Abstract
Based on their high performance in gas and liquid-phase separations, 1,2-bis(triethoxysilyl)ethane (BTESE)-derived organosilica membranes have attracted much attention. To improve performance, we focused on the acid molar ratio (AR) in sol preparation and its effect on the pore formation mechanism during sol-gel processing. BTESE-derived sols with AR = 10−4–100 were prepared, and the effect of the AR on the gel structure was evaluated in detail via FT-IR, nuclear magnetic resonance (NMR), N2 adsorption, and positron annihilation lifetime (PAL) measurements. The chemical structure of the gels was confirmed by FT-IR and NMR and showed that sols with the largest number of silanol groups (AR = 10−2) experienced a significant increase in condensation during the firing process. The porous structures of fired gels characterized by N2 adsorption and PAL measurement showed that the AR = 10−2 fired gel consisted of a larger number of small pores that had formed during the firing process. Single-gas permeation experiments showed high H2 permeance (5–9 × 10−7 mol/(m2 Pa s)) and H2/CF4 selectivity (700–20,000). The gas permselectivity (He/H2, H2/N2, and H2/CF4) was highest for the intermediate AR (=10−2), which corresponded to the greatest amount of silanol groups in unfired gels and confirmed that small pores had formed from the condensation of silanol groups during firing.
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Sun B, Zhou G, Zhang H (2016) Synthesis functionalization, and applications of morphology-controllable silica-based nanostructures: a review. Prog Solid State Chem 44:1–19
Singh LP, Bhattacharyya SK, Kumar R, Mishra G, Sharma U, Singh G, Ahalawat S (2014) Sol-gel processing of silica nanoparticles and their applications. Adv Colloid Interface Sci 214:17–37
Park SS, Moorthy MS, Ha CS (2014) Periodic mesoporous organosilicas for advanced applications. NPG Asia Mater 6:96
Yamamoto E, Kuroda K (2016) Colloidal mesoporous silica nanoparticles. Bull Chem Soc Jpn 89:501–539
Alarcos N, Cohen B, Ziolek M, Douhal A (2017) Photochemistry and photophysics in silica-based materials: ultrafast and single molecule spectroscopy observation. Chem Rev 117:13639–13720
Tsuru T (2008) Nano/subnano-tuning of porous ceramic membranes for molecular separation. J Sol-Gel Sci Technol 46:349–361
de Vos RM, Verweij H (1998) High-selectivity, high-flux silica membranes for gas separation. Science 279:1710–1711
Duke MC, da Costa JCD, Do DD, Gray PG, Lu GQ (2006) Hydrothermally robust molecular sieve silica for wet gas separation. Adv Func Mater 16:1215–1220
Kanezashi M, Sasaki T, Tawarayama H, Yoshioka T, Tsuru T (2013) Hydrogen permeation properties and hydrothermal stability of sol–gel-derived amorphous silica membranes fabricated at high temperatures. J Am Ceram Soc 96:2950–2957
Kreiter R, Rietkerk MDA, Castricum HL, van Veen HM, ten Elshof JE, Vente JF (2011) Evaluation of hybrid silica sols for stable microporous membranes using high-throughput screening. J Sol-Gel Sci Technol 57:245–252
Kanezashi M, Yoneda Y, Nagasawa H, Toshinori T, Yamamoto K, Ohshita J (2017) Gas permeation properties for organosilica membranes with different Si/C ratios and evaluation of microporous structures. AIChE J 63:4491–4498
Kanezashi M, Yada K, Yoshioka T, Tsuru T (2009) Design of silica networks for development of highly permeable hydrogen separation membranes with hydrothermal stability. J Am Chem Soc 131:414–415
Niimi T, Nagasawa H, Kanezashi M, Yoshioka T, Ito K, Tsuru T (2014) Preparation of BTESE-derived organosilica membranes for catalytic membrane reactors of methylcyclohexane dehydrogenation. J Membr Sci 455:375–383
Yu X, Meng L, Niimi T, Nagasawa H, Kanezashi M, Yoshioka T, Toshinori T (2016) Network engineering of a BTESE membrane for improved gas performance via a novel pH-swing method. J Membr Sci 511:219–227
Castricum HL, Paradis GG, Mittelmeijer-Hazeleger MC, Bras W, Eeckhaut G, Vente JF, Rothenberg G, ten Elshof JE (2014) Tuning the nanopore structure and separation behavior of hybrid organosilica membranes. Microporous Mesoporous Mater 185:224–234
Castricum HL, Qureshi HF, Nijimeijer A, Winnubst L (2015) Hybrid silica membranes with enhanced hydrogen and CO2 separation properties. J Membr Sci 488:121–128
Song H, Wei Y, Qi H (2017) Tailoring pore structures to improve the permselectivity of organosilica membranes by tuning calcination parameters. J Mater Chem A 5:24657–24666
Gong G, Wang J, Nagasawa H, Kanezashi M, Yoshioka T, Tsuru T (2014) Synthesis and characterization of a layered-hybrid membrane consisting of an organosilica separation layer on a polymeric nanofiltration membrane. J Membr Sci 472:19–28
Wang J, Kanezashi M, Yoshioka T, Tsuru T (2012) Effect of calcination temperature on the PV dehydration performance of alcohol aqueous solutions through BTESE-derived silica membranes. J Membr Sci 415–416:810–815
Rong X, Zou Lin, Lin Peng, Zhang Qi, Zhong Jing (2016) Pervaporative desulfurization of model gasoline using PDMS/BTESE-derived organosilica hybrid membranes. Fuel Process Technol 154:188–196
Ibrahim SM, Nagasawa H, Kanezashi M, Tsuru T (2015) Robust organosilica membranes for high temperature reverse osmosis (RO) application: Membrane preparation, separation characteristics of solutes and membrane regeneration. J Membr Sci 493:515–523
Qureshi HF, Nijmeijer A, Winnubst L (2013) Influence of sol–gel process parameters on the micro-structure and performance of hybrid silica membranes. J Membr Sci 446:19–25
Igi R, Yoshioka T, Ikuhara YH, Iwamoto Y, Tsuru T (2008) Characterization of Co-doped silica for improved hydrothermal stability and application to hydrogen separation membranes at high temperatures. J Am Ceram Soc 91:2975–2981
Ito K, Oka T, Kobayashi Y, Suzuki R, Ohdaira T (2012) Variable-energy positron study of nanopore structure in hydrocarbon-siliconoxide hybrid PECVD films. Phys Procedia 35:140–144
Kirkegaard P, Jørgen N, Eldrup M (1989) PATFIT-88: a data processing system for positron annihilation spectra on mainframe and personal computers. Riso National Laboratory, Denmark
Tao SJ (1972) Psitronium annihilation in molecular substances. J Chem Phys 56:5499–5510
Eldrup M, Lightbody D, Sherwood JN (1981) The temperature dependence of positron lifetimes in solid pivalic acid. Chem Phys 63:51–58
Lee HR, Kanezashi M, Shimomura Y, Yoshioka T, Tsuru T (2011) Evaluation and fabrication of pore-size-tuned silica membranes with tetraethoxydimethyl disiloxane for gas separation. AIChE J 57:2755–2765
Yoshioka T, Kanezashi M, Tsuru T (2013) Micropore size estimation on gas separation membranes: a study in experimental and molecular dynamics. AIChE J 59:2179–2194
Gao B, Tang Y, Zhu C, Zhang Z (1997) Synthesis and hydrolysis of hybridized silicon alkoxide: Si(OEt)x(OBut)4−x. Part I: synthesis and Identification of the Si(OEt)x(OBut)4−x. J Sol-Gel Sci Technol 10:247–253
Grill A (2009) Porous pSICOH ultralow-k dielectrics for chip interconnects prepared by PECVD. Annu Rev Mater Res 39:49–69
Ishida H, Koenig JL (1978) Fourier transform infrared spectroscopic study of the silane coupling agent/porous silica interface. J Colloid Interface Sci 64:555–564
Liang Y, Anwander R (2004) Synthesis of pore-enlarged mesoporous organosilicas under basic conditions. Microporous Mesoporous Mater 72:153–165
Wahab MA, Kim II, Ha CS (2004) Hybrid periodic mesoporous organosilica materials prepared from 1,2-bis(triethoxysilyl)ethane and (3-cyanopropyl)triethoxysilane. Microporous Mesoporous Mater 69:19–27
Masse S, Laurent G, Babonneau F (2007) High temperature behavior of periodic mesoporous ethanesilica glasses prepared from a bridged silsesquioxane and a non-ionic triblock copolymer. J Non Cryst Solids 53:1109–1119
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Highlights
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Pore formation mechanism of 1,2-bis(triethoxysilyl)ethane (BTESE)-derived gels was proposed.
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BTESE-derived sols and gels were characterized by DLS, FTIR, PALS, NMR, and N2 adsorption.
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Small pores were formed by the condensation of silanol groups via a firing process.
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Pore sizes of fired gels were controlled by tuning the amount of acid catalyst.
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Optimized BTESE-derived membranes showed high permselectivity.
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Moriyama, N., Nagasawa, H., Kanezashi, M. et al. Bis(triethoxysilyl)ethane (BTESE)-derived silica membranes: pore formation mechanism and gas permeation properties. J Sol-Gel Sci Technol 86, 63–72 (2018). https://doi.org/10.1007/s10971-018-4618-x
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DOI: https://doi.org/10.1007/s10971-018-4618-x