PL232037B1 - Method for surface functionalization of porous monoliths, preferably silicon dioxide monoliths - Google Patents

Description

Description of the invention

The subject of the invention is a method of functionalisation of the surface of porous monoliths, especially of silica.

There are known methods of functionalization of powder surfaces, porous silica supports with various active groups. The most frequently used method is the cocondation method, which, however, adversely affects the arrangement of the porous structure of the support [A. Sayari, S. Hamoundi, Chem. Mater., 13 (2001) 3151] or post-synthesis introduction of functional groups under conditions of magnetic or mechanical stirring, often at the boiling point of the solvent [K. Szymańska, J. Bryjak, A.B. Jarzębski, Top. Catal., 52 (8) (2009) 1030; A.B. Jarzębski, K. Szymańska, J. Bryjak, J. Mrowiec-Białoń, Catal. Today, 124 (2007) 2]. In the case of post-synthesis modification of monoliths, the problem arises of efficient mixing of the reaction system without exposing the monolith to damage by the rotating stirrer.

Surprisingly, it has been found that very good effects are obtained when the magnetic or mechanical stirrer is separated from the monolithic support by a perforated partition, which protects the monolith against the damaging effects of the stirrer, without limiting the intensity of the penetration of the activating substance inside it.

The method according to the invention consists in dividing the intensive mixing zone with a perforated partition into a zone under the partition in which there is a stirrer and a zone above the partition in which there are monoliths.

Functionalized, cylindrical silica monoliths with a diameter of 2 to 15 mm and a length of 20 to 200 mm, characterized by a bimodal porous structure, are used as carriers for immobilizing enzymes, used as biocatalysts intended for operation in aqueous and non-aqueous environments [K. Szymańska, W. Pudło, J. Mrowiec-Białoń, A. Czardybon, J. Kocurek, A.B Jarzębski, Micropor. Mesopore. Materials, 170 (2013) 75]. The functionalization is preferably carried out by means of a perforated partition, the stirrer being placed under the partition and the monoliths above the partition or directly on the partition.

The invention enables an intensive penetration of the activating substance into the porous monolith while maintaining its structure and shape, which is very important in the case of their subsequent applications. Thus, the invention enables a technologically simple and efficient method to obtain functionalized monolithic porous silica supports.

P r z k ł a d 1

Silicas with multimodal pore structure (MH) were obtained by the sol-gel method with the use of phase separation phenomenon. The surface functionalization was performed in toluene at 80 ° C. A magnetic stirrer was placed in the ground glass reactor, over which a perforated partition with holes 1 mm x 1 mm was mounted, on which the monoliths were placed. The functionalizing agent (aminopropyltriethoxysilane) in 100 mL of toluene was introduced into the reactor. Then a reflux condenser was connected and the reactor was placed in an oil bath for thermostating. The process was carried out for 24 h with continuous stirring ensuring a homogeneous concentration of functional groups in the entire volume of the apparatus, after which the monoliths were removed, washed with ethanol and dried.

P r z k ł a d 2

Silicas with a multimodal pore structure (MH) were obtained by the sol-gel method with the use of phase separation. Ni ions were introduced to their surface in three stages.

A magnetic stirrer was placed in the ground glass reactor, over which a perforated partition with holes 1 mm x 1 mm was mounted, on which the monoliths were placed. The functionalizing agent (3-iodopropyl trimethoxysilane) in 100 mL of toluene was introduced into the reactor. Then a reflux condenser was connected and the reactor was placed in an oil bath for thermostat (110 ° C). The process was carried out for 12 h under an inert gas atmosphere with constant stirring, ensuring a homogeneous concentration of functional groups, then the monoliths were removed and washed with acetonitrile. In the second stage, a solution of 1,4,8,11-tetraazacyclotetradecan in acetonitrile was introduced into the same reactor, then the monoliths were placed in it, a reflux condenser was connected and the reactor was placed in an oil bath for thermostating (90 ° C). The process was carried out for 36 h with agitation, then the monoliths were removed and washed with distilled water. In the third step, an aqueous NiCl 2 solution was introduced into the same reactor. Then a reflux condenser was connected and the reactor was placed in an oil bath for thermostating (100 ° C).

PL 232 037 B1

The process was carried out for 3 h with continuous stirring, then the monoliths were taken out, washed with distilled water and dried. After nickel was introduced, the monoliths turned from white to yellow-orange, with the intensity of the color being identical throughout the monolith volume.

Claims (1)

Patent claim A method of functionalisation of the surface of porous monoliths under intensive mixing conditions, characterized in that the intensive mixing zone is divided by a perforated partition into a zone under the partition in which there is a stirrer and a zone above the partition in which the monoliths are located.