zero charge and the isoelectric point. Colloidal particles and crystal surfaces of the same materials were investigated and the results were compared with each other. The point of zero charge of inert particles was determined by the potentiometric mass titration and the acid-base titration. The isoelectric point of inert particles was determined by the electrophoresis while the isoelectric point of crystal surfaces was determined by the streaming potential measurements. Singlecrystal electrodes were constructed and the dependence of the surface potential on the pH of the aqueous electrolyte solution was determined. By measuring the electrokinetic and surface potential at different ionic strengths, influence of the counterions on the processes within the interfacial water layer was observed. Computer simulations of classical molecular dynamics simulated selected interfacial systems and determined the distribution of water molecules and ions along the studied inert surfaces.

• Keywords: inertne površine; molekularna dinamika; termodinamika površinskih reakcija
• Keywords (english): inert surfaces; molecular dynamics; thermodynamics of surface reactions
• Language: croatian
• URN:NBN: urn:nbn:hr:217:098632
• Promotion: 2020
• Study programme: Title: Doctoral study in chemistry; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor/doktorica znanosti, područje prirodnih znanosti, polje kemija (doktor/doktorica znanosti, područje prirodnih znanosti, polje kemija)
• Type of resource: Text
• Extent: 171 str. ; 30 cm
• File origin: Born digital
• Access conditions: Open access; Embargo expiration date: 2021-11-12
• Created on: 2020-12-11 09:24:03