SINTESIS DAN KARAKTERISASI SILIKA AEROGEL BERBASIS TEOS (TETRAETHYLORTHOSILICATE) MENGGUNAKAN METODE SOL-GEL

Abstract

Abstrak Sintesis silika aerogel berbahan dasar TEOS (Tetraethylorthosilicate) melalui metode sol – gel dengan penambahan larutan pemodifikasi permukaan TMCS (Tetramethylchlorosilane). dilakukan dengan tujuan mendeskripsikan pengaruh variasi penambahan larutan modifikasi permukaan terhadap ukuran nanopartikel silika aerogel. Sintesis silika aerogel dilakukan melalui percampuran antara larutan prekursor TEOS (Tetraethylorthosilicate) dengan ethanol, aquades katalis NH3 menggunakan magnetik stirrer sampai terjadi kehomogenitasan sehingga nantinya akan terbentuk larutan sol silika. Larutan sol silika diletakkan ke dalam botol PE (polyethilene) dan dibiarkan (aging) selama 15 hari sampai terbentuk gel silika. Setelah gel terbentuk direndam kedalam ethanol selama 30 menit kemudian dikeringkan pada suhu 60oC selama 24 jam. Selanjutnya gel direndam ke dalam larutan ethanol, n – hexane dan TMCS (Tetramethylclhorosilane) sebagai agen sililasi dengan komposisi TMCS 15 mL dan 25 mL selama 24 jam. Selanjutnya dikeringkan pada suhu 600oC selama 24 jam. Silika aerogel yang diperoleh dikarakterisasi menggunakan FTIR (Fourier Transform Infrared Spectroscopy) dan SEM (Scanning Electron Microscope). Hasil perhitungan diperoleh massa jenis dengan perendaman TMCS sebanyak 15 mL sebesar 0,0418 gr/mL sedangkan 25 mL diperoleh massa jenis sebesar 0,0291 gr/mL. Hasil karakterisasi FTIR menunjukkan bahwa pada daerah 1257,17 cm-2 pada perendaman TMCS sebanyak 15 mL dan pada daerah 1173,5 cm-2mengindikasikan bahwa gugus metil telah berikatan dengan struktur silika. Karakterisasi SEM menunjukkan bahwa dengan melalui analisis perhitungan sampel dimana perendaman TMCS sebanyak 15 mL diperoleh diameter rata-rata sebesar 6,868432 nm – 67,03631 nm sedangkan untuk perendaman sebanyak 25 mL berukuran sebesar 2,181567 nm – 25,36593 nm. Kata kunci : silika aerogel, sol – gel, TMCS , TEOS Abstrack Synthesis of silica aerogel made from basic TEOS (Tetraethylorthosilicate) through the method of sol – gel with the addition of a solution of a surface modifier TMCS (Tetramethylchlorosilane). Done with the aim of describing the influence of variations of surface modification solution against the addition of the size of nanoparticles of silica aerogel. Synthesis of silica aerogel made through a blended solution precursor of TEOS (Tetraethylorthosilicate) with ethanol, catalyst aquades NH3 using a magnetic stirrer to occur so that the kehomogenitasan will be formed of aqueous silica sol. Aqueous silica sol is put into the bottles PE (polyethilene) and left (aging) for 15 days until the silica gel is formed. After the gel formed soaked into ethanol for 30 minutes then dried at a temperature of 60oC for 24 hours. Furthermore the gel is immersed into a solution of ethanol, n – hexane and TMCS (Tetramethylclhorosilane) as a sililasi agent with the composition of TMCS 15 mL and 25 mL for 24 hours. Next is dried at a temperature of 600oC for 24 hours. Silica aerogel is obtained are characterized using FTIR (Fourier Transform Infrared Spectroscopy) and SEM (Scanning Electron Microscopy). The calculation result obtained by submersion of TMCS 15 mL of 0.0418 gr/mL while 25 mL obtained density of 0.0291 g/mL. FTIR characterization of the results show that in the area of 1257.17 cm-2 on soaking TMCS 15 mL and in the area of 1173.5 cm-2 indicates that the methyl group has bonded with the structure of silica. SEM characterization shows that through the analysis of the sample calculation with which the soaking TMCS 15 mL obtained an average diameter of 6.868432 nm – 67.03631 nm as for soaking as much as 25 mL size of 2.181567 nm – 25.36593 nm. Keywords: silica aerogel, sol – gel, TMCS, TEOS