the surface is specially  treated with stearic acid or Silance.

 2.because surface is after organic reaction,so it greatly reduces surface energy,
and improves the dispersion and liquidity inorganic matter accordingly,

3.as a no halogen flame retardant,it can be used in plastic. such as PVC-P,PVC-U,PE copolymer
and rubber.Low smoke density and high thermal stability. initial decomposition temperature 
is about 340 degrees centigrade.No Poisonous and causticity air when degradation.