Sains Malaysiana 39(2)(2010): 275–280

Silica Aerogels’ Nanostructure Studied using Small Angle Neutron Scatterring Technique

(Struktur Nano Aerogel Silika dikaji menggunakan TeknikSerakan Sudut Kecil Neutron)

Noorddin Ibrahim* & Tan Chier Fang

Department of Physics, Faculty of Science

Universiti Teknologi Malaysia (UTM), 81310 Skudai, Johor, Malaysia

Received: 28 May 2009 / Accepted: 12 August 2009

ABSTRACT

Small angle neutron scattering (SANS) technique has been widely employed in probing the microstructure of amorphous materials in the nanometer range. In aerogels system, the size range of 1 – 100 nm is of particular interest since the structural units, such as the pores and particles, often fall in this range. In a typical scattering experiment, scattered neutron intensity is measured as a function of the scattering angle. Various plots of intensity I(Q) and scattering vector, Q, can provide information about fractal dimensions, and particle and cluster sizes. In this study, SANS facilities, at Nuklear Malaysia (NM) and Badan Tenaga Atom Nasional(BATAN), Indonesia were used to analyse particle and cluster size of silica aerogels and titanium containing silica aerogels. Results from NM showed that silica aerogels have surface fractal dimension while titanium containing silica aerogels have mass fractal dimension. On the other hand, results from BATAN showed that both silica aerogels and titanium containing silica aerogels have mass fractal dimension. The particle size for silica aerogels and titanium containing silica aerogels samples obtained by NM were 11.18 ± 0.03 and 9.19 ± 0.06 nm, respectively while the respective values obtained from BATAN measurements were 11.78 ± 0.06 and 10.57 ± 0.07 nm.

Keywords: aerogels; particle size; small angle neutron scattering (SANS)

ABSTRAK

Teknik serakan neutron sudut kecil(SANS) digunakan dengan meluas bagi mengkaji mikrostruktur bahan amorfos pada julat nanometer. Dalam sistem aerogel, julat saiz 1 – 100 nm diminati kerana unit struktur seperti liang dan zarah berada dalam julat sebegini. Dalam eksperimen serakan, keamatan neutron terserak diukur sebagai fungsi sudut serakan. Berbagai plot keamatan I(Q) dan vektor serakan, Q boleh memberikan maklumat mengenai dimensi fraktal, serta saiz zarah dan klusternya. Dalam kajian ini, kemudahan SANS di Nuklear Malaysia (NM) dan di Badan Tenaga Atom Nasional(BATAN), Indonesia digunakan bagi menganalisis saiz zarah dan kluster aerogel silika dan titanium mengandungi aerogel silika. Keputusan daripada NM menunjukkan aerogel silika mempunyai dimensi fraktal permukaan sementara titanium mengandungi aerogel silika mempunyai dimensi fraktal jisim. Sebaliknya keputusan dari BATAN menunjukkan kedua-dua sampel mempunyai dimensi fraktal jisim. Saiz zarah bagi aerogel silika dan titanium mengandungi aerogel silika dariNM ialah 11.18 ± 0.03 and 9.19 ± 0.06 nm sementara dari BATAN adalah 11.78 ± 0.06 and 10.57 ± 0.07 nm.

Kata kunci: aerogel; saiz zarah; serakan neutron kecil sudut(SANS)

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*Corresponding author; email: noorddin@mel.fs.utm.my