NEAR-INFRARED REFLECTIVE CARBON BLACK

Abstract

A near-infrared reflective carbon black composite comprising carbon black and TiO2 coating and a method for making of carbon black composite are disclosed. The method comprises providing a dispersion of a carbon black in a solvent; mixing the dispersion with water and a TiO2 precursor under conditions sufficient to form an oligomer coating comprising a Ti compound on at least a portion of the surface of the carbon black, wherein the TiO2 precursor is at least partially soluble in the solvent; and converting the oligomer coating comprising the Ti compound to TiO2 to form the carbon black composite.

Claims

1. A near-infrared reflective carbon black composite comprising a carbon black and a TiO.sub.2 layer at least partially coating the carbon black.

2. The composite of claim 1, wherein the carbon black has an oil absorption number (OAN) ranging from 45-260 cm.sup.3/100 g.

3. The composite of claim 1, wherein the carbon black has a nitrogen surface area (NSA) ranging from 25-600 m.sup.2/g.

4. The composite of claim 1, which is free of transition metals other than Ti.

5. The composite of claim 1, which is free of iron and chromium.

6. The composite of claim 1, wherein the TiO.sub.2 layer has an average thickness ranging from 0.5 nm to 200 nm.

7. (canceled)

8. The composite of claim 1, having a median particle size ranging from 0.1 m to 5 m.

9. (canceled)

10. (canceled)

11. A method for making a carbon black composite, the method comprising: a) providing a carbon black having an oligomer coating comprising a Ti compound on at least a portion of the surface of the carbon black; and b) converting the oligomer coating comprising the Ti compound to TiO.sub.2 to form the carbon black composite.

12. (canceled)

13. (canceled)

14. The method of claim 11, wherein the Ti compound is formed from TiO.sub.2 precursor.

15. The method of claim 14, wherein the TiO.sub.2 precursor is a titanium alkoxide.

16. The method of claim 15, wherein the titanium alkoxide is titanium ethoxide, titanium propoxide, titanium isopropoxide, titanium butoxide, or a mixture thereof.

17. The method of claim 11, wherein the Ti compound is prepared from a precursor derived from a titanium sulphate, a titanium oxychloride, a titanium tetrachloride, a titanium (III) chloride, or a mixture thereof.

18. The method of claim 11, wherein the Ti compound is a condensation product of a titanic acid.

19. A method for making a carbon black composite, the method comprising: a) providing a dispersion of a carbon black in a solvent; b) mixing the dispersion with water and a TiO.sub.2 precursor under conditions sufficient to form an oligomer coating comprising a Ti compound on at least a portion of the surface of the carbon black, wherein the TiO.sub.2 precursor is at least partially soluble in the solvent; and c) converting the oligomer coating comprising the Ti compound to TiO.sub.2 to form the carbon black composite.

20. (canceled)

21. (canceled)

22. The method of claim 19, wherein the TiO.sub.2 precursor is a titanium alkoxide.

23. The method of claim 22, wherein the titanium alkoxide is titanium ethoxide, titanium propoxide, titanium isopropoxide, titanium butoxide, or a mixture thereof.

24. The method of claim 19, wherein the TiO.sub.2 precursor is a titanium sulphate, a titanium oxychloride, a titanium tetrachloride, a titanium (III) chloride, or a mixture thereof.

25. The method of claim 19, wherein the molar ratio of water to TiO.sub.2 precursor ranges from 2:1 to 10:1.

26. The method of claim 19, wherein the molar ratio of water to TiO.sub.2 precursor is about 3:1.

27. The method of claim 19, wherein the Ti compound is a condensation product of a titanic acid.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The foregoing summary, as well as the following description of the disclosure, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the disclosure, the drawings illustrate some, but not all, alternative embodiments. This disclosure is not limited to the precise arrangements and instrumentalities shown. The following figures, which are incorporated into and constitute part of the specification, assist in explaining the principles of the disclosure.

[0012] FIG. 1 is an exemplary process for modifying the surface of carbon black with a layer of TiO.sub.2.

[0013] FIG. 2 is a scheme showing TiO, synthesis from titanium ethoxide.

[0014] FIG. 3 shows TEM morphology of exemplary-TiOTi oligomer coated RAVEN 1080 ULTRA (R1080U) powders with 37% TiO.sub.2.

[0015] FIG. 4 shows a TEM image and corresponding EDS analysis of exemplary-TiOTi oligomer coated RAVEN 1080 ULTRA (R1080U) powders (Example 3).

[0016] FIG. 5 shows TEM morphology of exemplary TiO.sub.2 coated RAVEN 1080 ULTRA (R1080U) powders with 37% TiO.sub.2 (Example 2).

[0017] FIG. 6 shows a TEM image and corresponding EDS analysis of exemplary TiO.sub.2 coated RAVEN 1080 ULTRA (R1080U) powders (Example 2).

[0018] FIG. 7 shows XRD patterns of exemplary TiO.sub.2 coated RAVEN 1080 ULTRA (R1080U).

[0019] FIG. 8 shows TEM morphology of exemplary TiO.sub.2 coated RAVEN 1080 ULTRA (R1080U) powders with 46% TiO.sub.2 (Example 3).

[0020] FIG. 9 shows absolute reflectance % of pure RAVEN 1080 ULTRA (R1080U), TiO.sub.2 coated RAVEN 1080 ULTRA (R1080U), and R1080/T595 physical blend from 300 nm to 2500 nm.

[0021] FIG. 10 shows Rutile TiO.sub.2 XRD patterns for Example 8.

[0022] FIG. 11 shows absolute reflectance % for Examples 5-11 from 300 nm to 2500 nm.

DETAILED DESCRIPTION

A. Definitions

[0023] When the term about precedes a numerical value, the numerical value can vary within +10% unless specified otherwise.

[0024] Nitrogen surface area (NSA) and statistical thickness surface area (STSA) refers to nitrogen surface area and statistical thickness surface area as measured according to ASTM Test Method D6556, which is incorporated by reference.

[0025] Iodine absorption number refers to iodine absorption values as measured according to ASTM D1510.

[0026] Oil absorption number (OAN) refers to oil absorption values as measured according to ASTM D2414.

[0027] Compressed oil absorption number (COAN) refers to compressed oil absorption values as measured according to ASTM D3493.

[0028] 325 mesh water wash residue refers to residue values as measured according to ASTM D1514.

[0029] All the above-described ASTM methods are incorporated by reference in their entireties.

B. Near-IR Reflective Carbon Blacks

[0030] In one aspect, the near-infrared reflective carbon black composite comprises a carbon black and a TiO.sub.2 layer at least partially coating the carbon black. The composite is not limited to any particular type of carbon black. In one aspect, carbon blacks useful in paints, automotive top coats, plastics, and the like can be used. In a further aspect, the carbon black has an oil absorption number (OAN) ranging from 45-260 cm.sup.3/100 g. In a further aspect, the carbon black has a nitrogen surface area (NSA) ranging from 25-600 m.sup.2/g.

[0031] The carbon black can be produced by any suitable method. In one aspect, the carbon black is produced by a furnace black process, a lampblack process, a channel black process, a thermal black process, an acetylene black process, or a microwave plasma process. In a further aspect, the carbon black has been heat treated, chemically treated, ozone treated, or acid treated.

[0032] In one aspect, the composite retains useful properties of carbon black while imparting near-IR reflectivity to the composition. Thus, in some aspects, the composite can be free of metals that typically cause degradation of coatings and plastics, including transitions metals other than Ti, e.g., chromium and iron.

[0033] The thickness of the TiO.sub.2 layer can vary. In one aspect, the TiO.sub.2 layer has an average thickness ranging from 0.5 nm to 200 nm. In a further aspect, the TiO.sub.2 layer has an average thickness ranging from 0.5 nm to 20 nm, e.g., 0.5 nm to 15 nm. In one aspect, the TiO.sub.2 layer coats a portion of the carbon black, with some carbon black surface not being coated with the TiO.sub.2 layer. In a further aspect, the TiO.sub.2 layer coats the entire surface of the carbon black. The composite can have a range of median particle sizes, e.g., ranging from 0.1 m to 5 m.

[0034] In one aspect, the method for making the carbon black composite comprises: providing a carbon black having an oligomer coating comprising a Ti compound on at least a portion of the surface of the carbon black; and converting the oligomer coating comprising the Ti compound to TiO.sub.2 to form the carbon black composite. In one aspect, the Ti compound is formed from a TiO.sub.2 precursor such as a titanium alkoxide, e.g., titanium ethoxide, titanium propoxide, titanium isopropoxide, titanium butoxide, or a mixture thereof. In a further aspect, the Ti compound is formed from a TiO.sub.2 precursory such as a titanium sulphate, a titanium oxychloride, a titanium tetrachloride, a titanium (III) chloride, or a mixture thereof.

[0035] In a further aspect, the Ti compound is a condensation product of a titanic acid. For example, a TiO.sub.2 precursor such as a titanium alkoxide can hydrolyze in the presence of water to form a titanic acid such as titanium hydroxide, which can then be condensed to form the Ti compound, which in the case of titanium hydroxide will be the condensation reaction product shown in Reaction 1 of FIG. 2. This condensation product can then be converted to TiO.sub.2 through various means such as calcination in a pyrolysis chamber. Similar hydrolysis and condensation reactions can be performed on a titanium sulphate, a titanium oxychloride, a titanium tetrachloride, a titanium (III) chloride, or a mixture thereof, to provide the Ti compound.

[0036] In a further aspect, the method for making the composite comprises providing a dispersion of a carbon black in a solvent; mixing the dispersion with water and a TiO.sub.2 precursor under conditions sufficient to form an oligomer coating comprising a Ti compound on at least a portion of the surface of the carbon black, wherein the TiO.sub.2 precursor is at least partially soluble in the solvent; and converting the oligomer coating comprising the Ti compound to TiO.sub.2 to form the carbon black composite.

[0037] A small amount of water added to the carbon black dispersion can allow the TiO.sub.2 to sufficiently hydrolyze into the oligomer compound. e.g., a titanic acid. In one aspect, the molar ratio of water to TiO.sub.2 precursor ranges from 2:1 to 10:1. In a further aspect, the molar ratio of water to TiO.sub.2 precursor is about 3:1.

[0038] The solvent can be any solvent capable of at least partially dissolving the TiO.sub.2 such that the precursor can react to form the oligomer compound which can in turn be converted into the TiO.sub.2 layer. For titanium alkoxides such as titanium ethoxide for example, a suitable solvent is an organic hydrocarbon solvent such as pentane, heptane, and the like.

C. Exemplary Embodiments

[0039] The following embodiments are exemplary, specific embodiments of the disclosure.

[0040] (1) A near-infrared reflective carbon black composite comprising a carbon black and a TiO.sub.2 layer at least partially coating the carbon black.

[0041] (2) The composite of embodiment (1), wherein the carbon black has an oil absorption number (OAN) ranging from 45-260 cm.sup.3/100 g.

[0042] (3) The composite of embodiment (1) or (2), wherein the carbon black has a nitrogen surface area (NSA) ranging from 25-600 m.sup.2/g.

[0043] (4) The composite of any preceding embodiment, which is free of transition metals other than Ti.

[0044] (5) The composite of any preceding embodiment, which is free of iron and chromium.

[0045] (6) The composite of any preceding embodiment, wherein the TiO.sub.2 layer has an average thickness ranging from 0.5 nm to 200 nm.

[0046] (7) The composite of any preceding embodiment, wherein the TiO.sub.2 layer has an average thickness ranging from 0.5 nm to 20 nm.

[0047] (8) The composite of any preceding embodiment, having a median particle size ranging from 0.1 m to 5 m.

[0048] (9) The composite of any preceding embodiment, wherein the carbon black is produced by a furnace black process, a lampblack process, a channel black process, a thermal black process, an acetylene black process, or a microwave plasma process.

[0049] (10) The composite of any preceding embodiment, wherein the carbon black has been heat treated, chemically treated, ozone treated, or acid treated.

[0050] (11) A method for making a carbon black composite, the method comprising: a) providing a carbon black having an oligomer coating comprising a Ti compound on at least a portion of the surface of the carbon black; and b) converting the oligomer coating comprising the Ti compound to TiO.sub.2 to form the carbon black composite.

[0051] (12) The method of embodiment (11), wherein the carbon black is produced by a furnace black process, a lampblack process, a channel black process, a thermal black process, an acetylene black process, or a microwave plasma process.

[0052] (13) The method of embodiment (11) or (12), wherein the carbon black has been heat treated, chemically treated, ozone treated, or acid treated.

[0053] (14) The method of any of embodiments (11)-(13), wherein the Ti compound is formed from TiO.sub.2 precursor.

[0054] (15) The method of embodiment (14), wherein the TiO.sub.2 precursor is a titanium alkoxide.

[0055] (16) The method of embodiment (15), wherein the titanium alkoxide is titanium ethoxide, titanium propoxide, titanium isopropoxide, titanium butoxide, or a mixture thereof.

[0056] (17) The method of embodiment (11), wherein the Ti compound is prepared from a titanium sulphate, a titanium oxychloride, a titanium tetrachloride, a titanium (III) chloride, or a mixture thereof.

[0057] (18) The method of any of embodiments (11)-(14), wherein the Ti compound is a condensation product of a titanic acid.

[0058] (19) A method for making a carbon black composite, the method comprising: a) providing a dispersion of a carbon black in a solvent; b) mixing the dispersion with water and a TiO.sub.2 precursor under conditions sufficient to form an oligomer coating comprising a Ti compound on at least a portion of the surface of the carbon black, wherein the TiO.sub.2 precursor is at least partially soluble in the solvent; and c) converting the oligomer coating comprising the Ti compound to TiO.sub.2 to form the carbon black composite.

[0059] (20) The method of embodiment (19), wherein the carbon black is produced by a furnace black process, a lampblack process, a channel black process, a thermal black process, an acetylene black process, or a microwave plasma process.

[0060] (21) The method of embodiment (19) or (20), wherein the carbon black has been heat treated, chemically treated, ozone treated, or acid treated.

[0061] (22) The method of any one of embodiments (19)-(21), wherein the TiO.sub.2 precursor is a titanium alkoxide.

[0062] (23) The method of embodiment (22), wherein the titanium alkoxide is titanium ethoxide, titanium propoxide, titanium isopropoxide, titanium butoxide, or a mixture thereof.

[0063] (24) The method of any of embodiments (19)-(21), wherein the TiO.sub.2 precursor is a titanium sulphate, a titanium oxychloride, a titanium tetrachloride, a titanium (III) chloride, or a mixture thereof.

[0064] (25) The method of any of embodiments (19)-(24), wherein the molar ratio of water to TiO.sub.2 precursor ranges from 2:1 to 10:1.

[0065] (26) The method of any of embodiments (19)-(25), wherein the molar ratio of water to TiO.sub.2 precursor is about 3:1.

[0066] (27) The method of any of embodiments (19)-(26), wherein the Ti compound is a condensation product of a titanic acid.

D. Examples

[0067] The following Examples further illustrate this disclosure. The scope of the disclosure and claims is not limited by the scope of the following Examples.

[0068] Examples shown in Table 1 were prepared according to the following procedure.

TABLE-US-00001 TABLE 1 Samples Sample Number Sample Description Example 1 Raven 1080U Powder Example 2 Raven 1080U - TiO.sub.2 Nanocoat - 37% A-106073 TiOTi Oligomer Coated Raven 1080U Example 3 Raven 1080U - TiO.sub.2 Nanocoat - 46% Example 4 Raven 1080/T595 - 46% Example 5 RAVEN 1080 ULTRA (R1080U) Example 6 Anatase TiO.sub.2 grafted RAVEN 1080 ULTRA (R1080U)-80% Example 7 physical blend of RAVEN 1080 ULTRA (R1080U)/anatase TiO.sub.2-80% Example 8 Rutile TiO.sub.2 grafted RAVEN 1080 ULTRA (R1080U)-80%, Example 9 Physical blend of RAVEN 1080 ULTRA (R1080U)/rutile TiO.sub.2-80% Example 10 Anatase TiO.sub.2 grafted RAVEN 1080 ULTRA (R1080U)-90% Example 11 Physical blend of RAVEN 1080 ULTRA (R1080U)/anatase TiO.sub.2-90%

[0069] General Procedure: The surface of carbon black was modified by TiO.sub.2 following the procedure shown in FIG. 1. Nitrogen gas was used to purge the moisture out of a 100 mL polypropylene (PP) bottle for 30 min. The PP bottle was filled with 50 mL of heptane, and 100 mg of RAVEN 1080 ULTRA (R1080U) powder was added into the heptane. The sonication probe was inserted into heptane/RAVEN 1080 ULTRA (R1080U) mixture to disperse the carbon black. The mixture was sonicated for 20 min with the intensity and cycle set as 5 and 8, respectively. A small amount of water was added into the heptane/RAVEN 1080 ULTRA (R1080U) dispersion, and the dispersion was sonicated vigorously for 15 min after adding water.

[0070] The calculated amount of titanium ethoxide (TEO) was dissolved in 20 mL heptane in a vial. The amount of added water and TEO can be found in Table 2. The TEO/heptane solution was pipetted into the PP bottle with the heptane/RAVEN 1080 ULTRA (R1080U) dispersion while sonication was on. The dispersion was sonicated for 10 min to allow the hydrolysis and condensation reaction of TEO as shown in FIG. 2. After the reaction was completed, the oligomer coated RAVEN 1080 ULTRA (R1080U) powders were collected using centrifuge and dried in the chemical hood. TiOTi oligomer coated RAVEN 1080 ULTRA (R1080U) powders was heat treated at 600 C. under nitrogen for 1 hour in a pyrolysis chamber. The oligomer was transformed to anatase phase TiO.sub.2 after the heat treatment. The percentage of TiO.sub.2 in the modified RAVEN 1080 ULTRA (R1080U) was analyzed by TGA by heating to 800 C. at 10 C./min under air condition. The morphology and element composition were characterized by TEM and EDAX as shown in Table 3. The NIR reflectance % of the powders was tested by UV-Vis-NIR spectrometer.

TABLE-US-00002 TABLE 2 Ratio of H.sub.2O/TEO and TiO.sub.2 % in the modified RAVEN 1080 ULTRA (R1080U) R1080U Water Water film Actual Calculated TiO.sub.2 % H.sub.2O/TEO Mass added thickness Stoichiometric in modified Example mol ratio (mg) (ul) (nm) TEO added (g) R1080U Example 2 2:1 100 35 3.89 0.245 46.7 Example 3 3:1 100 55 6.11 0.244 46.1

TABLE-US-00003 TABLE 3 Testing Method Test Method Test Method TGA-SPECIA XRD LS5-XRD TEM Micrograph LS5-302 NIR Reflectance EDAX

[0071] Procedure to prepare samples for Example 1: The RAVEN 1080 ULTRA carbon (R1080U) powder was produced from furnace carbon black process and treated with Ozone.

[0072] Procedure to prepare pigment samples for Examples 2, 3, 6, 8, and 10: The polypropylene (PP) bottle was filled with 50 mL heptane, and 100 mg of RAVEN 1080 ULTRA carbon (R1080U) black powder was added into heptane. The RAVEN 1080 ULTRA (R1080U) carbon black powder was dispersed in the heptane by inserting a sonication probe for 20 minutes. A small amount of water was added into the heptane/RAVEN 1080 ULTRA (R1080U) dispersion, and the dispersion was sonicated vigorously for 15 min after adding water. The calculated amount of titanium ethoxide (TEO) was dissolved in 20 ml heptane in a vial. The TEO/heptane solution was pipetted into the PP bottle with the heptane/RAVEN 1080 ULTRA (R1080U) powder dispersion while sonication was on. The dispersion was sonicated for 10 min to allow the hydrolysis and condensation reaction of TEO. After the reaction was completed, the oligomer coated RAVEN 1080 ULTRA (R1080U) powders were collected using centrifuge and dried in the chemical hood. The oligomer grafted RAVEN 1080 ULTRA (R1080U) powders was heat treated at 600 C. and 900 C. under nitrogen for 1 hour in the pyrolysis chamber to form anatase and rutile TiO.sub.2, respectively.

[0073] Procedure to prepare samples for Example 4: The commercial grade TiO.sub.2 of TIONA 595 was purchased from Tronox and used as it was received. The physical blend of RAVEN 1080 ULTRA (R1080U)/T595 was prepared by blending with RAVEN 1080 ULTRA (R1080U) and T595 with the mass ratio of 54/46.

[0074] Procedure to prepare pigment samples for Examples 7 and 10: The physical blends of RAVEN 1080 ULTRA (R1080U)/anatase TiO.sub.2 were prepared by blending anatase TiO.sub.2 and RAVEN 1080 ULTRA (R1080U) with the mass ratio of 80/20 and 90/10, respectively.

[0075] Procedure to prepare pigment samples for Example 9: The physical blends of RAVEN 1080 ULTRA (R1080U)/rutile TiO.sub.2 were prepared by blending rutile TiO.sub.2 and RAVEN 1080 ULTRA (R1080U) with the mass ratio of 80/20.

[0076] Procedure to prepare acrylic coating samples for Examples 5-11: The pigments were dispersed in the acrylic enamel recipe using Lau paint shaker. The coating was prepared using drawdown applicator, and air dried for 30 minutes followed with 15 minutes curing at 110 C.

[0077] Procedure to prepare samples for conductivity test: Test samples, 1 mm2.54 cm tape strands, were prepared using a tape header on a twin-screw extruder.

[0078] Procedure to test NIR reflectance %: The NIR reflectance % was measured from 300 nm to 2500 nm by Perkin Elmer Lambda 1050.

[0079] Procedure to characterize morphology: the morphology of TiO.sub.2 coated RAVEN 1080 ULTRA (R1080U) was characterized by TEM.

[0080] Procedure to evaluate element compositions and crystal structures: The element compositions and crystal structures of TiO.sub.2 coating on the surface of RAVEN 1080 ULTRA (R1080U) were characterize by EDAX analysis and XRD.

[0081] The ratio of H.sub.2O/TEO had an effect on the TiO.sub.2 percentage in the modified RAVEN 1080 ULTRA (R1080U). As the H.sub.2O/TEO ratio was 2:1 based on their ratio in the overall reaction in FIG. 2, the calculated TiO.sub.2% should be 47.7% as shown in Table 2. However, the actual TiO.sub.2% in Example 2 was found to be 36.8% as shown in Table 4, which was caused by insufficient water. Because the reactions occurred after pipetting TEO were the hydrolysis reaction and condensation reaction 1, and the ratio of H.sub.2O/TEO of these two combined reactions should be 3:1. Therefore, there was not enough water for TEO to react with and the unreacted TEO residuals in the heptane were discarded during the centrifuge process. As a result, the actual TiO.sub.2% in Example 2 was lower than the calculated percentage. When the H.sub.2O/TEO ratio was increased to 3:1, the actual TiO.sub.2% analyzed by TGA is 46.6% and it matched well with the calculated TiO.sub.2% in the Example 3. Therefore, TEO was fully transformed into TiO.sub.2 as the H.sub.2O/TEO ratio was 3:1.

TABLE-US-00004 TABLE 4 Actual TiO.sub.2% in modified RAVEN 1080 ULTRA (R1080U) powders analyzed by TGA Actual TiO.sub.2% in Sample Description modified R1080U Example 1 R1080U 0 Example 2 Anatase TiO.sub.2 grafted 36.8% R1080U - 37% Example 3 Anatase TiO.sub.2 grafted 46.6% R1080U - 46% Example 4 Physical Blend of 45.8% R1080U/T595 - 46%

[0082] The surface of RAVEN 1080 ULTRA (R1080U) powder was modified successfully via the hydrolysis and condensation reaction of TEO as revealed by the TEM images in FIG. 3. There was a layer of TiOTi oligomer nanocoating observed on the surface of RAVEN 1080 ULTRA (R1080U) powder. The thickness of TiOTi oligomer nanocoating varied from 1 nm to 17 nm. According to the EDAX analysis in FIG. 4, the modified RAVEN 1080 ULTRA (R1080U) is composed of C, Ti and O, which confirmed the deposition of TiOTi oligomer on the surface of RAVEN 1080 ULTRA (R1080U).

[0083] The TiOTi oligomer coated RAVEN 1080 ULTRA (R1080U) was calcined at 600 C. for 1 hour under nitrogen, and the oligomer was transformed to TiO, according to the condensation reaction 2 in FIG. 2. The TEM images in FIG. 5 show that the surface of RAVEN 1080 ULTRA (R1080U) was coated with a layer of TiO.sub.2. The thickness of the TiO.sub.2 shell in Example 2 ranges from 0.7 nm to 12.5 nm. There were also exposed surfaces without TiO.sub.2 nanocoating. The EDAX analysis in FIG. 6 confirms the composition of modified RAVEN 1080 ULTRA (R1080U) containing C, Ti and O. The XRD patterns in FIG. 7 confirm the transition from TiOTi oligomer to anatase phase TiO.sub.2 after heat treatment. Similarly, TiO.sub.2 nanocoating was observed on the RAVEN 1080 ULTRA (R1080U) for Example 3 with a higher percentage of TiO.sub.2 (46%) in FIG. 8. Comparing with Example 2, the thickness of the coating became more uniform ranging from 0.8 to 7 nm. More surfaces of RAVEN 1080 ULTRA (R1080U) were covered by TiO.sub.2 nanocoating in Example 3 due to higher TiO.sub.2 percentage.

[0084] The spectrum reflectance % of the TiO.sub.2 coated RAVEN 1080 ULTRA (R1080U) samples were characterized by UV-Vis-NIR spectrometer ranging from 300 nm to 2500 nm in FIG. 9. Their results were compared against the pure RAVEN 1080 ULTRA (R1080U) control and physical blends of RAVEN 1080 ULTRA (R1080U) and Tiona 595 (T595: a commercial grade of TiO.sub.2 for coating and plastic). In the NIR range from 700 nm to 2500 nm, carbon black showed only 2.08-2.43% of reflectance % due to the high NIR absorption nature of carbon black. The NIR reflectance % of TiO.sub.2 coated RAVEN 1080 ULTRA (R1080U) was enhanced significantly over 1.5 times as RAVEN 1080 ULTRA (R1080U) was partially covered by TiO, nanocoating with extremely high NIR reflection ability. The NIR reflectance % was increased with the percentage of TiO.sub.2 nanocoating. Although the physical blends of RAVEN 1080 ULTRA (R1080U) and T595 contained 45.8% TiO.sub.2, less than 20% improvement of NIR reflectance % was observed as the surface of T595 was covered by RAVEN 1080 ULTRA (R1080U) powder. Since the wavelength of LiDAR signal is located at 905 and 1550 nm, the NIR reflectance % and percentage of improvement at these two wavelengths as well as 2000 and 2500 nm was summarized in Tables 5 and 6, respectively. They showed that TiO.sub.2 nanocoated RAVEN 1080 ULTRA (R1080U) achieved more than 150% higher NIR reflectance % than the RAVEN 1080 ULTRA (R1080U). The TiO.sub.2 nanocoated carbon black showed much more effective improvement of NIR reflectance % than physical blends of carbon black and TiO.sub.2.

TABLE-US-00005 TABLE 5 NIR Reflectance % at Specific Wavelengths Example Description 905 nm 1550 nm 2000 nm Example 1 RAVEN 1080 ULTRA 2.43 2.23 2.21 (R1080U) Example 2 Anatase TiO.sub.2 grafted 4.57 4.55 4.56 R1080U - 37% Example 3 Anatase TiO.sub.2 grafted 4.71 5.3 5.66 R1080U - 46% Example 4 Physical Blend of 2.91 2.65 2.44 R1080U/T595 - 46%

TABLE-US-00006 TABLE 6 Percentage Improvement of NIR Reflectance % at Specific Wavelengths TiO.sub.2/ Example Description CB wt. ratio 905 nm 1550 nm 2000 nm Example 1 RAVEN 1080 ULTRA 0/100 100% 100% 100% (R1080U) Example 2 Anatase TiO.sub.2 grafted 37/63 184% 204% 206% R1080U - 37% Example 3 Anatase TiO.sub.2 grafted 46/54 190% 238% 256% R1080U - 46% Example 4 Physical Blend of 45/54 120% 119% 110% R1080U/T595 - 46%

[0085] As shown in Tables 7 and 8, similar results were seen with additional Examples. The NIR reflectance % increases with the percentage of TiO.sub.2 coating on the surface of RAVEN 1080 ULTRA (R1080U) as demonstrated by Examples 6 and 10.

[0086] TiO.sub.2 grafted RAVEN 1080 ULTRA (R1080U) pigment showed significantly better improvement in NIR reflectance % than the physical blend of RAVEN 1080 ULTRA (R1080U)/TiO.sub.2, regardless of the TiO.sub.2 crystal type. Example 8 demonstrates about 180% higher NIR reflectance % than Example 5. The NIR reflectance % of Example 9 is 64% higher than that of Example 5.

[0087] At the same ratio of TiO.sub.2 and carbon black, rutile TiO.sub.2 grafted RAVEN 1080 ULTRA (R1080U) can achieve more significant NIR reflectance improvement than anatase TiO.sub.2 grafted RAVEN 1080 ULTRA (R1080U) as demonstrated by Example 6 and 8.

TABLE-US-00007 TABLE 7 Percentage Improvement of NIR Reflectance % at Specific Wavelengths TiO.sub.2/CB Example Description wt. ratio 905 nm 1550 nm 2000 nm Example 5 RAVEN 1080 ULTRA 0/100 100% 100% 100% (R1080U) Example 6 Anatase TiO.sub.2 grafted 80/20 180% 160% 171% R1080U- 80% Example 7 physical blend of 80/20 147% 147% 142% R1080U/anatase TiO.sub.2-80% Example 8 Rutile TiO.sub.2 grafted 80/20 279% 229% 247% R1080U- 80%, Example 9 Physical blend of 80/20 164% 148% 139% R1080U/rutile TiO.sub.2-80% Example 10 Anatase TiO.sub.2 grafted 90/10 294% 383% 478% R1080U- 90% Example 11 Physical blend of 90/10 253% 269% 320% R1080U/anatase TiO.sub.2-90%

TABLE-US-00008 TABLE 8 Color of Acrylic Coating Containing Various Pigments. TiO.sub.2/CB wt. Example Description ratio My L a b Example 5 RAVEN 1080 ULTRA 0/100 234 6.74 0.06 0.04 (R1080U) Example 6 Anatase TiO.sub.2 grafted 80/20 189 11.32 0.01 2.50 R1080U-80% Example 7 Physical blend of 80/20 203 9.64 0.10 1.19 R1080U/anatase TiO.sub.2- 80% Example 8 Rutile TiO.sub.2 grafted 80/20 163 15.26 0.07 2.07 R1080U-80% Example 9 Physical blend of 80/20 186 11.81 0.03 1.68 R1080U/rutile TiO.sub.2-80% Example 10 Anatase TiO.sub.2 grafted 90/10 152 17.39 0.19 3.14 R1080U-90% Example 11 Physical blend of 90/10 157 16.40 0.08 1.93 R1080U/anatase TiO.sub.2- 90%

[0088] Features and advantages of this disclosure are apparent from the detailed specification, and the claims cover all such features and advantages. Numerous variations will occur to those skilled in the art, and any variations equivalent to those described in this disclosure fall within the scope of this disclosure. Those skilled in the art will appreciate that the conception upon which this disclosure is based may be used as a basis for designing other methods and systems for carrying out the several purposes of this disclosure. As a result, the claims should not be considered as limited by the description or Examples.