Characterization of Magnesium Silicate Hydrate (MSH) Gel Formed by Reacting MgO and Silica Fume

Tingting Zhang; Jing Zou; Baomin Wang; Zhenlin Wu; Yuan Jia; Christopher R Cheeseman

doi:10.3390/ma11060909

Characterization of Magnesium Silicate Hydrate (MSH) Gel Formed by Reacting MgO and Silica Fume

Materials (Basel). 2018 May 28;11(6):909. doi: 10.3390/ma11060909.

Authors

Tingting Zhang¹, Jing Zou², Baomin Wang³, Zhenlin Wu⁴, Yuan Jia⁵, Christopher R Cheeseman⁶

Affiliations

¹ Faculty of Infrastructure Engineering, Dalian University of Technology, Dalian 116023, China. tingtingzhang@dlut.edu.cn.
² Faculty of Infrastructure Engineering, Dalian University of Technology, Dalian 116023, China. zou_jing8@mail.dlut.edu.cn.
³ Faculty of Infrastructure Engineering, Dalian University of Technology, Dalian 116023, China. wangbm@dlut.edu.cn.
⁴ School of Optoelectronic Engineering and Instrumentation Science, Dalian University of Technology, Dalian 116023, China. zhenlinwu@dlut.edu.cn.
⁵ Hebei Provincial Key Laboratory of Inorganic Nonmetallic, College of Materials Science and Engineering, North China University of Science and Technology, Tangshan 063210, China. jia132012@ncst.edu.cn.
⁶ Department of Civil and Environmental Engineering, Imperial College London, London SW7 2AZ, UK. c.cheeseman@imperial.ac.uk.

Abstract

Magnesium silicate hydrate (MSH) gel was formed by reacting magnesium oxide (MgO) with silica fume (SF) in distilled water. The MSH was prepared using a MgO/SF molar ratio of 1.0 (40:60 weight ratio). Samples were analyzed during hydration process up to 300 days at room temperature. The MSH characterization has been carried out using a range of analytical techniques. Quantitative analysis was achieved using thermogravimetric analysis (TG/DTG) with a de-convolution technology. The structure of MSH gel was characterized using solid state nuclear magnetic resonance (²⁹Si NMR) and Fourier transform infrared (FT-IR) spectroscopy. Transmission electron microscopy (TEM) was used to investigate MSH microstructure. Compared with natural magnesium silicate hydrate minerals, the structure of MSH gel is highly disordered and generates on the surface of particles, producing a shell structure with cavity. The molecular structure of MSH phase is layered. The results also show that the extent of polymerization of MSH gel is related to the solution pH during hydration.

Keywords: MgO; amorphous material; hydration products; microstructure; silica fume.