Synthesis of SAPO-34 in The Presence of PEG as Non-Reactive Additive W. Rahmah 1), R. R. Mukti 2,3), K. Khoiruddin 1,3,4), I G. Wenten 1,3*)
1) Department of Chemical Engineering, Faculty of Industrial Technology, Institut Teknologi Bandung, Jl Ganesha no. 10, Bandung 40132, Indonesia
2) Division of Inorganic and Physical Chemistry, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl Ganesha no. 10, Bandung, 40132, Indonesia
3) Research Center for Nanosciences and Nanotechnology, Institut Teknologi Bandung, Jl. Ganesha no. 10, Bandung, 40132, Indonesia
4) Center for Catalysis and Reaction Engineering, Institut Teknologi Bandung, Jl. Ganesha no. 10, Bandung 40132, Indonesia
Abstract
Polyethylene glycol (PEG), a widely available organic polymer of ethylene glycol, has been utilized as a non-reactive reagent in many inorganic material syntheses. In this work, the degree of structural deformation of SAPO-34 zeotype by introducing PEG-20000 into the synthesis solution by means of hydrothermal treatment was investigated. The presence of PEG led to the formation of SAPO-34 crystal with vast defects. The deterioration of SAPO-34 crystals was observed by SEM images and the quantification of crystal dimension resulted in aspect ratio values. The increase value of aspect ratio suggests that the chain length of PEG has a great influence on modifying the particle size and crystal morphology within the three main crystallographic axes. Moreover, the addition of ethanol within solution precursor increases aspect ratio value over 3 times higher. The addition of ethanol as byproduct from the hydrolysis of tetraethyl orthosilicate (TEOS) or the use of PEG-6000 of lower molecular weight does not increase the aspect ratio. This confirms that PEG micelles of higher molecular weight selectively result in peculiar SAPO-34 particle shapes.
