Aie fluorescent probe composition, cmc determination method and device of surfactant solution, cmc determination method and device

Abstract

The present application provides an AIE fluorescent probe composition for determining the critical micelle concentration (cmc) of a surfactant solution, characterized by comprising a probe compound, which is a hydrophobic AIE molecule, and an auxiliary agent, which is at least one organic solvent represented by the following general formula (1), (R) n -X(1), wherein R is a substituted or unsubstituted straight-chain or branched-chain alkyl group having 3 to 10 carbon atoms, n is an integer of 1 or 2, when n is 2, the two R's can be the same or different, and X is a polar group selected from any one of a hydroxyl group, an amino group, a cyano group, a halogen group, an amide group, a carbonyl group, an aldehyde group, an ester group, and an ether group. The present application also provides a method and a device for determining the cmc of a surfactant solution using the above-described AIE fluorescent probe composition, and a method and a device for judging the cmc based on an AIE fluorescent probe.

Description

Technical Field

[0001] The present invention relates to an AIE fluorescent probe composition, a cmc (cmc) measurement method and device for a surfactant solution using the AIE fluorescent probe composition, and a cmc determination method and device based on the AIE fluorescent probe. Background Art

[0002] Critical micelle concentration (CMC) is an important dividing line of the solution properties of surfactants. Before and after the CMC, many physical and chemical properties of surfactant solutions, such as surface tension, light scattering, molar conductivity, density, osmotic pressure, and solubilization, change significantly.

[0003] Conventional methods for measuring cmc include surface tension, conductivity, and fluorescence spectroscopy (PL), but these methods have limitations in practical application. For example, surface tension requires a complex series of operations to determine cmc; conductivity cannot detect nonionic surfactants and surfactants with low conductivity; and fluorescence spectroscopy suffers from low sensitivity and requires high-precision testing equipment.

[0004] In recent years, it has been discovered that some organic molecules, while non-luminescent in solution, exhibit significantly enhanced luminescence in aggregated states or as solid films. Because this enhanced luminescence is caused by molecular aggregation, this phenomenon has been termed Aggregation-Induced Emission (AIE).

[0005] AIE fluorescent probes made from organic molecules exhibiting the above-mentioned AIE phenomenon can simply, quickly, and efficiently measure the cmc of surfactant solutions without the aid of precision instruments due to their aggregation-induced emission properties. Therefore, they can be effectively applied in various fields, such as the washing industry, for monitoring the surfactant content in washing water solutions, which has practical guiding significance.

[0006] Prototype AIE molecules include, for example, common tetraphenylethylene (TPE), hexaphenylthiolene (i.e., hexaphenylsilanol, HPS) and distyryl anthracene (DSA), etc., with advantages such as high quantum yield in the solid state and high chemical stability and photostability, but unsubstituted prototype AIE molecules limit their application in aqueous systems such as surfactant solutions due to their hydrophobicity. Non-patent literature 1 reports that hydrophobic AIE molecules are first dissolved in volatile organic solvents such as e.g., and then added to a surfactant solution, mixed by ultrasound, and the soluble organic solvents such as e.g., ...

[0007] In order to overcome the hydrophobicity problem of AIE fluorescent probes, current research ideas are mainly focused on introducing charged functional groups, such as ammonium groups and sulfonic acid groups, into the hydrophobic AIE molecular structure to increase its hydrophilicity. For example, a series of hydrophilic AIE fluorescent probes were prepared in Patent Document 1. This type of fluorescent probe uses a benzoquinoline structural unit as a parent and adds a sulfonic acid group as the main water-soluble group. The critical micelle concentration of the surfactant solution can be obtained by observing the fluorescence mutation from zero to the strongest under a 365nm wavelength ultraviolet lamp. Patent Document 2 reports the synthesis of amphiphilic molecules formed by introducing hydrophilic units into the hydrophobic skeleton of HPS molecules or TPE molecules, and their application in the field of biology. However, these synthetic technologies for derivatizing unsubstituted hydrophobic AIE molecules to obtain hydrophilic AIE molecules are relatively difficult, with high production costs, and are difficult to be widely applied in the industrial field.

[0008] Prior art literature

[0009] Non-patent literature

[0010] Non-patent document 1: "Detection of the critical micelle concentration of cationic and anionic surfactants based on aggregation-induced emission property of hexaphenylsilole derivatives" TANG Li et.al, Sci China Ser B-Chem, Jun. 2009, vol. 52, No. 6, 755-759

[0011] Patent Literature

[0012] Patent Document 1: CN110028446A

[0013] Patent Document 2: CN106566532A Summary of the Invention

[0014] Problems to be solved by the invention

[0015] The present invention is made in view of the above situation, and its purpose is to provide an AIE fluorescent probe composition that can be directly used to measure the cmc concentration of a surfactant solution without derivatizing the hydrophobic AIE molecules, and to provide a method and device for measuring the cmc of a surfactant solution using the AIE fluorescent probe composition, as well as a method and device for determining the cmc based on the AIE fluorescent probe.

[0016] Methods used to solve problems

[0017] The inventors conducted in-depth research to address this issue and discovered that some hydrophobic AIE molecules can dissolve in organic solvents with specific structures to form stable solutions. These solutions exhibit distinct AIE properties within a suitable concentration range, without waiting for the organic solvent to evaporate. Therefore, by using a fluorescent probe composition containing such hydrophobic AIE molecules and a specific organic solvent, it can be directly used to measure the cmc concentration of surfactant solutions, effectively resolving the aforementioned problem.

[0018] The present invention provides an AIE fluorescent probe composition, which is a probe solution for measuring the critical micelle concentration (cmc) of a surfactant solution, characterized in that it comprises a probe compound and an auxiliary agent, wherein the probe compound is a hydrophobic AIE molecule, and the auxiliary agent is at least one organic solvent represented by the following general formula (1):

[0019] (R) n -X (1)

[0020] Wherein, R is a substituted or unsubstituted straight-chain or branched alkyl group having 3 to 10 carbon atoms, n is an integer of 1 or 2, and when n is 2, the two Rs may be the same or different.

[0021] X is a polar group selected from any one of a hydroxyl group, an amino group, a cyano group, a halogen group, an amide group, a carbonyl group, an aldehyde group, an ester group, and an ether group.

[0022] The present invention also provides a method for measuring the cmc of a surfactant solution, comprising the following steps in sequence:

[0023] Solution preparation steps: Prepare a series of test solutions with increasing concentrations of surfactants in multiple sample cells.

[0024] adding a probe step: adding a certain amount of probe solution to each of the plurality of sample pools; detecting step: detecting the fluorescence intensity of each solution to be tested by a detection mechanism; and

[0025] Determination step: Determine the CMC concentration of the surfactant solution according to the change trend of the fluorescence intensity of each test solution detected,

[0026] It is characterized in that the probe solution is the AIE fluorescent probe composition of the present invention.

[0027] In addition, the present invention also provides a CMC measuring device for a surfactant solution, comprising:

[0028] A plurality of sample cells are prepared with a series of test solutions having increasing concentrations of surfactants,

[0029] a probe container containing a probe solution containing a probe compound,

[0030] The sample adding mechanism is used to take out a certain amount of probe solution from the probe container and add it into the multiple sample pools.

[0031] A detection mechanism, configured to detect the fluorescence intensity of the solution to be tested in the plurality of sample pools, and

[0032] A determination mechanism determines the cmc concentration of the surfactant solution according to a change trend of the fluorescence intensity of each test solution detected by the detection mechanism,

[0033] It is characterized in that the probe solution is the AIE fluorescent probe composition of the present invention.

[0034] In addition, the present invention also provides a cmc determination method based on an AIE fluorescent probe, which is a determination method for determining whether a surfactant solution has reached a critical micelle concentration cmc, and is characterized in that it comprises the following steps in sequence:

[0035] Solution preparation steps: add an initial amount of surfactant to water, stir, and prepare a test solution;

[0036] Sampling step: taking a small amount of the solution to be tested and transferring it to a sample pool;

[0037] Probe adding step: adding the AIE fluorescent probe into the sample cell and applying slight vibration to form a mixed solution;

[0038] Detection step: detecting the fluorescence intensity of the mixed solution by a fluorescence detector and outputting a detection signal S; and

[0039] Determining step: determining whether the critical micelle concentration (cmc) is reached based on the changing trend of the detection signal S; if the determination result is yes, outputting the concentration of the test solution as the cmc concentration, and terminating all steps; if the determination result is no, emptying the sample pool, returning to the solution preparation step, adding a specified amount of surfactant to the test solution, and continuing to perform the following sampling step, probe addition step, detection step, and determination step.

[0040] In the judging step, if the judging result is negative but the number of times the predetermined amount of surfactant is added in the liquid preparation step has reached a predetermined threshold, all steps are terminated.

[0041] In addition, the present invention also provides a CMC determination device based on an AIE fluorescent probe, which is used to determine whether a surfactant solution has reached a critical micelle concentration (CMC). The device includes a surfactant storage mechanism, an addition mechanism, a sampling mechanism, a sample pool, an AIE fluorescent probe storage mechanism, a sample addition mechanism, a detection mechanism, a CMC determination mechanism, and a determination mechanism, wherein the following operations are performed in sequence:

[0042] The adding mechanism takes out a certain amount of surfactant from the surfactant storage mechanism and mixes it with water to prepare a solution to be tested.

[0043] The sampling mechanism takes a small amount of the solution to be tested and transfers it to the sample pool.

[0044] The sample adding mechanism takes out a trace amount of probe solution from the storage mechanism of the AIE fluorescent probe and adds it into the sample pool, and applies slight vibration to form a mixed solution.

[0045] The detection mechanism detects the fluorescence intensity of the mixed solution and transmits the obtained detection signal to the CMC judgment mechanism.

[0046] The CMC judgment mechanism judges whether the critical micelle concentration (cmc) is reached based on the change trend of the detection signal.

[0047] If the determination result of the cmc determination mechanism is yes, the determination mechanism outputs the concentration of the solution to be tested as the cmc concentration, and all operations are terminated;

[0048] If the judgment result of the CMC judgment mechanism is negative and the execution number of the adding mechanism is lower than the predetermined threshold, the sample pool is emptied, the adding mechanism adds a specified amount of surfactant to the solution to be tested, and continues to perform subsequent operations.

[0049] If the judgment result of the cmc judgment mechanism is no, and the execution times of the adding mechanism have reached a predetermined threshold, all operations are terminated.

[0050] Effects of the Invention

[0051] The AIE fluorescent probe composition of the present invention adopts unsubstituted hydrophobic AIE molecules. By introducing an appropriate organic solvent as an auxiliary agent, it can be stably and well dispersed in an aqueous system, thereby solving the hydrophobicity problem of the unsubstituted AIE probe molecules; after the AIE fluorescent probe composition of the present invention is added to a surfactant solution, the auxiliary agent (organic solvent) helps the hydrophobic AIE molecules to form a stable dispersed structure in aggregates such as micelles in the surfactant solution, and the cmc concentration of the surfactant solution can be measured without the volatilization step of the auxiliary agent, which greatly improves the ease of use in actual scenarios; and, as a probe solution, the AIE fluorescent probe composition of the present invention can accurately detect the fluorescence intensity change corresponding to the cmc concentration within an appropriate concentration range using a conventional fluorescence detector, thereby bringing new solutions and research directions for the application of AIE fluorescent molecules in a wider range of fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 Schematic diagrams showing the molecular simulation results of the solubilization effect of the auxiliary agent of the present invention on the hydrophobic AIE molecules in the mixed micelles of the surfactant. (A) The auxiliary agent is butylamine, and (B) the auxiliary agent is butanol.

[0053] Figure 2 1 is a graph showing the change in fluorescence intensity with concentration when the AIE fluorescent probe composition of the present invention is added (Example 1) and when the AIE fluorescent probe composition of the present invention is not added (Reference Example 1) to the directly prepared supreme clean detergent aqueous solution.

[0054] Figure 3 1 is a graph showing the change in surface tension of the directly prepared Supreme Clean detergent aqueous solution used in Example 1 as a function of concentration.

[0055] Figure 4 3 is a graph showing the change in fluorescence intensity versus concentration when the AIE fluorescent probe composition of the present invention is added to the aqueous solution of the supreme clean detergent for actual machine washing in Example 7.

[0056] Figure 5 3 is a graph showing the change in interfacial tension of the Supreme Clean detergent aqueous solution used in actual machine washing in Example 7 as a function of concentration. DETAILED DESCRIPTION

[0057] Hereinafter, specific embodiments of the present invention will be described. However, the present invention is not limited to the following embodiments and can be implemented with appropriate modifications within the scope of the purpose of the present invention.

[0058] In this specification, the numerical range expressed using "to" means a range including the numerical values ​​described before and after "to" as the minimum value and the maximum value, respectively.

[0059] In this specification, when a plurality of surfactant components are present in a surfactant (detergent) solution, the concentration of a surfactant refers to the total amount of the plurality of surfactant components present in the surfactant (detergent) solution unless otherwise specified.

[0060] (AIE fluorescent probe composition)

[0061] The AIE fluorescent probe composition of the present invention is a probe solution for measuring the critical micelle concentration (cmc) of a surfactant solution, characterized in that it comprises a probe compound and an auxiliary agent, wherein the probe compound is a hydrophobic AIE molecule, and the auxiliary agent is at least one organic solvent represented by the following general formula (1):

[0062] (R) n -X(1)

[0063] Wherein, R is a substituted or unsubstituted straight-chain or branched alkyl group having 3 to 10 carbon atoms, n is an integer of 1 or 2, and when n is 2, the two Rs may be the same or different.

[0064] X is a polar group selected from any one of a hydroxyl group, an amino group, a cyano group, a halogen group, an amide group, a carbonyl group, an aldehyde group, an ester group, and an ether group.

[0065] Hereinafter, each component contained in the AIE fluorescent probe composition of the present invention will be described in detail.

[0066] [Probe compound]

[0067] The probe compound of the present invention is a hydrophobic AIE molecule with aggregation-induced emission properties.

[0068] Aggregation-induced emission (AIE) is a phenomenon discovered by chance in 2001 by a team led by Academician Tang Benzhong: some silole molecules (HPS, such as 1,1,2,3,4,5-hexaphenylsilole) emit almost no light in solution, but their emission is greatly enhanced when aggregated or in solid films. Because this enhanced emission is caused by aggregation, the phenomenon was defined as "aggregation-induced emission."

[0069] From a structural perspective, common AIE molecules exhibiting aggregation-induced emission properties can be broadly categorized into pure hydrocarbon systems, heteroatom-containing systems, macromolecular systems, and metal-containing systems. Most of these molecules possess an aromatic conjugated planar backbone, capable of forming helical structures in space. This conjugation is affected by different aggregation states, altering their conjugation properties, thereby manifesting AIE characteristics in fluorescence spectra. Due to the presence of the aromatic backbone, these molecules, in their unsubstituted native state, are mostly hydrophobic and insoluble in water.

[0070] The probe compound of the present invention is preferably a hydrophobic AIE molecule comprising a compound represented by any one of the following Chemical Formulas 1 to 12 as a basic skeleton:

[0071]

[0072] The hydrophobic AIE molecules used in the present invention preferably include unsubstituted AIE molecules such as tetraphenylethylene (TPE) represented by Chemical Formula 1, hexaphenylsilole (HPS) represented by Chemical Formula 7, distyrenylanthracene (DSA) represented by Chemical Formula 2, and 1,12-Benzoperylene (BP) represented by Chemical Formula 10. They may also be derivatives, polymers, or metal complexes containing the basic skeleton structure of these AIE molecules, and exhibit hydrophobicity to aqueous solutions. In the present invention, "hydrophobicity" refers to the property of being insoluble or poorly soluble in water.

[0073] The aforementioned AIE molecules exhibit distinct fluorescence properties in different aggregated and dispersed states. Furthermore, the luminescence mechanisms of different AIE molecules in different solution systems may also differ. For example, tetraphenylethylene (TPE) exhibits no fluorescence emission when dissolved in a good solvent, but produces very high fluorescence emission when in a poor solvent. The principle behind using TPE molecules to detect the cmc of various surfactant solutions is that, at low surfactant concentrations, most TPE molecules aggregate in the aqueous phase. Since water is a poor solvent for TPE molecules, this aggregation produces strong fluorescence. At high surfactant concentrations, the TPE molecules are encapsulated within the hydrophobic core of the micelle molecules. At this point, the TPE molecules are dispersed between individual micelle molecules and within the micelle core, unrestricting their internal rotation. Consequently, their fluorescence is significantly reduced. Given the distinct fluorescence properties of TPE in its aggregated and dispersed states, it can be used to detect the cmc of surfactant solutions and track the assembly and disassembly of amphiphilic molecules.

[0074] In addition, non-patent document 1 reports the use of hydrophobic hexaphenylsilole (HPS) molecules as probes to measure the cmc of surfactant solutions. The method is to first dissolve HPS in a volatile organic solvent (such as n-hexane) and then add it to the aqueous surfactant solution. Due to its hydrophobicity, HPS is difficult to disperse in water, so it forms a covering layer and must be evenly mixed by ultrasound. After the cyclohexane evaporates, the HPS enters the micelles formed by the surfactant molecules, thereby emitting strong fluorescence. In other words, when n-hexane is used as a good solvent to dissolve the HPS probe molecules, whether the solvent evaporates has a decisive influence on the fluorescence results: when the solvent is not evaporated, the HPS probe molecules will preferentially dissolve in the solvent, HPS will not emit fluorescence, and the surfactant solution will not emit light; only after the solvent evaporates, the HPS will precipitate to varying degrees, and some will enter and aggregate in the hydrophobic core of the surfactant micelles, in order to exhibit the AIE property of aggregated luminescence.

[0075] However, n-hexane itself is a highly volatile, colorless liquid with low boiling and flash points. The probe solution is difficult to store after preparation, and the CMC measurement process requires a solvent evaporation step. Direct addition of AIE molecules without dissolving them in an organic solvent can result in inaccurate AIE dosage and uneven mixing, affecting the accuracy of the test results.

[0076] [Additives]

[0077] Through research and screening, the inventors have found some organic solvents with specific structures as adjuvants for hydrophobic AIE molecules. These organic solvents are not easily volatile and can enable the AIE probe molecules to exhibit obvious AIE properties within a suitable concentration range.

[0078] As a typical hydrophobic AIE molecule, hexaphenylsilylene (HPS) is highly soluble in good solvents such as acetonitrile, tetrahydrofuran, and chloroform, slightly soluble in alcohols such as methanol, but completely insoluble in water. It is generally believed that the type or polarity of the solvent has little effect on the fluorescence absorption or emission spectra of HPS.

[0079] The present inventors studied the solubility of HPS in a series of organic solvents and its AIE properties in a surfactant solution (Blue Moon Supreme Detergent aqueous solution). The results are shown in Table 1.

[0080] Table 1. Comparison of properties of various solvents and AIE performance tests

[0081]

[0082]

[0083] The results in Table 1 indicate that among various organic solvents, n-butanol and n-pentanol exhibit significant AIE within a certain detergent concentration range. Furthermore, they are slightly soluble in water, slightly soluble in HPS, and nonvolatile, making them suitable as adjuvants for inclusion in the probe compositions of the present invention. n-Butanol, in particular, exhibits significant AIE within a suitable detergent concentration range and is therefore a preferred adjuvant for the present invention.

[0084] Further research results indicate that not only organic alcohols but also any organic solvent with a specific amphiphilic structure can be used as the adjuvant of the present invention. These organic solvents are characterized by having alkyl chains of a certain length within the molecule and polar groups (functional groups) at the ends or in the middle of the alkyl chains, thus forming an amphiphilic structure with both hydrophilic regions composed of polar groups and hydrophobic regions composed of alkyl chains.

[0085] That is, the auxiliary agent contained in the AIE fluorescent probe composition of the present invention is at least one organic solvent represented by the following general formula (1):

[0086] (R) n -X (1)

[0087] Wherein, R is a substituted or unsubstituted straight-chain or branched alkyl group having 3 to 10 carbon atoms, n is an integer of 1 or 2, and when n is 2, the two Rs may be the same or different.

[0088] X is a polar group selected from any one of a hydroxyl group, an amino group, a cyano group, a halogen group, an amide group, a carbonyl group, an aldehyde group, an ester group, and an ether group.

[0089] The hydrophobic AIE molecules of the present invention are soluble or slightly soluble in the additive, which is higher than their solubility in water. Thus, when the probe composition is added to an aqueous system such as a low-concentration surfactant solution, the probe compound tends to preferentially dissolve in the additive and, with the aid of the additive, stably disperse in the aqueous system. Consequently, the hydrophobic AIE molecules of the present invention dissolve in the additive to form a stable probe solution.

[0090] From the perspective of long-term storage stability, these adjuvant molecules are preferably non-volatile organic solvents. Generally speaking, the more volatile an organic solvent is, the lower its boiling point is, while the higher its boiling point is, the less volatile it is. Therefore, in the present invention, the boiling point of the adjuvant is preferably greater than 70°C, more preferably 70-155°C, and even more preferably 75-150°C.

[0091] In the general formula (1), n ​​is preferably 1, that is, the hydrophilic region composed of the polar group X is preferably located at the end of the alkyl molecular chain.

[0092] R in the general formula (1) is a substituted or unsubstituted straight or branched alkyl group with 3 to 10 carbon atoms, wherein the number of carbon atoms of R reflects the length of the alkyl chain in the auxiliary agent molecule. If the alkyl chain is too short, the hydrophobic region formed may not be sufficient to stabilize the AIE molecule, and the solubilization effect of the AIE molecule entering the surfactant micelle is insufficient. Moreover, if the number of carbon atoms is too small, the volatility of the auxiliary agent molecule may be too large, which is not conducive to the storage stability of the probe solution. On the other hand, if the alkyl chain is too long, the water solubility of the auxiliary agent itself is reduced, which is also not conducive to the stability of the probe solution, and may not play a solubilization effect on the AIE molecule entering the surfactant micelle. From the perspective of further improving the solubilization effect on micelles and maintaining the stability of the probe solution, R in the general formula (1) is preferably an unsubstituted straight or branched alkyl group with 3 to 6 carbon atoms, and more preferably 4 to 5 carbon atoms.

[0093] In addition, from the perspective of safety, availability and water solubility of the auxiliary agent molecule, the polar group X in the general formula (1) is preferably selected from hydroxyl groups or amino groups.

[0094] More preferably, the auxiliary agent is one or more selected from n-propanol, isopropanol, tert-butanol, n-butanol, n-butylamine, and pentylamine. The auxiliary agent may be a single agent or a mixture of two or more agents.

[0095] In the AIE fluorescent probe composition of the present invention, preferred combinations of hydrophobic AIE molecules and auxiliary agents include AIE molecules that are unsubstituted HPS, TPE, DSA, or benzoperylene, and auxiliary agents that are organic alcohols or organic amines having 3 to 5 carbon atoms.

[0096] In addition, the inventors discovered that the preparation method of the probe solution also has a certain impact on the fluorescence properties of the AIE fluorescent probe composition. For example, when the auxiliary agent is a mixed solvent of an organic alcohol with 3 to 5 carbon atoms and acetone, due to the influence of the volatility of acetone on the aggregation state of the AIE molecules, a stable and obvious AIE phenomenon cannot be produced; however, when the AIE probe molecules are pre-dissolved in acetone, then evaporated and dried, and finally the above-mentioned organic alcohol is added to obtain a solution of the AIE fluorescent probe composition, a stable and obvious AIE phenomenon will be produced within the appropriate concentration range. It is speculated that this may be because the microscopic aggregation state of the AIE probe molecules changes after they are first dissolved in acetone and then evaporated and dried.

[0097] The present inventors speculate the following mechanism of the AIE phenomenon caused by the AIE fluorescent probe composition in a surfactant solution.

[0098] First, the hydrophobic AIE molecules are dissolved in an organic solvent serving as an adjuvant to form a probe solution. When the probe solution containing the probe compound and the adjuvant is added to a surfactant solution, when the surfactant concentration is low and has not yet reached the critical micelle concentration, the adjuvant, due to its specific amphiphilic structure, will adsorb or encapsulate the hydrophobic AIE molecules and stably disperse them in the surfactant aqueous solution. When the surfactant concentration increases to the critical micelle concentration (cmc), a large number of surfactant molecules begin to self-assemble to form micelles. At this time, the adjuvant molecules, without the need for an additional volatilization step, carry the hydrophobic AIE molecules into the internal cavity of the micelles formed by the surfactant molecules and intersperse and arrange with the surfactant molecules forming the micelles, forming a "palisade" structure. The AIE molecules aggregate near the palisade layer of the micelles, and this aggregation state triggers strong AIE luminescence.

[0099] That is to say, in the AIE fluorescent probe composition of the present invention, the auxiliary agent not only acts as a solvent for the hydrophobic AIE molecules, but also, due to its amphiphilic structural characteristics of hydrophilic and hydrophobic regions, can assist the hydrophobic AIE molecules to enter the fence layer of the surfactant micelles, has the effect of solubilization in the micelles, and exhibits obvious AIE characteristics within a suitable concentration range.

[0100] Furthermore, in order to verify the above-specified mechanism, the present inventors conducted the following molecular simulation experiments.

[0101] Figure 1 Schematic diagrams illustrating the molecular simulation results of the solubilization effect of the adjuvants of the present invention on hydrophobic AIE molecules in mixed micelles of surfactants, wherein (A) the adjuvant is butylamine and (B) the adjuvant is butanol.

[0102] Regarding the auxiliary agent molecules, a variety of polar organic solvents such as butylamine, pentylamine, pentanol, propylamine, butanol, butyraldehyde, butyric acid, isopropanol, n-propanol, and tert-butanol were selected; regarding the AIE fluorescent probe molecules, benzoperylene was selected, and molecular simulation experiments were carried out on solubilization in mixed micelles (1:1) of fatty alcohol polyether sulfate sodium (AES) and fatty alcohol polyoxyethylene ether (AEO).

[0103] First, a 21nm*21nm*21nm spherical micelle cubic water box was constructed. Each molecule was simulated using the United-Atom force field and gromacs software for 50ns of NPT pressure control. The results showed that stable micelles formed in all systems. However, due to the different solubility of the additive molecules in water, the size and shape of the micelles formed varied, and the number of additive molecules solubilized in the micelles varied from that dispersed in the water.

[0104] from Figure 1 As can be seen, when additive 1 is (A) butylamine or (B) butanol, stable spherical micelle models are obtained, with benzopyrene 2 (large dark spots in the image), the fluorescent probe molecule, solubilized within the micelles. Surfactant molecule 3 forms the micelle backbone, encapsulating the fluorescent probe molecule. It can be seen that the micelles formed when butylamine is used as the additive are more regular than those formed when butanol is used.

[0105] The inventors also calculated the distance between each fluorescent probe molecule and the water layer, finding that each was greater than 0.2 nm, further demonstrating that the fluorescent probe molecules were isolated from the water molecules and solubilized within the micelle core. Furthermore, a comparison of the number of hydrogen bonds revealed that butylamine, with its low solubility in water, is more likely to form micelles with surfactants, potentially stabilizing the micelles.

[0106] It can be seen from the results of the above molecular simulation that each system of the AIE fluorescent probe composition of the present invention can form stable micelles. It can be seen that the auxiliary molecules participate in the micelle formation and are located in the fence layer of the surfactant micelle close to the polar group side, which has a positive contribution to the formation of the mixed surfactant micelle and the coating of the AIE fluorescent probe molecules.

[0107] Judging from the current results, the constructed molecular model is reasonable, the method is feasible, and the results are also reasonable.

[0108] [Other ingredients]

[0109] The AIE fluorescent probe composition of the present invention may include, in addition to the hydrophobic AIE molecule as the probe compound and the specific organic solvent as the auxiliary agent, other components such as stabilizers, preservatives and other additives without affecting the AIE effect.

[0110] When other components are included, the total content of the other components is preferably less than 5% by mass, more preferably less than 1% by mass, relative to the total amount of the AIE fluorescent probe composition.

[0111] In the present invention, as long as the appropriate AIE intensity can be achieved, there is no particular restriction on the content ratio of the auxiliary agent and the probe compound in the AIE fluorescent probe composition. Preferably, the content ratio of the auxiliary agent relative to the entire AIE fluorescent probe composition is 40% to 90% by mass, more preferably 50% to 80% by mass; preferably, the content ratio of the probe compound relative to the entire AIE fluorescent probe composition is 10% to 60% by mass, more preferably 20% to 50% by mass. In addition, the AIE fluorescent probe composition may also contain only the auxiliary agent and the probe compound.

[0112] From the perspectives of probe solution solubility, storage stability, and AIE luminescence intensity, the concentration of the hydrophobic AIE molecule as the probe compound in the AIE fluorescent probe composition of the present invention is preferably 500-2000 μmol / L, more preferably 600-1500 μmol / L. When the AIE fluorescent probe composition is added to a surfactant solution to be tested, the concentration of the probe compound in the surfactant solution is preferably 1-1000 μmol / L, more preferably 10-500 μmol / L.

[0113] The probe composition of the present invention can form a stable probe solution by using hydrophobic AIE molecules as probe compounds and an organic solvent with a specific amphiphilic structure as an auxiliary agent. Moreover, the auxiliary agent has the effect of solubilizing the hydrophobic AIE molecules in the mixed micelles of the surfactant, and exhibits obvious AIE characteristics within an appropriate concentration range. Furthermore, after adding the test sample, the probe solution of the present invention can accurately measure the cmc without evaporating the solvent, which greatly improves the ease of use in actual scenarios and can meet the actual application requirements of AIE fluorescent probes in measuring the cmc concentration of surfactant solutions.

[0114] (Method for measuring CMC of surfactant solution)

[0115] The AIE fluorescent probe composition of the present invention comprising a hydrophobic AIE molecule and a specific organic solvent as an auxiliary agent can be directly used to measure the cmc concentration of a surfactant solution in the form of a stable probe solution.

[0116] Since the AIE fluorescent probe composition of the present invention contains charge-neutral hydrophobic AIE molecules, it is less susceptible to interference from charge interactions than derivatized hydrophilic AIE molecules and is therefore applicable to various types of surfactants.

[0117] The surfactant of the present invention may include at least one of anionic surfactants, nonionic surfactants, cationic surfactants, and amphiphilic surfactants. More preferably, the surfactant of the present invention includes at least anionic surfactants and / or nonionic surfactants.

[0118] Examples of the anionic surfactant include surfactants such as alkyl sulfate type, alkyl alcohol polyether sulfate type, alkyl carboxylate type, alkyl sulfonate type, and phosphate type.

[0119] Examples of the nonionic surfactant include alkyl glucoside, alkyl alcohol ether glucoside, polyoxyethylene alkyl ether, polyoxyethylene polyoxypropylene alkyl ether, polyoxyethylene fatty acid ester, and fatty acid alkanolamide.

[0120] In the surfactant solution as the test solution, the above-mentioned surfactants may be used alone or in combination of two or more.

[0121] In addition, the surfactant solution may also contain fluorescent whitening agents and the like.

[0122] The method for determining the critical micelle concentration (cmc) of the surfactant solution of the present invention comprises the following steps:

[0123] Solution preparation steps: Prepare a series of test solutions with increasing concentrations of surfactants in multiple sample cells.

[0124] adding a probe step: adding a certain amount of probe solution to each of the plurality of sample pools; detecting step: detecting the fluorescence intensity of each solution to be tested by a detection mechanism; and

[0125] Determination step: Determine the CMC concentration of the surfactant solution according to the change trend of the fluorescence intensity of each test solution detected,

[0126] It is characterized in that the probe solution is the AIE fluorescent probe composition of the present invention.

[0127] When hexaphenylsilylene (HPS) was used as the probe compound, it was found in the detection step that the fluorescence intensity of each test solution in multiple sample pools suddenly changed from low to high, and gradually weakened after reaching the maximum fluorescence intensity. Therefore, in the decision step, the concentration of the test solution in the sample pool corresponding to the detected maximum fluorescence intensity was used as the cmc concentration of the surfactant solution.

[0128] Preferably, the concentration of the probe compound in the AIE fluorescent probe composition is 500 to 2000 μmol / L, and the concentration of the probe compound in the surfactant solution is 1 to 1000 μmol / L.

[0129] Preferably, the range of a series of increasing concentrations of the surfactant is 0 to 20 g / L, and the fluorescent probe is added in a ratio of 1:1000 to 100:1000 by volume to the surfactant solution.

[0130] Since there are multiple sample pools, each containing a series of surfactants with increasing concentrations, the above method can be used to intuitively judge the intensity of fluorescence in each sample pool. Even without fluorescence detection equipment, the sample pool with the highest fluorescence intensity can sometimes be identified by the naked eye, thereby easily determining the cmc concentration of the surfactant solution.

[0131] Alternatively, instead of using multiple sample cells, a single sample cell can be used. In this case, a surfactant solution of an initial concentration is prepared in the sample cell, and a predetermined amount of fluorescent probe is added to form a mixed solution. The fluorescence intensity of the mixed solution is then detected. Subsequently, a predetermined amount of surfactant can be added to the sample cell at a predetermined number of times. The fluorescence intensity of the mixed solution is measured after each addition, and the CMC concentration of the surfactant solution is determined based on the trend of the detected fluorescence intensity. This determination method reduces reagent usage and saves costs because it only requires adding the probe once and adding the surfactant a predetermined number of times.

[0132] (CMC measurement device for surfactant solutions)

[0133] The present invention also provides a device for measuring the critical micelle concentration (cmc) of a surfactant solution, comprising:

[0134] A plurality of sample cells are prepared with a series of test solutions having increasing concentrations of surfactants,

[0135] a probe container containing a probe solution containing a probe compound,

[0136] The sample adding mechanism is used to take out a certain amount of probe solution from the probe container and add it into the multiple sample pools.

[0137] A detection mechanism, configured to detect the fluorescence intensity of the solution to be tested in the plurality of sample pools, and

[0138] A determination mechanism determines the cmc concentration of the surfactant solution according to a change trend of the fluorescence intensity of each test solution detected by the detection mechanism,

[0139] It is characterized in that the probe solution is the AIE fluorescent probe composition mentioned above in the present invention.

[0140] Preferably, the fluorescent probe is an HPS molecule. When the HPS molecule is used as the probe, the detected fluorescence intensity changes from low to high, and the strongest fluorescence intensity is generated in the sample pool corresponding to the cmc concentration.

[0141] The detection mechanism is preferably a fluorescence sensor with an excitation wavelength range of 275 to 375 nm and a receivable wavelength range of at least 350 to 370 nm or 720 to 740 nm, which outputs a fluorescence intensity detection signal by detecting changes in the peak intensity of the fluorescence emission of the surfactant solution within the wavelength range of 350 to 370 nm or 720 to 740 nm.

[0142] (cmc determination method based on AIE fluorescence probe)

[0143] One application area of ​​the AIE fluorescent probe composition of the present invention is as an intelligent marker for online judgment of an intelligent detergent delivery system in a washing device.

[0144] Current washing machines, such as automatic-dispensing washing machines, primarily rely on the weight of the fabric load to add detergent. This lacks intelligence, lacks universal applicability for different detergents, and lacks flexibility for various washing scenarios, leaving significant room for improvement. The goal of intelligent automatic-dispensing systems for washing machines is to identify markers that indicate not only complete or nearly clean cleaning, but also optimal cleaning efficiency or the most cost-effective solution.

[0145] The inventors have discovered through research that when the concentration of a detergent containing surfactant components reaches the critical micelle concentration, its washing effect reaches the optimal cost-effective balance point. Therefore, whether the detergent aqueous solution reaches the cmc concentration can be used as a basis for judging the intelligent dosing of detergent.

[0146] Therefore, the present invention also provides a cmc determination method based on an AIE fluorescent probe, which is a determination method for determining whether a surfactant has reached a critical micelle concentration cmc, characterized in that it comprises the following steps in sequence:

[0147] Solution preparation steps: add an initial amount of surfactant to water, stir, and prepare a test solution;

[0148] Sampling step: taking a small amount of the solution to be tested and transferring it to a sample pool;

[0149] Probe adding step: adding the AIE fluorescent probe into the sample cell and applying slight vibration to form a mixed solution;

[0150] Detection step: detecting the fluorescence intensity of the mixed solution by a fluorescence detector and outputting a detection signal S; and

[0151] Determining step: determining whether the critical micelle concentration (cmc) is reached based on the changing trend of the detection signal S; if the determination result is yes, outputting the concentration of the test solution as the cmc concentration, and terminating all steps; if the determination result is no, emptying the sample pool, returning to the solution preparation step, adding a specified amount of surfactant to the test solution, and continuing to perform the following sampling step, probe addition step, detection step, and determination step.

[0152] In the judging step, if the judging result is negative but the number of times the predetermined amount of surfactant is added in the liquid preparation step has reached a predetermined threshold, all steps are terminated.

[0153] The surfactant solution used in the CMC determination method of the present invention can be a directly prepared aqueous detergent solution or an aqueous detergent solution used in a washing machine. The aqueous detergent solution is an aqueous solution of a detergent containing one or more surfactant components, including at least an anionic surfactant and / or a nonionic surfactant.

[0154] Since the present invention uses an AIE fluorescent probe with aggregation-induced emission properties as a marker, a conventional fluorescence detector with low sensitivity can be used to accurately measure the fluorescence intensity of the detergent aqueous solution. By converting the fluorescence intensity into a detection signal S, online judgment of cmc and intelligent control of the detergent addition amount can be achieved.

[0155] The AIE fluorescent probe used in the CMC determination method of the present invention can be a fluorescent probe aqueous solution containing a water-soluble AIE molecule, or it can be an AIE fluorescent probe composition of the present invention containing a hydrophobic AIE molecule and an auxiliary agent. From the perspective of applicability and convenience, the AIE fluorescent probe composition of the present invention is preferably used.

[0156] Aqueous detergent solutions containing HPS molecules, acting as AIE fluorescent probes, exhibited yellow-green fluorescence observed by the naked eye within a certain range. The fluorescence intensity initially increased and then significantly decreased. In the case of directly prepared aqueous detergent solutions, the strongest fluorescence intensity observed by the naked eye occurred in the concentration range of approximately 0.1 g / L to 0.2 g / L. When the detergent concentration exceeded 2 g / L, the fluorescence intensity decreased significantly.

[0157] In order to realize automatic control of the washing equipment, the fluorescence intensity of the mixed liquid detected by the fluorescence detector needs to be output as a detection signal S. The detection signal S is a voltage signal corresponding to the fluorescence intensity F at a specific wavelength, and is output to the judgment mechanism or decision mechanism described later.

[0158] Regarding the threshold S0, the CMC determination method of the surfactant solution described above can be used to prepare a series of test solutions with increasing concentrations of surfactants in multiple sample pools or a single sample pool in advance, and the detection signal S corresponding to the maximum fluorescence intensity detected is set as the threshold S0.

[0159] Then, in the judgment step, if the detection signal S is equal to or higher than the preset threshold S0, the judgment result is yes (the detergent aqueous solution has reached the cmc concentration); if the detection signal S is lower than the threshold S0, the judgment result is no (the detergent aqueous solution has not reached the cmc concentration).

[0160] However, since the CMC concentration of the detergent aqueous solution in the actual machine washing washing equipment is affected by many factors (such as water temperature, fabric weight, etc.), sometimes the preset threshold S0 does not correspond to the actual CMC concentration. Usually, the apparent CMC concentration of the detergent aqueous solution in the actual machine washing is much greater than the CMC concentration corresponding to the above threshold S0. In this case, it is preferred to add detergent online during the actual washing process. The apparent CMC concentration of the detergent aqueous solution is judged online through the CMC judgment method of the present invention, thereby realizing intelligent addition of detergent.

[0161] Preferably, in the judgment step performed twice or more, by observing the detection signal S X 、S Y The difference between the two changes is used to determine whether the concentration of the surfactant has reached the critical micelle concentration cmc.

[0162] More specifically, in the two adjacent detection signals, if the latter detection signal S Y Compared with the previous detection signal S X The difference between S Y -S X is 0 or becomes a negative value, the judgment result is yes; if the difference S Y -S X If it is greater than 0, the judgment result is no.

[0163] When the CMC determination method is applied to the actual washing process of a washing machine, the determination step primarily determines whether additional detergent is needed. After the initial addition of detergent, the washing machine can begin washing. Multiple sampling and determinations can be performed during the washing process, and washing can also begin after all steps have been completed.

[0164] In the cmc judgment method based on AIE fluorescent probe of the present invention, since an AIE fluorescent probe with aggregation-induced emission characteristics is used, changes in AIE fluorescence intensity can be identified without the aid of precision instruments, using a conventional low-sensitivity fluorescence detector, or sometimes even just by the naked eye. Therefore, the cmc of the detergent aqueous solution can be determined simply, quickly, and efficiently. It can be effectively used in the washing industry for online monitoring of the detergent content in the washing aqueous solution, and has practical guiding significance in the intelligent dosing of detergents.

[0165] (CMC determination device based on AIE fluorescence probe)

[0166] Furthermore, the present invention also provides a CMC determination device based on an AIE fluorescent probe, which is used to determine whether a surfactant solution has reached a critical micelle concentration (CMC). The device includes a surfactant storage mechanism, an addition mechanism, a sampling mechanism, a sample cell, an AIE fluorescent probe storage mechanism, a sample addition mechanism, a detection mechanism, a CMC determination mechanism, and a determination mechanism, wherein the following operations are performed in sequence:

[0167] The adding mechanism takes out a certain amount of surfactant from the surfactant storage mechanism and mixes it with water to prepare a solution to be tested.

[0168] The sampling mechanism takes a small amount of the solution to be tested and transfers it to the sample pool.

[0169] The sample adding mechanism takes out a trace amount of probe solution from the storage mechanism of the AIE fluorescent probe and adds it into the sample pool, and applies slight vibration to form a mixed solution.

[0170] The detection mechanism detects the fluorescence intensity of the mixed solution and transmits the obtained detection signal to the CMC judgment mechanism.

[0171] The CMC judgment mechanism judges whether the critical micelle concentration (cmc) is reached based on the change trend of the detection signal.

[0172] If the determination result of the cmc determination mechanism is yes, the determination mechanism outputs the concentration of the solution to be tested as the cmc concentration, and all operations are terminated;

[0173] If the judgment result of the CMC judgment mechanism is negative and the execution number of the adding mechanism is lower than the predetermined threshold, the sample pool is emptied, the adding mechanism adds a specified amount of surfactant to the solution to be tested, and continues to perform subsequent operations.

[0174] If the judgment result of the cmc judgment mechanism is no, and the execution times of the adding mechanism have reached a predetermined threshold, all operations are terminated.

[0175] The AIE fluorescent probe used in the device is preferably the AIE fluorescent probe composition of the present invention.

[0176] When the above device is applied to an actual washing machine, the CMC concentration may not be output, and the decision of whether to add surfactant (detergent) may be made based solely on the determination result of the CMC determination mechanism. The determination mechanism may control the washing machine to start washing after the initial detection operation is completed or after all operations are completed.

[0177] The detection device can be a fluorescence sensor with an excitation wavelength range of 275 - 375 nm and a receivable emission wavelength range of 350 - 750 nm, preferably a fluorescence sensor with an excitation wavelength range of 275 - 375 nm and a receivable wavelength range that at least includes 350 - 370 nm or 720 - 740 nm.

[0178] When the HPS molecule as an AIE fluorescence probe is excited by 365 - nm ultraviolet light, there are mainly two emission peaks of fluorescence intensity: a sharp and relatively intense fluorescence peak within the range of 350 - 370 nm, and a relatively weak, broad and short fluorescence peak within the range of 720 - 740 nm, and these do not overlap with the emission peaks of the fluorescent whitening agents (such as CBS) contained in the actual detergent aqueous solutions (such as the Supreme Clean Detergent and Supreme Bright White Detergent produced by Blue Moon Company), that is, it avoids the wavelength range of 400 - 550 nm where the emission peak of the fluorescent whitening agent CBS appears. In this way, the interference of the fluorescent whitening agent on the cmc judgment result can be avoided.

[0179] By adopting the cmc judgment method and device based on the AIE fluorescence probe of the present invention, it can be actually applied to a washing device for online detection of cmc, online judgment and automatic addition of detergent, and thus can be applied to the intelligent dosing system of detergent in a washing device.

[0180] Examples

[0181] Hereinafter, the present invention will be described more specifically by way of examples, but the present invention is not limited to the following examples as long as it does not deviate from its gist.

[0182] (Example 1)

[0183] <Preparation of AIE Fluorescence Probe Composition>

[0184] Dissolve HPS (98% purity, molecular weight M = 938) as a probe compound in n - butanol as an auxiliary agent at a concentration of 0.001 mol / L to prepare a probe solution.

[0185] <Preparation of Test Solution Containing Surfactant>

[0186] As the test solution containing surfactant, directly prepare a series of detergent aqueous solutions with concentrations of 0.02 g / L, 0.05 g / L, 0.1 g / L, 0.2 g / L, 0.5 g / L, 1 g / L, 2 g / L, 5 g / L, 10 g / L, 20 g / L respectively from the Supreme Clean Detergent B1 - B10 (trade name, produced by Blue Moon Company). Add 150 μL of the above - mentioned probe solution to 5 mL of the above - mentioned detergent aqueous solution to prepare a test solution, and the concentration of the HPS probe in the test solution is 30 μmol / L.

[0187] (Reference Example 1)

[0188] For comparison, a test solution containing a surfactant of Reference Example 1 was prepared in the same manner as in Example 1 except that no probe solution was added.

[0189] <Measurement of Fluorescence Intensity>

[0190] A custom-assembled fluorescence detector (filters include an excitation filter (365 nm), a dichroic mirror, and an emission filter (729 nm), a light source with a peak wavelength of 365 nm, a wavelength range of 300-400 nm, a working current of 0.02 A, and a working voltage of 5 V) was used to perform fluorescence detection on the test solution to which the HPS probe was added. The fluorescence intensity was detected based on the brightness of the fluorescence (the luminescence intensity was converted into an effective voltage readable reading). The results of Example 1 and Reference Example 1 are shown in FIG. Figure 2 .

[0191] <Determination of CMC Concentration of Detergent Aqueous Solution>

[0192] Figure 2 1 is a graph showing the change in fluorescence intensity with concentration when the AIE fluorescent probe composition of the present invention is added to the above-mentioned directly prepared supreme clean detergent aqueous solution (Example 1) and when the AIE fluorescent probe composition of the present invention is not added (Reference Example 1).

[0193] from Figure 2 It can be seen that when no probe solution is added, the fluorescence intensity of the detergent aqueous solution is very low, and its intensity hardly changes with increasing detergent concentration (Reference Example 1).

[0194] In contrast, in Example 1, fluorescence of a certain intensity was also observed in the aqueous detergent solution containing the probe solution of the present invention (HPS-n-butanol), even at low concentrations (below the cmc). This is presumably because, after the addition of the detergent and HPS probe molecules to the system, the HPS / surfactant mixture begins to aggregate, driven by hydrophobic interactions between the surfactant alkyl chains in the detergent and π-π interactions between HPS molecules. This aggregation can form ordered or complex structures, effectively restricting intramolecular motion and thus exhibiting certain aggregated luminescence properties.

[0195] When the concentration of the detergent solution in the system reaches or exceeds the cmc (less than 10 times the cmc), the surfactant molecules begin to self-assemble into micelles. At this point, the micelles are mostly spherical, and their size and shape remain largely unchanged. Driven by hydrophilic-hydrophobic interactions, the lipophilic (hydrophobic) HPS probe molecules, with the assistance of the additive (n-butanol), enter and aggregate in the hydrophobic core of the spherical micelles, exhibiting strong fluorescence intensity AIE characteristics within the concentration range of 0.1 to 2 g / L. Figure 2 The peak value (maximum fluorescence intensity) of the middle curve corresponds to the concentration of the test solution at 0.1 g / L. Therefore, this concentration can be determined as the cmc concentration of the directly prepared detergent aqueous solution.

[0196] When the detergent aqueous solution concentration in the system is too high (for example, 10 times the cmc or more), the fluorescence emission intensity decreases significantly. This may be because the excessive surfactant concentration causes the spherical micelles to form anisotropic aggregates such as worm-like micelles or vesicles. The HPS is distributed into micelles or aggregates of different shapes, which destroys the π-π interactions between HPS molecules and weakens the restriction of HPS intramolecular motion. The excited molecules consume light energy in the form of heat through vibration and rotation, resulting in a decrease in HPS fluorescence. It is speculated that the anisotropy of the HPS probe fluorescence in the non-spherical micelle aggregate environment may also cause the significantly weakened fluorescence intensity observed by the naked eye.

[0197] In addition, the change in the AIE fluorescence intensity of the above-mentioned Supreme Clean Detergent aqueous solution can also be identified only by the naked eye. The concentration of the test solution with the strongest fluorescence intensity seen by the naked eye is determined as the cmc concentration. The observation result is basically consistent with the measurement result using the above-mentioned fluorescence detector.

[0198] In order to further verify the accuracy of the cmc measurement results of the AIE fluorescent probe composition of the present invention, we used a K100C surface tension meter to measure the cmc of the Supreme Clean detergent aqueous solution used in Example 1, and obtained the following: Figure 3 The surface tension curve shown is a function of concentration.

[0199] Through Figure 3 By fitting the change curve in , it is inferred that the cmc of the directly prepared supreme clean detergent aqueous solution is ≈ 0.09 g / L, which is close to the measurement result (0.1 g / L) using the AIE fluorescent probe method of the present invention, indicating that the cmc measurement method using the AIE fluorescent probe composition of the present invention is feasible and effective.

[0200] (Examples 2 to 6, Comparative Examples 1 to 3, Reference Example 2)

[0201] Except for using Supreme Whitening Detergent A0-A10 (trade name, manufactured by Blue Moon Company) containing the fluorescent whitening agent CBS instead of Supreme Cleaning Detergent B1-B10, and changing the composition of the AIE fluorescent probe composition as shown in Tables 2-1 and 2-2 below, the test solutions of Examples 2 to 6 and Comparative Examples 1 to 3 were directly prepared in the same manner as in Example 1, and the same measurements were performed.

[0202] In addition, a test solution of Reference Example 2 was prepared as a control in the same manner as in Example 2, except that the probe solution was not added. The results are shown in Tables 2-1 and 2-2. In the table, the bold numbers in the voltage column indicate the voltage corresponding to the maximum fluorescence intensity (peak).

[0203] Table 2-1:

[0204]

[0205] Table 2-2:

[0206]

[0207] Note: 1* “HPS-acetone-n-butanol” means that HPS is first dissolved in acetone, and n-butanol is added after the acetone has evaporated.

[0208] 2*“-” in the table means not determined.

[0209] 3* indicates the measurement result after the acetone is completely evaporated.

[0210] It can be seen from Table 2-1 and Table 2-2 that in Examples 2 to 6 of the present invention, although different types of additives were used, the concentration of the test solution corresponding to the maximum fluorescence intensity was 0.2 g / L. Therefore, this concentration can be determined as the cmc concentration of the directly prepared Supreme Whitening Detergent aqueous solution.

[0211] Furthermore, as shown in Example 6, when HPS was pre-dissolved in acetone and then evaporated and dried before adding n-butanol, a stable and obvious AIE phenomenon was also produced within the appropriate concentration range, and the maximum fluorescence intensity was shown near the cmc concentration.

[0212] In contrast, the number of carbon atoms in the alkyl chain of the auxiliary agent molecule (aminomethyl acetone) used in Comparative Example 1 does not meet the requirements of the general formula (1) of the present invention, and therefore, no obvious AIE phenomenon is shown in the concentration range of 0 to 20 g / L.

[0213] Comparative Example 2 employed a mixed solvent of n-butanol and acetone. However, acetone itself does not meet the requirements of general formula (1) of the present invention. Furthermore, due to the uncertainty of the degree of acetone's volatility in the mixed solvent, the luminescence intensity of the test solution exhibited an unstable trend, making it impossible to accurately determine the CMC concentration. This result demonstrates that incomplete evaporation of the volatile solvent in the probe solution can lead to inaccurate measurement results.

[0214] Comparative Example 3 directly used acetone as an auxiliary agent, and the measurement was performed after the acetone completely evaporated. The experimental results show that although acetone exhibited a clear AIE phenomenon after complete evaporation, its high volatility prevented its preparation into a stable probe solution, and the measurement process required waiting for the solvent to evaporate. Therefore, it was not suitable as a probe solution for the present invention and was excluded from the scope of auxiliary agents in the present invention, becoming a comparative example.

[0215] (Example 7)

[0216] <Preparation of detergent aqueous solution for actual machine washing>

[0217] 2.5 kg of clothes were added to a drum washing machine, and 13 L of water and 1 g of Supreme Clean Detergent B0-B10 (trade name, manufactured by Blue Moon Company) were added and stirred. Then, a certain amount of detergent was continuously added during the washing process of the washing machine, so that the amount of detergent added to 13 L of water was 1 g, 2 g, 4 g, 8 g, 12 g, 16 g, 20 g, 24 g, 28 g, and 32 g, respectively, and the corresponding Supreme Clean Detergent concentrations were 0.075 g / L, 0.15 g / L, 0.31 g / L, 0.62 g / L, 0.92 g / L, 1.23 g / L, 1.54 g / L, 1.85 g / L, 2.15 g / L, and 2.46 g / L, respectively. This series of actual machine-washed detergent aqueous solutions containing detergents of different concentrations were taken out from the drum washing machine in turn as test solutions.

[0218] In Example 7, the fluorescence intensity was measured in the same manner as in Example 1, except that the above-mentioned aqueous detergent solution for actual machine washing was used instead of the directly prepared aqueous detergent solution used in Example 1. The results are shown in FIG. Figure 4 .

[0219] Figure 4 3 is a graph showing the change in fluorescence intensity with concentration when the AIE fluorescent probe composition (HPS-n-butanol) of the present invention is added to the Supreme Clean detergent aqueous solution for actual machine washing.

[0220] like Figure 4 As shown, Figure 2The change trend of the detergent solution is the same as that of the other solutions. With the gradual increase of the detergent concentration in the detergent solution, the fluorescence intensity of each detergent solution changes from low to high, and gradually weakens after reaching the maximum fluorescence intensity. However, Figure 2 The difference is that the peak (maximum fluorescence intensity) in the curve corresponds to a concentration of 0.62 g / L of the detergent aqueous solution.

[0221] Therefore, it can be determined that, in the usage scenario described in Example 7, the cmc concentration of the detergent aqueous solution used for actual machine washing is 0.62 g / L. This cmc concentration is higher than the cmc concentration measured for the directly prepared detergent aqueous solution used in Example 1. This is because the detergent aqueous solution used for actual machine washing contains a large amount of clothing, which has a certain degree of detergent adsorption, resulting in an increased apparent cmc concentration. This result is reasonable.

[0222] In order to further verify the accuracy of the cmc measurement results of the AIE fluorescent probe composition of the present invention, we used a K100C surface tension meter to measure the cmc of the actual machine-washed Supreme Clean detergent aqueous solution used in Example 7, and obtained the following: Figure 5 The curve of interfacial tension changing with concentration is shown.

[0223] Through Figure 5 By fitting the change curve in , it is inferred that the cmc of the actual machine-washed Supreme Clean detergent aqueous solution is ≈ 0.7 g / L, which is close to the measurement result (0.62 g / L) using the AIE fluorescent probe method of the present invention, indicating that the cmc measurement method using the AIE fluorescent probe composition of the present invention is feasible and effective.

[0224] From the results of Examples 1 to 7 above, it can be seen that the AIE fluorescent probe composition of the present invention can form a stable probe solution, which is applicable to detergent aqueous solutions used in direct preparation or actual machine washing, and can avoid the interference of fluorescent whitening agents in detergent aqueous solutions. It exhibits AIE characteristics within a suitable cmc concentration range, and can therefore be applied to practical uses such as washing equipment to accurately and conveniently measure the cmc concentration of detergent aqueous solutions.

[0225] Industrial applicability

[0226] By adopting the AIE fluorescent probe composition of the present invention, it is possible to achieve online measurement and online judgment of the cmc concentration of the surfactant solution using only a simply assembled fluorescence detector in the ultraviolet-visible light range without the need for high-precision testing instruments, which is convenient for industrialization and plays an important role in the intelligent detergent addition system of washing equipment.

Claims

1. An AIE fluorescent probe composition, which is a probe solution for measuring the critical micelle concentration (cmc) of a surfactant solution, characterized in that: The method comprises a probe compound and an auxiliary agent, wherein the probe compound is a hydrophobic AIE molecule, and the auxiliary agent is at least one organic solvent represented by the following general formula (1). (R) n -X(1) Wherein, R is a substituted or unsubstituted straight-chain or branched alkyl group having 3 to 10 carbon atoms, n is an integer of 1 or 2, and when n is 2, the two Rs may be the same or different. X is a polar group selected from any one of hydroxyl, amino, cyano, halogen, amide, carbonyl, aldehyde, ester, and ether groups, The hydrophobic AIE molecules are dissolved in the auxiliary agent, The boiling point of the auxiliary agent is greater than 70°C.

2. The AIE fluorescent probe composition according to claim 1, wherein In the general formula (1), R is an unsubstituted straight-chain or branched alkyl group having 3 to 6 carbon atoms, and X is selected from a hydroxyl group or an amino group.

3. The AIE fluorescent probe composition according to claim 1 or 2, wherein The auxiliary agent is one or more selected from n-propanol, isopropanol, tert-butanol, n-butanol, n-butylamine, and pentylamine.

4. The AIE fluorescent probe composition according to claim 1 or 2, wherein The auxiliary agent has an amphiphilic structure, and has a hydrophilic region composed of the polar group and a hydrophobic region composed of the alkyl group in the molecule. The solubility of the probe compound in the auxiliary agent is higher than that in water.

5. The AIE fluorescent probe composition according to claim 1 or 2, wherein The auxiliary agent is an alkyl alcohol with 3 to 6 carbon atoms. The preparation method of the probe solution is: pre-dissolving the probe compound in acetone, then volatilizing it to dryness, and finally adding the alkyl alcohol to obtain the AIE fluorescent probe composition.

6. The AIE fluorescent probe composition according to claim 1 or 2, wherein The probe compound is a hydrophobic AIE molecule comprising a compound represented by any one of the following chemical formulas 1 to 12 as a basic skeleton:

7. The AIE fluorescent probe composition according to claim 6, wherein The hydrophobic AIE molecule is unsubstituted tetraphenylethylene represented by Chemical Formula 1, unsubstituted distyrylanthracene represented by Chemical Formula 2, unsubstituted hexaphenylsilanol represented by Chemical Formula 7, or unsubstituted benzoperylene represented by Chemical Formula 10.

8. The AIE fluorescent probe composition according to claim 1 or 2, wherein The surfactant solution contains at least an anionic surfactant and / or a nonionic surfactant.

9. The AIE fluorescent probe composition according to claim 1 or 2, wherein The concentration of the probe compound in the AIE fluorescent probe composition is 500 to 2000 μmol / L, and the concentration of the probe compound in the surfactant solution is 1 to 1000 μmol / L.

10. The AIE fluorescent probe composition according to claim 1 or 2, wherein The content ratio of the auxiliary agent relative to the total amount of the AIE fluorescent probe composition is 70% to 99% by mass, and the content ratio of the probe compound relative to the total amount of the AIE fluorescent probe composition is 1% to 30% by mass.

11. A method for determining the cmc of a surfactant solution, comprising the following steps in sequence: Solution preparation steps: Prepare a series of test solutions with increasing concentrations of surfactants in multiple sample cells. Probe adding step: adding a certain amount of probe solution to each of the plurality of sample cells, Detection steps: Use the detection mechanism to detect the fluorescence intensity of each test solution, and Determination step: Determine the CMC concentration of the surfactant solution according to the change trend of the fluorescence intensity of each test solution detected, It is characterized by: The probe solution is the AIE fluorescent probe composition according to any one of claims 1 to 10.

12. The cmc measurement method according to claim 11, wherein The probe compound is unsubstituted hexaphenylsilylcyclopentadiene, In the detection step, the fluorescence intensity of each solution to be tested in the multiple sample pools suddenly changes from low to high, and gradually weakens after reaching the maximum fluorescence intensity. In the determining step, the concentration of the test solution in the sample cell corresponding to the detected maximum fluorescence intensity is used as the cmc concentration of the surfactant solution.

13. A CMC measuring device for a surfactant solution, comprising: A plurality of sample cells are prepared with a series of test solutions having increasing concentrations of surfactants, a probe container containing a probe solution containing a probe compound, The sample adding mechanism is used to take out a certain amount of probe solution from the probe container and add it into the multiple sample pools. A detection mechanism, configured to detect the fluorescence intensity of the solution to be tested in the plurality of sample pools, and A determination mechanism determines the cmc concentration of the surfactant solution according to a change trend of the fluorescence intensity of each test solution detected by the detection mechanism, It is characterized by: The probe solution is the AIE fluorescent probe composition according to any one of claims 1 to 10.

14. A cmc determination method based on an AIE fluorescent probe is used to determine whether a surfactant solution has reached a critical micelle concentration (cmc), characterized by: The method includes the following steps in sequence: Solution preparation steps: add an initial amount of surfactant to water, stir, and prepare a test solution; Sampling step: taking a small amount of the solution to be tested and transferring it to a sample pool; Probe adding step: adding the AIE fluorescent probe into the sample cell and applying slight vibration to form a mixed solution; Detection step: detecting the fluorescence intensity of the mixed solution by a fluorescence detector and outputting a detection signal S; and Determining step: determining whether the critical micelle concentration (cmc) is reached based on the changing trend of the detection signal S; if the determination result is yes, outputting the concentration of the test solution as the cmc concentration, and terminating all steps; if the determination result is no, emptying the sample pool, returning to the solution preparation step, adding a specified amount of surfactant to the test solution, and continuing to perform the following sampling step, probe addition step, detection step, and determination step. In the judgment step, if the judgment result is negative, but the number of times the prescribed amount of surfactant is added in the liquid preparation step has reached a predetermined threshold, all steps are terminated. Wherein, the AIE fluorescent probe is the AIE fluorescent probe composition according to any one of claims 1 to 10.

15. The CMC determination method according to claim 14, wherein: In the judging step, if the detection signal S is equal to or higher than a preset threshold value S0, the judging result is yes; If the detection signal S is lower than the threshold S0, the judgment result is no.

16. The CMC determination method according to claim 14, wherein: In the judgment step, if the detection signal S of the latter detection signal obtained in two adjacent detection steps is Y Compared with the previous detection signal S X The difference between S Y -S X is 0 or becomes a negative value, the judgment result is yes; If the difference S Y -S X If it is greater than 0, the judgment result is no.

17. A CMC determination device based on an AIE fluorescent probe is used to determine whether a surfactant solution has reached a critical micelle concentration (CMC), comprising a surfactant storage mechanism, an addition mechanism, a sampling mechanism, a sample pool, an AIE fluorescent probe storage mechanism, a sample addition mechanism, a detection mechanism, a CMC determination mechanism, and a determination mechanism, wherein: Perform the following steps in order: The adding mechanism takes out a certain amount of surfactant from the surfactant storage mechanism and mixes it with water to prepare a solution to be tested. The sampling mechanism takes a small amount of the solution to be tested and transfers it to the sample pool. The sample adding mechanism takes out a trace amount of probe solution from the storage mechanism of the AIE fluorescent probe and adds it into the sample pool, and applies slight vibration to form a mixed solution. The detection mechanism detects the fluorescence intensity of the mixed solution and transmits the obtained detection signal to the CMC judgment mechanism. The CMC judgment mechanism judges whether the critical micelle concentration (cmc) is reached based on the change trend of the detection signal. If the determination result of the cmc determination mechanism is yes, the determination mechanism outputs the concentration of the solution to be tested as the cmc concentration, and all operations are terminated; If the judgment result of the CMC judgment mechanism is negative and the execution number of the adding mechanism is lower than the predetermined threshold, the sample pool is emptied, the adding mechanism adds a specified amount of surfactant to the solution to be tested, and continues to perform subsequent operations. If the judgment result of the cmc judgment mechanism is no, and the execution times of the adding mechanism have reached the predetermined threshold, all operations are terminated. Wherein, the AIE fluorescent probe is the AIE fluorescent probe composition according to any one of claims 1 to 10.

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