Određivanje brzine agregacije koloidnih čestica SiO2 i TiO2 metodom statičkog raspršenja svjetlosti

master's thesis

• Title (english): Determination of aggregation rate of SiO2 and TiO2 colloid particles by static light scattering
• Author: Ana Marija Kuzmić
• Mentor: Tajana Begović (mentor)
• Committee member: Tajana Begović (predsjednik povjerenstva)
• Committee member: Adriana Kenđel (član povjerenstva)
• Committee member: Đani Škalamera (član povjerenstva)
• Committee member: Davor Kovačević (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Chemistry); Zagreb
• Defense date and country: 2023-02-17, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Chemistry

Abstract

Uređajem za statičko raspršenje svjetlosti Mastersizer3000 određivane su brzine agregacije
čestica SiO2 (S-1000, S-200 i S-80) i TiO2 (T-250, T-50-70 i T-15). Mjerenja su provedena za
dvije pH vrijednosti pH (pH = 3 i pH = 7) i pri dvije ionske jakosti (Ic = 0,1 mol dm–3
i Ic =
0,001 mol dm–3
). Ispitano je kako pH i ionska jakost utječu na brzinu agregacije navedenih
čestica. Iz raspodjele veličine čestica po volumenu izračunate su ovisnosti brojčane
koncentracije čestica o vremenu i određene konstante brzine agregacije. Za čestice SiO2 (S200) izmjereno je statičko raspršenje svjetlosti pri pH = 4,5 za niz ionskih jakosti te je određena
kritična koagulacijska koncentracija koja iznosi cccc = 0,0326 mol dm–3
. Uređajem ZetasizerPro
metodom dinamičkog raspršenja svjetlosti za čestice SiO2 (S-1000, S-200 i S-80) i TiO2 (T250, T-50-70 i T-15) određene su ovisnosti veličine čestica o pH, a metodom elektroforeze
određene su izoelektrične točke.

Abstract (english)

Aggregation rates of SiO2 (S-1000, S-200 and S-80) and TiO2 (T-250, T-50-70 and T-15)
particles were determined using static light scattrering device Mastersizer3000. Measurements
were performed for two pH values (pH = 3 and pH = 7) and at two ionic strengths ((Ic = 0,1
mol dm–3
i Ic = 0,001 mol dm–3
). It was investigated how pH and ionic strength affect the speed
of aggregation of the mentioned particles. The numerical concentration of particles in time are
calculated from the prarticle size distribution by volume and used to determine aggregation rate
constant. Static light scattering was measured for SiO2 (S-200) particles at pH = 4,5 for a range
of ionic strengths and the critical coagulation concentration was determined, which is cccc =
0,0326 mol dm–3
. The ZetasizerPro device was used to detemine the dependence of particle size
on pH using using the dynamic light scattering method and isoelectric points using the
electrophoresis method for SiO2 (S-1000, S-200 and S-80) and TiO2 (T-250, T-50-70 and T15) particles.

• Keywords: agregacija; dinamičko raspršenje svjetlosti; izoelektrična točka; kritična koagulacijska koncentracija; silicijev dioksid; statičko raspršenje svjetlosti; titanijev dioksid
• Keywords (english): aggregation; critical coagulation concentration; dynamic light scattering; isoelectric point; silicon dioxide; static light scattering; titanium dioxide
• Language: croatian
• URN:NBN: urn:nbn:hr:217:239833
• Project: Number: IP-2020-02-9571; Title: Fizikalna kemija procesa na međupovršini mineral/otopina (poli)elektrolita; Title: Physical chemistry of processes at mineral/(poly)electrolyte solution interface; Acronym: POLYMIN2; Leader: Tajana Begović; Jurisdiction: Croatia; Funder: HRZZ; Funding stream: IP
• Study programme: Title: Graduate university studies in chemistry; specializations in: Research programme; Course: Research programme; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra kemije (magistar/magistra kemije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2023-03-16 14:31:55