Coaxial cables based on hydrophobically modified silica@quartz fiber composites.

Silica composites with low dielectric constants have broad application prospects in the fields of low dielectric and thermal insulation materials. However, silica composites still face challenges such as strong water absorption and strict storage conditions in practical applications. Modification of SiO2@quartz fiber composites was conducted with hydrophobic modifiers (hexamethyldisilazane HMDS, stearic acid, sodium dodecyl sulfate) to study the effects of type and mass fraction of hydrophobic modifiers on the hydrophobic and dielectric properties of the composites. The hydrophobic-modified composites were made into coaxial cables to study the effect of heat treatment on the performance of the cables. The results show that the 3% HMDS-modified composite have the best hydrophobic modification with contact angle of 151.6°, the lowest contact angle is 132.6° after 240 days of storage, and the dielectric constant is as low as 1.87 after 200 °C calcination. The hydrophobic-modified composites were made into coaxial communication cables, and the cables had a voltage standing wave ratio of 1.48, an attenuation value of 1.56 dB, and a characteristic impedance of 48 Ω. The hydrophobic-modified composite materials exhibit excellent cable performance, demonstrating potential application value in communication cables and other fields. [ABSTRACT FROM AUTHOR]