Microencapsulated thermochromic materials and uses thereof

Patent metadata

Field	Value
Publication number	US-11359137-B2
Application number	US-201816610107-A
Country	US
Kind code	B2
Filing date	May 3, 2018
Priority date	May 3, 2017
Publication date	Jun 14, 2022
Grant date	Jun 14, 2022

Abstract

A variety of particles forming microencapsulated thermochromic materials are provided. The particles can include a thermochromic core and a metal oxide shell encapsulating the thermochromic core. The thermochromic core can include one or both of an organic thermochromic material and an inorganic salt thermochromic material. In some aspects, the particles include a dye selected from a crystal violet lactone dye, a fluoran dye, and a combination thereof. In still further aspects, the particles include a color developer selected from a hydroxybenzoate, a 4, 4′-dihydroxydiphenyl propane, a hydroxycoumarin derivative, a lauryl gallate, and a combination thereof. In some aspects, the metal oxide shell is a TiO2 shell. The particles can be used in cements and paints and for a variety of building materials. Methods of making the particles and building materials and methods of use, for example, for removing a volatile organic carbon from a building material, are also provided.

First claim

We claim:

1. A composition comprising a plurality of particles, each of which comprises:
a thermochromic core that includes one or both of an organic thermochromic material and an inorganic salt thermochromic material; and
a metal oxide shell encapsulating the thermochromic core,
wherein the plurality of particles is dispersed in a Portland cement, and
wherein the composition is a paint.

2. The composition according to claim 1 , wherein the metal oxide shell comprises a metal oxide selected from the group consisting of titanium dioxide (TiO 2 ), zinc oxide (ZnO), silicon oxide (SiO 2 ), tungsten oxide (WO 3 ), manganese oxide (MnO 2 ), indium oxide (In 2 O 3 ), aluminum oxide (Al 2 O 3 ), iron oxide (Fe 2 O 5 ), molybdenum oxide (MoO 2 ), and a combination thereof.

3. The composition according to claim 1 , wherein the thermochromic core comprises an organic thermochromic material that includes a dye, a color developer, and a solvent.

4. The composition according to claim 3 , wherein the dye is selected from the group consisting of a crystal violet lactone dye, a fluoran dye, and a combination thereof.

5. The composition according to claim 4 , wherein the color developer is selected from the group consisting of a hydroxybenzoate, a 4, 4′-dihydroxydiphenyl propane, a hydroxycoumarin derivative, a lauryl gallate, and a combination thereof.

6. The composition according to claim 4 , wherein the solvent is selected from the group consisting of an alcohol, a phenol, an ester, and a mixture thereof.

7. The composition according to claim 1 ,
wherein the thermochromic core comprises an organic thermochromic material;
wherein the organic thermochromic material comprises
(i) a dye selected from the group consisting of a crystal violet lactone dye, a fluoran dye, and a combination thereof;
(ii) a color developer selected from the group consisting of a hydroxybenzoate, a 4, 4′-dihydroxydiphenyl propane, a hydroxycoumarin derivative, a lauryl gallate, and a combination thereof; and
(iii) a solvent selected from the group consisting of an alcohol, a phenol, an ester, and a mixture thereof; and

wherein the metal oxide shell comprises TiO 2 .

8. The composition according to claim 1 , wherein the thermochromic core comprises an inorganic salt thermochromic material.

9. The composition according to claim 1 , wherein the thermochromic core comprises an inorganic salt thermochromic material selected from the group consisting of silver mercury iodide, cuprous mercury iodide, bis(diethylammonium) tetrachloronickelate, benzimidazolium tetrachlorocuprate, and a combination thereof; and
wherein the metal oxide shell comprises TiO 2 .

10. A composition comprising a plurality of particles, each of which comprises:
a thermochromic core that includes one or both of an organic thermochromic material and an inorganic salt thermochromic material; and
a metal oxide shell encapsulating the thermochromic core,
wherein the plurality of particles is dispersed in a binder that is a hydraulic binder or a cementitious binder.

11. The composition according to claim 10 , wherein the metal oxide shell comprises a metal oxide selected from the group consisting of titanium dioxide (TiO2), zinc oxide (ZnO), silicon oxide (SiO 2 ), tungsten oxide (WO 3 ), manganese oxide (MnO 2 ), indium oxide (In 2 O3), aluminum oxide (Al 2 O 3 ), iron oxide (Fe 2 O 5 ), molybdenum oxide (MoO 2 ), and a combination thereof.

12. The composition according to claim 10 , wherein the thermochromic core comprises an organic thermochromic material.

13. The composition according to claim 12 , wherein the organic thermochromic material comprises a dye, a color developer, and a solvent.

14. The composition according to claim 13 , wherein the dye is selected from the group consisting of a crystal violet lactone dye, a fluoran dye, and a combination thereof.

15. The composition according to claim 13 , wherein the color developer is selected from the group consisting of a hydroxybenzoate, a 4, 4′-dihydroxydiphenyl propane, a hydroxycoumarin derivative, a lauryl gallate, and a combination thereof.

16. The composition according to claim 13 , wherein the solvent is selected from the group consisting of an alcohol, a phenol, an ester, and a mixture thereof.

17. The composition according to claim 10 , wherein the thermochromic core comprises an organic thermochromic material;
wherein the organic thermochromic material comprises
a. a dye selected from the group consisting of a crystal violet lactone dye, a fluoran dye, and a combination thereof;
b. a color developer selected from the group consisting of a hydroxybenzoate, a 4, 4′-dihydroxydiphenyl propane, a hydroxycoumarin derivative, a lauryl gallate, and a combination thereof; and
c. a solvent selected from the group consisting of an alcohol, a phenol, an ester, and a mixture thereof; and
wherein the metal oxide shell comprises TiO 2 .

18. The composition according to claim 10 , wherein the thermochromic core comprises an inorganic salt thermochromic material.

19. The composition according to claim 18 , wherein the inorganic salt thermochromic material is selected from the group consisting of silver mercury iodide, cuprous mercury iodide, bis(diethylammonium) tetrachloronickelate, benzimidazolium tetrachlorocuprate, and a combination thereof.

20. The composition according to claim 10 , wherein the thermochromic core comprises an inorganic salt thermochromic material;
wherein the inorganic salt thermochromic material is selected from the group consisting of silver mercury iodide, cuprous mercury iodide, bis(diethylammonium) tetrachloronickelate, benzimidazolium tetrachlorocuprate, and a combination thereof; and
wherein the metal oxide shell comprises TiO 2 .

21. The composition according to claim 10 , wherein a particle has a radius of about 2 μm to 10 μm.

22. A method of removing a volatile organic carbon from a building material that comprises a plurality of particles, wherein each particle includes:
a thermochromic core comprising one or both of an organic thermochromic material and an inorganic salt thermochromic material; and
a metal oxide shell encapsulating the thermochromic core;
the method comprising:
radiating the building material with light from a light source to excite metal oxide in the metal oxide shell to produce a radical, and
reacting the radical with the volatile organic carbon to oxidize the volatile organic carbon.

Assignees

• Univ South Florida

Inventors

• Ram Manoj Kumar
• Stefanakos Elias K

Classifications

• C04B20/1066

  Oxides, Hydroxides · CPC title

• C09D5/26

  Thermosensitive paints · CPC title

• C09D1/06

  cement · CPC title

• B01J2219/1203

  Incoherent waves · CPC title

• B01J13/06

  by phase separation · CPC title