The invention relates to a method for producing aerogels, in particular silica aerogels, by way of a sol-gel process.

The problem addressed by the invention is that of producing aerogels which have as high and permanent a hydrophobicity as possible and which have a reduced combustibility, that is as low a carbon content as possible, and are simultaneously less rigid and brittle than known systems, i.e. which with reduced combustibility have a high flexibility and high stability at the same time, that is high mechanical load-bearing capacity. Said problem is solved in that the invention provides gels chosen from lyogel or aerogel, which are synthesised from oxide units and [R.sub.xSiO.sub.(4-x)/2] units, wherein the primary particles have a change of concentration in [R.sub.xSiO.sub.(4-x)/2] units from the inside to the outside, wherein x can be the same or different and is 1 or 2, and R can be the same or different and is hydrogen or an organic substituted or unsubstituted radical, and wherein the oxide units contain [SiO.sub.4/2] units, and a method for producing same. The gels provided can be used in cosmetic, medical or for chromatographic applications, and as a catalyst or catalyst support. If the gels are aerogels, same are preferably used for thermal and/or acoustic insulation.

The invention relates to a method for producing aerogels, in particular silica aerogels, by way of a sol-gel process.

The synthesis of an organosilicone adsorbent, which can be used in medicine as an enterosorbent for the removal of organic and toxic metabolites from the body obtains a new branched organosilicone polymerous polynuclear adsorbent of high molecular toxins. According to the analysis by Si.sup.29NMR method, the adsorbent contains superpositions of at least three silicon signals with values of chemical shifts 80 ppm, 100 ppm, 115 ppm, and ratio of their integral intensities close to 2:2:1. This adsorbent has a high adsorption activity, and the synthesis of its obtaining can reduce labour costs, increase output of the target product in manufacture and reduce their self-cost/net-cost.

Provided is a silica aerogel with enhanced physical properties. The silica aerogel can have a tap density of 0.030 to 0.070 g/mL, and a carbon content of 11.2 to 12.1 wt %.

It is an object of the invention to provide an economically viable process for the production of hydrophobized aerogels which works both inexpensively and in a resource-conserving manner. 2.2. This object is achieved by the provision of a process for producing organically modified aerogels by producing a sol containing [SiO.sub.4/2] units and [R.sub.xSiO.sub.(4X)/2] a units, where x may be the same or different and is 1, 2 or 3, and R may be the same or different and is hydrogen or an organic substituted or unsubstituted radical, using the sol to form a gel, surface-modifying the gel obtained in the presence of more than 0.1% by weight of a phase modifier in a mixture comprising organosiloxane and initiator, wherein the mixture contains at least 20% by weight of organosiloxane and wherein the initiator consists of acid or organosiloxane or mixtures thereof and the gels obtained are dried. 2.3. The aerogels provided can be used as insulating materials, especially in thermal insulation.

It is an object of the invention to provide an economically viable process for the production of hydrophobized aerogels which works both inexpensively and in a resource-conserving manner. 2.2. This object is achieved by the provision of a process for producing organically modified aerogels by producing a sol containing [SiO.sub.4/2] units and [R.sub.xSiO.sub.(4X)/2] a units, where x may be the same or different and is 1, 2 or 3, and R may be the same or different and is hydrogen or an organic substituted or unsubstituted radical, using the sol to form a gel, surface-modifying the gel obtained in the presence of more than 0.1% by weight of a phase modifier in a mixture comprising organosiloxane and initiator, wherein the mixture contains at least 20% by weight of organosiloxane and wherein the initiator consists of acid or organosiloxane or mixtures thereof and the gels obtained are dried. 2.3. The aerogels provided can be used as insulating materials, especially in thermal insulation.

The present invention relates to a method for producing a silica aerogel and a silica aerogel produced thereby. More specifically, a first water glass solution is used to form a first silica wet gel, and then a second water glass solution is additionally added to form a second silica wet gel organically bonded to the first silica wet gel which serves as a basic skeleton, so that a silica aerogel with enhanced physical properties is formed to increase the resistance to shrinkage in ambient drying. Thus, a low-density silica aerogel may be formed, and the concentrations of the first and second water glass solutions may be adjusted to control the physical properties of the silica aerogel.

Processes for preparing porous particles are disclosed, in which the resulting particles release an encapsulated active ingredient more readily in aqueous media than they do in alcoholic media. Also described are the particles themselves, as well as tamperproof, abuse-deterrent, dosage forms comprising the porous particles. The release characteristics of the porous particles make them useful for overcoming drug-abuse techniques, such as dose-dumping in alcoholic media.

Processes for preparing porous particles are disclosed, in which the resulting particles release an encapsulated active ingredient more readily in aqueous media than they do in alcoholic media. Also described are the particles themselves, as well as tamperproof, abuse-deterrent, dosage forms comprising the porous particles. The release characteristics of the porous particles make them useful for overcoming drug-abuse techniques, such as dose-dumping in alcoholic media.