CZ2005326A3 - Process for preparing active form of alkali titanate - Google Patents

Abstract

In the process for the production of an active form of alkaline titanate capable of decomposing chemicals, especially chemical warfare agents, the alkaline titanate suspension is neutralized by reaction with a strong acid to a pH in the range of 3 to 8.

Description

Process for preparing an active form of an alkali titanate

DESCRIPTION OF THE INVENTION

Technical field

The invention relates to a process for the production of an active form of alkali titanate capable of decomposing chemical substances, in particular combat poisoning substances.

BACKGROUND OF THE INVENTION

One of the possible methods of detoxification of corrosive sensitive materials, which are contaminated with very toxic substances, is the application of finely dispersed inorganic oxides with the size of crystallites or crystals of the order of tens to hundreds of nanometers (hereinafter also called nanodisperse oxides). The ability of nanodisperse metal oxides (MgO, CaO, ZnO, A10 _x (H0) _y , ZrO2, T1O2, etc.) to effectively decompose very toxic substances (namely sarin, soman, VX or mustard) into non-toxic products has been studied in detail by the authors Koperova et al. (Salt Lake City, 2000; Kopper, O., Lucas, E., klabunde, KJJAppl.Toxicol. 1999, 79, 59-70) and Wagner et al. (Wagner, GW; Bartram, PW Journal of Molecular Catalysis A: Chemical 1999, 144, 419-429; Wagner, GW, Bartram, PW, Koper O, Klabunde, KJJ Phys. Chem. B 1999, 3225-3228; Wagner , GW, Koper, O., Lucas, E., Decker, S., Klabunde, KJJ Phys. Chem. B 2000, 104, 5118-5123). For the reactions of the reported toxic substances on the solid oxide phase, reaction products were determined and the reaction mechanism postulated. Without exception, it has been shown that all toxic substances are normally decomposed by a heterogeneous chemical reaction with the corresponding metal oxide, predominantly on the surface of its particles. Properties of aluminum oxides, resp. and its oxidohydroxides, their structure and reactivity is the work (Wagner, GW, Proccell, L.

R., O'Connor, RJ, Munavalli, S., Carnes, CL., Kapoor, CL, Klabunde, KJJ. Am. Chem. Soc. 2001, 1636-1644). Among the metal oxides studied so far, alumina is characterized by a sufficiently high detoxification activity, which, besides its negligible material aggressiveness, predestines it for practical use for decontamination of sensitive components of technology and materials. Nanodisperse MgO is usually prepared by thermal decomposition of Mg (OH) ₂ or MgCO3 (Aramendia, MA, Borau, VJMater. Chem. 1996, 6, 1943-1949), but sol-gel methods (Xu, BQ, Wei, JMCT Catalysis Today 2001, 68, 217-225; Choi, HS, Hwang, STJ Mat (Res. 2000, 75, 842845). Large surface area nanodisperse Mg oxides were prepared by hydrolysis of magnesium methoxide or ethoxide followed by supercritical drying (Lopez, T., Gomez, R., Navarrete, J., Lopez-Salinas, E. Journal of Sol-Gel Science and Technology 1998, 75, 1043-1047, Utamapanya, S., Klabunde, KJ, Schlup, J. R. CM Chem.Mater., 1991, 3, 175181; Stark, JV, Klabunde, KJ Chem. Material 1996, 8, 1913-1918; Stark, JV, Park, DG Chem Mater 1996, 8, 1904-1912, Znaidi, L., Chhor, K., Pommier, C. Mat.Res.Bull 1996, 57, 1527-1535; Koper, OB Lagadic, I., Volodin, A., Klabunde, KJ Chem. Mater. 1997, 9, 2468-2480) or using ultrasound in hydrolysis (Stengl, V., Bakardjieva, S., Marikova, M., Bezdicka, P., Subrt, J. Matterials Letters 2003, 57, 3998-4003). According to results published in the literature (Mizushima, Y., Hori, M. Journal of Non-Crystalline Solids 1994, 167, 1-8; Mizushima, Y., Hori, M. Journal of Materials Research 1993, 8, 2993-2999;

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Haridas, Μ. M., Bellare, JR Bulletin of Materials Science 1997, 20, 49-66) aluminum aerogels were prepared by reacting aluminum sec.butoxide with ethyl acetoacetate and supercritically dried with carbon dioxide having a specific surface area of 400-600 m ² / g. According to another work (Suh, DJ, Park, T. I, Kim, JH, Kim, KL Chemistry of Materials 1997, 9, 1903-1905) aluminum aerogels were prepared by sol-gel method from aluminum butoxide with a specific surface area of 300,700 m ² / g, in publications (Walendziewski, J., Stolarski, M., Steininger, M., Pniak, B. Reaction Kinetics and Catalysis Letters 1999, 66, Ί \ -ΊΊ \ Walendziewski, J., Stolarski, M. Reaction Kinetics and Catalysis Letters 2000, 71, 201-207), aluminum isopropoxide was used as the starting material. Most of the works (Mizushima, Y., Hori, M. Journal of Non-Crystalline Solids 1994, 167, 1-8; Pierre, AC, Elaloui, E., Pajonk, GM Langmuir 1998, 66-73; Sayilkan, H., Arpac, E., Sener, E. Synthesis and Reactivity (Inorganic and Metallic-Organic Chemistry 1997, 27, 14371452) after the preparation of the gel by hydrolysis of the alkoxide gives carbon dioxide for supercritical drying. By modifying the procedure for the preparation of nanodisperse magnesium oxides (Štengl, V., Bakardjieva,

S. Maříková, M., Šubrta J. Ceramics 2003, 4, 175-178) may be prepared Al precursor with a specific surface of 1000 g of n ^ ^'first For the preparation of nanodisperse oxides Al and Mg which are suitable for detoxification, the starting compounds are their alkoxides, which are relatively expensive chemicals. Their synthesis is associated with work in an inert atmosphere and supercritical drying with CO2 or with solvating agents (e.g., toluene) in an autoclave. For these reasons, the possible processes for the preparation of these nanodisperse oxides are only possible on a laboratory scale.

SUMMARY OF THE INVENTION

SUMMARY OF THE INVENTION The present invention provides a process for the production of an active form of an alkali titanate which comprises neutralizing the alkali titanate slurry to a pH of 3-8 by reaction with a strong acid.

DETAILED DESCRIPTION OF THE INVENTION

In the following, the invention is illustrated in more detail by way of example

Example 1

The aqueous suspension of alkaline titanate (Precheza as Prerov) was neutralized with sulfuric acid to pH = 6 at room temperature. The reacted suspension was washed with water, filtered and dried in an oven at 105 ° C. The product is a white, very loose powder with a specific surface area of 690 m ² g -1 with a particle size <1 nm.

Example 2

The aqueous suspension of alkaline titanate (Precheza as Prerov) was neutralized with sulfuric acid to pH = 5.5 at room temperature. The reacted suspension was washed with water, filtered and dried in an oven at 105 ° C. The product is a white, fluffy powder with a specific surface of 745 m ² g ^_1 with a particle size <1 nm.

Industrial applicability

The process for the production of the active form of the alkali titanate according to the invention can be used in the decomposition of chemical substances, in particular combat poisoning substances - eg mustard, sarin, soman and VX.

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A process for producing an active form of an alkali titanate

Claims (2)

PATENT CLAIMS: A process for the production of an active form of an alkali titanate suspension, characterized in that the alkaline titanate suspension is neutralized by reaction with sulfuric acid to a pH value in the Method according to claim 1, characterized in that another strong acid can be used instead of sulfuric acid.