Karakterizacija i priprema pH-senzorskih filmova sol-gel metodom za primjenu u mikroreaktorima

master's thesis

• Title (english): Characterization and preparation of pH sensor films by the sol-gel method for application in the microreactors
• Author: Elizabeta Forjan
• Mentor: Domagoj Vrsaljko (mentor)
• Committee member: Domagoj Vrsaljko (predsjednik povjerenstva)
• Committee member: Petar Kassal (član povjerenstva)
• Committee member: Igor Dejanović (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2023-10-27, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

Cilj ovog rada bio je pripremiti pH-senzorske filmove na bazi indikatora lakmusa imobiliziranog u silanskom filmu na stijenkama kanala mikroreaktora. Za izradu mikroreaktora u ovom radu korištena je tehnologija proizvodnje rastaljenim filamentom (engl. Fused Filament Fabrication – FFF), a kao materijal filamenta korištenog za 3D-ispis upotrjebljen je poli(etilen-tereftalat) obogaćen glikolom (PETG). Na stijenke kanala 3D-ispisanih mikroreaktora potom je nanesen pH-senzorski film. Za pripremu pH-senzorskih filmova odabrana je sol-gel metoda zato što omogućava pripravu senzora u obliku tankih filmova. Kao prekursori za sol-gel metodu odabrani su tetraetoksisilan (TEOS) i feniltrimetoksisilan (FTMS), a u silanski film imobiliziran je indikator lakmus. Promjena boje filma na stijenkama kanala mikroreaktora u određenim je slučajevima bila teško uočljiva okom pa je za analizu promjene boje korišten RGB softver za analizu boje. Pripremljeni filmovi karakterizirani su metodom kontaktnog kuta gdje su kao testne kapljevine korišteni voda i dijodometan te je provedena infracrvena spektroskopija s Fourierovom transformacijom (FTIR). Analizom RGB vrijednosti zaključeno je kako senzorski film pripremljen dodatkom uparene indikatorske otopine i nano-titanijevog dioksida daje najintenzivniju promjenu boje pa je taj film korišten i na stijenkama kanala mikroreaktora.
pH-senzorski film uspješno je nanesen na stijenke kanala mikroreaktora.
Promjenom pH-vrijednosti kapljevine u mikroreaktoru dolazi do promjene boje filmova na stijenkama kanala mikroreaktora unutar jedne minute, a brzina ovisi o pH-vrijednosti otopine. Potvrđeno je da se senzorski filmovi mogu višekratno koristiti.

Abstract (english)

The aim of this work was to prepare and characterise pH sensor films based on litmus indicator immobilized in a silane film in the microreactor channels. The microreactors were made using fused filament fabrication technology (FFF) and polyethylene terephthalate glycol (PETG) filament. The pH-sensor film was then applied inside the channels of the
3D-printed microreactor. The sol-gel method was chosen for the preparation of the
pH sensor films because it enables the preparation of the sensor films in the form of thin films. Tetraethoxysilane (TEOS) and phenyltrimethoxysilane (FTMS) were selected as precursors for the sol-gel method and litmus indicator was immobilized in the silane film.
The colour change of the film in the channels of the microreactor was difficult to see with the naked eye in certain cases, so an RGB analysis software was used to analyse the colour change of the sensor films. The prepared films were characterized by the contact angle method, where water and diiodomethane were used as test liquids, and Fourier-transform infrared spectroscopy was performed. The analysis of the RGB values showed that the sensor film prepared with the addition of vaporized indicator solution and nano-titanium dioxide gives the most intense colour change, so this film was used in the channels of the microreactor. The pH sensor film was successfully applied to the surface of the microreactor channels. Due to the change in the pH of the solution inside the microreactor, the colour of the pH senor film changes within one minute, and rate of change depends on the pH of the solution. It was confirmed that the pH sensor films can be used multiple times.

• Keywords: aditivna proizvodnja; mikroreaktor; PETG; sol-gel metoda; pH-senzorski filmovi; lakmus
• Keywords (english): additive manufacturing; microreactor; PETG; sol-gel method; pH-sensor films; litmus
• Language: croatian
• URN:NBN: urn:nbn:hr:149:378394
• Study programme: Title: Materials Science and Engineering - Graduate study; Study programme type: university; Study level: graduate; Academic / professional title: sveučilišni/a magistar/magistra inženjer/inženjerka kemijskog inženjerstva (sveučilišni/a magistar/magistra inženjer/inženjerka kemijskog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2023-11-24 15:14:22