Butyltrimethoxysilane Used in the Synthesis of SiBOC Ceramics
Aysegul Gencer, et al. Journal of Sol-Gel Science and Technology, 2015, 73, 171-180.
Using n-butyltrimethoxysilane (n-BTMS) and iso-butyltrimethoxysilane (i-BTMS) as silicon sources, and triethyl borate, B(OEt), (TEB) and B(OH) as boron sources, ceramic precursor polymers were successfully synthesized. These new ceramic precursor polymers were pyrolyzed at 400-1400 °C to prepare new SiBOC ceramics.
Synthesis of SiBOC ceramic precursor polymers
· The sample solutions with B/Si molar ratios of 0.1, 0.2 and 0.3 were prepared dissolving the proper amount of B(OH)3 in the silicon alkoxide (n-BTMS or i-BTMS) without addition of water. The reaction mixture was stirred under a condenser at room temperature until B(OH)3 totally dissolved. The clear solutions were cast in plastic test tubes and left open at room temperature for gelation. After completion of the gelation, all gels were dried for at least 10 days at 60 °C.
· The synthesis of the preceramic polymers using TEB as boron sources were carried out under nitrogen atmosphere to prevent hydrolysis of TEB in the air. n-BTMS and TEB containing samples with B/Si molar ratios of 0.1, 0.2 and 0.3 were prepared by hydrolyzing of n-BTMS with acidic water (pH = 1, HCl) using the ratio of H2O/Si = 1.5. After hydrolysis and reaction with TEB, the same gelation treatment as above was performed to obtain the polymer.
Butyltrimethoxysilane Modified Alginate Capsules for Transesterification Reaction
Furusawa, Takeshi, et al. Chemical Engineering Journal, 2016, 288, 473-481.
Butyltrimethoxysilane (n-BTMS) can effectively strengthen the alginate shell to prevent mechanical damage. The capsule breakage rate of n-BTMS modified CaO-loaded alginate (dAlg-T-B) capsules can be reduced from 18.8% to 2.6% after operation. This dAlg-T-B capsule can be used to methanolyze rapeseed oil into fatty acid methyl esters (FAME).
Capsule preparation progress
· Firstly, CaO powder was encapsulated in an alginate shell by the coextrusion method using a coaxial needle with concentric nozzles to obtain Alg capsules.
· The second type of capsule was obtained by putting the Alg capsules into 1% (w/v) sodium alginate solution and stirring them at 300 rpm for 5 min to form second alginate layer on the Alg capsule shell.
· The residual Ca2+ in the first alginate layer formed the second alginate layer. The capsules were collected, washed and then dried to obtain dAlg capsules.
· The prepared dAlg capsules were treated by immersion in 0.1 M tetramethoxysilane(TMOS)/hexane solution for 24 h followed by recovery, washing and drying to obtain dAlg-T capsules.
· The prepared dAlg-T capsules were immersed in 0.01 M BTMS/hexane solution or 0.01 M OTMS/hexane solution for 24 h to prepare dAlg-T-B or dAlg-T-O capsules, respectively. After washing with hexane, the capsules were dried at 323 K for 10 h.
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