TY - JOUR
T1 - Sintering mechanisms and dielectric properties of cold sintered (1-x) SiO2 - x PTFE composites
AU - Ndayishimiye, Arnaud
AU - Tsuji, Kosuke
AU - Wang, Ke
AU - Bang, Sun Hwi
AU - Randall, Clive A.
N1 - Publisher Copyright:
© 2019 Elsevier Ltd
PY - 2019/12
Y1 - 2019/12
N2 - This study reports the sintering mechanisms of SiO2 and the relationship between structure, dielectric properties and processing of 1-xSiO2-xPTFE composites with volume fractions up to x = 0.25, prepared by the cold sintering process (270 °C, 430 MPa, 60 min). The importance of transient liquids was evaluated by using TEOS and 5 M NaOH and the densification behavior was investigated by using a semiautomated uniaxial press equipped with a dilatometer. The shrinkage behavior observed when 5 M NaOH was used highlighted the kinetics of nucleation and growth during the phase transition from amorphous silica to α-quartz. Dielectric properties (ε’ and tan δ) of cold sintered composites were studied at frequencies between 10−1 Hz and 107 Hz. For composites cold sintered with 5 M NaOH, investigations allowed to confirm the presence of PTFE polymer at the interface between two α-quartz grains by STEM EDS analysis and the presence of a dielectric relaxation at 103-104 Hz.
AB - This study reports the sintering mechanisms of SiO2 and the relationship between structure, dielectric properties and processing of 1-xSiO2-xPTFE composites with volume fractions up to x = 0.25, prepared by the cold sintering process (270 °C, 430 MPa, 60 min). The importance of transient liquids was evaluated by using TEOS and 5 M NaOH and the densification behavior was investigated by using a semiautomated uniaxial press equipped with a dilatometer. The shrinkage behavior observed when 5 M NaOH was used highlighted the kinetics of nucleation and growth during the phase transition from amorphous silica to α-quartz. Dielectric properties (ε’ and tan δ) of cold sintered composites were studied at frequencies between 10−1 Hz and 107 Hz. For composites cold sintered with 5 M NaOH, investigations allowed to confirm the presence of PTFE polymer at the interface between two α-quartz grains by STEM EDS analysis and the presence of a dielectric relaxation at 103-104 Hz.
UR - http://www.scopus.com/inward/record.url?scp=85069957559&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85069957559&partnerID=8YFLogxK
U2 - 10.1016/j.jeurceramsoc.2019.07.048
DO - 10.1016/j.jeurceramsoc.2019.07.048
M3 - Article
AN - SCOPUS:85069957559
SN - 0955-2219
VL - 39
SP - 4743
EP - 4751
JO - Journal of the European Ceramic Society
JF - Journal of the European Ceramic Society
IS - 15
ER -