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Krupinski K, Wagler J, Brendler E, Kroke E. A Non-Hydrolytic Sol–Gel Route to Organic-Inorganic Hybrid Polymers: Linearly Expanded Silica and Silsesquioxanes. Gels 2023; 9:gels9040291. [PMID: 37102903 PMCID: PMC10138140 DOI: 10.3390/gels9040291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 03/27/2023] [Accepted: 03/30/2023] [Indexed: 04/05/2023] Open
Abstract
Condensation reactions of chlorosilanes (SiCl4 and CH3SiCl3) and bis(trimethylsilyl)ethers of rigid, quasi-linear diols (CH3)3SiO–AR–OSi(CH3)3 (AR = 4,4′-biphenylene (1) and 2,6-naphthylene (2)), with release of (CH3)3SiCl as a volatile byproduct, afforded novel hybrid materials that feature Si–O–C bridges. The precursors 1 and 2 were characterized using FTIR and multinuclear (1H, 13C, 29Si) NMR spectroscopy as well as single-crystal X-ray diffraction analysis in case of 2. Pyridine-catalyzed and non-catalyzed transformations were performed in THF at room temperature and at 60 °C. In most cases, soluble oligomers were obtained. The progress of these transsilylations was monitored in solution with 29Si NMR spectroscopy. Pyridine-catalyzed reactions with CH3SiCl3 proceeded until complete substitution of all chlorine atoms; however, no gelation or precipitation was found. In case of pyridine-catalyzed reactions of 1 and 2 with SiCl4, a Sol–Gel transition was observed. Ageing and syneresis yielded xerogels 1A and 2A, which exhibited large linear shrinkage of 57–59% and consequently low BET surface area of 10 m2⋅g−1. The xerogels were analyzed using powder-XRD, solid state 29Si NMR and FTIR spectroscopy, SEM/EDX, elemental analysis, and thermal gravimetric analysis. The SiCl4-derived amorphous xerogels consist of hydrolytically sensitive three-dimensional networks of SiO4-units linked by the arylene groups. The non-hydrolytic approach to hybrid materials may be applied to other silylated precursors, if the reactivity of the corresponding chlorine compound is sufficient.
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Affiliation(s)
- Katrin Krupinski
- Institute of Inorganic Chemistry, Department of Chemistry and Physics, Technische Universität Bergakademie Freiberg (TUBAF), Leipziger Strasse 29, 09596 Freiberg, Saxony, Germany
| | - Jörg Wagler
- Institute of Inorganic Chemistry, Department of Chemistry and Physics, Technische Universität Bergakademie Freiberg (TUBAF), Leipziger Strasse 29, 09596 Freiberg, Saxony, Germany
- Center of Efficient High Temperature Processes and Material Conversion (ZeHS), Technische Universität Bergakademie Freiberg (TUBAF), Winklerstr. 5, 09599 Freiberg, Saxony, Germany
| | - Erica Brendler
- Institute of Analytical Chemistry, Department of Chemistry and Physics, Technische Universität Bergakademie Freiberg (TUBAF), Leipziger Strasse 29, 09596 Freiberg, Saxony, Germany
| | - Edwin Kroke
- Institute of Inorganic Chemistry, Department of Chemistry and Physics, Technische Universität Bergakademie Freiberg (TUBAF), Leipziger Strasse 29, 09596 Freiberg, Saxony, Germany
- Center of Efficient High Temperature Processes and Material Conversion (ZeHS), Technische Universität Bergakademie Freiberg (TUBAF), Winklerstr. 5, 09599 Freiberg, Saxony, Germany
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Hong Y, Qu G, Du Y, Yuan T, Hao S, Yang W, Dai Z, Ma Q. Experimental Investigations into the Pyrolysis Mechanism and Composition of Ceramic Precursors Containing Boron and Nitrides with Different Boron Contents. MATERIALS (BASEL, SWITZERLAND) 2022; 15:8390. [PMID: 36499887 PMCID: PMC9739848 DOI: 10.3390/ma15238390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 10/25/2022] [Accepted: 10/27/2022] [Indexed: 06/17/2023]
Abstract
In this work, a novel ceramic precursor containing boron, silicon, and nitrides (named SiBCN) was synthesized from liquid ceramic precursors. Additionally, its pyrolysis, microstructure, and chemical composition were studied at 1600 °C. The results showed that the samples with different boron contents had similar structural composition, and both of the two precursors had stable amorphous SiBN structures at 1400 °C, which were mainly composed of B-N and Si-N and endowed them with excellent thermo-oxidative stability. With the progress of the heating process, the boron contents increased and the structures became more amorphous, significantly improving the thermal stability of the samples in high-temperature environments. However, during the moisture treatment, the introduction of more boron led to worse moisture stability.
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Affiliation(s)
- Yiqiang Hong
- Science and Technology on Advanced Ceramic Fibers and Composites Laboratory, College of Aerospace Science, National University of Defense Technology, Changsha 410073, China
- Beijing System Design Institute of Mechanical-Electrical Engineering, Beijing 100871, China
| | - Guoxin Qu
- The Fourth Academy of CASIC, Beijing 100028, China
| | - Youpei Du
- Beijing System Design Institute of Mechanical-Electrical Engineering, Beijing 100871, China
| | - Tingting Yuan
- Beijing System Design Institute of Mechanical-Electrical Engineering, Beijing 100871, China
| | - Shuangshuang Hao
- Beijing System Design Institute of Mechanical-Electrical Engineering, Beijing 100871, China
| | - Wei Yang
- Beijing System Design Institute of Mechanical-Electrical Engineering, Beijing 100871, China
| | - Zhen Dai
- Beijing System Design Institute of Mechanical-Electrical Engineering, Beijing 100871, China
| | - Qingsong Ma
- Science and Technology on Advanced Ceramic Fibers and Composites Laboratory, College of Aerospace Science, National University of Defense Technology, Changsha 410073, China
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Anand R, Nayak BB, Behera SK. A Novel TiO2–TiC–TiC0.3N0.7–C–SiCN Multiphase Ceramic Nanocomposite from Preceramic Polymer Pyrolysis. J Inorg Organomet Polym Mater 2022. [DOI: 10.1007/s10904-022-02359-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Iwase Y, Horie Y, Daiko Y, Honda S, Iwamoto Y. Synthesis of a Novel Polyethoxysilsesquiazane and Thermal Conversion into Ternary Silicon Oxynitride Ceramics with Enhanced Thermal Stability. MATERIALS 2017; 10:ma10121391. [PMID: 29206217 PMCID: PMC5744326 DOI: 10.3390/ma10121391] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 11/27/2017] [Accepted: 11/29/2017] [Indexed: 11/25/2022]
Abstract
A novel polyethoxysilsesquiazane ([EtOSi(NH)1.5]n, EtOSZ) was synthesized by ammonolysis at −78 °C of ethoxytrichlorosilane (EtOSiCl3), which was isolated by distillation as a reaction product of SiCl4 and EtOH. Attenuated total reflection-infra red (ATR-IR), 13C-, and 29Si-nuclear magnetic resonance (NMR) spectroscopic analyses of the ammonolysis product resulted in the detection of Si–NH–Si linkage and EtO group. The simultaneous thermogravimetric and mass spectrometry analyses of the EtOSZ under helium revealed cleavage of oxygen-carbon bond of the EtO group to evolve ethylene as a main gaseous species formed in-situ, which lead to the formation at 800 °C of quaternary amorphous Si–C–N with an extremely low carbon content (1.1 wt %) when compared to the theoretical EtOSZ (25.1 wt %). Subsequent heat treatment up to 1400 °C in N2 lead to the formation of X-ray amorphous ternary Si–O–N. Further heating to 1600 °C in N2 promoted crystallization and phase partitioning to afford Si2N2O nanocrystallites identified by the XRD and TEM analyses. The thermal stability up to 1400 °C of the amorphous state achieved for the ternary Si-O-N was further studied by chemical composition analysis, as well as X-ray photoelectron spectroscopy (XPS) and 29Si-NMR spectroscopic analyses, and the results were discussed aiming to develop a novel polymeric precursor for ternary amorphous Si–O–N ceramics with an enhanced thermal stability.
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Affiliation(s)
- Yoshiaki Iwase
- Applied Research Laboratory, General Center of Research and Development, Toagosei Co., Ltd., 8, Showa-cho, Minato-ku, Nagoya 455-0026, Japan.
| | - Yoji Horie
- Applied Research Laboratory, General Center of Research and Development, Toagosei Co., Ltd., 8, Showa-cho, Minato-ku, Nagoya 455-0026, Japan.
| | - Yusuke Daiko
- Department of Life Science and Applied Chemistry, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan.
| | - Sawao Honda
- Department of Life Science and Applied Chemistry, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan.
| | - Yuji Iwamoto
- Department of Life Science and Applied Chemistry, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan.
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Sun ZG, Qiao XJ, Ren QG, Guo XD, Wei L, Liu PZ, Li WC. Synthesis of SiC/SiO 2 nanochains by carbonthermal reduction process and its optimization. ADV POWDER TECHNOL 2016. [DOI: 10.1016/j.apt.2016.05.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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