PVA / MXene supramolecular gel lubricating material, and preparation method and application thereof

Abstract

The application belongs to the technical field of supramolecular gels, and provides a PVA / MXene supramolecular gel lubricating material, a preparation method and application thereof.The PVA / MXene supramolecular gel lubricating material comprises the following raw materials: MXene aqueous dispersion, PVA and a liquid lubricant; the liquid lubricant is a polyhydric alcohol.The application constructs an environmentally-friendly and low-temperature-resistant PVA / MXene supramolecular gel lubricating material driven by hydrogen bonds through the hydrogen bond interaction among PVA, MXene and the polyhydric alcohol.The supramolecular gel fixes the lubricant polyhydric alcohol in a three-dimensional network structure, thereby solving the problems of climbing and leakage of the liquid lubricant during use.Meanwhile, the various hydrogen bond interactions among PVA, MXene and the polyhydric alcohol increase the proportion of combined water in the gel, so that the gel cannot freeze at an environment of-80 DEG C, thereby further improving the low-temperature resistance of the supramolecular gel.The viscosity of the PVA / MXene supramolecular gel lubricating material increases at low temperature, and the film-forming capacity is stronger, so that a relatively thick lubricating film can be formed between the friction pairs to prevent the direct contact of the friction pairs, thereby significantly reducing the friction and wear.Meanwhile, the MXene material has excellent self-lubricating performance, and can further improve the lubricating effect of the supramolecular gel.

Description

Technical Field

[0001] This invention relates to the field of supramolecular gel technology, and in particular to a PVA / MXene supramolecular gel lubricating material, its preparation method, and its application. Background Technology

[0002] Mineral oils and polyalphaolefin oils are widely used in industrial production due to their excellent wear resistance, thermal stability, and low volatility. However, the non-renewable nature of traditional lubricants and their susceptibility to creep and leakage during use cause serious environmental pollution. Therefore, there is an urgent need for an environmentally friendly, renewable, and pollution-free lubricant to meet the requirements of energy conservation and environmental protection.

[0003] Supramolecular gels are three-dimensional network structures formed by non-covalent interactions between molecules (such as hydrogen bonds, π-π stacking, and van der Waals forces). They can firmly bind liquid lubricants to their internal cross-linked three-dimensional network structure, thus avoiding problems such as lubricant creep and leakage. Therefore, supramolecular gels can serve as a novel lubricating material. Traditional supramolecular gels use mineral oil or polyalphaolefin oil as lubricants, but these lubricants have poor lubrication performance at low temperatures and are environmentally polluting. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a PVA / MXene supramolecular gel lubricating material, its preparation method, and its applications. The PVA / MXene supramolecular gel lubricating material provided by this invention is green and pollution-free, and exhibits excellent lubrication performance at low temperatures.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0006] This invention provides a PVA / MXene supramolecular gel lubricating material, comprising the following raw materials:

[0007] MXene aqueous dispersion, PVA and liquid lubricant;

[0008] The liquid lubricant is a polyol.

[0009] Preferably, the PVA / MXene supramolecular gel lubricating material contains 3-8% PVA by mass, 0.3-0.5% MXene by mass, and 60-75% liquid lubricant by mass.

[0010] Preferably, the MXene aqueous dispersion has 1 to 5 MXene layers, the polyol includes one or more of glycerol, ethylene glycol, 1,4-butanediol and sorbitol, and the PVA is of type PVA105.

[0011] This invention also provides a method for preparing the PVA / MXene supramolecular gel lubricating material described in the above technical solution, comprising the following steps:

[0012] MXene aqueous dispersion, PVA, and liquid lubricant were dissolved and mixed to obtain a mixed system;

[0013] The mixture was allowed to stand to obtain the PVA / MXene supramolecular gel lubricant material.

[0014] Preferably, the concentration of the MXene aqueous dispersion is 10-15 mg / mL.

[0015] Preferably, the dissolution and mixing of the MXene aqueous dispersion, PVA, and liquid lubricant includes: mixing the MXene aqueous dispersion and the liquid lubricant to obtain an MXene-liquid lubricant aqueous solution; deoxygenating the MXene-liquid lubricant aqueous solution to obtain an oxygen-deoxygenated MXene-liquid lubricant aqueous solution; and mixing the oxygen-deoxygenated MXene-liquid lubricant aqueous solution and PVA in a water bath.

[0016] Preferably, the water bath mixing temperature is 90-95°C and the time is 1.5-3 hours.

[0017] Preferably, the dissolution and mixing of the MXene aqueous dispersion, PVA, and liquid lubricant includes: deoxygenating the MXene aqueous dispersion to obtain a deoxygenated MXene aqueous dispersion, and sequentially adding PVA and liquid lubricant to the deoxygenated MXene aqueous dispersion.

[0018] Preferably, the settling temperature is 20-25°C and the settling time is 24-48 hours.

[0019] This invention also provides the application of the PVA / MXene supramolecular gel lubricating material described in the above technical solution or the PVA / MXene supramolecular gel lubricating material prepared by the preparation method described in the above technical solution in the field of friction lubrication.

[0020] This invention provides a PVA / MXene supramolecular gel lubricating material, comprising the following raw materials: MXene aqueous dispersion, PVA, and liquid lubricant; wherein the liquid lubricant is a polyol.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] This invention constructs a hydrogen-bonded, environmentally friendly, low-temperature-resistant PVA / MXene supramolecular gel lubricant material through hydrogen bonding interactions between PVA, MXene, and polyols. This supramolecular gel immobilizes the lubricant polyol within a three-dimensional network structure, solving the problems of creep and leakage of liquid lubricants during use. Aqueous solutions of polyols are commonly used as antifreeze; when the mass ratio of polyol to water is 2:1, its freezing point can drop to -40 to -50°C. Simultaneously, the various hydrogen bonding interactions among PVA, MXene, and polyols increase the proportion of bound water in the gel, preventing it from freezing at -80°C, thus further improving the low-temperature resistance of the supramolecular gel. At low temperatures, the viscosity of the PVA / MXene supramolecular gel lubricant material increases, enhancing its film-forming ability. It can form a thicker lubricating film between friction pairs to prevent direct contact, thereby significantly reducing friction and wear. Furthermore, MXene possesses excellent self-lubricating properties, further improving the lubrication effect of the supramolecular gel. In addition, the raw materials used in the preparation of this invention are green and pollution-free.

[0023] This invention also provides a method for preparing the PVA / MXene supramolecular gel lubricating material described in the above technical solution. The preparation method provided by this invention is simple, and environmentally friendly, low-temperature resistant PVA / MXene supramolecular gel lubricating material can be prepared through a simple liquid-phase reaction. Attached Figure Description

[0024] Figure 1 Optical images of the hydrogen-bonded, environmentally friendly, low-temperature resistant supramolecular gel lubricating materials prepared for Comparative Example 1 and Example 1;

[0025] Figure 2 Optical images of the hydrogen-bonded, environmentally friendly, low-temperature resistant supramolecular gel lubricating materials prepared in Examples 1, 3, 4 and 5;

[0026] Figure 3 Image showing the viscosity of the supramolecular gel lubricating materials prepared in Comparative Example 1 and Example 1 as a function of shear rate;

[0027] Figure 4 Differential scanning calorimetry curves of the supramolecular gel lubricating materials prepared in Comparative Example 1 and Example 1;

[0028] Figure 5 Image showing the change in the coefficient of friction of the supramolecular gel lubricating materials prepared in Comparative Example 1 and Example 1 over time;

[0029] Figure 6 The images show the change of the friction coefficient over time for the supramolecular gel lubricating material prepared in Example 1 under different friction pairs.

[0030] Figure 7Images showing the change in the friction coefficient over time for the supramolecular gel lubricating materials prepared in Examples 1, 3, 4 and 5. Detailed Implementation

[0031] This invention provides a PVA / MXene supramolecular gel lubricating material, comprising the following raw materials:

[0032] MXene aqueous dispersion, PVA and liquid lubricant;

[0033] The liquid lubricant is a polyol.

[0034] Unless otherwise specified, all raw materials used in this invention are preferably commercially available products.

[0035] The raw materials for preparing the PVA / MXene supramolecular gel lubricating material provided by this invention include an MXene aqueous dispersion. In this invention, the number of MXene layers in the MXene aqueous dispersion is preferably 1 to 5. Specifically, the MXene in the MXene aqueous dispersion is preferably Ti3C2T. x In this invention, the Ti3C2T x The material is preferably prepared by etching Ti3AlC2 with acid and a fluoride salt; the acid is preferably 9 mol / L hydrochloric acid, and the fluoride salt is preferably LiF. This invention relates to the etching of Ti3C2T... x There are no particular limitations on the preparation method; any method well known to those skilled in the art can be used. In this invention, the mass fraction of MXene in the PVA / MXene supramolecular gel lubricant is preferably 0.3-0.5%, more preferably 0.31-0.48%, and specifically preferably 0.32% or 0.48%.

[0036] The raw material for preparing the PVA / MXene supramolecular gel lubricating material provided by this invention includes PVA. In this invention, the PVA type is preferably PVA105. In this invention, the mass fraction of PVA in the PVA / MXene supramolecular gel lubricating material is preferably 3-8%, more preferably 4-7%, and even more preferably 5-6%.

[0037] The raw materials for preparing the PVA / MXene supramolecular gel lubricating material provided by this invention include a liquid lubricant. In this invention, the liquid lubricant preferably includes one or more of glycerol, ethylene glycol, 1,4-butanediol, and sorbitol. In this invention, the mass fraction of the liquid lubricant in the PVA / MXene supramolecular gel lubricating material is preferably 60-75%, more preferably 60-65%, and specifically preferably 61%, 63%, or 64%.

[0038] In this invention, the mass ratio of polyol to water in the PVA / MXene supramolecular gel lubricant is preferably 1.5:1 to 3:1, and more preferably 2:1.

[0039] This invention provides a method for preparing a PVA / MXene supramolecular gel lubricating material, comprising the following steps:

[0040] MXene aqueous dispersion, PVA, and liquid lubricant were dissolved and mixed to obtain a mixed system;

[0041] The mixture was allowed to stand to obtain the PVA / MXene supramolecular gel lubricant material.

[0042] The present invention involves dissolving and mixing MXene aqueous dispersion, PVA, and liquid lubricant to obtain a mixed system.

[0043] In this invention, the dissolution and mixing of the MXene aqueous dispersion, PVA, and liquid lubricant includes: mixing the MXene aqueous dispersion and the liquid lubricant to obtain an MXene-liquid lubricant aqueous solution; deoxygenating the MXene-liquid lubricant aqueous solution to obtain an oxygen-deoxygenated MXene-liquid lubricant aqueous solution; and mixing the oxygen-deoxygenated MXene-liquid lubricant aqueous solution and PVA in a water bath with stirring. In this invention, the mixing of the MXene aqueous dispersion and the liquid lubricant is preferably carried out under stirring conditions, and the stirring time is preferably 10–15 min. In this invention, the deoxygenation method is argon gas purging, and the argon gas purging time is preferably 10–20 min. In this invention, the water bath stirring temperature is preferably 90–95°C, and the time is preferably 1.5–3 h.

[0044] In this invention, the dissolution and mixing of the MXene aqueous dispersion, PVA, and liquid lubricant preferably further includes: deoxygenating the MXene aqueous dispersion to obtain a deoxygenated MXene aqueous dispersion, and then sequentially adding PVA and liquid lubricant to the deoxygenated MXene aqueous dispersion. In this invention, the deoxygenation method is preferably purging with argon gas, and the argon gas purging time is preferably 10–20 minutes.

[0045] After obtaining the mixed system, the present invention allows the mixed system to stand to obtain the PVA / MXene supramolecular gel lubricating material.

[0046] In this invention, the preferred temperature for the settling period is 20-25°C, and the preferred time is 24-48 hours.

[0047] This invention also provides the application of the PVA / MXene supramolecular gel lubricating material described in the above technical solution or the PVA / MXene supramolecular gel lubricating material prepared by the preparation method described in the above technical solution in the field of friction lubrication.

[0048] This invention does not impose specific limitations on the application of the PVA / MXene supramolecular gel lubricating material; those skilled in the art can make settings according to actual needs.

[0049] The following detailed description, in conjunction with embodiments, illustrates the PVA / MXene supramolecular gel lubricating material, its preparation method, and its applications provided by the present invention. However, these descriptions should not be construed as limiting the scope of protection of the present invention.

[0050] Comparative Example 1

[0051] (1) Mix 2 mL of water and 4 g of glycerol and stir for 10 min to obtain an aqueous glycerol solution.

[0052] (2) Pass argon gas into the glycerol aqueous solution for 10 min to remove dissolved oxygen from the solution.

[0053] (3) Add 0.25g of PVA solid to an aqueous glycerol solution and stir for 2h under a water bath at 95℃.

[0054] (4) The mixed solution was left to stand at room temperature (25°C) for 24 hours to obtain an environmentally friendly, low-temperature resistant PVA supramolecular gel lubricating material driven by hydrogen bonds.

[0055] Example 1

[0056] (1) Add 2 mL of MXene (Ti3C2T) with a concentration of 15 mg / mL x Mix 4g of MXene glycerol aqueous solution with 4g of glycerol and stir for 10min to obtain MXene glycerol aqueous solution.

[0057] (2) Pass argon gas into the MXene glycerol aqueous solution for 10 min to remove dissolved oxygen from the solution.

[0058] (3) Add 0.25g of PVA solid to MXene glycerol aqueous solution and stir for 2h under water bath heating at 95℃.

[0059] (4) The mixed solution was left to stand at 25°C for 24 hours to finally obtain an environmentally friendly, low-temperature resistant PVA / MXene supramolecular gel lubricant material driven by hydrogen bonds.

[0060] Example 2

[0061] (1) Add 2 mL of MXene (Ti3C2T) with a concentration of 10 mg / mL x Mix 4g of MXene glycerol aqueous solution with 4g of glycerol and stir for 10min to obtain MXene glycerol aqueous solution.

[0062] (2) Pass argon gas into the MXene glycerol aqueous solution for 10 min to remove dissolved oxygen from the solution.

[0063] (3) Add 0.316g of PVA solid to MXene glycerol aqueous solution and stir for 3h under water bath heating at 95℃.

[0064] (4) The mixed solution was left to stand at 20°C for 18 hours to obtain an environmentally friendly, low-temperature resistant PVA / MXene supramolecular gel lubricant material driven by hydrogen bonds.

[0065] Example 3

[0066] (1) Add 2 mL of MXene (Ti3C2T) with a concentration of 15 mg / mL x Mix 4g of aqueous solution and 4g of ethylene glycol and stir for 15min to obtain MXene ethylene glycol aqueous solution.

[0067] (2) Pass argon gas into the MXene ethylene glycol aqueous solution for 15 min to remove dissolved oxygen from the solution.

[0068] (3) Add 0.25g of PVA solid to MXene ethylene glycol aqueous solution and stir for 2h under water bath heating at 92℃.

[0069] (4) The mixed solution was left to stand at 25°C for 48 hours to obtain an environmentally friendly, low-temperature resistant PVA / MXene supramolecular gel lubricant material driven by hydrogen bonds.

[0070] Example 4

[0071] (1) Add 2 mL of MXene (Ti3C2T) with a concentration of 15 mg / mL x The aqueous solution and 4g of 1,4-butanediol were mixed and stirred for 15min to obtain MXene-1,4-butanediol solution.

[0072] (2) Argon gas was passed through the MXene-1,4-butanediol aqueous solution for 15 min to remove dissolved oxygen from the solution.

[0073] (3) Add 0.522g of PVA solid to MXene-1,4-butanediol aqueous solution and stir for 2h under water bath heating at 95℃.

[0074] (4) The mixed solution was left to stand at 25°C for 48 hours to obtain an environmentally friendly, low-temperature resistant PVA / MXene supramolecular gel lubricant material driven by hydrogen bonds.

[0075] Example 5

[0076] (1) Add 2 mL of MXene (Ti3C2T) with a concentration of 15 mg / mL x Mix 4g of sorbitol with an aqueous solution and stir for 15 minutes to obtain MXene sorbitol aqueous solution.

[0077] (2) Pass argon gas into the MXene sorbitol aqueous solution for 15 min to remove dissolved oxygen from the solution.

[0078] (3) Add 0.25g of PVA solid to MXene sorbitol aqueous solution and stir for 2h under water bath heating at 95℃.

[0079] (4) The mixed solution was left to stand at 25°C for 24 hours to finally obtain an environmentally friendly, low-temperature resistant PVA / MXene supramolecular gel lubricant material driven by hydrogen bonds.

[0080] Figure 1 Optical images of the hydrogen-bonded, environmentally friendly, low-temperature-resistant supramolecular gel lubricating materials prepared for Comparative Example 1 and Example 1. From Figure 1 It can be seen that the PVA supramolecular gel lubricating material prepared in Comparative Example 1 is white, and the PVA / MXene supramolecular gel lubricating material prepared in Example 1 is black. Neither of them flows when tilted.

[0081] Figure 2 Optical images of the hydrogen-bonded, environmentally friendly, low-temperature resistant supramolecular gel lubricants prepared in Examples 1, 3, 4, and 5; from Figure 2 It can be seen that the PVA / MXene supramolecular gel lubricating materials prepared in Examples 1, 3, 4 and 5 are all black and do not flow when tilted.

[0082] Figure 3 This is an image showing the viscosity of the supramolecular gel lubricating materials prepared in Comparative Example 1 and Example 1 as a function of shear rate. Figure 3 It can be seen that the viscosity of the gel gradually decreases with increasing shear rate, exhibiting shear-thinning characteristics.

[0083] Figure 4 Differential scanning calorimetry (DSC) curves of the supramolecular gel lubricating materials prepared in Comparative Example 1 and Example 1. Figure 4 It can be seen that no exothermic peaks appeared in the gel between -80 and 0℃, indicating that the prepared gel will not freeze at -80℃ and has excellent low-temperature resistance.

[0084] Figure 5 The graph shows the change in the coefficient of friction over time for the supramolecular gel lubricating materials prepared in Comparative Example 1 and Example 1. The friction pair used in the friction test was 9Cr18Mo steel and ZrO2 balls, and the test parameters were 50 N, 25 Hz, 1 mm, 30 min, and -20 °C. Figure 5It can be seen that the supramolecular gel lubricating material has a low coefficient of friction at low temperatures and excellent lubrication effect. Furthermore, due to the addition of the nanomaterial MXene, the coefficient of friction in Example 1 is lower than that in Comparative Example 1.

[0085] Figure 6 The images show the coefficient of friction of the supramolecular gel lubricant prepared in Example 1 as a function of time under different friction pairs. The test parameters were 50 N, 25 Hz, 1 mm, 30 min, and -20 °C. Figure 6 It can be seen that the PVA / MXene supramolecular gel lubricant prepared in Example 1 exhibits excellent lubrication performance under various friction pairs. Among them, the supramolecular gel lubricant has the lowest coefficient of friction under the nylon / zirconia friction pair.

[0086] Figure 7 The graphs show the coefficient of friction of the supramolecular gel lubricating materials prepared in Examples 1, 3, 4, and 5 as a function of time. The friction pair used in the friction test was 9Cr18Mo steel and ZrO2 balls, and the test parameters were 50 N, 25 Hz, 1 mm, 30 min, and -20 °C. Figure 7 It can be seen that PVA / MXene supramolecular gel lubricants prepared using different polyols all exhibit excellent lubrication effects at low temperatures. Among them, the supramolecular gel lubricant prepared using sorbitol has the lowest coefficient of friction.

[0087] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A PVA / MXene supramolecular gel lubricant, characterized in that, Prepared from the following raw materials: MXene aqueous dispersion, PVA and liquid lubricant; The liquid lubricant is a polyol; the polyol is sorbitol; The PVA / MXene supramolecular gel lubricating material contains 3-8% PVA, 0.3-0.5% MXene, 60-75% liquid lubricant, and the remainder is water. The mass ratio of polyol to water is 2:

1.

2. The PVA / MXene supramolecular gel lubricant material according to claim 1, characterized in that, The MXene aqueous dispersion contains 1 to 5 layers of MXene, and the PVA is of type PVA105.

3. The method for preparing the PVA / MXene supramolecular gel lubricating material according to any one of claims 1 to 2, characterized in that, Includes the following steps: MXene aqueous dispersion, PVA, and liquid lubricant were dissolved and mixed to obtain a mixed system; The mixture was allowed to stand to obtain the PVA / MXene supramolecular gel lubricant material.

4. The preparation method according to claim 3, characterized in that, The concentration of the MXene aqueous dispersion is 10~15 mg / mL.

5. The preparation method according to claim 3 or 4, characterized in that, The dissolution and mixing of MXene aqueous dispersion, PVA and liquid lubricant includes: mixing MXene aqueous dispersion and liquid lubricant to obtain MXene-liquid lubricant aqueous solution; After deoxygenating the MXene-liquid lubricant aqueous solution, an oxygen-deoxygenated MXene-liquid lubricant aqueous solution is obtained; the oxygen-deoxygenated MXene-liquid lubricant aqueous solution is then mixed with PVA in a water bath.

6. The preparation method according to claim 5, characterized in that, The water bath mixing temperature is 90~95℃, and the time is 1.5~3h.

7. The preparation method according to claim 3 or 4, characterized in that, The process of dissolving and mixing the MXene aqueous dispersion, PVA, and liquid lubricant includes: deoxygenating the MXene aqueous dispersion to obtain a deoxygenated MXene aqueous dispersion, and sequentially adding PVA and liquid lubricant to the deoxygenated MXene aqueous dispersion.

8. The preparation method according to claim 3, characterized in that, The settling temperature is 20~25℃, and the time is 24~48h.

9. The application of the PVA / MXene supramolecular gel lubricating material according to any one of claims 1 to 2 or the PVA / MXene supramolecular gel lubricating material prepared by the preparation method according to any one of claims 3 to 8 in the field of friction lubrication.

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