co-crystal solvent

Abstract

A novel eutectic solvent (NES) comprising one or more methanesulfonic acid derivatives, one or more ammonium salts, and one or more hydrogen bond donors is disclosed. The disclosed NES is characterized by, for example, a low freezing point and eutectic point, low viscosity, negligible vapor pressure, non-volatility, low water content, high potential window, high thermal stability, high solubility, long shelf life, high recyclability, high biodegradability, high ionic character, air and moisture stability, non-corrosive, non-mutagenic, economical, non-flammable, and the like, and thus has a wider range of applications.

Description

Technical Field

[0001] This invention generally relates to chemical solvents, and more specifically to a novel eutectic solvent comprising a derivative of methanesulfonic acid. This novel eutectic solvent has broad application prospects. Background Technology

[0002] Solvents are chemical substances that dissolve solutes. They have a wide range of applications in the chemical, pharmaceutical, and oil and gas industries, and are used in various processes and applications, including but not limited to electrochemical applications, chemical synthesis, electroplating, and purification processes. The use of solvents typically involves large quantities. Typically, solvents constitute approximately 80% of the total volume of chemicals used in a particular application / process.

[0003] Traditional solvents used in industry, including ethylene carbonate, dimethyl carbonate, and propylene carbonate, are highly toxic, volatile, irritating, carcinogenic, mutagenic, costly, and difficult to use in electrochemical applications, chemical synthesis, and electroplating processes. The purification processes involved in these processes further hinder their suitability for large-scale industrial applications. Therefore, researchers have long sought, experimented with, invented, developed, and improved alternatives to traditional solvents.

[0004] Various alternatives are proposed from time to time. However, their application remains limited due to their slow kinetics (reaction rate), low efficiency, and high capital costs.

[0005] Toxic solvents used in the chemical industry can be easily replaced by less harmful organic solvents such as ethanol; however, such substitutions would lead to limitations in synthesis and are uneconomical.

[0006] For decades, ionic liquids have been studied and experimented with in search of green and sustainable alternatives to traditional solvents. Some ionic liquids have been found to be outstanding alternatives to traditional solvents due to their unusual physical and chemical properties, such as wide electrochemical potential windows, high ionic conductivity, negligible vapor pressure, wide temperature range for solvent retention, excellent thermal stability, tunable solubility for both organic and inorganic molecules, and great synthetic flexibility. Furthermore, the discovery of room-temperature ionic liquids (RTILs) has expanded the applications of ionic liquids as solvents. Siddhartha Pandey's review article, "Analytical applications of room-temperature ionic liquids: A review of recent efforts," published in Analytica Chimica Acta 556 (2006) 38-45 (doi:10.1016 / j.aca.2005.06.038), details the potential of RTILs.

[0007] Nevertheless, ionic liquids have their own limitations and drawbacks. Most ionic liquids are manufactured from petrochemical resources, and most production pathways require the participation of halogen atoms. The use of halogen components in ionic liquids is undesirable due to their low hydrolytic stability and high toxicity. The further production costs of RTILs compared to conventional solvents are a real limitation to expanding their industrial applications. Furthermore, other drawbacks of common ionic liquids have been observed, such as limited solute solubility, high viscosity, low biodegradability, and high processing costs. A review article titled "Toxicity of Ionic Liquids" published in the journal *Clean* by Dongbin Zhao et al. (DOI:10.1002 / clen.200600015) mentions the toxicity of ionic liquids.

[0008] In 2003, Abbott et al. proposed a new class of ionic liquids called eutectic solvents (ES), also known as deep eutectic solvents, which contain quaternary ammonium salts such as choline chloride and urea in a molar ratio of 1:2.

[0009] ES are eutectic liquids with melting points much lower than those of the corresponding compounds synthesized in the synthetic solvent. ES are formed by mixing Lewis or Brønsted acids and bases with different classes of cations and anions. A review article titled "Deep Eutectic Solvents (DESs) and Their Applications" published in Chemical Reviews by Emma L. Smith et al. (dx.doi.org / 10.1021 / cr300162p|Chem.Rev.2014,114,11060-11082) has discussed several aspects of various existing ESs. Another review article published in Microchemical Journal, titled "Deep eutectic solvents vs ionic liquids: Similarities and differences" (https: / / doi.org / 10.1016 / j.microc.2020.105539), has compared the characteristics of ionic liquids and eutectic solvents.

[0010] Typically, estrogen compounds (ES) are mixtures of quaternary ammonium salts and various hydrogen bond donor compounds in specific molar ratios. The purity of the resulting ES depends on the purity of the respective individual components. ESs are readily and cost-effectively manufactured without any post-purification issues and are considered relatively easy to dispose of compared to conventional solvents and existing ionic solvents. At ambient temperatures, ES are preferably liquids. Due to the enormous potential and industrial applications of ES as a solvent, interest in it as an alternative green solvent is rapidly increasing. Furthermore, applications of ES in carbon dioxide absorption have been discovered, but this is still in its early stages and has significant room for improvement.

[0011] However, like other solvents used in the chemical industry, existing estrogen compounds (ES) have their limitations. The use of multiple quaternary ammonium salts in the synthesis of existing ES is common; however, most quaternary ammonium salts are toxic. Typically, components are stored in a vacuum and require drying before use in ES preparation. In the preparation of common existing ES, components are mixed and slowly heated at around 100°C for 8-10 hours, and then stored in a vacuum. Most ES are highly viscous and difficult to handle. There is considerable room for improvement / modification in the manufacturing process and the time required to produce ES. Furthermore, existing ES require special storage arrangements to maintain their properties. Therefore, a new type of ES is needed to address the limitations of existing ES and possess improved desired characteristics such as low freezing point and eutectic point, low viscosity, negligible vapor pressure, non-volatility, low water content, high potential window, high thermal stability, high solubility, long shelf life, high recyclability, high biodegradability, high ionic properties, air and moisture stability, non-corrosiveness, non-mutagenicity, economy, and non-flammability, thus having broader applications. Summary of the Invention

[0012] This invention discloses a novel ES (NES) that overcomes the limitations of existing ESs and has the aforementioned improved characteristics and wider applications compared to existing ESs.

[0013] The NES comprises one or more methanesulfonic acid derivatives selected from salts of methanesulfonic acid and various metal ions, wherein the metal ions are selected from the group consisting of manganese, zinc, cerium, nickel, titanium, copper, sodium, potassium, and calcium; one or more ammonium salts having the general formula NH4X, wherein X can be selected from the group consisting of chloride, methanesulfonate, acetate, sulfate, trifluoromethanesulfonate, and trimethanesulfonate; and one or more hydrogen bond donors selected from the group consisting of urea, thiourea, glycerol, oxalic acid, acetic acid, ethylene glycol, acetamide, benzamide, adipic acid, benzoic acid, and citric acid; wherein the molar ratio of methanesulfonic acid derivatives, ammonium salts, and hydrogen bond donors is in the range of 0.5-3:2-7:8-13. The NES has a potential window in the range of 0.1-3.5V and a conductivity in the range of 10-90 mS / cm. Furthermore, the NES has a viscosity in the range of 1-60 mPa·s. The NES remains liquid at ambient pressure and temperatures as low as 5°C. Attached Figure Description

[0014] Figure 1 Cyclic voltammetry curves of NES in Example 1 on a three-electrode system, scan rate 1 mV / s.

[0015] Figure 2 The NES in Example 1 is at 2.5 mA / cm 2Voltage-time electrochemical stability and electroplating characteristics in an asymmetric current setting for carbon steel / Zn.

[0016] Figure 3 As the temperature increases, the molecules in the NES of Example 1 gain more energy, accompanied by a decrease in viscosity. As a result, the ions are in a higher energy state, which leads to an increase in mobility and thus an increase in the conductivity of the NES. Detailed Implementation

[0017] I. Definition

[0018] For the purpose of interpreting the specification and appended claims, the following terms shall be given the meanings listed below:

[0019] The term "solvent" should refer to a liquid medium that can dissolve other substances.

[0020] The term "ambient temperature" should refer to temperatures falling within the range of 25-30°C.

[0021] The term "environmental pressure" should refer to an environmental pressure of 1 bar.

[0022] II. Description

[0023] Various embodiments of the invention are described in detail herein, examples of which are illustrated in the accompanying drawings and described below. It is to be understood that the invention according to this specification is not intended to be limited to these exemplary embodiments. The invention is intended to cover various alternatives, modifications, equivalents, and other embodiments that may be included within the spirit and scope of the invention as defined in the claims.

[0024] NES comprises one or more methanesulfonic acid derivatives selected from salts of methanesulfonic acid and various metal ions selected from the group consisting of manganese, zinc, cerium, nickel, titanium, copper, sodium, potassium, and calcium; one or more ammonium salts having the general formula NH4X, wherein X can be selected from the group consisting of chloride, methanesulfonate, acetate, sulfate, trifluoromethanesulfonate, and trimethanesulfonate; and one or more hydrogen bond donors selected from the group consisting of urea, thiourea, glycerol, oxalic acid, acetic acid, ethylene glycol, acetamide, benzamide, adipic acid, benzoic acid, and citric acid; wherein the molar ratio of methanesulfonic acid derivatives, ammonium salts, and hydrogen bond donors is in the range of 0.5-3:2-7:8-13. The NES has a potential window in the range of 0.1-3.5V and a conductivity in the range of 10-90 mS / cm. Furthermore, the NES has a viscosity in the range of 1-60 mPa·s. The NES remains liquid at ambient pressure and temperatures as low as 5°C.

[0025] NES is prepared by mixing the following: one or more methanesulfonic acid derivatives selected from salts of methanesulfonic acid and various metal ions selected from the group consisting of manganese, zinc, cerium, nickel, titanium, copper, sodium, potassium, and calcium; one or more ammonium salts having the general formula NH4X, wherein X may be selected from the group consisting of chloride, methanesulfonate, acetate, sulfate, trifluoromethanesulfonate, and trimethanesulfonate; and one or more hydrogen bond donors selected from the group consisting of urea, thiourea, glycerol, oxalic acid, acetic acid, ethylene glycol, acetamide, benzamide, adipic acid, benzoic acid, and citric acid; wherein the molar ratio of the methanesulfonic acid derivatives, ammonium salts, and hydrogen bond donors is in the range of 0.5-3:2-7:8-13. After proper mixing, the mixture begins to transform into a liquid at ambient temperature and pressure. To ensure proper mixing of the components and accelerate the process, the mixture can be uniformly heated at temperatures up to 60°C. After the eutectic solvent is prepared, it can be stored in a container. The eutectic solvent remains liquid at ambient pressure and a temperature as low as 5°C.

[0026] No special heating / vacuum drying conditions are required in the preparation of NES. Unlike many other eutectic solvents, the mixing of the constituent components is an endothermic phenomenon, making the synthesis process safer and less flammable than existing eutectic solvents. The resulting transparent liquid NES according to the invention can reach room temperature and be stored in sealed containers, making it readily usable in a variety of applications.

[0027] NES are safer for the environment due to their non-toxicity and are easy to dispose of because of the inherent properties of their components. Methanesulfonic acid is an organic acid that undergoes biodegradation to form carbon dioxide and sulfuric acid. It is also considered a green acid because it is less toxic and corrosive than other mineral acids. Other components of the proposed NES are hydrogen bond donors and one or more ammonium salts, making NES biodegradable and environmentally friendly.

[0028] Compared to existing ES (electrolyte solvents), NES is relatively economical because all components are economical and abundant in nature, making the proposed NES a sustainable eutectic solvent. The proposed NES exhibits low viscosity, high thermal and chemical stability, a wide potential window, low volatility, and non-flammability. The unique chemical and chemical bonding between components makes it more chemically and thermally stable than existing solvents. Due to its advantages over existing ES, ionic liquids, and organic solvents, the proposed NES has a wide range of applications, including but not limited to electrochemical applications, energy storage devices, electroplating of metals, their composites and alloys, carbon dioxide capture, catalysis, organic synthesis, refining processes, biorefining processes, pharmaceuticals, water treatment, metal processing, coatings, electroless coatings, metal nanoparticle synthesis, metal electropolishing, metal extraction, metal oxide processing, gas adsorption, bioconversion, and electronics.

[0029] Example

[0030] The following illustrative examples are provided to further describe how to manufacture and use the preferred NES compositions according to the invention. These illustrative examples are not intended to limit the scope of the invention.

[0031] Example 1

[0032] In the preparation of the NES composition, 2 moles of zinc methanesulfonate, 10 moles of thiourea, and 5 moles of ammonium chloride were mixed in a round-bottom flask. The flask was rotated at 50 rpm for proper mixing. After approximately 45 minutes of rotation, the solid mixture began to convert into the NES solvent. However, to accelerate the process and obtain rapid results, the components were mixed in an oil bath and rotated at 45°C for 15 minutes to obtain a clear liquid NES solvent.

[0033] Example 2

[0034] In the preparation of the NES composition, 1.7 mol of calcium methanesulfonate, 9 mol of thiourea, and 5 mol of ammonium chloride were mixed in a round-bottom flask. The flask was rotated at 50 rpm to ensure adequate mixing. After approximately 45 minutes of rotation, the solid mixture began to convert into the NES solvent. However, for faster results, the components were mixed in an oil bath and rotated at 60°C for 15 minutes to obtain a clear liquid NES solvent.

[0035] Example 3

[0036] In the preparation of the NES composition, 1.7 mol of calcium methanesulfonate, 10 mol of ethylene glycol, and 4 mol of ammonium acetate were mixed in a round-bottom flask. The flask was rotated at 50 rpm for proper mixing. After approximately 45 minutes of rotation, the solid mixture began to convert into the NES solvent. However, for faster results, the components were mixed in an oil bath and rotated at 45°C for 15 minutes to obtain a clear liquid NES solvent.

[0037] IV. Experiment

[0038] Experiment 1

[0039] Cyclic voltammetry was performed at 1 mV s⁻¹ using a Biologic VPM3 electrochemical workstation within a voltage range of -1.5 V to 2.5 V (compared to Ag / AgCl), employing a three-electrode system with graphite as the working electrode, platinum mesh as the counter electrode, and Ag / AgCl as the reference electrode.

[0040] Cyclic voltammetry of a three-electrode system. To determine the potential window of NES 1, CV experiments were performed using the three-electrode system described above, with a scan rate of 1 mV / s from -1.5 V to 2.5 V.

[0041] like Figure 1The cyclic voltammograms of the NES in Example 1 illustrate the reversible electrochemical deposition / dissolution of zinc. The initial onset potentials for zinc plating / stripping were -0.31 V and -0.01 V, respectively. Compared to other existing solvents, NES exhibits a smaller potential separation and a higher response current, indicating better reversibility and faster kinetics of zinc deposition / dissolution. Notably, NES demonstrates a wide and stable electrochemical window from -1.5 V to 2 V. The coulombic efficiency (CE) gradually increases, reaching approximately 99.9% after the third cycle.

[0042] Experiment 2

[0043] To determine the metal plating and deplating capabilities in NES solutions.

[0044] A carbon steel / zinc asymmetric cell, consisting of a rectangular carbon steel working electrode (sheet: 10mm*0.2mm*50mm) and a zinc reverse / reference electrode (diameter: 10mm*0.2mm*50mm), was suspended in the NES of Example 1.

[0045] The results of voltage-time electrochemical stability tests on Zn-carbon steel asymmetric cells are shown in... Figure 2 NES exhibits excellent electroplating capabilities. It also demonstrates greater stability even during cycling.

[0046] Experiment 3

[0047] To determine the effect of temperature changes on the ionic conductivity and viscosity of NES in Example 1.

[0048] Ionic conductivity was measured using an S230 benchtop conductivity meter (Mettler-Toledo GmbH). The equipment was calibrated with standard KCl solution before each experiment.

[0049] The viscosity of NES was evaluated using a Dv2t Brookfield viscometer.

[0050] Table 1

[0051] Temperature (°C) Electrical conductivity (mS / cm) Viscosity (mPa.s) 10 25.97 50 20 58.39 20 25 62.71 15 30 64.92 13 35 68.81 11 40 71.91 10 50 75.26 7 60 81.42 5

[0052] In both cases, a static water bath is used to control the temperature within ±0.5℃.

[0053] Within the measurement temperature range of 10–60 °C, NES exhibited better ionic conductivity, particularly at increasing temperatures, where it increased from 25.97 mS / cm to 81.42 mS / cm. This can be explained by the increased energy gained by molecules in the NES medium with increasing temperature, accompanied by a decrease in viscosity (from 50 mPa·s at 10 °C to 5 mPa·s at 60 °C). Consequently, ions are in a higher energy state, leading to increased mobility and thus increased conductivity of NES. NES is thermally stable, as no decomposition products were observed.

[0054] refer to Figure 3 As the temperature increases, the molecules in NES gain more energy, which is accompanied by a decrease in viscosity. As a result, the ions are in a higher energy state, which leads to an increase in mobility and thus an increase in the conductivity of NES.

[0055] Experiment 4

[0056] CO2 absorption was measured using the NES developed in Examples 1, 2, and 3. CO2 gas was blown into vials (10 ml) containing 5 ml of the developed NES at a flow rate of 10 ml / min. The vials were weighed at regular intervals using a balance with an accuracy of 0.1 mg to calculate the weight percentage of absorbed CO2. During the experiments, the vials were partially immersed in a water bath at a constant temperature to minimize the influence of temperature.

[0057] The test was prepared using the method described above and conducted at a constant CO2 flow rate and a constant temperature of 27°C.

[0058] Based on the screening of NES, calcium-containing NES showed high CO2 adsorption capacity when measured at atmospheric pressure, with a fixed molar ratio of NES.

[0059] Table 2 shows the relative CO2 intake of different NES during the 2-hour experiment.

[0060]

Claims

1. A eutectic solvent, characterized in that, Include: One or more methanesulfonic acid derivatives selected from salts of methanesulfonic acid and metal ions, wherein the metal ions are selected from the group consisting of manganese, zinc, cerium, nickel, titanium, copper, sodium, potassium and calcium; One or more ammonium salts having the general formula NH4X, wherein X is selected from the group consisting of chloride, methanesulfonate, acetate, sulfate, trifluoromethanesulfonate, and trimethanesulfonate; wherein the molar ratio of methanesulfonic acid derivative, ammonium salt, and hydrogen bond donor is in the range of 0.5-3:2-7:8-13; One or more hydrogen bond donors selected from the group consisting of urea, thiourea, glycerol, oxalic acid, acetic acid, ethylene glycol, acetamide, benzamide, adipic acid, benzoic acid, and citric acid.

2. The eutectic solvent according to claim 1, characterized in that, It has a potential window ranging from 0.1 to 3.5V.

3. The eutectic solvent according to any one of claims 1-2, characterized in that, It has an electrical conductivity in the range of 10-90 mS / cm.

4. The eutectic solvent according to claim 3, characterized in that, It has a viscosity in the range of 1-60 mPa·s.

5. The eutectic solvent according to claim 4, characterized in that, It remains liquid at temperatures as low as 5°C under ambient pressure; the ambient pressure refers to an ambient pressure of 1 bar.

Images