Ultralight Three-Dimensional Boron Nitride Foam with Ultralow Permittivity and Superelasticity

• Published in: Nano letters Vol. 13; no. 7; pp. 3232 - 3236
• Main Authors: Yin, Jun, Li, Xuemei, Zhou, Jianxin, Guo, Wanlin
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 10.07.2013
• Subjects: Boron nitride; Chemical synthesis methods; Chemical vapor deposition (including plasma-enhanced cvd, mocvd, etc.); Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Density; Dielectric constant; Dielectric, piezoelectric, ferroelectric and antiferroelectric materials; Dielectrics; Dielectrics, piezoelectrics, and ferroelectrics and their properties; Exact sciences and technology; Foams; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Methods of nanofabrication; Permittivity; Physics; Thermal properties of condensed matter; Thermal properties of small particles, nanocrystals, nanotubes; Thermal stability; Three dimensional; superelasticity; aerogels; Ultralight; three-dimensional; boron nitride; ultralow permittivity; Aerogels; CVD; Thermal properties; Superelasticity; Dielectric materials; Porous materials; Boron nitride; Template reaction; Nickel; Permittivity; Silica; Thermal stability
• DOI: 10.1021/nl401308v
• ISSN: 1530-6984; 1530-6992

Dielectrics with ultralow permittivity within 2 times that of air, excellent mechanical performance, and high thermal stability are highly attractive to many applications. However, since the finding of silica aerogels in the 1930s, no alternative ultralight porous dielectric with density below 10 mg/cm3 has been developed. Here we present three-dimensional hierarchical boron nitride foam with permittivity of 1.03 times that of air, density of 1.6 mg/cm3, and thermal stability up to 1200 °C obtained by chemical vapor deposition on a nickel foam template. This BN foam exhibits complete recovery after cyclic compression exceeding 70% with permittivity within 1.12 times that of air. Gathering all these exceptional characters, the BN foam should create a breakthrough development of flexible ultralow-permittivity dielectrics and ultralight materials.