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Catalytic Effect of CaF 2 Nanoparticles on Sintering Behavior of Kaolin‐Based Materials
Author(s) -
Lomeli Martha,
FloresVelez Luisa Maria,
Esparza Imelda,
Torres Roberto,
Domínguez Octavio
Publication year - 2009
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1551-2916.2009.03071.x
Subject(s) - sintering , dispersant , materials science , nanoparticle , chemical engineering , aqueous solution , particle size , phase (matter) , catalysis , particle (ecology) , composite material , nanotechnology , dispersion (optics) , chemistry , organic chemistry , physics , oceanography , engineering , geology , optics
The present work represents preliminary results concerning the effect of nanometric CaF 2 particles on the sintering behavior of kaolin. The nanoparticles were synthesized using aqueous solutions of CaCl 2 dissolved with an organic dispersant and HF. The morphology and particle size of the obtained nanoparticles were square‐like, having a mean length of 25 nm. Kaolin was mixed with different amounts of nanometric CaF 2 (from 0.625 to 5.0 wt%) and the mixtures were milled, pressed, and sintered. From sintering experiments, it was observed that additions of CaF 2 nanoparticles in kaolin clay could shift the phase transition temperatures to lower values. Specifically, the densification temperature could be reduced by almost 150°C when 2.5 wt% of CaF 2 was incorporated. Besides, adding 1.25% of nanometric CaF 2 can achieve that compressive strength augments from 125 to 185 MPa in kaolin samples sintered at 1200°C, meaning an improvement of 40% in the properties of the final material.