Beneficiation of Inorganic Matrices with Wet, Non-Agglomerated, High-Concentration and Stable Graphite Nanoplatelets without Any Extra Measures to Disperse the Nanoplatelets

• US 20190315654A1
• Filed: 08/15/2016
• Published: 10/17/2019
• Est. Priority Date: 08/15/2016
• Status: Active Application

• Current Assignee: Metna Co.
• Original Assignee: Metna Co.
• Inventors: Balachandra, Anagi Manjula
• Application Number:
  US15/237,510
• Publication Number:
  US 20190315654A1
• Time in Patent Office: Days
• CPC Class Codes: B28B 1/14 by simple casting, the material being neither forcibly fed nor positively compacted for molten material B28B1/54
• CPC Class Codes: B28B 11/24 for curing, setting or hardening processes for influencing or modifying the setting or hardening ability of mortars, concrete or artificial stone compositions, in general C04B40/00
• CPC Class Codes: B28C 5/402 Methods
• CPC Class Codes: C04B 14/024 Graphite
• CPC Class Codes: C04B 14/106 Kaolin
• CPC Class Codes: C04B 14/386 Carbon carbon nanotubes C04B14/026
• CPC Class Codes: C04B 14/42 Glass
• CPC Class Codes: C04B 14/48 Metal
• CPC Class Codes: C04B 16/06 fibrous
• CPC Class Codes: C04B 18/023 Fired or melted materials
• CPC Class Codes: C04B 18/08 Flue dust , i.e. fly ash
• CPC Class Codes: C04B 18/10 Burned or pyrolised refuse
• CPC Class Codes: C04B 18/141 Slags
• CPC Class Codes: C04B 18/146 Silica fume
• CPC Class Codes: C04B 20/006 Microfibres; Nanofibres
• CPC Class Codes: C04B 2111/00008 Obtaining or using nanotechnology related materials
• CPC Class Codes: C04B 28/02 containing hydraulic cements other than calcium sulfates
• CPC Class Codes: C04B 28/04 Portland cements
• CPC Class Codes: C04B 28/06 Aluminous cements monolithic refractories or refractory mortars C04B35/66
• CPC Class Codes: C04B 28/065 Calcium aluminosulfate cements, e.g. cements hydrating into ettringite
• CPC Class Codes: C04B 28/10 : Lime cements or magnesium oxide cements
• CPC Class Codes: C04B 40/0028 : Aspects relating to the mixing step of the mortar preparation
• CPC Class Codes: C04B 40/0046 : characterised by their processing, e.g. sequence of mixing the ingredients when preparing the premixtures
• CPC Class Codes: C04B 40/0067 : making use of vibrations
• CPC Class Codes: Y02W 30/91 : Use of waste materials as fillers for mortars or concrete

Abstract

The present invention relates generally to beneficiation of inorganic matrices via addition of nano-materials without altering the production conditions of the inorganic matrix, and more specifically it relates to enhancement of concrete with wet graphite nanoplatelets using conventional concrete production equipment and procedures without any need for extra measures such as sonication, use of surfactants or functionalization of nanomaterials for dispersion of nanoplatelets.

Claims

1. A method of producing a fresh cementitious material with dispersed graphite nanoplatelets, the method comprising:

(a) Adding graphite nanoplatelets with 0.3 to 300 nanometer thickness and 3 to 300 micrometer planar dimensions to a mixer in wet, non-agglomerated state with 50 to 95% by weight of water molecules which occur in physically adsorbed state on the surfaces of said nanoplatelets, and hinder their agglomeration via secondary bonding;

(b) Adding to said mixer water and hydraulic cement with a total volume that is 50 to times the solid volume of said graphite nanoplatelets, and with water-to-cement weight ratio of 0.1 to 0.9; and

(c) Mixing of water, hydraulic cement and graphite nanoplatelets at 3 to 300 rounds per minute rotational speed for 1 to 45 minutes.

2. The method of claim 1, wherein the mixer is one of planetary mixer, drum mixer, pan mixer, vertical axis mixer, and twin shaft mixer that is stationary or mixed on a vehicle, or a manual mixing method.

3. The method of claim 1, wherein the hydraulic cement is Portland cement, Portland-limestone cement, Portland-slag cement, Portland-pozzolan cement, ternary blended cement, general use cement, high early strength cement, moderate sulfate resistance cement, high sulfate resistance cement, moderate heat of hydration cement, low heat of hydration cement, masonry cement, calcium aluminate cement, calcium sulfoaluminate cement, aluminosilicate-based cement, shrinkage compensating cement, gypsum, lime, and combinations thereof.

4. The method of claim 1, wherein 5% to 75% by weight of hydraulic cement is replaced with coal ash, ground steel slag, silica fume, natural pozzolan, metakaolin, calcined clay, biomass ash, and combinations thereof.

5. The method of claim 1, wherein one or more additives selected from the group consisting of chemical additives, polymer additives, mineral additives and coloring additives is added to the mix prior to, during and after the addition of other mix ingredients, or during mixing.

6. The method of claim 1, wherein one or more aggregates selected from the group of fine aggregates with maximum particle size less than 4.75 mm and coarse aggregates with maximum particle size more than 4.75 mm is added to the mix prior to, during and after the addition of other mix ingredients, or during mixing, with a total aggregate weight that is 0.1 to times the weight of hydraulic cement.

7. The method of claim 1, wherein one or more fibers selected from the group consisting of steel, polymer, glass and carbon fibers with 0.1 to 5000 micrometer diameter and length-to-diameter ratio of 10 to 1000 is added to the mix prior to, during and after the addition of other mix ingredients, or during mixing, with a total fiber volume that is 1 to 100 times the volume of graphite nanoplatelets.

8. A method of producing a cementitious product with dispersed graphite nanoplatelets, the method comprising:

(a) Adding graphite nanoplatelets with 0.3 to 300 nanometer thickness and 3 to 300 micrometer planar dimensions to a mixer in wet, non-agglomerated state with 15 to 95% by weight of water molecules which occur in physically adsorbed state on the surfaces of said graphite nanoplatelets, and hinder their agglomeration via secondary bonding;

(b) Adding to said mixer water and hydraulic cement with a total volume that is 50 to times the solid volume of said graphite nanoplatelets, and with water-to-cement weight ratio of 0.1 to 0.9; and

(c) Mixing of water, hydraulic cement and graphite nanoplatelets at 3 to 300 rounds per minute rotational speed for 1 to 45 minutes to produce a fresh cementitious material with dispersed graphite nanoplatelets;

(d) Placing, consolidating and finishing of said fresh cementitious material with dispersed graphite nanoplatelets inside a mold;

(e) Curing the cementitious material with dispersed graphite nanoplatelets by preventing moisture loss at temperatures ranging from 5°

C. to 250°

C. over periods ranging from hour to 28 days.

9. The method of claim 8, wherein the mixer is one of planetary mixer, drum mixer, pan mixer, vertical axis mixer, and twin shaft mixer that is stationary or mixed on a vehicle, or a manual mixing method.

10. The method of claim 8, wherein consolidation of the fresh cementitious material with dispersed graphite nanoplatelets is accomplished via internal vibration, external vibration, force of gravity, and combinations thereof.

11. The method of claim 8, wherein finishing of the fresh cementitious material with dispersed graphite nanoplatelets is accomplished via screeding, troweling, floating, edging, broom finishing, and combinations thereof.

12. The method of claim 8, wherein the hydraulic cement is Portland cement, Portland-limestone cement, Portland-slag cement, Portland-pozzolan cement, ternary blended cement, general use cement, high early strength cement, moderate sulfate resistance cement, high sulfate resistance cement, moderate heat of hydration cement, low heat of hydration cement, masonry cement, calcium aluminate cement, calcium sulfoaluminate cement, aluminosilicate-based cement, shrinkage compensating cement, gypsum, lime, and combinations thereof.

13. The method of claim 8, wherein 5% to 75% by weight of hydraulic cement is replaced with coal ash, ground steel slag, silica fume, natural pozzolan, metakaolin, calcined clay, biomass ash, and combinations thereof.

14. The method of claim 8, wherein one or more additives selected from the group consisting of chemical additives, polymer additives, mineral additives and coloring additives is added to the mix prior to, during and after the addition of other mix ingredients, or during mixing.

15. The method of claim 8, wherein one or more aggregates selected from the group of fine aggregates with maximum particle size less than 4.75 mm and coarse aggregates with maximum particle size more than 4.75 mm is added to the mix prior to, during and after the addition of other mix ingredients, or during mixing, with a total aggregate weight that is 0.1 to times the weight of hydraulic cement.

16. The method of claim 8, wherein one or more fibers selected from the group consisting of steel, polymer, glass and carbon fibers with 0.1 to 5000 micrometer diameter and length-to-diameter ratio of 10 to 1000 is added to the mix prior to, during and after the addition of other mix ingredients, or during mixing, with a total fiber volume that is 1 to 100 times the volume of graphite nanoplatelets.

17. The method of claim 8, wherein the mold incorporates 0.25% to 10% by volume of reinforcing steel, prestressing steel, reinforcing composite, prestressing composite, and combinations thereof.

18. A blend of fresh cementitious paste and graphite nanoplatelets in a state that said nanoplatelets can be dispersed within the cementitious paste in a mixer with 3 to 300 rounds per minute rotational speed over 1 to 45 minutes, comprising:

(a) Graphite nanoplatelets with 0.3 to 300 nanometer thickness and 3 to 300 micrometer planar dimensions in wet, non-agglomerated state with 15 to 95% by weight of water molecules which occur in physically adsorbed state on the surfaces of said nanoplatelets, and hinder their agglomeration via secondary bonding; and

(b) Water and hydraulic cement with a total volume that is 50 to 5000 times the solid volume of said graphite nanoplatelets, and with water-to-cement weight ratio of 0.1 to 0.9.

19. The blend of fresh cementitious paste and graphite nanoplatelets of claim 18, wherein the mixer is one of planetary mixer, drum mixer, pan mixer, vertical axis mixer, and twin shaft mixer mixer that is stationary or mixed on a vehicle, or a manual mixing method.

20. The blend of fresh cementitious paste and graphite nanoplatelets of claim 18, wherein the hydraulic cement is Portland cement, Portland-limestone cement, Portland-slag cement, Portland-pozzolan cement, ternary blended cement, general use cement, high early strength cement, moderate sulfate resistance cement, high sulfate resistance cement, moderate heat of hydration cement, low heat of hydration cement, masonry cement, calcium aluminate cement, calcium sulfoaluminate cement, aluminosilicate-based cement, shrinkage compensating cement, gypsum, lime, and combinations thereof.

21. The blend of fresh cementitious paste and graphite nanoplatelets of claim 18, wherein 5% to 75% by weight of hydraulic cement is replaced with coal ash, ground steel slag, silica fume, natural pozzolan, metakaolin, calcined clay, biomass ash, and combinations thereof.

22. The blend of fresh cementitious paste and graphite nanoplatelets of claim 18, wherein one or more additives selected from the group consisting of chemical additives, polymer additives, mineral additives and coloring additives is added to the blend.

23. The blend of fresh cementitious paste and graphite nanoplatelets of claim 18, wherein one or more aggregates selected from the group of fine aggregates with maximum particle size less than 4.75 mm and coarse aggregates with maximum particle size more than 4.75 mm is added to the blend at a total aggregate weight that is 0.1 to 10 times the weight of hydraulic cement.

24. The blend of fresh cementitious paste and graphite nanoplatelets of claim 18, wherein one or more fibers selected from the group consisting of steel, polymer, glass and carbon fibers with 0.1 to 5000 micrometer diameter and length-to-diameter ratio of 10 to 1000 is added to the blend at a total fiber volume that is 1 to 100 times the volume of graphite nanoplatelets.