This study reported the effect of sodium lauryl sulfate (SLS) as a template on silica morphology and its properties. The precursor was prepared by producing silica nanofluid by the sol-gel method and mixed with various SLS concentrations. After that, the precursor was spray-dried to generate silica powder. An increase in SLS concentration up to 2 critical micelle concentration (CMC) indicates an increase in the silica particle size from 2.12 μm in untemplated silica particles to 2.58 μm. On the other hand, when the SLS concentration increases to 3 CMC, the particle size decreases to 2.19 μm. A significant increase in total pore volume and surface area is obtained for silica particles synthesized at least at the SLS concentration of 2 CMC, around eight higher volumes than without SLS addition. In addition, they have a macropore compared to silica particles synthesized without SLS addition that only exhibits mesopore. The surface area was 1,011 m2/g for the SLS concentration at 3 CMC, whereas the silica without SLS has only a surface area of 131 m2/g. The SLS concentration at 2 CMC or higher leads to a significant increase in its physical properties because the micelle formation is enough for sacrificed template formation. Methylene blue solution was used as an adsorbate for evaluating the dye adsorption capacity that followed the Langmuir isothermal adsorption model. The highest theoretical maximum monolayer adsorption capacity was 142.9 mg/g, obtained by silica adsorbent with the SLS concentration at 3 CMC.

Amine functionalized silica has been successfully prepared using a direct co-condensation method in spray-assisted with sodium silicate as silica source and γ-aminopropyltriethoxysilane (APTS) as amine source. This study aims to synthesize amine grafted silica in one step process which includes particle formation and surface modification. Silica-amine nanofluids were prepared in stable colloidal phase as precursor solution for spray drying system. Amine sourced from APTS was condensed separately with silica nanofluids. The process of controlling the condensation rate of APTS can prevent the occurrence of silica precipitates in the precursor. The silica-amine precursor solution was then processed by spray drying at a temperature of 200°C. Silica particles that have been modified by amine groups were characterized using FT-IR, TG-DTA, and Adsorption-desorption N2. The silica-amine showed the presence of an amine group that was successfully grafted. This is indicated by the presence of characteristic amine peaks on FT-IR and mass changes due to amine decomposition in TG-DTA. The number of amines that were successfully grafted was 0.5 mmol/g sample. The washing of amine-modified silica particles with ethanol showed that the type of bond that occurred between silica and the amine functional group was a physical bond. The surface area of amine-modified silica is 169 m2/g with the pore size distribution in the micro-mesopore regime. The average pore size of amine-modified silica was 0.1288 nm.

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Pemanfaatan gas alam sebagai sumber energi alternatif masih belum optimal karena masalah beban cairan pada sumur gas, surfaktan merupakan solusi yang menjanjikan untuk mengatasi masalah tersebut, namun dengan kondisi sumur gas yang ekstrem diperlukan stabilizer untuk meningkatkan stabilitasnya. Penelitian ini mempelajari pengaruh pencampuran surfaktan dan stabilizer berupa silika (SiO2) nanopartikel yang disintesa dari sodium silikat (Na2SiO3) untuk mendapatkan kondisi optimum nanofluida SiO2 terhadap waktu paruh busa yang menunjukkan kestabilannya. Silika nanopartikel disintesa dengan metode sol-gel dan dipertahankan dalam fase koloid stabil yang kemudian didispersikan ke dalam larutan surfaktan tanpa perlu penambahan bahan penyambung. Nanofluida SiO2 kemudian dimatangkan dengan variasi waktu dan konsentrasi silika. Dari hasil yang diperoleh menunjukkan bahwa peningkatan waktu pematangan dan konsentrasi silika memengaruhi nilai tegangan permukaan yang berakibat menurunkan waktu paruh busa. Penurunan kestabilan busa terjadi karena peristiwa adsorbsi fisik molekul surfaktan oleh silika nanopartikel yang ditunjukkan oleh nilai tegangan permukaan, karena silika yang bersifat hidrofilik akan membentuk ikatan fisik dengan surfaktan, semakin meningkatnya waktu pematangan dan konsentrasi silika yang didispersikan kedalam larutan akan meningkatkan adsorbsi molekul surfaktan pada permukaan silika dan menyebabkan terjadinya peningkatan nilai tegangan permukaan nanofluida. Stabilitas busa terbaik diperoleh pada sampel dengan waktu pematangan selama 6 jam dan konsentrasi silika 0,001% menghasilkan waktu paruh selama 1170 menit yang jika dibandingkan dengan surfaktan tanpa penambahan silika nanopartikel hanya memeroleh waktu paruh selama 90 menit, sehingga penggunaan silika nanopartikel sebagai stabilizer memberikan efek yang signifikan terhadap kestabilan busa.

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