Nanoparticles and method for producing uniform silicate-based nanoparticles

Patent metadata

Field	Value
Publication number	US-10815128-B2
Application number	US-201716468665-A
Country	US
Kind code	B2
Filing date	Nov 27, 2017
Priority date	Dec 12, 2016
Publication date	Oct 27, 2020
Grant date	Oct 27, 2020

Abstract

Nanoparticles and method for producing uniform silicate-based nanoparticles are disclosed. The method comprises a step of injecting into tubular branched elements comprising static mixers a first aqueous solution comprising a water-soluble silicate compound and a second aqueous solution comprising a water-soluble compound releasing cationic species in solution, and allowing the reaction between the first and the second aqueous solutions in a micro-mixing regime, the method being characterized in that the overall mixing time is kept below 10−5 s. A further step of allowing the solution obtained in the micro-mixing regime to mix in a macromixing regime. Nanoparticles obtained through the present method are also disclosed.

First claim

The invention claimed is:

1. A method for producing uniform silicate-based nanoparticles, comprising the following steps:
a) providing a first aqueous solution comprising a water-soluble silicate compound and a second aqueous solution comprising a water-soluble compound releasing cationic species in solution;
b) allowing the reaction between the first and the second aqueous solution in a micro-mixing regime; and
c) allowing the solution obtained in the micro-mixing regime to mix in a macro-mixing regime, the macro-mixing regime performed in a batch reactor under stirring conditions,
wherein the overall mixing time for the micro-mixing regime and the macro-mixing regime is kept below 10 −5 s.

2. The method of claim 1 , wherein a pH value of the reaction volume is between 7 and 14.

3. The method of claim 1 , wherein the micro-mixing step is performed through the flow of the first and the second aqueous solutions into a branched tubular structure comprising static mixing elements, wherein the first and the second aqueous solution mix at a connection point between the branches.

4. The method of claim 3 , wherein the sum of the flow-rates of the first and the second aqueous solution flowing into the branches of the tubular structure is comprised between 30 and 45 ml/min.

5. The method of claim 3 , wherein the branches of the tubular structure have a relative orientation angle comprised between 30° and 180°.

6. The method of claim 1 , wherein the overall mixing time is between two and three orders of magnitude higher than the interval between step b) and step c).

7. The method of claim 1 , wherein the first aqueous solution comprises a water soluble silicate compound selected from the list comprising sodium silicate, calcium silicate, potassium silicate, water glass, di-calcium silicate, tri-calcium silicate, silic acid, sodium metasilicate, potassium metasilicate or any combination thereof.

8. The method of claim 1 , wherein the second aqueous solution comprises a water soluble calcium compound, a water soluble zinc compound, a water soluble iron compound, a water soluble magnesium compound, a water soluble aluminium compound or any combination of the foregoing.

9. The method of claim 8 , wherein the relative amount of calcium is between 0.1 to 11 mol %, the relative amount of zinc is between 0 to 10 mol %, the relative amount of iron is between 0 to 10 mol %, the relative amount of silicium is between 0.1 to 22 mol %, the relative amount of magnesium is between 0.1 to 2 mol %, and the relative amount of aluminium is between 0.1 to 2 mol % in each of the used water soluble compounds.

10. The method of claim 8 , wherein the water soluble calcium compound is selected from the list comprising calcium bromide, calcium carbonate, calcium nitrate, calcium formate, calcium bicarbonate, calcium borate, calcium sulphide, calcium tartrate, di-calcium silicate, tri-calcium silicate, calcium chlorate, calcium iodide, calcium aluminate, calcium phosphate, calcium propionate, calcium oxide, calcium phosphate tribasic, calcium phosphate dibasic dehydrate, calcium phosphate dibasic anhydrous, calcium glycerophosphate, calcium stearate, calcium gluceptate, calcium gluconate or calcium acetate, or any combination of the foregoing.

11. The method of claim 8 , wherein the water soluble zinc compound is selected from the list comprising zinc bromide, zinc carbonate, zinc nitrate, zinc formate, zinc bicarbonate, zinc borate, zinc sulphide, zinc tartrate, di-zinc silicate, tri-zinc silicate, zinc chlorate, zinc iodide, zinc aluminate, zinc phosphate, zinc propionate, zinc oxide, zinc phosphate tribasic, zinc phosphate dibasic dehydrate, zinc phosphate dibasic anhydrous, zinc glycerophosphate, zinc chloride, zinc gluconate, zinc gluceptate or zinc stearate, or any combination of the foregoing.

12. The method of claim 8 , wherein the water soluble iron compound is selected from the list comprising iron bromide, iron carbonate, iron nitrate, iron formate, iron bicarbonate, iron borate, iron sulphide, iron tartrate, di-iron silicate, tri-iron silicate, iron chlorate, iron iodide, iron aluminate, iron stearate, iron phosphate, iron propionate, iron oxide, iron phosphate tribasic, iron phosphate dibasic dehydrate, iron phosphate dibasic anhydrous, iron glycerophosphate, iron chloride, iron gluconate, iron gluceptate or iron stearate, or any combination of the foregoing.

13. The method of claim 8 , wherein the water soluble magnesium compound is selected from the list comprising magnesium bromide, magnesium carbonate, magnesium nitrate, magnesium formate, magnesium bicarbonate, magnesium borate, magnesium sulphide, magnesium tartrate, di-magnesium silicate, tri-magnesium silicate, magnesium chlorate, magnesium iodide, magnesium aluminate, magnesium stearate, magnesium phosphate, magnesium propionate, magnesium oxide, magnesium phosphate tribasic, magnesium phosphate dibasic dehydrate, magnesium phosphate dibasic anhydrous, magnesium glycerophosphate, magnesium chloride, magnesium gluconate, magnesium gluceptate or magnesium stearate, or any combination of the foregoing.

14. The method of claim 8 , wherein the water soluble aluminium compound is selected from the list comprising aluminium bromide, aluminium carbonate, aluminium nitrate, aluminium formate, aluminium bicarbonate, aluminium borate, aluminium sulphide, aluminium tartrate, di-aluminium silicate, tri-aluminium silicate, aluminium chlorate, aluminium iodide, aluminium aluminate, aluminium stearate, aluminium phosphate, aluminium propionate, aluminium oxide, aluminium phosphate tribasic, aluminium phosphate dibasic dehydrate, aluminium phosphate dibasic anhydrous, aluminium glycerophosphate, aluminium chloride, aluminium gluconate, aluminium gluceptate or aluminium stearate, or any combination of the foregoing.

15. The method of claim 1 , wherein the solution obtained in the micro-mixing step is kept in low carbon conditions that is lower than 100 parts per million.

16. Nanoparticles obtained through the method of claim 1 , wherein they have a uniformity of up to 99.9%.

17. Nanoparticles obtained through the method of claim 1 , wherein, in each nanoparticle, the ratio between an atom derived from a cationic species and silicon is comprised between 1.6 and 2.25.

18. The method of claim 1 , wherein a pH value of the reaction volume is between 11 and 14.

Assignees

• Ecole Polytechnique Fed Lausanne Epfl

Inventors

• Kumar Abhishek
• Bowen Paul

Classifications

• C01B33/26 Primary

  Aluminium-containing silicates {, i.e. silico-aluminates} · CPC title

• C01B33/20 Primary

  Silicates (persilicates C01B15/14 {; containing aluminium C01B33/26}) · CPC title

• C01B33/22

  Magnesium silicates · CPC title

• C01P2004/64

  Nanometer sized, i.e. from 1-100 nanometer · CPC title

• C01B33/24

  Alkaline-earth metal silicates · CPC title