Formation of Magnesium Hydrosilicate Nanoscrolls with the Chrysotile Structure from Nanocrystalline Magnesium Hydroxide and Their Thermally Stimulated Transformation

This paper examines the effect of size parameters of magnesium hydroxide nanoparticles prepared by different methods on the formation of hydrosilicate nanoscrolls with the composition Mg3Si2O5(OH)(4) under hydrothermal conditions, their geometric characteristics, and their thermal behavior. Magnesium hydrosilicate nanoscrolls with the chrysotile structure have been shown to form regardless of the hydrothermal treatment time and the method used to prepare magnesium hydroxide. At the same time, the nanoscroll length distribution and, especially, the nanoscroll diameter distribution depend on the method used to prepare magnesium hydroxide. In the case of hydrosilicate samples synthesized from Mg(OH)(2) prepared by mixing reagents in microreactor with free impinging jets, the exothermic peak due to the conversion of magnesium hydrosilicate into magnesium silicate with the forsterite structure is located at a temperature of 817 degrees C, whereas in the case of samples prepared from magnesium hydroxide synthesized via reverse precipitation the peak is shifted to higher temperatures (825 degrees C).

Automated summary

This study examines the effects of different methods on the size parameters of magnesium hydroxide nanoparticles and their influence on the formation, geometric characteristics, and thermal behavior of hydrosilicate nanoscrolls. Regardless of the method and treatment time, magnesium hydrosilicate nanoscrolls with chrysotile structure can be formed. However, the distribution of nanoscroll length and diameter depends on the method of preparing magnesium hydroxide. The exothermic peak temperature of the conversion from magnesium hydrosilicate to magnesium silicate with forsterite structure is higher when using reverse precipitation method (825°C) compared to the microreactor method (817°C).