| Abstract | Cilj ovog istraživanja bio je usporediti proces emulgacije ulje/voda (s otopljenim polietilen glikolima različitih molekulskih masa) u šaržnom reaktoru te u mikroreaktoru s pasivnim miješalima, volumena 2 μL, mjerenjem zeta potencijala nastalih emulzija. Prilikom oba tipa eksperimenta korišteni su polietilen glikoli (PEG-ovi) molekulskih masa 1500, 6000 i 20000 otopljeni u vodenoj fazi koncentracija 0,2; 0,7; 1; 2 % (w/w) koja je iznosila 71 % ukupnog volumena emulzije, a ostatak od 29 % bila je uljna faza. Dok je za šaržni proces praćen utjecaj molekulske mase PEG-a, koncentracije otopljenog PEG-a u vodi te brzine miješanja (22000, 28000 i 35000 okr min-1), za mikroreaktorski sustav praćen je utjecaj molekulske mase PEG-a, koncentracije otopljenog PEG-a u vodi te ukupnog protoka uljne i vodene faze u mikroreaktoru (200, 300 i 400 μL min-1). Rezultati su pokazali da emulzije proizvedene u šaržnom reaktoru imaju veću stabilnost s najvišim izmjerenim zeta potencijalom od -88,3 mV, dok je u mikroreaktorskom sustavu najveća vrijednost bila -71,3 mV. Procijenjeni optimalni parametri za šaržni eksperiment iznosili su: PEG 1500, koncentracije 0,2 % (w/w) pri brzini miješanja 35000 okr min-1, dok su za mikroreaktorski sustav bili: PEG 1500, koncentracije 0,2 % (w/w) pri ukupnom protoku od 200 μL min-1. |
| Abstract (english) | The aim of this study was to compare the oil/water emulsification process (with dissolved polyethylene glycols of different molecular weights) in a batch reactor and in a microreactor with passive mixers, volume of 2 μL, by measuring the zeta potential of the resulting emulsions. Polyethylene glycols (PEG-s) with molecular weights of 1500, 6000 and 20000 dissolved in the aqueous phase at concentrations of 0.2; 0.7; 1 and 2 % (w/w) were used in both types of experiments which was 71 % of of total volume and the remaining 29 % was the oil phase. While for the batch process the influence of PEG molecular weight, dissolved PEG concentration in water and mixing speed (22000, 28000 and 35000 rpm) were monitored, for microreactor system the influence of PEG molecular weight, dissolved PEG concentration and total flow of oil and aquaous phase (200, 300 and 400 μL min-1) were monitored. The results showed that the emulsions produced in the batch reactor had higher stability with the highest measured zeta potential of -88.3 mV, while in the microreactor system the highest observed value was -71.3 mV. The estimated optimal parameters for the batch experiment were: PEG 1500, concentration 0.2 % (w/w) at a stirring speed of 35000 rpm, while for the microreactor system optimal parameters were: PEG 1500, concentration 0.2 % (w/w) at total flow of 200 μL min-1. |
