Kesan parameter proses atas sifat fizikokimia SBA-15 silika mesopore tersusun telah
disiasat. SBA-15 telah disintesiskan melalui kaedah templat halus menggunakan surfaktan
tanpa-ionik Pluronic P123 dan tetraetilena orthosilikat TEOS sebagai sumber silika serta asid
hidroklorik (HCl) sebagai pemangkin. Parameter proses yang diubah termasuklah konsentrasi
HCl (2.5 – 1.0 M), suhu penuaan (40 – 70 °C) dan masa penuaan (12 – 48 jam). Sampel SBA-
15 yang disintesis telah diuji dengan eksperimen penjerapan metilena biru (MB) dan kondisi
proses yang menghasilkan SBA-15 dengan prestasi terbaik adalah 2.0 M HCl, pada 40 °C dan
48 jam penuaan. Kecekapan penyingkiran metilena biru yang terbaik adalah sebanyak 19.63%.
Pencirian fizikokimia dilakukan melalui teknik pengimbasan elektron mikroskopi (SEM)
dengan tenaga serakan x-ray spektroskopi (EDX), transmisi elektron mikroskopi (TEM), BET
analisis kawasan permukaan, perubahan inframerah spektrofotometer Fourier (FTIR), dan
pembelauan x-ray (XRD). SBA-15 dengan prestasi penjerapan MB terbaik menunjukkan
dinding mesopore setebal 6.98 nm, saiz liang sebesar 4.06 nm (cawangan penjerapan BJH),
kawasan permukaan sebanyak 364.71 m2/g dengan kawasan permukaan liang mikro sekecil
42.29 m2/g. Turut diperhatikan dalam kajian ini adalah morfologi SBA-15 yang bertukar dari
bentuk rod panjang ke rod pendek sehingga kemunculan campuran bentuk rod dan sfera apabila
kepekatan HCl dikurangkan daripada 2.5 M ke 1.0 M. Apabila suhu penuaan dinaikkan
daripada 40 ke 70 °C, SBA-15 berubah daripada struktur rod pendek ke struktur serat nipis.
Masa penuaan yang diubah daripada 12 ke 48 jam tidak menunjukkan apa-apa kesan ke atas
perubahan morfologi SBA-15.
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Effect of process parameters on physicochemical characteristics of ordered mesoporous
silica SBA-15 has been investigated. SBA-15 was synthesised by soft-templating method using
non-ionic surfactant Pluronic P123 and tetraethyl orthosilicate TEOS as silica source with
aqueous hydrochloric acid (HCl) as catalyst. Process parameters varied include HCl
concentration (2.5 – 1.0 M), ageing temperature (40 – 70 °C) and ageing time (12 – 48 hours).
The as-synthesised SBA-15 samples were tested with methylene blue (MB) batch adsorption
experiments and the process conditions which produces SBA-15 with best adsorption
performance is 2.0 M HCl, with ageing carried out at 40 °C for 48 hours, with methylene blue
removal efficiency reported at 19.63%. Physicochemical characterisation of SBA-15 was
carried out using scanning electron microscopy (SEM) with energy dispersive x-ray
spectroscopy (EDX), transmission electron microscopy (TEM), BET surface area analysis,
Fourier transform infrared spectrophotometer (FTIR) and x-ray diffraction (XRD) techniques.
SBA-15 with the best MB adsorption capacity prepared exhibits thick mesoporous walls of
6.98 nm, pore size of 4.06 nm (BJH-adsorption branch), BET surface area of 364.71 m2/g with
small micropore surface area of 42.29 m2/g. It was observed that the surface morphology of
SBA-15 transformed from longer rods to shorter rods until a mixture of rods and spheres are
present upon reducing HCl concentration from 2.5 M to 1.0 M. Upon increasing ageing
temperature from 40 to 70°C, SBA-15 changed from short rods to thin-fibre like structure.
Ageing time varied from 12 to 48 hours did not show any significant effect on morphological
changes in SBA-15.
Effect of process parameters on physicochemical characteristics of ordered mesoporous silica SBA-15 / Koh Ming Hooi