Addition of BaTiO₃ and carbon nanoparticles to silica aerogel and its dielectric properties

Abstract

A tetramethylorthosilicate(TMOS)/ethanol solution was gelled together with BaTiO 3 nanoparticles or carbon nanoparticles. The wet gel was dried in supercritical carbon dioxide, resulting in aerogel nanocomposites with compositions in the range of BaTiO 3 / SiO 2 = 1/100 to 20/100 and C/SiO 2 = 20/100 to 80/100. The bulk density of the aerogel obtained was in the range of 0.1 to 0.2 g/cm 3 , the porosity was about 95%, and the specific surface area was in the range of 400 to 700 m 2 /g. These values represent the characteristics of the aerogel. The relative permittivity and dielectric loss were respectively approximately 2 and 5 © 10 ¹3 for the BaTiO 3 -silica aerogel nanocomposite, and in the range of 5 to 10 and 0.012 to 0.4 for the carbon-silica aerogel nanocomposite.

Novel, flexible, and transparent thin film polyimide aerogels with enhanced thermal insulation and high service temperature

“…As illustrated in Fig. 11, the aerogels fabricated in this work have an improved performance compared to other materials such as the SiO 2 xerogel, 124,125 ODA-PMDA aerogel, 84 BPDA-ODA/6FAPB aerogel, 126 F88/MSQ, 127 CBDA/TFDB/OAPS aerogel, 128 PTFE/FEP, 129 and BTFB/ODPA/POSS aerogel 130 and are comparable to the FPEN film, 131 BaTiO 3 -silica aerogel 132 and BPDA-ODA/TFMB aerogel. 133…”

Preparation and evaluation of Au nanoparticle–silica aerogel nanocomposite

“…Enhancement of permittivity below the percolation threshold has been observed in polymeric composites filled with conductive particles, such as metal or carbon [24][25][26][27]. We have also reported on the permittivity enhancement of silica aerogel by loading with carbon nanoparticles [7], where a carbon-silica aerogel composite showed a relative permittivity of ca. 6 and a dielectric loss of ca.…”

“…The preparation process used was the same as that previously reported [5][6][7]. Tetramethyl orthosilicate (TMOS; Tokyo Chem.…”

“…We have thus considered the preparation of a variety of functional aerogels by combining functional nanoparticles and silica aerogel. We have already reported on the preparation of a magnetic aerogel that consists of a ferrite-silica aerogel nanocomposite [5,6], and dielectric aerogels that consist of a BaTiO 3 -silica aerogel nanocomposite and a carbon-silica aerogel nanocomposite [7]. Anderson et al also reported on various composite aerogels [8][9][10].…”

“…(a) Relative permittivity and (b) dielectric loss for the silica aerogel, Au nanoparticle-silica aerogel nanocomposite, and a carbon-silica aerogel nanocomposite[7].…”