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

RUJUKAN

 

Appaturi, J.N., Adam, F. & Khanam, Z. 2012. A comparative study of the regioselective ring opening of styrene oxide with aniline over several types of mesoporous silica materials. Microporous and Mesoporous Materials 156: 16-21.

Artkla, S., Kim, W., Choi, W. & Wittayakun, J. 2009. Highly enhanced photocatalytic degradation of tetramethylammonium on the hybrid catalyst of titania and MCM-41 obtained from rice husk silica. Applied Catalysis B: Environmental 91(1- 2): 157-164.

Beck, J.S., Vartuli, C., Roth, W.J., Kresge, C.T., Schimitt, K.D., Chu, T.W., Olson, D.H., Sheppard, E.W., McCullen, S.B., Higgins, J.B. & Schlenker, J.L. 1992. A new family of mesoporous molecular sieves prepared with liquid crystal templates. Journal of the American Chemical Society 114: 10834-10843.

Beim, H.J., Spero, J. & Theodore, L. 1998. Rapid Guide to Hazardous Air Pollutants. New York: Van Nostrand Reinhold.

Boonpoke, A., Chiarakorn, S., Laosiripojana, N., Towprayoon, S. & Chidthaisong, A. 2011. Synthesis of activated carbon and MCM-41 from bagasse and rice husk and their carbon dioxide adsorption capacity. Journal of Sustainable Energy and Environment 2(2): 77-81.

Branton, P.J., Reynolds, P.A., Studer, A., Sing, K.S.W. & White, J.W. 1999. Adsorption of carbon tetrachloride by 3.4 nm pore diameter siliceous MCM-41: Isotherms and neutron diffraction. Adsorption 5: 91-96.

Burleigh, M.C., Markowitz, M.A., Spector, M.S. & Gaber, B.P. 2001. Direct synthesis of periodic mesoporous organosilicas: Functional incorporation by co-condensation with organosilanes. Journal of Physical Chemistry B. 105: 9935-9942.

Chiarakorn, S., Areerob, T. & Grisdanurak, N. 2007. Influence of functional silanes on hydrophobicity of MCM-41 synthesized from rice husk. Science and Technology of Advanced Materials 8(1-2): 110-115.

Chumee, J., Grisdanurak, N., Neramittagapong, A. & Wittayakun, J. 2009. Characterization of platinum-iron catalysts supported on MCM-41 synthesized with rice husk silica and their performance for phenol hydroxylation. Science and Technology of Advanced Materials 10(1): Art. no. 015006.

Deschner, T., Liang, Y. & Anwander, R. 2010. Silylation efficiency of chlorosilanes, alkoxysilanes and monosilazanes on aeriodicmesoporous silica. The Journal of Physical Chemistry C. 114: 22603-22609.

Fujita, I., Kuroda, K. & Ogawa, M. 2005. Adsorption of alcohols from aqueous solutions into a layered silicate modified with octyltrichlorosilane. Chemistry of Materials 17: 3717-3722.

Fujita, I., Kuroda, K. & Ogawa, M. 2003. Synthesis of interlamellarsilylatedderivatives of magadiite and the adsorption behavior for aliphatic alcohols. Chemistry of Materials 15: 3134-3141.

Grisdanurak, N., Chiarakorn, S. & Wittayakun, J. 2003. Utilization of mesoporous molecular sieves synthesized from natural source rice husk silica to chlorinated volatile organic compounds (CVOCs) adsorption. Korean Journal of Chemical Engineering 20: 950-955.

Hakuman, M. & Naono, H. 2001. A new method of calculating pore size distribution: Analysis of adsorption isotherms of N2 and CCl4 for a series of MCM-41 mesoporous silicas. Journal of Colloid and Interface Science 241(1): 127-141.

Idris, S.A., Robertson, C., Morris, M.A. & Gibson, L.T. 2010. A comparative study of selected sorbents for sampling of aromatic VOCs from indoor air. Analytical Methods 2: 1803-1809.

Ketcome, N., Grisdanurak, N. & Chiarakorn, S. 2009. Silylated rice husk MCM-41 and its binary adsorption of water-toluene mixture. Journal of Porous Materials 16: 41-46.

Klankaw, P., Chawengkijwanich, C., Grisdanurak, N. & Chiarakorn, S. 2012. The hybrid photocatalyst of TiO2–SiO2 thin film prepared from rice husk silica. Superlattices and Microstructures 51(3): 343-352.

Koyano, K.A., Tatsumi, T., Tanaka, Y. & Nakata, S. 1997. Stabilization of mesoporous molecular sieves by trimethylation. Journal of Physical Chemistry B. 101: 9436-9440.

Lang, N. & Tuel, A. 2004. A fast and efficient ion-exchange procedure to remove surfactant molecules from MCM-41 materials. Chemistry of Materials 16(10): 1961-1966.

Liao, Q., Sun, J. & Gao, L. 2008. The adsorption of resorcinol from water using multi-walled carbon nanotubes. Colloids and Surfaces A: Physicochemical and Engineering Aspects 312: 160-165.

Lin, D.H., Jiang, Y.X., Wang, Y. & Shi-Gang, S. 2008. Silver nanoparticles confined in SBA-15 mesoporous silica and the application as a sensor for detecting hydrogen peroxide. Journal of Nanomaterials. Article ID 473791 doi:10.1155/2008/473791.

Liu, Y.H., Lin, H.P. & Mou, C.Y. 2004. Direct method for surface silylfunctionalization of mesoporous silica. Langmuir 20(8): 3231-3239.

Ogawa, M., Okutomo, S. & Kuroda, K. 1998. Control of interlayer microstructures of a layered silicate by surface modification with organochlorosilanes. Journal of the American Chemical Society 120: 7361-7362.

Ohashi, F., Maeda, M., Inukai, K., Suzuki, M. & Tomura, S. 1999. Study on intelligent humidity control materials: Water vapor adsorption properties of mesostructured silica derived from amorphous fumed silica. Journal of Materials Science 34(6): 1341-1346.

Okutomo, S., Kuroda, K. & Ogawa, M. 1999. Preparation and characterization of silylated-magadiites. Applied Clay Science 15: 253-264.

Patel, D.B., Singh, S. & Bandyopadhyaya, R. 2011. Enrichment of benzene from benzene-water mixture by adsorption in silylated mesoporous silica. Microporous and Mesoporous Materials 137(1-3): 49-55.

Shimojima, A., Mochizuki, D. & Kuroda, K. 2001. Synthesis of silylatedderivatives of a layered polysilicatekanemite with mono-, di-, and tri-chloro(alkyl)silanes. Chemistry of Materials 13: 3603-3609.

Tong-On, W., Sthiannopkao, S., Kim, K.W. & Chiarakorn, S. 2009. Adsorption of arsenic in aqueous solution by RH-Fe-MCM-41. Water Science and Technology: Water Supply 9(2): 121-126.

Wantala, K., Sthiannopkao, S., Srinameb, B., Grisdanurak, N. & Kim, K.W. 2010. Synthesis and characterization of Fe- MCM-41 from rice husk silica by hydrothermal technique for arsenate adsorption. Environmental Geochemistry and Health 32(4): 261-266.

Yalcin, N. & Sevinc, V. 2001. Studies on silica obtained from rice husk. Ceramic International 27(2): 219-224.

Yokoi, T., Yoshitake, H. & Tatsumi, T. 2004. Synthesis of amino-functionalized MCM-41 via direct co-condensation and post-synthesis grafting methods using mono-, di- and tri-amino-organoalkoxysilanes. Journal of Materials Chemistry 14: 951-957.

Yoshitake, H., Yokoi, T. & Tatsumi, T. 2002. Adsorption of chromate and arsenate by amino-functionalized MCM-41 and SBA-1. Chemistry of Materials 14(11): 4603-4610.

Yuan, P., Yang, D., Lin, Z.G., He, H.P., Wen, X.Y., Wang, L.J. & Deng, F. 2006. Influences of pretreatment temperature on the surface silylation of diatomaceous amorphous silica with trimethylchlorosilane. Journal of Non-Crystalline Solids 352: 3762-3771.

Zhao, X.S. & Lu, G.Q. 1998. Modification of MCM-41 by surface silylation with trimethylchlorosilane and adsorption study. The Journal of Physical Chemistry B 102: 1556-1561.

 

*Pengarang untuk surat-menyurat; email: Siriluk.chi@kmutt.ac.th

 

 

 

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