Interakcije suprotno nabijenih polielektrolita u otopini i na površini

doctoral thesis

• Title (english): Interactions of oppositely charged polyelectrolytes in solution and on the surface
• Author: Jasmina Salopek
• Mentor: Davor Kovačević (mentor)
• Mentor: Josip Požar (komentor)
• Committee member: Vesna Petrović-Peroković (predsjednik povjerenstva)
• Committee member: Davor Kovačević (član povjerenstva)
• Committee member: Suzana Šegota (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Chemistry); Zagreb
• Defense date and country: 2017-12-19, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Chemistry
• Universal decimal classification (UDC): 54 - Chemistry. Crystallography. Mineralogy

Abstract

U svrhu istraživanja korelacije procesa nastanka polielektrolitnih kompleksa i višeslojeva ispitana je interpolielektrolitna neutralizacija triju parova sintetskih linearnih polimera visoke gustoće naboja u vodenim otopinama binarnih monovalentnih natrijevih soli (NaX; X = F, Cl, Br, I, NO3, ClO4). Pri nižim koncentracijama elektrolita, reakcije u otopini rezultirale su nastankom metastabilnih netopljivih kompleksa približno jednakih udjela suprotno nabijenih monomera. Porastom koncentracije elektrolita zbila se anion-specifična agregacija pozitivno nabijenih koloidnih kompleksa, a produkti reakcija dobiveni uz suvišak monomera pozitivnog naboja sadržavali su veći udio monomera polikationa s ekstrinzički kompenziranim nabojem. Analogna asimetrična interpolielektrolitna neutralizacija zamijećena je u slučaju odgovarajućih višeslojeva, priređenih pri jednakim ionskim uvjetima. Svi su polikationi pokazivali najveći afinitet prema perkloratnom ionu, vezanje je nitrata i jodida bilo podjednako, dok se afinitet prema ostalim halogenidima smanjivao u nizu Br– > Cl– > F–. Energetika kompleksiranja slabo je ovisila o vrsti i koncentraciji protuiona. Inverzija naboja primarnih kompleksa karakteristična za procese nastanka višeslojeva, prvi put je opažena kod polielektrolitnih parova istraženih tijekom izrade ovog doktorskog rada. Preraspodjela sparenih monomera u metastabilnim produktima reakcije zbivala se sporo i ovisila je o vrsti poliiona, te vrsti i koncentraciji prisutnog elektrolita. Provedena istraživanja ukazuju na potpunu korelaciju procesa interpolielektrolitne neutralizacije koji se zbivaju u otopinama i na električki nabijenim površinama.

Abstract (english)

The interpolyelectrolyte neutralization involving three pairs of linear high charge density polylelectrolytes was examined in aqueous solution of binary salts (NaX; X = F, Cl, Br, I, NO3, ClO4) with the aim of exploring the correlation between the processes of polyelectrolyte complex and multilayer formation. At lower electrolyte concentrations, metastable precipitates containing similar amounts of oppositely charged monomers were formed in solution. At higher salt content, and in the case when the polycation was present in excess, the obtained metastable products contained more positively charged monomers (asymmetric neutralization). The amount of extrinsically compensated positive charge was strongly anion dependant. The analogous behaviour was noticed in the case of the corresponding multilayers. The polycations exhibited the highest affinity towards perchlorates, the amount of bound nitrates and iodides was found to be similar, whereas the affinity for other halides decreased in the order Br– > Cl– > F–. The complexation energetics was weakly influenced by ionic conditions. The primary complex overcharging, characteristic for multilayer built-up, was observed in solution. The conversion of metastable to equilibrium products proceeded extremely slowly, exclusively at higher salt concentrations. The redestribution of monomers within precipitates was polylelectrolyte and counteranion specific. The performed investigations indicate that no fundamental differences related to outcome and the course of interpolylectrolyte neutralization in solutions and at electricaly charged surfaces exist.

• Keywords: interpolielektrolitna neutralizacija; ion-specifični efekti; polielektroliti; polielektrolitni kompleksi; višeslojevi; prenabijanje
• Keywords (english): interpolyelectrolyte neutralization; ion-specific effects; polyelectrolytes; polyelectrolyte complexes; multilayers; overcharging
• Language: croatian
• URN:NBN: urn:nbn:hr:217:583215
• 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: 126 str. ; 30 cm
• File origin: Born digital
• Access conditions: Open access
• Created on: 2018-01-08 14:38:06