Online measuring method of self clean glass contact angle

[0042] Example 1: On-line measurement for on-line production of self-cleaning glass:

[0043]The following are the test results of the same batch of production samples measured using the present invention and other existing methods:

[0044] A total of three groups of 100mm × 100mm samples were taken from the same original float glass sheet in the production line, and the number of each group was the same for comparative experiments.

[0045] 1) the first group is tested by the method of the present invention;

[0046] The relative humidity in the test room is 50%±5%, the humidity variation range is ±2%, and the temperature is 23±1℃. The test method adopts the hanging drop method, and the calculation method adopts the θ/2 method. This group uses SL series contact angle tester to measure, the SL series contact angle tester adopts the analysis system as CAST software system, the software system is installed in the computer, and then the contact angle tester is connected with the computer.

[0047] A: Scrub the above-mentioned sample numbered with absorbent cotton and tap water repeatedly until there is no visible dirt, then rinse with deionized water for 3-5 minutes, and irradiate it with a 500W UV lamp with a central wavelength of 365nm in a temperature-controlled light box for 1 hour. Move to a dust-free cooling box to cool for later use.

[0048] B. Adjust the bottom platform of the tester and the sample stage to the horizontal position, adjust the focal length and brightness of the optical system, and then adjust the height of the sample stage, so that the sample boundary line coincides with the boundary line in the computer testing system.

[0049] C Inject 20μl of deionized water into the autosampler, as shown in Figure 3, at a vertical distance of 50mm from the center 1 to the four sides 2 of the 100mm×100mm sample, take four points respectively as test points 3 for testing, each time The injection volume was 2 μl.

[0050] D records the results of each measurement, calculated by the θ/2 method, and depends on the average of 4 times as the final test result. The principle of the θ/2 method is shown in Figure 4. L1 is the tangent 1, L2 is the tangent 2, L3 is the liquid-solid interface line, h is the height of the spherical cap formed by the spread of the droplet on the solid surface, and r is the diameter of the droplet, then

[0051] θ=2×θ1

[0052] Tanθ1=h/r

[0053] θ=2×tan (-1) (h/r)

[0054] The CAST software system installed in the computer can automatically measure the values ​​of h and r (the values ​​are not shown in detail), and obtain the value of θ through automatic calculation, see Table 1, and record the test results twice for each group.

[0055] ERepeat B-D to test other samples.

[0056] 2) The second group, applying the existing technology test:

[0057] The temperature was controlled at 25°C, and the relative temperature was controlled at 65%. The static drop method was used.

[0058] A: Rinse the above-mentioned samples with deionized water and absolute ethanol, then wipe them with absorbent cotton, rinse them with deionized water for 3-5 minutes, dry them in an oven at 100°C for 30 minutes, let them stand for 2 hours, and then Irradiate for 1 hour with an 18W UV lamp with a center wavelength of 365nm.

[0059] B. Place the static sample horizontally on the sample holder in the sealed box in the reactor, adjust the distance between the UV lamp and the magnetic test to 10cm, close and seal all the doors and holes of the reactor, and cover it with a black flannel Reactor, turn on the UV lamp, and irradiate the sample for 90 minutes.

[0060] C Connect the contact angle meter to the reactor and then to the computer, and then turn on the power of the contact angle meter. Place the UV-irradiated sample on the contact angle meter platform and number the sample.

[0061] D. Use a micro-syringe to drip water droplets at 4 different positions on the surface of the sample, and use a contact angle meter to measure the contact angles of water at the above 4 different positions on the sample surface. The computer displays and records the results of each measurement, and takes the average of 4 times. value as the final test result.

[0062] E Repeat B-D to test other samples. The test results are shown in Table 1.

[0063] 3) The third group, simulating the actual working conditions of self-cleaning glass:

[0064] Compared with the first group, this group of experimental steps only changed the illumination mode to sunlight, the illumination time was changed to 50 hours, and other operations remained unchanged.

[0065] order

[0066] It can be seen from the test results that the results of the first group and the third group are the closest, that is, the hydrophilic angle obtained by the test method of the present invention is closer to the hydrophilic angle of the self-cleaning glass under actual use conditions, while The hydrophilic angle measured in the second group has a large deviation. The cleaning and drying process of the sample has a greater impact on the experimental results, and this process is also the longest time-consuming process. No practical significance in online production.

[0067] Example 2: Testing the contact angle of superhydrophilic self-cleaning glass using the method of the present invention.

[0068] The contact angle of the super-hydrophilic self-cleaning glass is very small, also called the hydrophilic angle, which is generally less than or equal to 3°. When the contact angle measured by a general contact angle tester is less than or equal to 3°, it is difficult to use the general test method. Accurate measurement; and the measurement method of the present invention is also relatively accurate in the measurement result of this situation, and the error is less than 1°. The following is the application of the present invention in testing the hydrophilic angle test of super-hydrophilic self-cleaning glass:

[0069] In the test of the hydrophilic angle of the superhydrophilic film layer, there is no need to make any adjustment in operation. The measurement results are shown in Table 2, which records the two measurement results.

[0070] order

[0071] It can be seen from the test results that the result measured by the method of the present invention is very close to 3°, so it is more accurate, and it can be proved that the method of the present invention is also suitable for testing the hydrophilic angle of superhydrophilic self-cleaning glass.