METHOD FOR PREPARING MODIFIED GRAPHENE AND METHOD FOR PREPARING SLURRY CONTAINING THE MODIFIED GRAPHENE
20220017370 · 2022-01-20
Assignee
Inventors
Cpc classification
C09C3/10
CHEMISTRY; METALLURGY
International classification
C09C3/10
CHEMISTRY; METALLURGY
Abstract
A method for preparing modified graphene and a method for preparing a slurry containing the modified graphene are disclosed. The method for preparing a modified graphene comprises: putting a flake graphite powder, a silicon molecular modifier, water and a boric acid solution into a high pressure container, filling a liquid gas into the high pressure container, connecting the high pressure container to a solid gas preparation apparatus, to solidify the liquid qas and obtain a solid gas, putting the solid gas into a ultraviolet washing machine for ultraviolet high-energy radiation, exfoliating the graphene flake, continuously exposing to ultraviolet light for a period of time to form a modified graphene, continuously exposing the modified graphene under the ultraviolet light, and storing the modified graphene in vacuum as an intermediate.
Claims
1.-14. (canceled)
15. A method for preparing a modified graphene, comprising the following steps: S1: putting a flake graphite powder, a silicon molecular modifier, water and a boric acid solution with a molar concentration of 1-2 mol/L into a high pressure container, sealing the container, and forming a vacuum ranging from 0.09 to 0.1 MPa; S2: filling at least one liquid gas chosen from liquid carbon dioxide, liquid ozone, and liquid nitrogen into the high pressure container in step S1, shaking and then letting the container stand for 20-28 hours; S3: connecting the high pressure container in step S2 to a solid gas preparation apparatus, to solidify the liquid gas and obtain a solid gas; S4: putting the solid gas obtained in step S3 into a ultraviolet washing machine with wavelengths of 185 nm and 254 nm in sequence for ultraviolet high-energy radiation, exfoliating the flake graphite powder to obtain a modified graphene flake, and functionally modifying the modified graphene flake with the solid gas to form carbonyl groups and carbon hydroxyl groups on the surface of the modified graphene flake, and grafting the carbonyl groups and carbon hydroxyl groups with silicon hydroxyl groups to obtain a crude modified graphene; and S5: exposing the crude modified graphene obtained in step S4 to ultraviolet light for 20-60 minutes while functionally modifying as described in step S4 to form carbonyl groups and carbon hydroxyl groups on the surface of the crude modified graphene, and grafting the carbonyl groups and carbon hydroxyl groups with silicon hydroxyl to form a modified graphene.
16. The method of claim 15, wherein raw materials for preparing the modified graphene comprise the following components in parts by weight: 5-25 parts of a flake graphite powder, 70-90 parts of a liquid gas, 1-5 parts of a silicon molecular modifier, 0.5-3 parts of distilled water, and 1-3 parts of a boric acid solution.
17. The method of claim 15, wherein the flake graphite powder has a particle size of 1000-3000 mesh.
18. The method of claim 15, wherein the silicon molecular modifier is at least one chosen from compounds comprising an Si—OH functional group.
19. The method of claim 18, wherein the silicon molecular modifier is at least one chosen from silane coupling agents.
20. The method of claim 19, wherein the silane coupling agent is at least one chosen from low molecular silica sol, silicone resin, amino silane, epoxy silane, and mercapto silane.
21. The method of claim 15, wherein the solid gas obtained in step S3 has a size of (80-120) mm×(40-60) mm×(10-30) mm.
22. The method of claim 15, wherein the silicon hydroxyl groups are formed by hydrolysis of the silicon molecular modifier with high energy radiation.
23. A method for preparing a silicon-titanium modified graphene slurry, comprising the following steps: S1: adding a nano-titanium powder, a silane coupling agent and an organic solvent into a container, mixing, adding a modified graphene prepared according to claim 1 into the container, dispersing the contents of the container with ultrasound, and adding water to the container, wherein the silicon molecular modifier used in the preparation of the modified graphene prepared according to claim 1 has functional groups and the silane coupling agent has functional groups different from the functional groups of the modified graphene; and S2: autoclaving at 110-120° C. for 6-12 hours to obtain a silicon-titanium modified graphene slurry.
24. The method as claimed in claim 23, wherein the silicon-titanium modified graphene slurry comprises the following components in parts by weight: 8-12 parts of a silane coupling agent, 20-40 parts of an organic solvent, 10-20 parts of a high purity nano-titanium powder, 30-40 parts of the modified graphene, and 0.5-1 parts of distilled water.
25. The method as claimed in claim 23, wherein the organic solvent is at least one chosen from absolute ethanol, acetone, and methylpyrrolidone.
26. The method as claimed in claim 23, wherein the silane coupling agent is at least one chosen from low molecular silica sol, silicone resin, amino silane, epoxy silane, and mercapto silane.
27. A silicon-titanium modified graphene slurry, as prepared by the method according to claim 23.
28. The method as claimed in claim 16, wherein the flake graphite powder has a particle size of 1000-3000 mesh.
29. The method as claimed in claim 23, wherein the flake graphite powder has a particle size of 1000-3000 mesh.
30. The method as claimed in claim 23, wherein the silicon molecular modifier is at least one chosen from compounds comprising an Si—OH functional group.
31. The method as claimed in claim 24, wherein the organic solvent is at least one chosen from absolute ethanol, acetone, and methylpyrrolidone.
32. The method as claimed in claim 24, wherein the silane coupling agent is at least one chosen from low molecular silica sol, silicone resin, amino silane, epoxy silane, and mercapto silane.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0043]
[0044]
[0045]
DETAILED DESCRIPTION
[0046] In the following, the technical proposals in the embodiments of the present disclosure will be clearly and completely described, so that those skilled in the art could better understand the advantages and features of the present disclosure, so as to make a clearer definition for the protection scope of the present disclosure. The embodiments of the present disclosure as described are only a part of the embodiments of the present disclosure, not all of them. Based on the embodiments of the present disclosure, all other embodiments obtained by those skilled in the art without creative labor shall fall within the protection scope of the present disclosure.
EXAMPLE 1
[0047] A method for preparing a modified graphene included the following steps:
[0048] S1: a flake graphite powder, a silane coupling agent, distilled water and boric acid solution with a molar concentration of 1.5 mol/L were placed into a stainless steel high pressure bottle, and the bottle was sealed. The air in the bottle was slowly extracted, so that the vacuum degree in the bottle reached 0.09 MPa;
[0049] S2: a liquid gas was filled in the stainless steel high pressure bottle in step S1, and the resulting system was shaken well and stood for 24 hours;
[0050] S3: the stainless steel high pressure bottle in step S2 was connected to a solid gas preparation apparatus to obtain a solid gas;
[0051] S4: the solid gas obtained in step S3 was placed into a ultraviolet washing machine for ultraviolet irradiation until the solid gas was disappeared completely, to obtain a crude modified graphene; and
[0052] S5: the crude modified graphene in step S4 was continuously exposed to the ultraviolet light for 30 minutes to remove organic matters contained on the surface of the crude modified graphene, and meanwhile, the functional modification was performed to form carbonyl groups and carbon hydroxyl groups, and the groups was grafted with the silicon hydroxyl formed by the hydrolysis of the silicon molecular modifier by high energy radiation, to obtain a functionalized modified graphene. The modified graphene was stored in vacuum.
[0053] Wherein, the raw materials for preparing the modified graphene comprised the following components in parts by weight:
[0054] 6 parts of a flake graphite powder;
[0055] 87.5 parts of a liquid gas;
[0056] 3 parts of a silicon molecular modifier;
[0057] 1.5 parts of distilled water; and
[0058] 2 parts of a boric acid solution.
[0059] Wherein, the flake graphite powder had a particle size of 2500 mesh.
[0060] Wherein, the liquid gas was liquid carbon dioxide.
[0061] Wherein, the silicon molecular modifier was a low molecular silica sol.
[0062] Wherein, the solid gas in step S3 had a size of 100 mm×50 mm×20 mm
[0063] Wherein, the ultraviolet washing machine was a drawer type with reflective cover, and the ultraviolet light in the ultraviolet washing machine had wavelengths of 185 nm and 254 nm.
[0064] A method for preparing a silicon-titanium modified graphene slurry included the following steps:
[0065] S1: a high purity nano-titanium powder, a silane coupling agent and an organic solvent were added into a beaker and mixed uniformly, and then the modified graphene was taken and put into the beaker, the resulting mixture was dispersed by ultrasound, distilled water was added, and then the resulting system was immediately put into a stainless steel autoclave and sealed;
[0066] S2: the stainless steel autoclave in step S1 was placed into an oven with a temperature of 115° C. for 9 hours to fully react, then cooled to 25° C., and after that, the resulting materials were taken out, to obtain the silicon-titanium modified graphene slurry.
[0067] Wherein, the silicon-titanium modified graphene slurry comprised the following components in parts by weight:
[0068] 9 parts of a silane coupling agent,
[0069] 40 parts of an organic solvent,
[0070] 35 parts of a modified graphene,
[0071] 15 parts of a high purity nano-titanium powder, and
[0072] 1 part of distilled water.
[0073] Wherein, the organic solvent was absolute ethanol.
[0074] Wherein, the functional groups of the silicon molecular modifier used in the preparation of modified graphene were different from those of the silane coupling agent used in the formulation of silicon-titanium modified graphene slurry.
[0075] TEM test was performed on the obtained silicon-titanium modified graphene slurry, and the result was shown in
EXAMPLE 2
[0076] A method for preparing a modified graphene included the following steps:
[0077] S1: a flake graphite powder, a silane coupling agent, distilled water and boric acid solution with a molar concentration of 1 mol/L were placed into a stainless steel high pressure bottle, and the bottle was sealed. The air in the bottle was slowly extracted, so that the vacuum degree in the bottle reached −0.09 MPa;
[0078] S2: a liquid gas was filled in the stainless steel high pressure bottle in step S1, and the resulting system was shaken well and stood for 20 hours;
[0079] S3: the stainless steel high pressure bottle in step S2 was connected to a solid gas preparation apparatus to obtain a solid gas;
[0080] S4: the solid gas obtained in step S3 was placed into a ultraviolet washing machine for ultraviolet irradiation until the solid gas was disappeared completely, to obtain a crude modified graphene; and
[0081] S5: the crude modified graphene in step S4 was continuously exposed to the ultraviolet light for 20 minutes to remove organic matters contained on the surface of the crude modified graphene, and meanwhile, the functional modification was performed to form carbonyl groups and carbon hydroxyl groups, and the groups was grafted with the silicon hydroxyl formed by the hydrolysis of the silicon molecular modifier by high energy radiation, to obtain a functionalized modified graphene. The modified graphene was stored in vacuum.
[0082] Wherein, the raw materials for preparing the modified graphene comprised the following components in parts by weight:
[0083] 10 parts of a flake graphite powder;
[0084] 87 parts of a liquid gas;
[0085] 3.5 parts of a silicon molecular modifier;
[0086] 0.5 parts of distilled water; and
[0087] 1 parts of a boric acid solution.
[0088] Wherein, the flake graphite powder had a particle size of 2000 mesh.
[0089] Wherein, the liquid gas was liquid carbon dioxide or liquid nitrogen.
[0090] Wherein, the silicon molecular modifier was a low molecular silica sol, silicone resin, or functional bis-silanes, such as amino siloxane, epoxy silane, and mercapto silane.
[0091] Wherein, the solid gas in step S3 had a size of 120 mm×60 mm×10 mm
[0092] Wherein, the ultraviolet washing machine was a drawer type with reflective cover, and the ultraviolet light in the ultraviolet washing machine had wavelengths of 185 nm and 254 nm.
[0093] A method for preparing a silicon-titanium modified graphene slurry included the following steps:
[0094] S1: a high purity nano-titanium powder, a silane coupling agent and an organic solvent were added into a beaker and mixed uniformly, and then the modified graphene was taken and put into the beaker, the resulting mixture was dispersed by ultrasound, distilled water was added, and then the resulting system was immediately put into a stainless steel autoclave and sealed;
[0095] S2: the stainless steel autoclave in step S1 was placed into an oven with a temperature of 110° C. for 12 hours to fully react, then cooled to 20° C., and after that, the resulting materials were taken out, to obtain the silicon-titanium modified graphene slurry.
[0096] Wherein, the silicon-titanium modified graphene slurry comprised the following components in parts by weight:
[0097] 12 parts of a silane coupling agent,
[0098] 40 parts of an organic solvent,
[0099] 35 parts of a modified graphene,
[0100] 10 parts of a high purity nano-titanium powder, and
[0101] 1 part of distilled water.
[0102] Wherein, the organic solvent was methyl pyrrolidone.
[0103] Wherein, the functional groups of the silicon molecular modifier used in the preparation of modified graphene were different from those of the silane coupling agent used in the formulation of silicon-titanium modified graphene slurry.
[0104] TEM test was performed on the obtained silicon-titanium modified graphene slurry, and the result was shown in
EXAMPLE 3
[0105] A method for preparing a modified graphene included the following steps:
[0106] S1: a flake graphite powder, a silane coupling agent, distilled water and boric acid solution with a molar concentration of 2 mol/L were placed into a stainless steel high pressure bottle, and the bottle was sealed. The air in the bottle was slowly extracted, so that the vacuum degree in the bottle reached 0.1 MPa;
[0107] S2: a liquid gas was filled in the stainless steel high pressure bottle in step S1, and the resulting system was shaken well and stood for 28 hours;
[0108] S3: the stainless steel high pressure bottle in step S2 was connected to a solid gas preparation apparatus to obtain a solid gas;
[0109] S4: the solid gas obtained in step S3 was placed into a ultraviolet washing machine for ultraviolet irradiation until the solid gas was disappeared completely, to obtain a crude modified graphene; and
[0110] S5: the crude modified graphene in step S4 was continuously exposed to the ultraviolet light for 30 minutes to remove organic matters contained on the surface of the crude modified graphene, and meanwhile, the functional modification was performed to form carbonyl groups and carbon hydroxyl groups, and the groups was grafted with the silicon hydroxyl formed by the hydrolysis of the silicon molecular modifier by high energy radiation, to obtain a functionalized modified graphene. The modified graphene was stored in vacuum.
[0111] Wherein, the raw materials for preparing the modified graphene comprised the following components in parts by weight:
[0112] 9 parts of a flake graphite powder;
[0113] 80 parts of a liquid gas;
[0114] 5 parts of a silicon molecular modifier;
[0115] 3 parts of distilled water; and
[0116] 3 parts of a boric acid solution.
[0117] Wherein, the flake graphite powder had a particle size of 3000 mesh.
[0118] Wherein, the liquid gas was liquid nitrogen.
[0119] Wherein, the silicon molecular modifier was the mixture of epoxy silane and mercaptosilane.
[0120] Wherein, the solid gas in step S3 had a size of 80 mm×60 mm×30 mm.
[0121] Wherein, the ultraviolet washing machine was a drawer type with reflective cover, and the ultraviolet light in the ultraviolet washing machine had wavelengths of 185 nm and 254 nm.
[0122] A method for preparing a silicon-titanium modified graphene slurry included the following steps:
[0123] S1: a high purity nano-titanium powder, a silane coupling agent and an organic solvent were added into a beaker and mixed uniformly, and then the modified graphene was taken and put into the beaker, the resulting mixture was dispersed by ultrasound, distilled water was added, and then the resulting system was immediately put into a stainless steel autoclave and sealed;
[0124] S2: the stainless steel autoclave in step S1 was placed into an oven with a temperature of 120° C. for 6 hours to fully react, then cooled to 30° C., and after that, the resulting materials were taken out, to obtain the silicon-titanium modified graphene slurry.
[0125] Wherein, the silicon-titanium modified graphene slurry comprised the following components in parts by weight:
[0126] 9 parts of a silane coupling agent,
[0127] 40 parts of an organic solvent,
[0128] 30 parts of a modified graphene,
[0129] 20 parts of a high purity nano-titanium powder, and
[0130] 1 part of distilled water.
[0131] Wherein, the organic solvent was methyl pyrrolidone; Wherein, the functional groups of the silicon molecular modifier used in the preparation of modified graphene were different from those of the silane coupling agent used in the formulation of silicon-titanium modified graphene slurry.
[0132] TEM test was performed on the obtained silicon-titanium modified graphene slurry, and the result was shown in
[0133] Performance Testing
[0134] The silicon-titanium modified graphene slurries obtained from Examples 1-3 were each mixed with an epoxy resin and a crosslinker to obtain a silicon-titanium-carbon composite modified graphene nano anti-corrosive coating. Wherein, the epoxy resin included bisphenol A epoxy resin 901 and bisphenol A epoxy resin 904 produced by Kunshan Nanya Company (JiangSu, China), and the mass ratio of the bisphenol A epoxy resin 901 to the bisphenol A epoxy resin 904 is 1:1. The crosslinker was purchased from Zhuhai Cardolite Co., Ltd., with the trade name of 2015 cardanol modified phenolic amine. The mass ratio of the epoxy resin, the titanium modified graphene slurry and the crosslinker in the anti-corrosive coating was 75:5:20.
[0135] The paintcoats obtained from the graphene nano anti-corrosive coatings were subjected to high temperature and high pressure acid and alkali cooking test, water cooking wet adhesion test, strong acid and alkali soaking test, salt spray test, high-low temperature hot and humid test, boiling saturated salt solution cooking test, sandblasted steel plate adhesion test, rust construction test, and strong acid cooking resistance test. The results were listed in Table 1. A comparative example was carried out, in which the epoxy resin coating without silicon-titanium modified graphene slurry was used.
[0136] Wherein, the high temperature and high pressure acid and alkali cooking test was performed by cooking a paintcoat with a thickness of 200 micron in an acid solution with a pH of 3 or in an alkali solution with a pH of 12.5 at a temperature of 150° C. and a pressure of 70 MPa for 24 hours, and observing the blistering and peeling of the paintcoat.
[0137] The water cooking wet adhesion test was performed by cooking a paintcoat with a thickness of 200 micron in pure water at a temperature of 80° C. for 48 hours, and testing the adhesion grade with a knife pick process.
[0138] The strong acid and alkali soaking test was perfomed by soaking a paintcoat in 10% hydrochloric acid, or 10% sulfuric acid, or 10% sodium hydroxide solution at room temperature for more than one year, and observing the blistering, peeling and cracking of the paintcoat.
[0139] The salt spray test was performed by subjecting a paintcoat with a thickness of 200 micron to intermittent spraying or salt spray test for more than 10,000 hours (without scratching), and observing the blistering, peeling and rust of the paintcoat.
[0140] The high-low temperature hot and humid test was performed by cycling a paintcoat with a thickness of 23 micron once under the conditions of a temperature of −20 to 120° C. and a humidity of 50-95% for every 24 hours, and after 10000 hours, observing the blistering, peeling and cracking of the paintcoat.
[0141] The boiling saturated salt solution cooking test was performed by cooking a paintcoat with a thickness of 100 micron in a saturated salt solution at a temperature of 100° C. for 720 hours, and observing the blistering, peeling, and rust of the paintcoat.
[0142] The sandblasted steel plate adhesion test was performed by applying the coating to a sandblasted steel plate and testing the adhesion of the paintcoat obtained from the coating on the surface of the sandblasted steel plate.
[0143] The rust construction test was performed by applying the coating on the rust layer with a thickness of 20-60 micron and testing the adhesion of the paintcoat on the rust layer.
[0144] The strong acid cooking resistance test was performed by applying the coating on a round steel rod made of polished Q235 carbon steel rod with a dimension of 13 mm×120 mm to form a paintcoat with a thickness of 120-150 micron, and testing the resistance to 10% HCl and 10% H.sub.2SO.sub.4 cooking of the paintcoat at a temperature of 60° C.
TABLE-US-00001 TABLE 1 Performance test results of the silicon-titanium modified graphene slurries obtained from Examples 1-3 and Comparative Example. Comparative Test Item Example 1 Example 2 Example 3 Example High temperature No blistering No blistering No blistering Blistering and and high pressure and no and no and no peeling within acid and alkali peeling peeling peeling 2 h cooking test Water cooking wet Level 1 Level 1 Level 1 No pass adhesion test Strong acid and No blistering, No blistering, No blistering, Blistering alkali soaking test no peeling, no peeling, no peeling, after 15 days and no cracking and no cracking and no cracking Salt spray test No blistering, No blistering, No blistering, Blistering, no peeling, no peeling, no peeling, peeling, and and no rust and no rust and no rust rust after 1000 h High-low No blistering, No blistering, No blistering, Blistering, temperature hot no peeling, no peeling, no peeling, peeling, and and humid test and no cracking and no cracking and no cracking cracking after 1000 h Boiling saturated No blistering, No blistering, No blistering, Blistering, salt solution no peeling, no peeling, no peeling, peeling, and cooking test and no rust and no rust and no rust rust within 168 h Sandblasted steel ≥25 MPa ≥25 MPa ≥25 MPa 6-10 MPa plate adhesion test Rust construction test ≥10 MPa ≥10 MPa ≥10 MPa <5 MPa 60° C. acid cooking ≥120 Day ≥120 Day ≥120 Day <7 Day resistance test
[0145] As can be seen from Table 1, using the silicon-titanium modified graphene slurry of the present disclosure as a modifier for anti-corrosive coating makes it possible to effectively improve the adhesion and corrosion resistance of the coating.
[0146] Finally, it should be noted that the examples as described above are only used to illustrate the technical proposals of the present disclosure, rather than to limit the protection scope of the present disclosure. Although the present disclosure has been described in detail with reference to preferred embodiments, those skilled in the art could understood that the technical proposals of the present disclosure can be modified or equivalently replaced without departing from the principle and scope of the technical proposals of the present disclosure.