Magnesium hydroxide nanoparticles synthesized in water-in-oil microemulsions

Well-dispersed magnesium hydroxide nanoplatelets were synthesized by a simple water-in-oil (w/o) microemulsion process, blowing gaseous ammonia (NH 3) into microemulsion zones solubilized by magnesium chloride solution (MgCl 2). Typical quaternary microemulsions of Triton X-100/cyclohexane/ n-hexanol/water were used as space-confining microreactors for the nucleation, growth, and crystallization of magnesium hydroxide nanoparticles. The obtained magnesium hydroxide was characterized by field-emission scanning electron microscopy (FESEM), high-resolution transmission election microscopy (HRTEM), X-ray powder diffraction (XRD), laser light scattering, Fourier transform infrared spectroscopy (FT-IR), and thermogravimetric analysis–differential scanning calorimetry (TGA–DSC). The mole ratio of water to surfactant ( ω 0 ) played an important role in the sizes of micelles and nanoparticles, increasing with the increase of ω 0 . The compatibility and dispersibility of nanoparticles obtained from reverse micelles were improved in the organic phase. This paper focuses on the synthesis of well-dispersed and size-controllable magnesium hydroxide nanoparticles with uniform shape and even size in a quaternary microemulsion of Triton X-100/cyclohexane/ n-hexanol/water.