In situ preparation and surface modification of magnesium hydroxide nanoparticles

Hydrophobic magnesium hydroxide (Mg(OH)2) nanoparticles were successfully synthesized via a one-step solution precipitation method with octadecyl dihydrogen phosphate (n-C18H37OPO3H2, ODP) as a surface modifier. The ODP was used to control the growth of crystal in the c direction (direction perpendicular to the layers) and to modify the surface property of the Mg(OH)2 particles produced from the precipitation. Measurements of relative contact angle and active ratio indicated that Mg(OH)2 samples were hydrophobic. The samples were characterized by using field emission scanning electron microscope (SEM), X-ray diffraction (XRD), infrared analysis (IR). The mechanism of influence of ODP on the surface property and morphology of Mg(OH)2 was discussed. Furthermore, from the results of the thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) tests, it was confirmed that small amount of magnesium alkyl phosphate on the surface of Mg(OH)2 particles enhanced the thermal stability of the low density polyethylene(LDPE)/Mg(OH)2.