STUDY OF EMULSION SYSTEM AS MEDIUM FOR SYNTHESIZING TIO2 TOWARDS THE FORMATION OF CONTROLLABLE MORPHOLOGY

• Main Author: EKARISTA NDUA NIM: 10513033, APRILIA
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/25709
• Institution: Institut Teknologi Bandung

TiO2 is an important semiconductor materials in the development of technology. In its application, TiO2 is widely used as a photocatalyst and catalyst supporting material. The arrangement of the morphology of TiO2 is important to support its application as a photocatalyst. One of the morphologies of interest today is bicontinous concentric lamellar (bcl). Materials that have been successfully synthesized with this morphology are silica based materials. Silica bcl which has been successfully synthesized using emulsion synthesis media and in reverse micelle system. If this morphology is owned by TiO2 it will improve TiO2 performance as a photocatalyst and previously no one has done TiO2 synthesis with an emulsion system that produces bcl morphology. To produce TiO2 bcl then emulsion is used as emulsion synthesis medium. The emulsion that can be used as a synthesis medium of TiO2 bcl is a stable emulsion. In the emulsion system, micelles are used as template/container for the formation TiO2 particles with certain morphology. One type of micelle commonly used as a template is a reverse micelle. Reverse micelle are produced by adjusting the water phase and oil phase ratios, in which the number of oil phases is larger than that of the water. Reverse micelle can be obtained using surfactant with packing parameter large than unity. In this study, a number of parameters were varied: the type of surfactant, the surfactant concentration, and the volume ratio between water and oil to produce a stable emulsion. Here, benzalkonium chloride (BZK) and cetyltrimethylammonium bromide (CTAB) were used as surfactants. Polymorph of TiO2 were determined using Raman spectroscopy, whereas their morphology was observed using an scanning electron microscope (SEM). In this study, stable emulsions were obtained by using CTAB producing reverse micelle. The CTAB surfactant may produce reversed micelle because CTAB has packing parameter larger than unity. The synthesized TiO2 is an anatase as exhibited by Raman spectroscopy. The synthesized TiO2 has an irregular aggregate morphology as observed by SEM. This occurs due to the rapid hydrolysis of titanium isopropoxide (TTIP) thus they cannot readily diffuse into reverse micelles to proceed phase segregation. Therefore, modification of the method was carried out to slow down the rate of TTIP hydrolysis by replacing water with ethanol. This modified produces a spherically ordered TiO2 particles with bicontinous lamellar (bcl) morphology as observed by SEM.