Pseudomorphical synthesis of glasses with hierarchical macro- and mesoporosity

Herein a new synthetic approach, based on pseudomorphical transformation using sodium hydroxide to attack silica matrix during the dissolution/precipitation process, is proposed. Porous silica with the formation of a new mesoporosity inside of glass samples and with the possibility to close its porosity by a thermal treatment is then obtained. Indeed we report on the simple and successful conversion of a purely macroporous glass (obtained via a Vycor® type synthesis) into a macro- and mesoporous solid without modification of the macroscopic shape of the solid. The obtained multi-porous silica was functionalised and further tested as a support for catalysis or solid phase extraction.