Sains Malaysiana 44(3)(2015): 429–439
Enhancement
of Gaseous BTEX Adsorption on RH-MCM-41
by Chlorosilanes
(Peningkatan Penjerapan Gas BTEX pada RH-MCM-41 oleh Klorosilana)
T. AREEROB1,4, S. CHIARAKORN2*
& N. GRISDANURAK3
1Division
of Environmental Technology, Joint Graduate School of Energy and Environment
King Mongkut's University of Technology
Thonburi, 10140 Thailand
2Division of
Environmental Technology, School of Energy, Environment and Materials
King Mongkut's University of Technology Thonburi, 10140 Thailand
3Department of
Chemical Engineering, Thammasat University, 12120 Thailand
4Center for Energy
Technology and Environment, Ministry of Education, Thailand
Diserahkan: 14 Januari 2014/Diterima: 25 Ogos 2014
ABSTRACT
In this research, the surface hydrophobicity of a mesoporous
molecular sieve synthesized from rice husk silica, called RH-MCM41
was improved via silylation techniqueto enhance the adsorption efficiency of
non-polar volatile organic compound. The effect of chlorosilane leaving on was
analyzed with three silanes containing different numbers of chloride leaving
group; trimethylchlorosilane (TMCS), dimethyldichlorosilane (DMDCS)
and methyltrichlorosilane (MTCS). The unmodified RH-MCM-41
was soaked in 100 mL of 5% v/v of silane reagent at 30ºC for 24 h. The results
showed that the silane loading on the RH-MCM-41 was in the order of
increasing number of leaving groups as MTCS > DMDCS > TMCS.
The crystallinity results studied by X-ray diffractometry indicated that the
silylation did not affect the hexagonal pattern of RH-MCM-41.
However, the porosity of the silylated RH-MCM-41 was significantly
decreased after silylation, especially by MTCS,
due to pore blocking. After silylation, the adsorption performance of gaseous BTEX (benzene, toluene, ethylbenzene and xylene) on the silylated RH-MCM-41
was determined by gas chromatography equipped with flame ionization detector (GC-FID).
From the results of humidity effect on adsorbability, the BTEX adsorption
capacity of the unsilylated RH-MCM-41 was dropped a half,
conversely the BTEX adsorption capacity of all
silylated RH-MCM-41 was decreased in range of 20-30% when the relative
humidity increased from 25 to 99%. This was indicated that the influence of
humidity on the BTEX adsorption was relieved after
silylation. In additions, the maximum BTEX adsorption capacity
belonged to RH-MCM-41 silylated by TMCS which
was recommended for the enhancement of non-polar volatile organic compounds
adsorption.
Keywords: Adsorption; BTEX; MCM-41;
rice husk silica; silylation
ABSTRAK
Dalam kajian ini, permukaan kehidrofobian penapis molekul mesoporous
disintesis daripada sekam padi silika, dikenali sebagai RH-MCM41
bertambah baik melalui teknik sililasi untuk mempertingkatkan kecekapan penjerapan sebatian organik yang
tidak berkutub. Kesan klorosilana yang tertinggal dianalisis dengan
tiga silana yang mengandungi jumlah klorida berbeza meninggalkan
kumpulan; trimetilklorosilana (TMCS),
dimetildiklorisilana (DMDCS) dan metiltriklrosilana (MTCS).
RH-MCM-41
yang tidak diubah suai, direndam dalam 100 mL 5% v/v bagi bahana
uji silana pada 30ºC untuk 24 h. Hasil kajian menunjukkan bahawa
bebanan silana ke atas RH-MCM-41
adalah dalam aturan penambahan bilangan meninggalkan kumpulan sebagai
MTCS
> DMDCS > TMCS.
Keputusan habluran yang dikaji oleh belauan sinar-x menunjukkan
bahawa sililasi tidak menjejaskan corak hexagon RH-MCM-41.
Walau bagaimanapun, keliangan sililasi
RH-MCM-41 menurun dengan sekata
selepas sililasi, terutamanya MTCS, kerana menghalang liang.
Selepas sililasi, prestasi penjerapan gas BTEX (benzena,
toluena, etilbenzena dan xilena) pada sililasi
RH-MCM-41
ditentukan melalui kromatografi gas dilengkapi dengan pengesan pengionan
api (GC-FID).
Hasil daripada serapan kelembapan menunjukkan kapasiti penjerapan
BTEX
sililasi
RH-MCM-41 jatuh separuh, sebaliknya kapasiti
penjerapan BTEX untuk semua sililasi
RH-MCM-41
adalah menurun dalam julat 20-30% apabila kelembapan bandingan meningkat
daripada 25 kepada 99%. Ini menunjukkan bahawa pengaruh kelembapan
pada penjerapan BTEX
lebih baik selepas sililasi. Sebagai tambahan, kapasiti maksimum penjerapan BTEX adalah kepunyaan RH-MCM-41
sililasi oleh TMCS yang dicadangkan untuk meningkatkan
penjerapan-tidak berkutup organik meruap.
Kata kunci: BTEX;
MCM-41; penjerapan; sekam padi silika; sililasi
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*Pengarang
untuk surat-menyurat; email: Siriluk.chi@kmutt.ac.th
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