A method for detecting uniformity of diaphragm coating

Abstract

The present invention belongs to the technical field of detection methods, and in particular relates to a method for detecting the uniformity of diaphragm coating, comprising the following steps: step S1, cutting the diaphragm to be detected to obtain N samples to be tested, and recording the weight of each sample; step S2, respectively placing the above N samples into digestion tubes, and respectively adding solvent, nitric acid, perchloric acid, and phosphoric acid to obtain N test samples; step S3, preparing a control sample 1; step S4, respectively placing the N test samples and the control sample 1 into an ultrasonic washer for ultrasonic treatment, placing them into a graphite furnace for heating, and placing them into a microwave digester for digestion to obtain a digestion solution; step S5, preparing and drawing a standard curve, obtaining the aluminum content of the N test samples and the control sample 1, and calculating whether the standard deviation of the aluminum content in each sample and the aluminum content in the standard curve is greater than a preset value. A method for detecting the uniformity of diaphragm coating of the present invention can detect the uniformity of the test sample with high detection accuracy.

Description

Technical Field

[0001] The present invention belongs to the technical field of detection methods, and in particular relates to a method for detecting the uniformity of diaphragm coating. Background Art

[0002] Diaphragms generally consist of a base film and a coating applied to at least one surface of the base film. Coating enhances diaphragm performance. However, due to factors such as poor homogenization consistency and uneven coating thickness, the uniformity of the diaphragm coating can be inconsistent, resulting in poor diaphragm performance and quality. However, existing methods do not provide a method for determining the uniformity of ceramic powder coatings on diaphragms, making it impossible to assess diaphragm uniformity. Summary of the Invention

[0003] The purpose of the present invention is to provide a method for detecting the uniformity of membrane coating in order to address the deficiencies of the prior art, which can detect the uniformity of the sample with high accuracy.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] A method for detecting the uniformity of diaphragm coating comprises the following steps:

[0006] Step S1: Cut the membrane to be tested to obtain N samples to be tested, and record the weight of each sample, where N is a positive integer greater than or equal to 2;

[0007] Step S2, placing the N samples mentioned above into digestion tubes respectively, and adding solvent, nitric acid, perchloric acid, and phosphoric acid respectively to obtain N test samples;

[0008] Step S3, adding solvent, nitric acid, perchloric acid, and phosphoric acid to a blank digestion tube to obtain a control sample 1;

[0009] Step S4, placing N test samples and control sample 1 in an ultrasonic washer for ultrasonic treatment, placing them in a graphite furnace for heating, and placing them in a microwave digester for digestion to obtain digestion solutions;

[0010] Step S5: Prepare a standard solution with a concentration gradient and create a standard curve. According to the standard curve, obtain the aluminum content of N test samples and control sample 1, and calculate whether the standard deviation of the aluminum content in each sample and the aluminum content in the standard curve is greater than a preset value.

[0011] Preferably, in step S2, the volume ratio of the solvent, nitric acid, perchloric acid and phosphoric acid is 1-5:2-6:0.2-3:2-6.

[0012] Preferably, the concentration of nitric acid is 0.5-1.5 mol / L, the concentration of perchloric acid is 0.5-1.5 mol / L, and the concentration of phosphoric acid is 0.5-1.5 mol / L.

[0013] Preferably, the ultrasonic treatment power is 250-350W and the ultrasonic treatment time is 2-10 minutes.

[0014] Preferably, the heating temperature in the graphite furnace is 90-130° C., and the heating time is 30-90 minutes.

[0015] Preferably, the digestion pressure is 2-6 MPa, the time is 80-120 minutes, and the temperature is 100-400°C.

[0016] Preferably, the solvent is one of pure water, deionized water and ultrapure water.

[0017] Preferably, the weight of the sample in step S1 is 0.0100 to 30.0000 g.

[0018] Compared with the prior art, the beneficial effect of the present invention is that the method for detecting the uniformity of membrane coating of the present invention can detect the uniformity of the test sample, thereby obtaining the uniformity of the sample, so as to facilitate subsequent adjustment or optimization of the sample. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of cutting a sample according to the present invention. DETAILED DESCRIPTION

[0020] The present invention will be described in further detail below with reference to specific implementation methods and the accompanying drawings, but the implementation methods of the present invention are not limited thereto.

[0021] A method for detecting the uniformity of diaphragm coating comprises the following steps:

[0022] Step S1: Cut the membrane to be tested to obtain N samples to be tested, and record the weight of each sample, where N is a positive integer greater than or equal to 2;

[0023] Step S2, placing the N samples mentioned above into digestion tubes respectively, and adding solvent, nitric acid, perchloric acid, and phosphoric acid respectively to obtain N test samples;

[0024] Step S3, adding solvent, nitric acid, perchloric acid, and phosphoric acid to a blank digestion tube to obtain a control sample 1;

[0025] Step S4, placing N test samples and control sample 1 in an ultrasonic washer for ultrasonic treatment, placing them in a graphite furnace for heating, and placing them in a microwave digester for digestion to obtain digestion solutions;

[0026] Step S5: Prepare a standard solution with a concentration gradient and create a standard curve. According to the standard curve, obtain the aluminum content of N test samples and control sample 1, and calculate whether the standard deviation of the aluminum content in each sample and the aluminum content in the standard curve is greater than a preset value.

[0027] The difference in the coating uniformity of the diaphragm leads to the difference in the overall performance of the diaphragm. Therefore, testing the coating uniformity of the diaphragm is helpful to understand the difference in the performance of the diaphragm. The present invention first cuts the sample to be tested to obtain samples of each part, and the samples of each part can be from the upper part, middle part and lower part of the diaphragm respectively, and cuts the upper part, middle part and lower part of the diaphragm into two halves along the middle, such as Figure 1 As shown, six samples were obtained, two from the upper left and right sides of the membrane, two from the middle left and right sides, and two from the lower left and right sides. These six samples were collected from different locations on the membrane to be tested, enabling comprehensive testing of the membrane and ensuring more accurate detection. The samples from each location were added to a solvent, nitric acid, perchloric acid, and phosphoric acid to dissolve the samples in the solvent, converting solids into liquids, facilitating subsequent elemental content testing. A blank control group was also established for each experimental group test to improve test accuracy. The experimental and blank group solutions were then subjected to ultrasonic treatment, graphite furnace heating, and microwave digestion to obtain a completely digested solution containing all elements present in the sample to be tested. Therefore, elemental analysis of the digested solution revealed the coating uniformity of each sample. If the aluminum content of each sample was similar and the standard deviation was less than a preset value, the membrane tested exhibited good uniformity, with similar aluminum content across the membrane, consistent coating uniformity, and a high coating yield. If there are differences in aluminum content between samples, and the standard deviation of each data is greater than the preset value, then the uniformity of the tested diaphragm is poor, the aluminum content varies greatly in different parts of the diaphragm, the coating uniformity is inconsistent, and the coating process defect rate is high, which needs to be improved. Generally, the preset value is 0.002-0.2, and the preset value can be 0.002, 0.008, 0.01, 0.035, 0.05, 0.089, 0.1, 0.155, 0.2. Preferably, the preset value is 0.05.

[0028] The method for detecting the uniformity of membrane coating of the present invention can detect the uniformity of a test sample, thereby obtaining the uniformity of the sample, so as to facilitate subsequent adjustment or optimization of the sample.

[0029] Preferably, in step S2, the volume ratio of the solvent, nitric acid, perchloric acid and phosphoric acid is 1-5:2-6:0.2-3:2-6. Preferably, the volume ratio of the solvent, nitric acid, perchloric acid and phosphoric acid is 1-5:2-6:0.2-3:2-6, 2-5:3-6:0.5-3:3-6, 2-5:2-6:0.6-3:3-6, 1-5:2-6:0.8-3:2-6, 1-5:2-6:1.2-3:2-6, 2-5:3-6:2-3:2-6, 2-5:3-6:0.2-3:2-6, 3-5:2-6:0.2-3:2-6, 3-5:3-6:0.2-3:3-6, 3-4:3-5:0.2-3:3-6. Specifically, the volume ratios of the solvent, nitric acid, perchloric acid, and phosphoric acid are 1:3:2:4, 1:3:2.5:3, 1:3:2:5, 1:3:2:4, 1:6:2:3, 1:5:2:4, 1:5:2:4, 1:4:2:6, 2:4:2:5, 4:4:2:6, and 1:4:2:2.

[0030] Preferably, the concentration of nitric acid is 0.5-1.5 mol / L, the concentration of perchloric acid is 0.5-1.5 mol / L, and the concentration of phosphoric acid is 0.5-1.5 mol / L. Preferably, the concentration of nitric acid is 0.5-1.5 mol / L, 0.8-1.5 mol / L, 1.1-1.5 mol / L, 1.2-1.5 mol / L, 1.2-1.4 mol / L. Specifically, the concentration of nitric acid is 0.5 mol / L, 0.8 mol / L, 0.9 mol / L, 1.0 mol / L, 1.2 mol / L, 1.5 mol / L, and the concentration of perchloric acid is 0.5-1.5 mol / L, 0.7-1.5 mol / L, 0.9-1.5 mol / L, 1-1.5 mol / L, 1.1-1.4 mol / L, 1.2-1.4 mol / L, specifically, the concentration of perchloric acid is 0.5mol / L, 0.8mol / L, 0.9mol / L, 1.0mol / L, 1.2mol / L, and 1.5mol / L; the concentration of phosphoric acid is 0.5-1.5mol / L, 0.7-1.5mol / L, 0.9-1.5mol / L, 1-1.5mol / L, 1.1-1.4mol / L, and 1.2-1.4mol / L, specifically, the concentration of phosphoric acid is 0.5mol / L, 0.8mol / L, 0.9mol / L, 1.0mol / L, 1.2mol / L, and 1.5mol / L.

[0031] Preferably, the ultrasonic treatment power is 250-350W, and the ultrasonic treatment time is 2-10 minutes. The ultrasonic treatment power is 250-350W, 260-340W, 280-320W, 290-320W, 300-320W, specifically, the ultrasonic treatment power is 250W, 280W, 290W, 300W, 320W, 350W, and the ultrasonic treatment time is 2-10 minutes, 4-10 minutes, 4-8 minutes, 4-6 minutes, specifically, the ultrasonic treatment time is 2 minutes, 4 minutes, 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, 10 minutes.

[0032] Preferably, the heating temperature in the graphite furnace is 90-130°C, and the heating time is 30-90 minutes. The heating temperature is 90-130°C, 100-130°C, 105-130°C, 110-130°C, or 120-130°C. Specifically, the heating temperature is 90°C, 95°C, 100°C, 105°C, 110°C, 115°C, 120°C, or 130°C. The heating time is 30-90 minutes, 35-90 minutes, 40-90 minutes, 50-90 minutes, 50-80 minutes, or 50-80 minutes.

[0033] Preferably, the digestion pressure is 2-6 MPa, the time is 80-120 minutes, and the temperature is 100-400° C. The digestion pressure is 2-6 MPa, 2.5-6 MPa, 3-6 MPa, 4-6 MPa, specifically, the digestion pressure is 2 MPa, 3 MPa, 4 MPa, 5 MPa, 6 MPa, and the digestion time is 80-120 minutes, 85-120 minutes, 90-110 minutes, 90-120 minutes, 100-120 minutes, 110-120 minutes, specifically, the digestion time is 80 minutes, 90 minutes, 100 minutes, 110 minutes, 120 minutes.

[0034] Preferably, the solvent is one of pure water, deionized water, and ultrapure water. Ultrapure water is preferred. Pure and deionized water contain certain ions and organic matter, which can affect the testing of the digested liquid. Ultrapure water is free of ions and organic matter and virtually eliminates the conductive medium, providing a foundation for accurate testing of the digested liquid.

[0035] Preferably, the weight of the sample in step S1 is 0.0100-30.0000 g. Preferably, the mass of the diaphragm is 0.0100-30.0000 g, 0.0300-30.0000 g, 0.0500-30.0000 g, 0.1000-20.0000 g, 2.0000-20.0000 g, or 5.0000-20.0000 g. Specifically, the mass of the diaphragm is 0.0100 g, 0.1000 g, 0.8000 g, 1.5000 g, 2.0000 g, 3.0000 g, 15.0000 g, 20.0000 g, or 30.0000 g.

[0036] Example 1

[0037] A method for detecting the uniformity of diaphragm coating comprises the following steps:

[0038] Step S1, cutting the membrane to be tested to obtain samples 1-1, 1-2, 2-1, 2-2, 3-1, and 3-2, and recording the weight of each sample;

[0039] Step S2, respectively placing the above samples into digestion tubes, adding solvent, nitric acid, perchloric acid, and phosphoric acid to obtain test samples 1, 2, 3, 4, 5, and 6;

[0040] Step S3, adding solvent, nitric acid, perchloric acid, and phosphoric acid to a blank digestion tube to obtain a control sample 1;

[0041] Step S4, respectively placing the test samples 1, 2, 3, 4, 5, 6 and the control sample 1 in an ultrasonic washer for ultrasonic treatment, placing them in a graphite furnace for heating, and placing them in a microwave digester for digestion to obtain a digestion solution;

[0042] Step S5: Prepare a standard solution with a concentration gradient and create a standard curve. According to the standard curve, obtain the aluminum content of test samples 1, 2, 3, 4, 5, 6 and the control sample, and calculate whether the standard deviation of the aluminum content in each sample is greater than a preset value of 0.05.

[0043] Wherein, the volume ratio of the solvent, nitric acid, perchloric acid and phosphoric acid in step S2 is 2:4:1:3.

[0044] Wherein, the concentration of nitric acid is 1 mol / L, the concentration of perchloric acid is 1 mol / L, and the concentration of phosphoric acid is 1 mol / L.

[0045] The ultrasonic treatment power is 280W and the ultrasonic treatment time is 5 minutes.

[0046] The heating temperature in the graphite furnace is 110° C., and the heating time is 60 minutes.

[0047] The digestion pressure is 4 MPa, the time is 110 minutes, and the temperature is 260°C.

[0048] Wherein, the solvent is ultrapure water.

[0049] Wherein, the weight of the sample in step S1 is 10.0000 g.

[0050] Example 2

[0051] A method for detecting the uniformity of diaphragm coating comprises the following steps:

[0052] Step S1, cutting the membrane to be tested to obtain samples 1-1, 1-2, 2-1, 2-2, 3-1, and 3-2, and recording the weight of each sample;

[0053] Step S2, respectively placing the above samples into digestion tubes, adding solvent, nitric acid, perchloric acid, and phosphoric acid to obtain test samples 1, 2, 3, 4, 5, and 6;

[0054] Step S3, adding solvent, nitric acid, perchloric acid, and phosphoric acid to a blank digestion tube to obtain a control sample 1;

[0055] Step S4, respectively placing the test samples 1, 2, 3, 4, 5, 6 and the control sample 1 in an ultrasonic washer for ultrasonic treatment, placing them in a graphite furnace for heating, and placing them in a microwave digester for digestion to obtain a digestion solution;

[0056] Step S5: Prepare a standard solution with a concentration gradient and create a standard curve. According to the standard curve, obtain the aluminum content of test samples 1, 2, 3, 4, 5, 6 and the control sample, and calculate whether the standard deviation of the aluminum content in each sample is greater than a preset value of 0.02.

[0057] Wherein, the volume ratio of the solvent, nitric acid, perchloric acid and phosphoric acid in step S2 is 2:4:2:3.

[0058] Wherein, the concentration of nitric acid is 1 mol / L, the concentration of perchloric acid is 1 mol / L, and the concentration of phosphoric acid is 1 mol / L.

[0059] The ultrasonic treatment power is 280W and the ultrasonic treatment time is 5 minutes.

[0060] The heating temperature in the graphite furnace is 110° C., and the heating time is 60 minutes.

[0061] The digestion pressure is 4 MPa, the time is 110 minutes, and the temperature is 260°C.

[0062] Wherein, the solvent is ultrapure water.

[0063] Wherein, the weight of the sample in step S1 is 10.0000 g.

[0064] Example 3

[0065] A method for detecting the uniformity of diaphragm coating comprises the following steps:

[0066] Step S1, cutting the membrane to be tested to obtain samples 1-1, 1-2, 2-1, 2-2, 3-1, and 3-2, and recording the weight of each sample;

[0067] Step S2, respectively placing the above samples into digestion tubes, adding solvent, nitric acid, perchloric acid, and phosphoric acid to obtain test samples 1, 2, 3, 4, 5, and 6;

[0068] Step S3, adding solvent, nitric acid, perchloric acid, and phosphoric acid to a blank digestion tube to obtain a control sample 1;

[0069] Step S4, respectively placing the test samples 1, 2, 3, 4, 5, 6 and the control sample 1 in an ultrasonic washer for ultrasonic treatment, placing them in a graphite furnace for heating, and placing them in a microwave digester for digestion to obtain a digestion solution;

[0070] Step S5: Prepare a standard solution with a concentration gradient and create a standard curve. According to the standard curve, obtain the aluminum content of test samples 1, 2, 3, 4, 5, 6 and the control sample, and calculate whether the standard deviation of the aluminum content in each sample is greater than a preset value of 0.06.

[0071] Wherein, the volume ratio of the solvent, nitric acid, perchloric acid and phosphoric acid in step S2 is 2:4:1:5.

[0072] Wherein, the concentration of nitric acid is 1 mol / L, the concentration of perchloric acid is 1 mol / L, and the concentration of phosphoric acid is 1 mol / L.

[0073] The ultrasonic treatment power is 280W and the ultrasonic treatment time is 5 minutes.

[0074] The heating temperature in the graphite furnace is 110° C., and the heating time is 60 minutes.

[0075] The digestion pressure is 4 MPa, the time is 110 minutes, and the temperature is 260°C.

[0076] Wherein, the solvent is ultrapure water.

[0077] Wherein, the weight of the sample in step S1 is 10.0000 g.

[0078] Example 4

[0079] A method for detecting the uniformity of diaphragm coating comprises the following steps:

[0080] Step S1, cutting the membrane to be tested to obtain samples 1-1, 1-2, 2-1, 2-2, 3-1, and 3-2, and recording the weight of each sample;

[0081] Step S2, respectively placing the above samples into digestion tubes, adding solvent, nitric acid, perchloric acid, and phosphoric acid to obtain test samples 1, 2, 3, 4, 5, and 6;

[0082] Step S3, adding solvent, nitric acid, perchloric acid, and phosphoric acid to a blank digestion tube to obtain a control sample 1;

[0083] Step S4, respectively placing the test samples 1, 2, 3, 4, 5, 6 and the control sample 1 in an ultrasonic washer for ultrasonic treatment, placing them in a graphite furnace for heating, and placing them in a microwave digester for digestion to obtain a digestion solution;

[0084] Step S5: Prepare a standard solution with a concentration gradient and create a standard curve. According to the standard curve, obtain the aluminum content of test samples 1, 2, 3, 4, 5, 6 and the control sample, and calculate whether the standard deviation of the aluminum content in each sample is greater than a preset value of 0.02.

[0085] Wherein, the volume ratio of the solvent, nitric acid, perchloric acid and phosphoric acid in step S2 is 2:5:1:3.

[0086] Wherein, the concentration of nitric acid is 1 mol / L, the concentration of perchloric acid is 1 mol / L, and the concentration of phosphoric acid is 1 mol / L.

[0087] The ultrasonic treatment power is 280W and the ultrasonic treatment time is 5 minutes.

[0088] The heating temperature in the graphite furnace is 110° C., and the heating time is 60 minutes.

[0089] The digestion pressure is 4 MPa, the time is 110 minutes, and the temperature is 260°C.

[0090] Wherein, the solvent is ultrapure water.

[0091] Wherein, the weight of the sample in step S1 is 10.0000 g.

[0092] Example 5

[0093] A method for detecting the uniformity of diaphragm coating comprises the following steps:

[0094] Step S1, cutting the membrane to be tested to obtain samples 1-1, 1-2, 2-1, 2-2, 3-1, and 3-2, and recording the weight of each sample;

[0095] Step S2, respectively placing the above samples into digestion tubes, adding solvent, nitric acid, perchloric acid, and phosphoric acid to obtain test samples 1, 2, 3, 4, 5, and 6;

[0096] Step S3, adding solvent, nitric acid, perchloric acid, and phosphoric acid to a blank digestion tube to obtain a control sample 1;

[0097] Step S4, respectively placing the test samples 1, 2, 3, 4, 5, 6 and the control sample 1 in an ultrasonic washer for ultrasonic treatment, placing them in a graphite furnace for heating, and placing them in a microwave digester for digestion to obtain a digestion solution;

[0098] Step S5: Prepare a standard solution with a concentration gradient and create a standard curve. According to the standard curve, obtain the aluminum content of test samples 1, 2, 3, 4, 5, 6 and the control sample, and calculate whether the standard deviation of the aluminum content in each sample is greater than a preset value of 0.02.

[0099] Wherein, in step S1, the volume ratio of the solvent, nitric acid, perchloric acid and phosphoric acid is 2:4:2:5.

[0100] Wherein, the concentration of nitric acid is 1 mol / L, the concentration of perchloric acid is 1 mol / L, and the concentration of phosphoric acid is 1 mol / L.

[0101] The ultrasonic treatment power is 280W and the ultrasonic treatment time is 5 minutes.

[0102] The heating temperature in the graphite furnace is 110° C., and the heating time is 60 minutes.

[0103] The digestion pressure is 4 MPa, the time is 110 minutes, and the temperature is 260°C.

[0104] Wherein, the solvent is ultrapure water.

[0105] Wherein, the weight of the sample in step S1 is 10.0000 g.

[0106] Example 6

[0107] A method for detecting the uniformity of diaphragm coating comprises the following steps:

[0108] Step S1, cutting the membrane to be tested to obtain samples 1-1, 1-2, 2-1, 2-2, 3-1, and 3-2, and recording the weight of each sample;

[0109] Step S2, respectively placing the above samples into digestion tubes, adding solvent, nitric acid, perchloric acid, and phosphoric acid to obtain test samples 1, 2, 3, 4, 5, and 6;

[0110] Step S3, adding solvent, nitric acid, perchloric acid, and phosphoric acid to a blank digestion tube to obtain a control sample 1;

[0111] Step S4, respectively placing the test samples 1, 2, 3, 4, 5, 6 and the control sample 1 in an ultrasonic washer for ultrasonic treatment, placing them in a graphite furnace for heating, and placing them in a microwave digester for digestion to obtain a digestion solution;

[0112] Step S5: Prepare a standard solution with a concentration gradient and create a standard curve. According to the standard curve, obtain the aluminum content of test samples 1, 2, 3, 4, 5, 6 and the control sample, and calculate whether the standard deviation of the aluminum content in each sample is greater than a preset value of 0.02.

[0113] Wherein, the volume ratio of the solvent, nitric acid, perchloric acid and phosphoric acid in step S1 is 2:4:2:3.

[0114] Wherein, the concentration of nitric acid is 1 mol / L, the concentration of perchloric acid is 1 mol / L, and the concentration of phosphoric acid is 1 mol / L.

[0115] The ultrasonic treatment power is 280W and the ultrasonic treatment time is 5 minutes.

[0116] The heating temperature in the graphite furnace is 90° C., and the heating time is 60 minutes.

[0117] The digestion pressure is 4 MPa, the time is 110 minutes, and the temperature is 260°C.

[0118] Wherein, the solvent is ultrapure water.

[0119] Wherein, the weight of the sample in step S1 is 10.0000 g.

[0120] Example 7

[0121] A method for detecting the uniformity of diaphragm coating comprises the following steps:

[0122] Step S1, cutting the membrane to be tested to obtain samples 1-1, 1-2, 2-1, 2-2, 3-1, and 3-2, and recording the weight of each sample;

[0123] Step S2, respectively placing the above samples into digestion tubes, adding solvent, nitric acid, perchloric acid, and phosphoric acid to obtain test samples 1, 2, 3, 4, 5, and 6;

[0124] Step S3, adding solvent, nitric acid, perchloric acid, and phosphoric acid to a blank digestion tube to obtain a control sample 1;

[0125] Step S4, respectively placing the test samples 1, 2, 3, 4, 5, 6 and the control sample 1 in an ultrasonic washer for ultrasonic treatment, placing them in a graphite furnace for heating, and placing them in a microwave digester for digestion to obtain a digestion solution;

[0126] Step S5: Prepare a standard solution with a concentration gradient and create a standard curve. According to the standard curve, obtain the aluminum content of test samples 1, 2, 3, 4, 5, 6 and the control sample, and calculate whether the standard deviation of the aluminum content in each sample is greater than a preset value of 0.02.

[0127] Wherein, the volume ratio of the solvent, nitric acid, perchloric acid and phosphoric acid in step S1 is 2:4:2:3.

[0128] Wherein, the concentration of nitric acid is 1 mol / L, the concentration of perchloric acid is 1 mol / L, and the concentration of phosphoric acid is 1 mol / L.

[0129] The ultrasonic treatment power is 280W and the ultrasonic treatment time is 5 minutes.

[0130] The heating temperature in the graphite furnace is 90° C., and the heating time is 60 minutes.

[0131] The digestion pressure is 4 MPa, the time is 110 minutes, and the temperature is 260°C.

[0132] Wherein, the solvent is ultrapure water.

[0133] Wherein, the weight of the sample in step S1 is 10.0000 g.

[0134] Example 8

[0135] A method for detecting the uniformity of diaphragm coating comprises the following steps:

[0136] Step S1, cutting the membrane to be tested to obtain samples 1-1, 1-2, 2-1, 2-2, 3-1, and 3-2, and recording the weight of each sample;

[0137] Step S2, respectively placing the above samples into digestion tubes, adding solvent, nitric acid, perchloric acid, and phosphoric acid to obtain test samples 1, 2, 3, 4, 5, and 6;

[0138] Step S3, adding solvent, nitric acid, perchloric acid, and phosphoric acid to a blank digestion tube to obtain a control sample 1;

[0139] Step S4, respectively placing the test samples 1, 2, 3, 4, 5, 6 and the control sample 1 in an ultrasonic washer for ultrasonic treatment, placing them in a graphite furnace for heating, and placing them in a microwave digester for digestion to obtain a digestion solution;

[0140] Step S5: Prepare a standard solution with a concentration gradient and create a standard curve. According to the standard curve, obtain the aluminum content of test samples 1, 2, 3, 4, 5, 6 and the control sample, and calculate whether the standard deviation of the aluminum content in each sample is greater than a preset value of 0.02.

[0141] Wherein, the volume ratio of the solvent, nitric acid, perchloric acid and phosphoric acid in step S1 is 2:4:2:3.

[0142] Wherein, the concentration of nitric acid is 1 mol / L, the concentration of perchloric acid is 1 mol / L, and the concentration of phosphoric acid is 1 mol / L.

[0143] The ultrasonic treatment power is 280W and the ultrasonic treatment time is 5 minutes.

[0144] The heating temperature in the graphite furnace is 120° C., and the heating time is 60 minutes.

[0145] The digestion pressure is 4 MPa, the time is 110 minutes, and the temperature is 260°C.

[0146] Wherein, the solvent is ultrapure water.

[0147] Wherein, the weight of the sample in step S1 is 10.0000 g.

[0148] Example 9

[0149] A method for detecting the uniformity of diaphragm coating comprises the following steps:

[0150] Step S1, cutting the membrane to be tested to obtain samples 1-1, 1-2, 2-1, 2-2, 3-1, and 3-2, and recording the weight of each sample;

[0151] Step S2, respectively placing the above samples into digestion tubes, adding solvent, nitric acid, perchloric acid, and phosphoric acid to obtain test samples 1, 2, 3, 4, 5, and 6;

[0152] Step S3, adding solvent, nitric acid, perchloric acid, and phosphoric acid to a blank digestion tube to obtain a control sample 1;

[0153] Step S4, respectively placing the test samples 1, 2, 3, 4, 5, 6 and the control sample 1 in an ultrasonic washer for ultrasonic treatment, placing them in a graphite furnace for heating, and placing them in a microwave digester for digestion to obtain a digestion solution;

[0154] Step S5: Prepare a standard solution with a concentration gradient and create a standard curve. According to the standard curve, obtain the aluminum content of test samples 1, 2, 3, 4, 5, 6 and the control sample, and calculate whether the standard deviation of the aluminum content in each sample is greater than a preset value of 0.02.

[0155] Wherein, the volume ratio of the solvent, nitric acid, perchloric acid and phosphoric acid in step S1 is 2:4:2:3.

[0156] Wherein, the concentration of nitric acid is 1 mol / L, the concentration of perchloric acid is 1 mol / L, and the concentration of phosphoric acid is 1 mol / L.

[0157] The ultrasonic treatment power is 280W and the ultrasonic treatment time is 5 minutes.

[0158] The heating temperature in the graphite furnace is 90° C., and the heating time is 60 minutes.

[0159] The digestion pressure is 4 MPa, the time is 110 minutes, and the temperature is 260°C.

[0160] Wherein, the solvent is ultrapure water.

[0161] Wherein, the weight of the sample in step S1 is 10.0000 g.

[0162] Based on the disclosure and teachings of the above description, those skilled in the art will be able to make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the above specific embodiments. Any obvious improvements, substitutions, or modifications made by those skilled in the art based on the present invention fall within the scope of protection of the present invention. In addition, although certain specific terms are used in this description, these terms are only for convenience of description and do not constitute any limitation to the present invention.

Claims

1. A method for detecting the uniformity of diaphragm coating, characterized in that: The following steps are involved: Step S1: Cut the membrane to be tested to obtain N samples to be tested, and record the weight of each sample to be tested, where N is a positive integer greater than or equal to 2; Step S2, placing the N test samples into digestion tubes, respectively, and adding a solvent, nitric acid, perchloric acid, and phosphoric acid, respectively, to obtain N test samples; Step S3, adding solvent, nitric acid, perchloric acid, and phosphoric acid to a blank digestion tube to obtain a control sample 1; Step S4: N test samples and control sample 1 are respectively placed in an ultrasonic washer for ultrasonic treatment, placed in a graphite furnace for heating, and placed in a microwave digester for digestion to obtain a digestion solution; Step S5: Prepare a standard solution with a concentration gradient and create a standard curve. According to the standard curve, obtain the aluminum content of N test samples and control sample 1, and calculate whether the standard deviation of the aluminum content in each sample and the aluminum content in the standard curve is greater than a preset value; If the aluminum content in each sample is close and the standard deviation is less than the preset value, the uniformity of the tested diaphragm is good; In step S2, the volume ratio of the solvent, nitric acid, perchloric acid and phosphoric acid is 1-5:2-6:0.2-3:2-6; the solvent is deionized water; The concentration of the nitric acid is 1 mol / L, the concentration of the perchloric acid is 1 mol / L, and the concentration of the phosphoric acid is 1 mol / L.

2. The method for detecting the uniformity of diaphragm coating according to claim 1, characterized in that: The power of the ultrasonic treatment is 250-350W, and the ultrasonic treatment time is 2-10 minutes.

3. The method for detecting the uniformity of diaphragm coating according to claim 1, characterized in that: The heating temperature in the graphite furnace is 90-130° C., and the heating time is 30-90 minutes.

4. The method for detecting the uniformity of diaphragm coating according to claim 1, characterized in that: The digestion pressure is 2-6 MPa, the time is 80-120 minutes, and the temperature is 100-400°C.

5. The method for detecting the uniformity of diaphragm coating according to claim 1, characterized in that: The weight of the sample to be tested in step S1 is 0.0100 to 30.0000 g.

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