Method for in situ determination of the dissolution rate of optically measurable solutes in the presence of organic matter

Abstract

The application relates to a method for in-situ measuring the dissolution rate of an optically measurable solute in an organic matter environment, and relates to the technical field of solute dissolution rate measurement. The method comprises steps S1 to S5. S1: obtaining a sample to be measured, and coating an inert film on a non-test surface of the sample to be measured to obtain a coated sample. S2: obtaining an initial three-dimensional image of the coated sample by coherent light interference imaging technology, and extracting an initial surface height at the test surface. S3: obtaining an organic matter solution, and continuously flushing the surface of the coated sample with the organic matter solution. S4: obtaining a three-dimensional image of the coated sample after flushing by coherent light interference imaging technology, and extracting a dissolution surface height at the test surface. S5: combining the molar volume of the sample to be measured, and calculating the dissolution rate according to the change rate of the surface height of the initial surface height and the dissolution surface height.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of solute dissolution rate measurement, in particular to a method for in-situ determination of dissolution rate of optically measurable solute in organic matter environment. BACKGROUND

[0002] Cement minerals are a kind of solid minerals with hydraulicity, and the dissolution thereof is a process jointly driven by thermodynamics and kinetics, which is essentially the interaction of solid surface atoms and water phase atoms at the solid-liquid interface, constituting the initial step of cement hydration. The dissolution rate of cement minerals is a key indicator for characterizing the reactivity thereof, and the research on mineral dissolution kinetics is of great significance for exploring the dissolution mechanism and predicting the dissolution behavior, and is also a key link for in-depth analysis of cement hydration mechanism. Therefore, there is a clear practical demand for accurately determining the dissolution rate of cement minerals in organic matter environment.

[0003] At present, the main method for determining the dissolution rate of cement minerals is to calculate the dissolution rate by quantitatively detecting the change of mineral composition elements in the solution, and the chemical reactors used include batch reactors, fully mixed flow reactors and their derivative types. This method is relatively simple to operate, but has obvious limitations: firstly, it ignores the potential influence of ion accumulation and product precipitation in the dissolution process on the dissolution rate, and thus cannot accurately capture the real dissolution process of cement minerals. Secondly, this method relies on standard curves, and the measurement accuracy of the instrument is easily disturbed by organic matter.

[0004] Therefore, the existing method is not suitable for continuous measurement of the dissolution rate of cement minerals in the presence of dissolution-precipitation coupling dynamic process in organic matter environment, and it has significant deficiencies in anti-interference ability, measurement accuracy and applicability. SUMMARY

[0005] The present application provides a method for in-situ determination of dissolution rate of optically measurable solute in organic matter environment, aiming to improve at least one of the above technical problems.

[0006] The present application is implemented as follows: a method for in-situ determination of dissolution rate of optically measurable solute in organic matter environment, comprising S1 to S5.

[0007] S1, obtaining a to-be-measured sample made of optically measurable solute, and coating an inert film on the non-test surface of the to-be-measured sample to obtain a coated sample.

[0008] S2, obtaining an initial three-dimensional image of the coated sample by coherent light interference imaging technology, and extracting the initial surface height at the test surface h 0.

[0009] S3, obtaining an organic matter solution, and using the organic matter solution to continuously flush the surface of the coated sample.

[0010] S4, then reacquire the three-dimensional image of the coated sample by coherent light interference imaging technology, and extract the dissolution surface height at the test surface h 1.

[0011] S5, according to the initial surface height h 0 and the change rate of the surface height of the dissolution surface height h 1, calculate the dissolution rate v .

[0012] Further, the dissolution rate calculation model is: ; in the formula, is the molar volume of the sample to be tested, is the time difference between the acquisition of the corresponding three-dimensional image to the acquisition of the corresponding three-dimensional image.

[0013] Further, the optically measurable solute is a cement mineral or a water-soluble mineral.

[0014] Further, the organic matter solution uses polycarboxylic acid water reducer or sucrose retarder as a solute, and is obtained by dissolving in deionized water. The concentration of the solute is .

[0015] Further, the sample surface is continuously flushed with the organic matter solution, specifically: the organic matter solution is controlled to flush the sample surface at a constant flow rate.

[0016] Preferably, the concentration of the organic matter solution is , , or .

[0017] Preferably, the constant flow rate is .

[0018] Further, the time for the organic matter solution to continuously flush the sample surface is X. The time for reacquiring the three-dimensional image of the coated sample by coherent light interference imaging technology is Y. Wherein, X is greater than Y.

[0019] Further, the sample to be tested is made of an optically measurable solute, and an inert film is coated on the non-test surface of the sample to be tested to obtain a coated sample, specifically: the sample to be tested is made of an optically measurable solute. Cover the masking tape on the test surface of the sample to be tested. Use the coating instrument to deposit a layer of water-insensitive inert film on the exposed surface of the sample to be tested. After coating, remove the tape and obtain the coated sample.

[0020] Further, the three-dimensional image of the coated sample is acquired by the coherent light interference imaging technology, comprising: acquiring a coherent light interferometer and setting three-dimensional imaging parameters. The surface hologram data of the coated sample is collected by the coherent light interferometer. The three-dimensional image of the sample to be measured is established according to the collected hologram data.

[0021] Further, the three-dimensional imaging parameters include: laser wavelength, imaging area size, scanning step length.

[0022] Further, after obtaining the coated sample, the sample to be measured is placed in a dissolution reaction pool. After placing the sample to be measured in the dissolution reaction pool, the initial three-dimensional image of the coated sample is acquired by the coherent light interference imaging technology.

[0023] Further, the test surface covers at least the highest point of the sample to be measured.

[0024] By adopting the above technical solution, the following technical effects can be achieved:

[0025] The method for in-situ determination of the dissolution rate of the optically measurable solute in the organic matter environment is convenient to operate, high in accuracy, and wide in universality, can effectively avoid the limitations of the traditional solution ion concentration test method, such as the dependence on standard curve and the instrument accuracy being easily interfered by organic matter, and is especially suitable for in-situ dissolution determination of cement minerals or water-soluble minerals in the organic matter environment. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0027] Figure 1 is a step diagram of the method for in-situ determination of the dissolution rate of the optically measurable solute in the organic matter environment. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below. The specific conditions not mentioned in the embodiments are carried out according to the conventional conditions or the conditions suggested by the manufacturer. The reagents or instruments not mentioned by the manufacturer are all conventional products that can be purchased in the market.

[0029] In the prior art, the determination of the dissolution rate of cement minerals or minerals with water solubility (hereinafter referred to as optically measurable solute) usually adopts a solution ion concentration analysis method, which indirectly calculates the dissolution rate by detecting the change of the content of a specific element in the solution. However, in the presence of organic matter, organic matter such as polycarboxylic acid water reducing agent and sucrose retarder is easy to complex with the detection reagent, resulting in distortion of the spectral signal. In addition, the traditional method needs to establish a standard curve in advance, and the experimental operation involves multiple sampling, centrifugation, filtration and other steps, which is time-consuming and easy to introduce human error.

[0030] In order to solve the above problems, researchers observed that the dissolution process of optically measurable solute would cause surface morphology change, and tried to replace solution detection by directly measuring surface height change. Initial experiments found that dissolution in non-test areas would interfere with measurement accuracy, and after multiple verifications, it was proposed to coat an inert film on the non-test surface to form physical isolation. In order to solve the real-time monitoring problem under dynamic scouring conditions, coherent light interference imaging technology was introduced to capture nanoscale three-dimensional morphology. By establishing a mathematical relationship between surface height difference and molar volume, a direct calculation method of dissolution rate was finally formed.

[0031] Therefore, the present application proposes a technical scheme of obtaining a to-be-measured sample and coating an inert film on the non-test surface thereof, obtaining an initial three-dimensional image by coherent light interference imaging technology and extracting an initial surface height, obtaining a three-dimensional image again after continuously scouring the surface of the sample with an organic matter solution and extracting a dissolution surface height, and calculating the dissolution rate in combination with molar volume.

[0032] The in-situ determination method of the dissolution rate of optically measurable solute in the organic matter environment according to an embodiment of the present application will be described below. The method comprises steps S1 to S5.

[0033] Step S1, obtaining a to-be-measured sample made of optically measurable solute, and coating an inert film on the non-test surface of the to-be-measured sample to obtain a film-coated sample.

[0034] Step S2, obtaining an initial three-dimensional image of the film-coated sample by coherent light interference imaging technology, and extracting an initial surface height at the test surface .

[0035] Step S3, obtaining an organic matter solution, and continuously scouring the surface of the film-coated sample with the organic matter solution.

[0036] Step S4, then re-obtaining a three-dimensional image of the film-coated sample by coherent light interference imaging technology, and extracting a dissolution surface height at the test surface .

[0037] Step S5, in combination with the molar volume of the to-be-measured sample, calculating the dissolution rate according to the initial surface height and the dissolution surface height Calculate the dissolution rate based on the rate of change of surface height. .

[0038] Specifically, the method includes sample preparation, solution preparation, dissolution experiments, and performance testing. Specifically, it includes: 1. Coating the surface of the sample with an inert film: Covering a selected area of ​​the sample with residue-free masking tape, and depositing a water-free, non-sensitive film on its surface using a coating instrument. 2. Preparation of organic solutions: Both the polycarboxylate superplasticizer solution and the sucrose retarder solution are prepared using deionized water and corresponding additives. 3. Dissolution: Placing the sample to be tested in a dissolution reaction tank, and using a pump to control the liquid flow rate at a constant rate (…). 4. Dissolution rate calculation: Based on the molar volume of the sample, the dissolution rate is determined according to the rate of change of surface height of the uncoated area of ​​the sample under target conditions.

[0039] The present invention provides a method for in-situ determination of the dissolution rate of optically measurable solutes in an organic environment. This method is convenient to operate, highly accurate, and widely applicable. It can effectively avoid the limitations of traditional solution ion concentration testing methods, such as reliance on standard curves and the susceptibility of instrument accuracy to interference from organic matter. It is especially suitable for in-situ determination of the dissolution rate of optically measurable solutes in an organic environment.

[0040] Inert film coating refers to the formation of a chemically inert protective layer in non-test areas using physical vapor deposition (PVD). For example, a silicon nitride thin film can be used, with a thickness controlled within the range of 200-500 nanometers. This process effectively prevents the organic solution from corroding the non-test areas. Coherent optical interferometry (COI) imaging technology utilizes the principle of phase-shifting interference, reconstructing the three-dimensional morphology by acquiring multiple interference fringe patterns. Continuous rinsing of the organic solution is achieved through constant flow control using a peristaltic pump; for example, the flow rate can be set to a range of 30-40 ml / min to ensure the dissolution reaction is in dynamic equilibrium. The dissolution rate calculation model is based on the ratio of surface height change to time interval, combined with molar volume parameters to convert geometric variables into chemical dissolution rate values.

[0041] Specifically, Teflon tape was first applied to the surface of the tricalcium aluminate sample, exposing a 5×5 mm test area before a 300 nm thick silicon nitride film was deposited. After placing the sample in a reaction chamber, a three-dimensional image was acquired using coherent optical interferometry (CIOM), and the height was determined to be 1523.6 nm. Subsequently, a solution containing 2 g / L polycarboxylic acid was pumped in at a flow rate of 34 mL / min, continuously flushing for 1 second before scanning again, resulting in a surface height reduction to 1465.2 nm. Based on the height difference of 58.4 nm and a molar volume of 89.1 cm³ / mol, the dissolution rate was calculated to be 0.65 mmol / m² / s. This process, through the synergistic effect of physical isolation of the non-reactive zone, optical measurement of deformation, and mathematical modeling transformation, achieved accurate in-situ determination of the dissolution rate.

[0042] Compared to existing technologies, traditional methods require establishing a calcium ion concentration-absorbance standard curve before each experiment, while this method directly measures surface morphology changes, eliminating the need for standard curve preparation. In existing technologies, organic matter in the solution easily undergoes side reactions with the colorimetric reagent; for example, the complexation of EDTA with polycarboxylic acid can cause absorbance measurements to deviate from the true value by up to 25%. This method, by directly measuring surface morphology, completely avoids interference from solution components. Regarding the operational process, traditional methods require more than five solution samplings and three centrifugation and filtration processes, while this method only requires two optical scans to complete data acquisition.

[0043] Through the above technical solution, this application effectively solves the three major technical problems of traditional methods for determining dissolution rate in organic environments: large signal interference, complex operation procedures, and reliance on standard curves. This method reduces the dissolution rate determination time from 6-8 hours in traditional methods to within 30 minutes, and eliminates the need for expensive spectroscopic detection equipment, making it of significant application value in fields such as cement hydration research and concrete durability assessment.

[0044] Based on the above embodiments, in an optional embodiment of the present invention, step S1 includes steps S11 to S14.

[0045] S11. Obtain the sample to be tested prepared from an optically measurable solute. Preferably, the optically measurable solute is a cement mineral or a water-soluble mineral. Specifically, the cement mineral can be tricalcium aluminate, dicalcium silicate, tricalcium silicate, or tetracalcium aluminoferrite. Water solubility refers to the property of a material to undergo a dissolution reaction with a solvent. Water-soluble minerals can be calcite, gypsum, or feldspar.

[0046] S12. Cover the test surface of the sample with residue-free masking tape. Preferably, the test surface should at least cover the highest point of the sample. Specifically, covering the highest point of the sample allows for more accurate measurement of the surface height.

[0047] S13. Use a coating instrument to deposit a water-free inert film on the exposed surface of the sample to be tested.

[0048] S14. Remove the tape after coating to obtain the coated sample.

[0049] Residue-free masking tape refers to a protective material that leaves no adhesive residue after the adhesive layer is removed. This can be achieved using a polyester substrate combined with a silicone adhesive, etc. During peeling, an interfacial separation mechanism prevents adhesive transfer; for example, Teflon tape can be used. This tape is used to cover the test surface to prevent coating materials from contaminating the test area.

[0050] Anhydrous inert membranes are protective layers that do not chemically react with water or organic solutions. Specifically, they can be achieved by generating silicon nitride thin films using physical vapor deposition. These membranes isolate and protect non-test areas by blocking the solution's permeation path.

[0051] After the test surface is covered with tape, the coating apparatus deposits an inert film on the exposed non-test areas of the sample. The tape acts as a temporary barrier, ensuring that the coating process only affects the non-test areas. Once the inert film has formed, the tape is removed to expose the test area, at which point the non-test areas are completely covered by the inert film. This dual protection mechanism, through the synergistic effect of physical isolation and chemical stability, ensures that the organic solution only contacts the surface of the test area during rinsing, thereby eliminating the influence of dissolution of non-target areas on the measurement data.

[0052] Through the above technical solution, this application solves the measurement error problem caused by the erosion of non-test surfaces during the rinsing process of organic solution. Precise isolation between the test area and the non-test area avoids non-target dissolution reactions, and the chemical stability of the inert film ensures the integrity of the protective layer during rinsing, thereby ensuring that the dissolution rate measurement data only reflects the true reaction process in the designated area.

[0053] The test surface refers to the region selected for measuring changes in surface height. This region can be determined by performing a three-dimensional scan of the sample surface using coherent interferometry imaging. This region is limited to include the geometrically highest point of the sample surface to ensure that the measurement data reflects the most significant dissolution behavior. The highest point is the point on the sample surface with the maximum vertical coordinate value in three-dimensional space, which can be automatically identified using a three-dimensional image reconstruction algorithm. This feature is used to determine the boundary conditions of the measurement region, thereby ensuring that the selected area contains the region with the fastest dissolution rate.

[0054] When using coherent optical interferometry (COI) imaging for continuous monitoring, surface height variation data in this region is prioritized for acquisition, and the accurate dissolution rate value is obtained by calculating the height change rate. This measurement method avoids data bias caused by selecting regions with low dissolution activity. Traditional methods typically select measurement areas randomly or use averaging when measuring dissolution rates, failing to consider the spatial differences in dissolution behavior caused by sample surface morphology. Especially in samples with complex surface morphologies, the difference in dissolution rates between different regions can reach orders of magnitude. This scheme fundamentally eliminates measurement errors caused by improper region selection by explicitly limiting the measurement area to cover the highest point.

[0055] Based on the above embodiments, in an optional embodiment of the present invention, step S3 specifically includes S31 and S32.

[0056] S31. Obtain an organic matter solution. Preferably, the organic matter solution is obtained by dissolving a polycarboxylate superplasticizer or a sucrose retarder in deionized water. The concentration of the solute is 1-5 g / L. More preferably, the concentration of the organic matter solution is... , , or .

[0057] S32. The organic solution is controlled by a pump to rinse the surface of the coated sample at a constant flow rate. Preferably, the constant flow rate is... Specifically, the constant flow rate is: .

[0058] More preferably, the time for the organic solution to continuously rinse the sample surface is X; the time for re-acquiring the three-dimensional image of the coated sample using coherent optical interferometry imaging is Y; wherein X is greater than Y. Specifically, the specific duration of Y can be set by those skilled in the art according to actual needs, and Y can be 0.93 s, within 4 s, 25 s, or 30 s, which is not limited in this invention. X being greater than Y ensures the stability of the variables during measurement and avoids errors caused by changes in solution flow rate due to the water flow being turned off in the last one or two seconds before measurement.

[0059] Polycarboxylate superplasticizers are high-molecular polymers containing carboxylic acid groups. Specifically, they can be produced by dissolving industrial-grade polycarboxylate superplasticizer powder in deionized water. The polar groups in their molecular structure can adsorb onto the surface of optically measurable solutes to form a stable dispersion system. Sucrose retarders are retarding substances with sucrose as the main component. Specifically, they can be produced by dissolving food-grade sucrose crystals in deionized water. Their hydroxyl structures can undergo physical adsorption onto the surface of optically measurable solutes. Constant flow rate refers to a fluid maintaining a constant volumetric flow rate per unit area per unit time. This can be achieved using peristaltic pumps or metering pumps, with the solution delivery rate controlled by adjusting the pump's rotational speed.

[0060] When polycarboxylate superplasticizers or sucrose retarders are used as solutes, specific functional groups in their molecular structure preferentially adsorb onto the optically measurable solute surface to form a monolayer. This adsorption avoids side reactions that interfere with the dissolution process and maintains the chemical stability of the solution system. Deionized water, as a solvent, effectively eliminates interference from impurities such as calcium and magnesium ions on the dissolution reaction. Constant flow rate flushing maintains stable hydrodynamic conditions, ensuring that the dissolution reaction interface remains in a uniform mass transfer state, thus avoiding calculation errors in the dissolution rate caused by flow rate fluctuations. When the flushing flow rate is stable, the thickness of the boundary layer formed on the sample surface remains constant, and the diffusion rate of the dissolved products reaches a dynamic equilibrium with the flushing flow rate, thereby ensuring that changes in surface height only reflect the kinetic characteristics of the dissolution reaction.

[0061] Compared to existing technologies, traditional methods often use organic acids that readily react with optically measurable solutes when selecting organic solutions. These solutes can alter the solution's pH or form complexes, causing the measured dissolution rate to deviate from the true value. Existing flushing methods often employ intermittent or variable flow rate approaches. These unsteady fluid conditions induce repeated wetting and drying cycles at the dissolution interface, resulting in periodic fluctuations in surface height measurements. Furthermore, existing technologies do not explicitly define solvent purity requirements; dissolved impurities in ordinary tap water can affect the repeatability of test results.

[0062] Through the above technical solution, this application effectively eliminates unnecessary chemical reaction interference between organic matter and optically measurable solutes, avoids measurement errors caused by fluctuations in fluid conditions, and solves the problem of inaccurate dissolution rate measurement caused by improper selection of organic matter solution components and inaccurate control of rinsing conditions in traditional methods. By using a specific solute type and constant flow rate control, the dissolution reaction only reflects the intrinsic dissolution characteristics of the optically measurable solute, and a stable correlation is formed between surface height change data and the true dissolution rate. The repeatability error of the test results can be controlled within 5%.

[0063] By setting the flushing time X to be greater than the imaging time Y, it is ensured that the flushing process remains stable throughout the 3D image acquisition process, avoiding surface height measurement errors caused by interruptions in flushing or failure to reach a steady state. For example, when the flushing time is set to 60 seconds and the 3D image acquisition takes 40 seconds, the flushing operation has already lasted for 20 seconds before imaging begins and continues during the imaging process, ensuring that surface morphology changes are entirely caused by continuous dissolution.

[0064] Based on the above embodiments, in an optional embodiment of the present invention, after obtaining the coated sample, the method further includes: placing the sample to be tested in a dissolution reaction chamber. After placing the sample to be tested in the dissolution reaction chamber, an initial three-dimensional image of the coated sample is obtained using coherent optical interferometry imaging technology. This operation enables the measurement of the initial surface height. h 0 and dissolution surface height h At step 1, keeping the position of the coated sample unchanged makes the measured values ​​more reliable and reduces errors during the testing process.

[0065] Placing the sample in a dissolution reaction tank refers to fixing the coated sample in a sealed container with a solution circulation function. Understandably, to measure the sample's surface height in real time, the water mirror of the coherent light interferometer must also be immersed in an organic solution.

[0066] Based on the above embodiments, in an optional embodiment of the present invention, an initial three-dimensional image of the coated sample is obtained by coherent optical interferometry imaging technology, including steps A1 to A3.

[0067] A1. Obtain the coherent optical interferometer and set the three-dimensional imaging parameters. Preferably, the three-dimensional imaging parameters include: laser wavelength, imaging area size, and scanning step size.

[0068] A2. Collect surface holographic data of the coated sample using a coherent optical interferometer.

[0069] A3. Reconstruct a three-dimensional image of the surface of the sample to be tested based on the collected holographic data.

[0070] It should be noted that the use of coherent optical interferometry imaging technology to acquire three-dimensional images is prior art and will not be elaborated upon in this invention. This invention constructs the test surface to cover the highest point of the sample under test, and uses the highest point of the entire sample as the measured value of the initial surface height and the dissolved surface height, resulting in more accurate measurement values.

[0071] Based on the above embodiments, in an optional embodiment of the present invention, the dissolution rate calculation model is as follows: In the formula, The molar volume of the sample to be tested, To obtain The corresponding 3D image is obtained The time difference between the corresponding 3D images.

[0072] in, It refers to the initial surface height obtained through coherent light interferometry imaging technology. Specifically, the reference height data of the test area can be extracted using a three-dimensional image reconstruction algorithm to characterize the original surface morphology before dissolution. This refers to the height of the dissolved surface obtained after rinsing using the same technology. Specifically, real-time dynamic monitoring technology can be used to capture changes in surface morphology and quantify the amount of height reduction caused by dissolution. This refers to the time interval between two 3D image acquisitions. Specifically, a high-precision time synchronization device can be used to record the image acquisition time, which is then used to accurately calculate the amount of dissolution per unit time. It refers to the molar volume of the sample to be tested, which can be obtained by crystal structure analysis or density measurement methods. It is used to convert the change in geometric height into the molar amount of chemical dissolution rate.

[0073] Specifically, by establishing a direct mathematical relationship between surface height change and dissolution rate, three-dimensional morphology data is combined with physicochemical parameters. During the scouring process, coherent optical interferometry (COI) continuously acquires holographic data of the sample surface, and the surface height before and after scouring is extracted using image reconstruction algorithms. and Time difference The instrument's built-in clock precisely records the time points of the two measurements, ensuring a consistent time reference. The height difference ( Divide by the time difference This yields the geometric dissolution rate per unit time, which is then combined with... By converting geometric quantities into molar quantities, the final dissolution rate is obtained. This calculation model bypasses the intermediate conversion of solution ion concentration in traditional methods, directly establishing a quantitative relationship between surface deformation and dissolution rate.

[0074] Compared to existing technologies, traditional dissolution rate measurements rely on solution sampling and ion concentration detection, require the establishment of standard curves, and are easily affected by organic matter. This proposed method, however, eliminates the influence of solution composition on the detection results by monitoring surface morphology changes in situ, thus avoiding errors in standard curve calibration. Existing technologies typically use solution contact time as a benchmark for dissolution time measurement, while this method uses the precise image acquisition time difference as the calculation benchmark, improving the accuracy of time parameter measurements.

[0075] Through the above technical solution, this application achieves direct in-situ measurement of dissolution rate, eliminating interference errors from organic matter components in ion concentration detection and avoiding the operational complexity of standard curve calibration. This model, through direct conversion relationships between physical quantities, ensures that the measurement results only reflect the sample's own dissolution characteristics and are unaffected by changes in the composition of the environmental solution, significantly improving the accuracy of dissolution rate determination under organic conditions.

[0076] This invention provides an in-situ method for determining the dissolution rate of optically measurable solutes in an organic environment, which has the following advantages: 1. Simple operation. No standard curve calibration is required, thus avoiding errors caused by non-standard curves. It also significantly reduces the complexity and tediousness of experimental operations. 2. High accuracy. Traditional methods for measuring solution ion concentration calculate the dissolution rate by quantitatively detecting changes in the mineral composition elements in the solution. This invention takes a different approach, calculating the dissolution rate by quantitatively studying changes in the surface height of the optically measurable solute. This invention directly measures the three-dimensional morphology of the surface of the optically measurable solute in an organic environment, unaffected by the influence of environmental organic matter on the ion concentration of the solution after dissolution. Therefore, this invention avoids interference from environmental organic matter on measurement accuracy. 3. Wide applicability. First, this invention does not rely on relative light intensity signals to obtain the dissolution rate of cement minerals, thus it is unaffected by the state of the coherent light interferometer and laboratory conditions. Second, this invention is applicable to all water-soluble minerals, thus the method has a very wide range of applications.

[0077] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0078] In all embodiments, the sample surface coating process is the same: after covering with masking tape, a vacuum coating instrument is used to coat the sample for 120 seconds to obtain the coated sample. The specific operation of rinsing the sample surface with organic solution is also the same: the organic solution is rinsed with a peristaltic pump at a constant flow rate of 34 mL / min.

[0079] The laser wavelength used in coherent optical interferometry imaging can be 600-800 nm, such as 666, 684, or 790 nm. The size of the imaging area is related to the magnification of the imaging lens. Generally, the imaging area of ​​a 20x lens is around 200 μm x 200 μm. The scan step size can be freely set, with a minimum scan step size of 90 milliseconds.

[0080] Example 1

[0081] Preparation of polycarboxylate superplasticizer An organic solution was used to wash the surface of the tricalcium aluminate sample. The surface height of the tricalcium aluminate sample was continuously monitored using a coherent optical interferometer, showing a decrease of 58 nm within 0.93 s, with a surface height change rate of 62.4 nm / s. The molar volume of the bound tricalcium aluminate was determined. The dissolution rate can be calculated as follows: .

[0082] Example 2

[0083] Preparation of sucrose retarder An organic solution was used to wash the surface of the tricalcium aluminate sample. The surface height of the tricalcium aluminate sample was continuously monitored using a coherent optical interferometer, showing a decrease of 48 nm within 0.93 s, with a surface height change rate of 51.6 nm / s. The molar volume of the bound tricalcium aluminate was determined. The dissolution rate can be calculated as follows: .

[0084] Example 3

[0085] Preparation of polycarboxylate superplasticizer An organic solution was used to wash the surface of the tricalcium silicate sample. The surface height of the tricalcium silicate sample was continuously monitored using a coherent optical interferometer, showing a decrease of 12 nm within 4 seconds, with a surface height change rate of 3 nm / s. The molar volume of the bound tricalcium silicate was determined. The dissolution rate can be calculated as follows: .

[0086] Example 4

[0087] Preparation of sucrose retarder An organic solution was used to wash the surface of a tetracalcium aluminoferrite (TAF) sample. The surface height of TAF was continuously monitored using a coherent optical interferometry (COI) imager, showing a decrease of 4 nm within 25 s, at a rate of 0.16 nm / s. The molar volume of TAF was also measured. The dissolution rate can be calculated as follows: .

[0088] Example 5

[0089] Preparation of sucrose retarder An organic solution was used to wash the surface of a dicalcium silicate sample. Using a coherent optical interferometry imager, the surface height of the dicalcium silicate sample decreased by 3 nm within 30 s, with a surface height change rate of 0.1 nm / s. The molar volume of the bound dicalcium silicate was determined. The dissolution rate can be calculated as follows: .

[0090] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the invention by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the invention should be included within the scope of protection of the invention.

Claims

1. A method for in-situ determination of the dissolution rate of an optically measurable solute in an organic environment, characterized in that, include: S1. Obtain a test sample made of an optically measurable solute, and deposit an inert film on the non-test surface of the test sample to obtain a coated sample; S2. Obtain an initial three-dimensional image of the coated sample using coherent optical interferometry imaging technology, and extract the initial surface height at the test surface. ; S3. Obtain an organic solution and use the organic solution to continuously rinse the surface of the coated sample at a constant flow rate; S4. Then, a three-dimensional image of the coated sample is re-acquired using coherent optical interferometry imaging technology, and the dissolution surface height at the test surface is extracted. ; S5. Based on the molar volume of the sample to be tested and the initial surface height... and the height of the dissolved surface Calculate the dissolution rate based on the rate of change of surface height. ; The dissolution rate calculation model is as follows: In the formula, The molar volume of the sample to be tested, To obtain The corresponding 3D image is obtained The time difference between the corresponding 3D images; The optically measurable solute is cement mineral or a water-soluble mineral; The organic matter solution is obtained by dissolving polycarboxylate superplasticizer or sucrose retarder in deionized water; wherein the concentration of the solute is... .

2. The method for in-situ determination of the dissolution rate of an optically measurable solute in an organic environment according to claim 1, characterized in that, The concentration of the organic matter solution is , , or ; The constant flow velocity is ; The time for the organic solution to continuously rinse the sample surface is X; the time for re-acquiring the three-dimensional image of the coated sample using coherent optical interferometry is Y; where X is greater than Y.

3. The method for in-situ determination of the dissolution rate of an optically measurable solute in an organic environment according to claim 1, characterized in that, A test sample made from an optically measurable solute is obtained, and an inert film is deposited on a non-test surface of the test sample to obtain a coated sample, specifically: S11. Obtain the sample to be tested made from an optically measurable solute; S12. Cover the test surface of the sample with masking tape; S13. Deposit a water-free, inert film on the exposed surface of the sample to be tested using a coating instrument; S14. Remove the tape after coating to obtain the coated sample.

4. The method for in-situ determination of the dissolution rate of an optically measurable solute in an organic environment according to any one of claims 1 to 3, characterized in that, A three-dimensional image of the coated sample is obtained using coherent optical interferometry imaging technology, including: Acquire coherent light interferometer and set three-dimensional imaging parameters; Surface holographic data of the coated sample were acquired using a coherent optical interferometer. A three-dimensional image of the sample to be tested is created based on the collected holographic data.

5. The method for in-situ determination of the dissolution rate of an optically measurable solute in an organic environment according to claim 4, characterized in that, The three-dimensional imaging parameters include: laser wavelength, imaging area size, and scanning step size.

6. The method for in-situ determination of the dissolution rate of an optically measurable solute in an organic environment according to any one of claims 1 to 3, characterized in that, After obtaining the coated sample, the process also includes: placing the sample to be tested in a dissolution reaction tank; After placing the sample to be tested in the dissolution reaction chamber, the initial three-dimensional image of the coated sample is obtained using coherent optical interferometry.

7. The method for in-situ determination of the dissolution rate of an optically measurable solute in an organic environment according to any one of claims 1 to 3, characterized in that, The test surface must at least cover the highest point of the sample under test.

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