In situ preparation of hydrophobic CaCO3 nanoparticles in a gas–liquid microdispersion process--颗粒学报PARTICUOLOGY

Du, L., Wang, Y., & Luo, G. (2013). In situ preparation of hydrophobic CaCO3 nanoparticles in a gas–liquid microdispersion process. Particuology, 11(4), 421–427. https://doi.org/10.1016/j.partic.2012.07.009

In situ preparation of hydrophobic CaCO₃ nanoparticles in a gas–liquid microdispersion process

Le Du, Yujun Wang, Guangsheng Luo^*

The State Key Laboratory of Chemical Engineering, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China

10.1016/j.partic.2012.07.009

Volume 11, Issue 4, August 2013, Pages 421-427

Received 30 April 2012, Revised 13 June 2012, Accepted 19 July 2012, Available online 5 March 2013.

E-mail: gsluo@tsinghua.edu.cn

Highlights

► In situ surface-modified CaCO₃ nanoparticles were prepared in a microreactor.

► Particles prepared were highly hydrophobic and monodisperse with average size of 30 nm.

► Mechanism was speculated to explain surfactant effect in suspension system.

Abstract

This study presents a novel process of in situ surface modification of CaCO₃ nanoparticles using a multiple-orifice dispersion microreactor. CO₂/Ca(OH)₂ precipitation reaction was employed to prepare CaCO3 nanoparticles with sodium stearate surfactant. Synthesized CaCO₃ products were characterized by thermogravimetric analysis (TGA), infra-red (IR), X-ray diffraction (XRD), transmission electron microscopy (TEM) and Brunauer–Emmet–Teller analysis (BET). The effect of various operation parameters on nanoparticles and the dosage of sodium stearate were determined. The results showed that the preparation process could be precisely controlled with efficient mass transfer process. The particles were highly hydrophobic with a contact angle of 117° and monodisperse with an average size of 30 nm. The adsorptions of sodium stearate and calcium ion on solid particles during the in situ surface modification process were investigated.

Graphical abstract

Keywords

CaCO₃ nanoparticles; In situ surface modification; Microreactor; Mass transfer

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