A new route to the surface functionalisation of porous silicon

A method is proposed for grafting unsaturated hydrocarbons onto the surface of porous silicon (PS) by direct reaction from the gas phase. When the sample is heated at an adequate temperature (≅ 350 °C), Si–Hx species (x=1, 2, 3) covering PS internal surfaces decompose: in the presence of olefins, the CC double bond inserts into the SiH bond (probably following a radicalic mechanism) yielding saturated species, for instance a SiCH2CH3 group with ethylene.