Preparation and structural studies of black glasses based on ladder-like silsesquioxanes

Sitarz, Maciej; Jastrzębski, Witold; Jeleń, Piotr; Długoń, E.; Gawęda, M.

doi:10.1016/j.saa.2014.05.028

Cited by 33 publications

(16 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Also water and OH bands are less visible. It is also worth to mention that during this step intensity of Si-O-Si band at 1100 cm -1 decreases, while the 440 cm -1 (Si-O bending mode) is starting to be more visible [18]. This confirms that during this step T/D-oligomers and D-oligomers, which are not involved into creation of glass structure, are being evaporated from the tested samples [19,21].…”

Section: Resultsmentioning

confidence: 54%

“…It is typical to receive two amorphous ''halo'' on diffraction patterns of ladder-like silsesquioxane samples (Fig. 2) [7,8,18]. Their presence, along with the conducted MIR studies (Figs.…”

Section: Resultsmentioning

confidence: 89%

“…The Si-OH stretching bands at 3600-3800 cm -1 along with approx. 900 cm -1 bending vibration is visible, and therefore it can be concluded that the polycondensation process is not finished and the material will undergo further changes more easily during pyrolysis [7,8,18]. At approx.…”

Section: Resultsmentioning

confidence: 99%

“…The MTES-CH 3 Si(OCH 3 ) 3 (T units) and DMDES-((CH 3 ) 2 Si(OC 2 H 5 ) 2 ) (D units) were used as a silsesquioxane precursors [11,22,23] 2/1, and 4/1 were synthesized according to the procedure described in our previous papers [7,18,35]. To obtain glassy SiCxOy, dried samples (xerogels) were subsequently heat-treated in a tube furnace at 200, 400, 600, 800, and 1000°C temperature ranges under flowing argon atmosphere.…”

Section: Methodsmentioning

confidence: 99%

See 3 more Smart Citations

Thermal evolution of ladder-like silsesquioxanes during formation of black glasses

Jeleń

Szumera

Gawęda

et al. 2017

J Therm Anal Calorim

View full text Add to dashboard Cite

Pyrolysis of ladder-like silsesquioxanes in oxygen-free atmosphere leads to the formation of silicon oxycarbides (black glasses). Black glasses are materials of amorphous silica structure where some amount of O 2-ions were replaced by C 4-ions. This exchange leads to local increase in bonds density and therefore improvement in mechanical, thermal, and chemical properties. Thanks to this modification, silicon oxycarbide glasses can be used in a variety of applications like: protective coatings and interconnectors in solid oxide fuel cells. Xerogels were prepared by sol-gel method, and ladder-like silsesquioxanes were used as precursors. Samples were burned at 200-1000°C in inert atmosphere. Structural studies in the middle infrared range (MIR) and SEM with EDX confirmed the presence of SiOC bonds in obtained materials. MIR analysis of solid samples together with TG/dTG measurements allowed defining the process for the formation of black glasses.

show abstract

Section: Resultsmentioning

confidence: 54%

Section: Resultsmentioning

confidence: 89%

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Thermal evolution of ladder-like silsesquioxanes during formation of black glasses

Jeleń

Szumera

Gawęda

et al. 2017

J Therm Anal Calorim

View full text Add to dashboard Cite

show abstract

“…(bottom and middle spectra). The positions and intensities of predominant bands in both cases are almost the same and are related to stretching vibration of Si―O (950–1200 cm −1 ) and silicon oxide bending modes (below 600 cm −1 ) . However, a clear difference between the these two spectra is observed at 1380 cm −1 (broad band), where BN absorption is expected.…”

Section: Resultsmentioning

confidence: 99%

Epoxy composites with ceramic core–shell fillers for thermal management in electrical devices

Rybak

Gąska

Kapusta

et al. 2017

Polymers for Advanced Techs

View full text Add to dashboard Cite

In this work, a novel core–shell material has been manufactured in order to enhance the thermal conductivity of epoxy‐based composites. The polymer derived ceramics technique has been used to produce fillers whose core is composed of a standard material – silica, and whose outer layer consists of a boron nitride or silicon nitride shell. The synthesized filler was characterized by infrared spectroscopy, X‐ray diffraction, and scanning electron microscopy coupled with an energy dispersive spectroscopy analysis. The successful formation of core–shell structure was proven. Composite samples based on an epoxy resin filled with 31 vol% of synthetized core–shell filler have been investigated in order to determine the effective thermal conductivity of the modified system. The resulting core–shell composite samples exhibited improvements in thermal conductivity of almost 30% in relation to standard systems, making them a promising material for heat management applications. Additionally, the temperature dependence of the thermal conductivity was investigated over a broad temperature range indicating that the thermal behavior of the composite with incorporated core–shell filler is stable. This stability is a crucial factor when considering the potential of using this technology in applications such as electronics and power systems. Copyright © 2017 John Wiley & Sons, Ltd.

show abstract

New PEG‐Modified Ladder‐Like Silsesquioxane as an Antifoaming Agent

Goodarzi

Karimi

2020

ChemistrySelect

View full text Add to dashboard Cite

New ladder‐like silsesquioxane modified with polyethylene glycol as an antifoaming agent based on silicone was synthesized. Silsesquioxane containing polyethylene glycol fragments was successfully fabricated through the reaction of silsesquioxane bearing cyanuric chloride as a linker molecule with polyethylene glycol groups. The structure of the modified silsesquioxane was characterized by middle infrared spectroscopy (MIR), proton nuclear magnetic resonance (1H‐NMR), field emission scanning electron microscopy (FE/SEM), energy‐dispersive X‐ray spectroscopy (EDX), and transmission electron microscopy (TEM). In addition, thermogravimetric analysis (TGA) showed that the new silsesquioxane had excellent thermal stability. This modified structure was used as antifoaming agent for prevention of carryover in boiler systems. Furthermore, the results indicate that the combination of silsesquioxane and polyethylene glycol groups tends to increase the antifoaming properties of the new silicone‐based agent.

show abstract

Preparation and structural studies of black glasses based on ladder-like silsesquioxanes

Cited by 33 publications

References 24 publications

Thermal evolution of ladder-like silsesquioxanes during formation of black glasses

Thermal evolution of ladder-like silsesquioxanes during formation of black glasses

Epoxy composites with ceramic core–shell fillers for thermal management in electrical devices

New PEG‐Modified Ladder‐Like Silsesquioxane as an Antifoaming Agent

Contact Info

Product

Resources

About