Enhancing the Strength Organo Hybrid SiO2 Aerogels with Ultra Low Dielectric Properties

Abstract

To overcome a key bottleneck in the development of high-performance low-dielectric materials, this work presents a novel functionalized hybrid strategy based on benzocyclobutene (BCB)-driven molecular scaffold-synergistic crosslinking. To address the intrinsic brittleness and poor mechanical properties of conventional silica aerogels, flexible ethylene bis(siloxane) bridges were introduced together with a multifunctional BCB-based organic–inorganic reinforcement mechanism. This design allows controlled strengthening of the siloxane network while simultaneously improving hydrophobicity. By precisely tuning the ratio of difunctional to trifunctional BCB precursors, a highly crosslinked and mechanically robust hybrid aerogel framework was achieved. The resulting materials exhibit an ultralow dielectric constant of 1.94–2.04, excellent mechanical performance with a Young’s modulus of up to 1.2 GPa, and outstanding thermal stability, with a T5 value of up to 469.7 °C. Overall, this strategy shifts the design concept beyond conventional single-property low-dielectric materials toward the synergistic integration of high mechanical strength and ultralow dielectric performance, offering a promising material platform for next-generation microelectronic packaging and high-frequency communication applications.