Abstract: A porous SiO2 xerogel is produced using temporary pore fillers or solid skeletal supports, which are removed by thermal oxidation at the end of the production process (e.g. carbon or organic), by means of a sol-gel-process by subcritical drying of the gel. The SiO2 xerogel includes pores having a pore size from more than 50 nm to less than 1000 nm. The SiO2 xerogel has a density of less than 400 kg/m3, a carbon content of less than 10%, a thermal conductivity at 800° C. below 0.060 W/m*K, a thermal conductivity at 400° C. below 0.040 W/m*K, and a thermal conductivity at 200° C. below 0.030 W/m*K.

Abstract: In a method for producing a porous SiO2-xerogel starting solution containing a silicon compound is provided and organic monomers and an organically modified alkoxysilane are added to the starting solution. During gelification of the silicon compound, the organic monomers and the organically modified alkoxysilane react in situ to form organic solid skeletal supports in the silicon network. The resulting gel is dried under subcritical conditions and the solid skeletal supports removed by thermal oxidation.

Abstract: A porous SiO2 xerogel is produced using temporary pore fillers or solid skeletal supports, which are removed by thermal oxidation at the end of the production process (e.g. carbon or organic), by means of a sol-gel-process by subcritical drying of the gel. The SiO2 xerogel includes pores having a pore size from more than 50 nm to less than 1000 nm. The SiO2 xerogel has a density of less than 400 kg/m3, a carbon content of less than 10%, a thermal conductivity at 800° C. below 0.060 W/m*K, a thermal conductivity at 400° C. below 0.040 W/m*K, and a thermal conductivity at 200° C. below 0.030 W/m*K.

Abstract: In a method for producing a porous SiO2-xerogel starting solution containing a silicon compound is provided and organic monomers and an organically modified alkoxysilane are added to the starting solution. During gelification of the silicon compound, the organic monomers and the organically modified alkoxysilane react in situ to form organic solid skeletal supports in the silicon network. The resulting gel is dried under subcritical conditions and the solid skeletal supports removed by thermal oxidation.

Abstract: The invention relates to a microporous and mesoporous carbon xerogel and organic precursors thereof based on a phenol-formaldehyde xerogel. A characteristic parameter common to carbon xerogels is a peak in the mesopore size distribution determined by the BJH method (Barrett-Joyner-Halenda) from nitrogen absorption measurements at 77 K in the range from 3.5 nm to 4 nm. The production process is characterized firstly by the low starting material costs (use of phenol instead of resorcinol) and secondly by very simple and cost-effective processing; convective drying without solvent exchange instead of supercritical drying or freeze drying. The carbon xerogels and their organic phenol-formaldehyde xerogel precursors have densities of corresponding to a porosity of up to 89%, and the xerogels can also have a relevant mesopore volume. The carbon xerogels obtained from the phenol-formaldehyde xerogels are also microporous.