20.500.12556/DKUM-84060 Adsorpcija poliakrilne kisline (PAA) na površino kalcijevega karbonata diplomsko delo visokošolskega strokovnega študijskega programa I. stopnje Adsorption of polyacrylic acid (PAA) on the surface of calcium carbonate Cilj te naloge je bil preučiti adsorpcijo poliakrilne kisline na površino kalcijevega karbonata. Najprej smo opisali mehanizem adsorpcije poliakrilne kisline na površino kalcijevega karbonata in nato tudi mehanizem dispergiranja delcev v suspenziji. Proces adsorpcije smo potem preučevali s polielektrolitskimi titracijami, katerih rezultate smo pretvorili v količino prostega dispergenta v suspenziji in iz tega še v količino vezanega dispergenta na površino minerala. Na podlagi teh dveh količin smo konstruirali adsorpcijske izoterme. Obliko teh izoterm smo opisovali z Langmuirjevo teorijo adsorpcije. Z uporabo te teorije smo ovrednotili vpliv preiskovanih faktorjev na adsorpcijo. Faktorji, katere smo preučevali, so bili suha snov kalcijevega karbonata v suspenziji, vpliv sušenja suspenzije po dispergiranju, molska masa dispergenta in stopnja nevtralizacije dispergenta, oz. pH dispergenta. Najprej smo pa ovrednotili ponovljivost adsorpcijske izoterme. Rezultati eksperimentov so pokazali, da pri suhi snovi kalcijevega karbonata v suspenziji in pri sušenju suspenzije nismo zaznali vidnih trendov sprememb pri adsorpciji. Eksperiment z molsko maso dispergenta je pokazal, da je že standardno izbrani dispergent z srednjo vrednostjo molske mase v našem eksperimentu najoptimalnejši za adsorpcijo zaradi več aktivnih mest na daljši verigi ter omejitve hidrodinamičnega radija. Zadnji eksperiment stopnje nevtralizacije je pokazal jasen trend vpliva na adsorpcijo. Dokazali smo, da z večanjem stopnje nevtralizacije dispergenta oz. z večanjem pH-ja dispergenta učinkovitost adsorpcije pada. Več imamo prostega dispergenta v suspenziji in manj vezanega dispergenta na površino minerala. Zaključimo lahko, da ima stopnja nevtralizacije dispergenta negativen vpliv na učinkovitost adsorpcije. The goal of this thesis was to study the adsorption of polyacrylic acid on to the surface of calcium carbonate. First we described the mechanism behind the adsorption of polyacrylic acid on to the surface of calcium carbonate and also the mechanism of dispersing the particles in the slurry. The process of adsorption was then studied with polyelectrolitic titrations the results of which we transformed into the amount of free dispersant in the slurry and into the amount of bound dispersant to the surface of the mineral. Based on these two quantities we constructed adsorption isotherms. The shape of these isotherms was described by the Langmuir theory of adsorption. We used this theory to evaluate the effect of the factors that we studied. The factors which effect the adsorption that we studied are dry substance of calcium carbonate in the slurry, effect of drying of the slurry after dispersing, molar mass of dispersant and lastly the degree of dispersant neutralization or the pH of dispersant. Prior to these eperiments we also determined the repeteability of the adsorption isotherm. The results of the experiments have shown that the dry substance of calcium carbonate in slurry and the procees of slurry drying don´t have a significant effect on the adsorption. The experiment with molar mass of the dispersant showed that the standardly chosen dispersant was already optimal for the adsorption because of the longer polymer chain containing more active sites and the limitations of the hydrodynamic radius. Final experiment involving the degree of dispersant neutralization showed a distinctive trend of effect on adsorption. We proved that with the increase in the dispersant pH and consequently the higher degree of dispersant neutralization, the efficacy of adsorption declines. More of the dispersant is free in the slurry and less of it is bound on to the mineral surface. We can conclude that neutralization of dispersant has a negative effect on the adsorption. Adsorpcija dispergiranje polielektrolitska titracija PAA kalcijev karbonat Adsorption dispersing polyelectrolytic titration PAA calcium carbonate true true false [A. Kostevc] Slovenski jezik Angleški jezik Diplomsko delo/naloga 2023-04-04 09:40:46 2023-05-25 07:59:45 2023-07-01 03:07:18 0000-00-00 00:00:00 2023 0 Maribor 0 Maribor 1 spletni vir (1 datoteka PDF (VII, 30 f.)) 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 544.723+544.778.3.051.1(043.2) 157283331 VS_Kostevc_Alen_2023.pdf VS_Kostevc_Alen_2023.pdf 1 D8F8F02AE915598D10FFC09137382AB1 9f1d603857d4edb3f19212a1b63f12f30de0bc18387f9d701e090059b5edf081 14b5a970-fa1b-11ed-b1bf-00155d000105 https://dk.um.si/Dokument.php?lang=slv&id=167498 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0