Performance Optimization of SiO_2f/SiO₂ Composites Derived from Polysiloxane Ceramic Precursors.

Area of Science:

• Materials Science
• Ceramic Matrix Composites
• Nanotechnology

Background:

• Developing high-performance ceramic matrix composites is crucial for advanced applications.
• Enhancing mechanical strength and dielectric properties simultaneously presents a significant challenge.
• Quartz fiber-reinforced silica composites offer potential but require interface engineering.

Purpose of the Study:

• To synthesize a novel ceramic precursor for silica matrix composites.
• To manufacture quartz fiber-reinforced silica matrix composites with a tailored interface.
• To evaluate the mechanical and dielectric properties of the developed composites.

Main Methods:

• Synthesis of side ethoxy polysiloxane (PESO) ceramic precursor from polymethylhydrosiloxane (PMHS) and ethanol.
• Fabrication of SiO2f/SiO2 composites using precursor impregnation pyrolysis (PIP) with a PyC-SiO2/BNNSs interface.
• Characterization of mechanical properties (flexural strength, fracture toughness) and dielectric properties (dielectric constant, dielectric loss).

Main Results:

• The PESO precursor exhibited a high ceramic yield (87.15%) and low residual carbon.
• The SiO2f/SiO2 composites showed significant fiber pull-out and debonding.
• Achieved flexural strength of 63.3 MPa and fracture toughness of 2.52 MPa·m1/2.
• Obtained dielectric constant of ~2.5 and dielectric loss < 0.01.

Conclusions:

• The study successfully developed SiO2f/SiO2 composites with excellent mechanical and dielectric properties.
• The PyC-SiO2/BNNSs interface effectively enhances composite performance.
• This approach offers a promising strategy for wave-transmissivity composite materials.