The separation process can have two objectives: obtaining information (analysis), or purifying a product. Current separation methods (distillation, extraction, crystallisation) are only moderately effective. They can perform easy separations, but they soon fail when the molecules have a similar structure. Distillation is an energy-intensive process and is limited to simple separations. Extraction requires the use of flammable and toxic organic solvents, as well as a heavy investment. Crystallisation is a tricky technique that uses a large quantity of solvent and is limited to simple separations.
LC allows separations from 1000 to 10,000 times more effective than these other techniques. It is irreplaceable for complex separations that the other methods cannot achieve, but it is currently limited by low productivity, and it requires very high investments because of its operating pressure. These factors limit its penetration into markets that use separation processes. The Separative technology allows to use the multicapillary chromatography to solve this drawbacks.
The chromatography column can be compared to a filter. The current technologies use a chaos of particles, or fibrils, which create very strong drag, leading to the very high operating pressures. This filter’s drag can be drastically reduced by making it out of a set of rectilinear and parallel ordered channels, comparable toa honeycomb structure.
This leads to a breakthrough technological innovation reducing the pressure, volume and cost of equipment, for separation as efficient as, or slightly better than, the state of the art.
The monolithic silica gels that are known to the state of the art and obtained via the sol-gel process all undergo significant shrinkage during their synthesis. They cannot be obtained in diameters above a few millimetres.
Based on its own research, SEPARATIVE has developed an ultra-pure silica material. Flawless monolithic objects 20 cm in diameter were obtained without any difficulty. This substrate has a specific surface of 250 m2/g and a pore size of 8 nm. It does not contract on drying and it has the mechanical properties of a ceramic. These performance characteristics constitute a revolution in their own right. They form the basis of SEPARATIVE’s technological, industrial and economic potential..
Let us imagine a set of glass capillary tubes operating in parallel. Slight differences between them will cause a brutal drop in the efficiency of the separation. The efficiency reaches a maximum at a low value (see the blue curve below).
On the other hand, if the capillaries are open channels in a porous mass, molecular diffusion between the channels literally smooths out the dispersive phenomena and gives columns whose efficiency grows towards an infinite limit. The monolith potential is great, especially with multicapillary chromatography. (red curve).