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Cilj ovog rada bio je proizvesti senzorske filmove s lakmusom kao indikatorom i ispitati njihovo ponašanje. Korištenjem aditivne tehnologije ispisane su pločice i mikroreaktori različitih geometrija kanala od poli(vinil-butirala), termoplastičnog polimera povoljnih optičkih svojstava. pH-senzorski filmovi dobiveni su sol-gel metodom imobiliziranjem lakmus indikatora u silanskoj matrici. Korišteni prekursori za filmove bili su silicijevi alkoksidi tetraetoksisilan (TEOS) i feniltrimetoksisilan (FTMS). Metoda nanošenja filmova na površinu pločica i na stijenke kanala mikroreaktora bila je „drop coating“ metoda. Pločice i reaktori su zatim stavljeni na sušenje, te su na ovaj način dobiveni su optički kemijski senzori. Ispitivanja filma na pločicama pokazala su da senzorski film mijenja boju ovisno o pH medija u kojem se nalazi te je stabilan unutar vremena ispitivanja, dakle film se može nanositi na površinu kanala mikroreaktora. Promjena boje filma na stijenkama kanala mikroreaktora u otopinama različite pH-vrijednosti bilježi se kao vrijednost crvene, zelene i plave boje (engl. RGB – Red Green Blue). Za sve ispitivane reaktore uočava se porast vrijednosti za plavu boju s porastom pH-vrijednosti otopine. Boja se mijenja od crvene prema ljubičastoj s najvećom promjenom između pH 6 i 9, a promjena je reverzibilna. Dakle, ovakvi filmovi se mogu koristiti kao pH senzori u vodenim otopinama kiselina i lužina. The aim of this work was to produce sensor films using litmus as an indicator and to study their behavior. Using additive technology, plates and microreactors with different channel geometries were 3D printed from poly(vinylbutyral), a thermoplastic polymer with good optical properties. pH sensor films were made using the sol-gel method. The silicon alkoxides tetraethoxysilane (TEOS) and phenyltrimethoxysilane (FTMS) were used as precursors for the films. A litmus indicator was immobilized in the silane matrix. The films were applied to the surface of the plates and the channel of the microreactors using the "drop coating" method, and the reactors were then dried. Optical chemical sensors were fabricated in this manner. Tests of the film on the plates showed that the sensor film changes color depending on the pH of the solution and is stable within the test time, making the film suitable for use in microreactors. The color change of films on the wall of the microreactor tube in solutions with different pH values is recorded as red, green and blue color (RGB). For all reactors tested, an increase in the value for the blue color is observed with an increase in the pH of the solution. The color changes from red to purple, with the greatest change occurring between pH 6 and 9, and the change is reversible. Thus, these silane films can be used as pH sensors in aqueous solutions of acids and bases. |
