Method for testing change of iron reduction index in glass before and after irradiation

Abstract

The application belongs to the technical field of glass testing, and discloses a method for testing the change of iron reduction index in glass before and after irradiation. 2+ Absorbance at characteristic wave bands 1055 nm and 520 nm; taking the absorbance at 520 nm in the absorption spectrum as the baseline absorbance, the relationship between the iron reduction index in the glass before and after irradiation and the product of the extinction coefficient and the total iron concentration is obtained: wherein is the iron reduction index, K Fe2+ is the product of the extinction coefficient and the total iron concentration of Fe 2+ , and cm ‑1 ; then the change rate of the iron reduction index in the glass before and after irradiation is calculated; the method can quickly calculate the iron reduction index of the glass and the change before and after irradiation.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of glass testing and relates to a method for testing the change of iron reduction index in glass before and after irradiation. BACKGROUND

[0002] Irradiated glass is a kind of glass material with changed performance after radiation treatment and is widely used in the fields of spacecraft components, nuclear waste solidification, radiation shielding and optical devices. Irradiation can cause the valence state of some overstate metal oxides in the glass to change, affecting the optical effect, structural stability and shielding performance of the glass. Iron is one of the main transition metals in the glass, and the transformation of Fe 2+ and Fe 3+ is closely related to the performance of the glass.

[0003] At present, the test of ferrous content mainly adopts chemical titration, Mossbauer spectrum analysis and spectrophotometry, but these methods have obvious deficiencies: the chemical titration method destroys the sample and has low precision, the Mossbauer spectrum device is expensive and the operation is complex, and the existing technology of spectrophotometry generally needs to pretreat the sample to be tested, for example, the o-phenanthroline method needs to generate a stable orange-red complex of Fe 2+ in a solution with pH 2-9 and o-phenanthroline, and the ferrozine method needs to form a purple complex of Fe 2+ and ferrozine (3-(2-pyridyl)-5,6-diphenyl-1,2,4-triazine), then measure the absorbance at the corresponding maximum absorption wavelength, and finally calculate the concentration according to the standard curve, but these methods have long cycle, high cost and are not non-destructive in-situ detection.

[0004] The patent with the authorized announcement number CN102004084B discloses a method for determining the content of ferrous ions and iron ions in glass, which adopts spectrophotometry to test the continuous absorbance spectrum line of the glass sample in the interval of 1100 nm to 350 nm, obtains the peak area by integrating the two regions of 370-400 nm and 520-1100 nm corresponding to Fe 2+ and Fe 3+ , and then calculates the ion concentration of Fe 2+ and Fe 3+ . Although this method greatly improves the detection efficiency, however, in view of the complex components and structure of the glass, the long wavelength band of the absorption peak 520-1100 nm will contain the absorption characteristic peak of other elements, affecting the accuracy of the result, and the integration of the peak needs artificial operations such as baseline calibration and smoothing of the spectrum peak, increasing the introduction of uncertain factors.

[0005] Therefore, it is of great significance to study a rapid, non-destructive and high-precision test method for the change of iron reduction index in glass before and after irradiation. SUMMARY

[0006] The purpose of the present application is to solve the problems existing in the prior art and provide a method for testing the change of iron reduction index in glass before and after irradiation.

[0007] To achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0008] A method for testing the change of iron reduction index in glass before and after irradiation, first, the absorption spectrum of the glass before and after irradiation in the wavelength range of 200-1300 nm is determined by a spectrophotometer, then the absorbance of Fe 2+ The absorbance at the characteristic wavelength 1055 nm in the absorption spectrum and the absorbance at 520 nm in the absorption spectrum; wherein the composition of the glass contains iron oxide;

[0009] Taking the absorbance at 520 nm in the absorption spectrum as the baseline absorbance, the relationship between the iron reduction index in the glass before and after irradiation and the product of the extinction coefficient of Fe 2+ and the total iron concentration is obtained, and the change rate of the iron reduction index in the glass before and after irradiation is calculated;

[0010] The composition of the glass contains iron oxide, and the iron element exists in the form of Fe 3+ and / or Fe 2+ When the glass is irradiated, the mutual conversion of Fe 2+ and Fe 3+ occurs, and the iron reduction index refers to the ratio of the concentration of Fe 2+ to the total iron (ΣFe) concentration;

[0011] The relationship formula of the iron reduction index and the product of the extinction coefficient of Fe 2+ and the total iron concentration: ;

[0012] Wherein, is the iron reduction index, dimensionless; is the absorbance of Fe 2+ at the characteristic wavelength 1055 nm in the absorption spectrum, dimensionless; is the absorbance at 520 nm in the absorption spectrum, dimensionless; K Fe2+ is the product of the extinction coefficient of Fe 2+ and the total iron concentration, cm -1 ; L is the thickness of the glass, cm; and are read by the absorption spectrum; L is measured by a ruler, and the measurement accuracy needs to be high, reaching 0.01 mm or higher;

[0013] The iron reduction index and the product of the extinction coefficient of Fe 2+The formula of the product of the extinction coefficient of Fe and the total iron concentration is evolved from the formula of Beer's law, which is A = -log (I / I0) = ε•c•L; wherein A is the absorbance, dimensionless, •c•L; wherein A is the absorbance, dimensionless, ε is the extinction coefficient, unit: L•mol -1 •cm -1 c is the concentration of the absorbing substance, unit: mol / L, and L is the thickness of the glass, unit: cm; in consideration of removing the baseline absorbance, the formula for calculating the concentration of Fe 2+ is as follows: ; The formula for calculating the concentration of Fe 2+ is as follows: The formula for calculating the concentration of Fe 2+ is as follows: 2+ In order to obtain the formula of the product of the extinction coefficient of Fe and the total iron concentration, the formula on both sides needs to be divided by the total iron concentration; the method of the present application is used to calculate the change rate of the iron reduction index of the glass before and after irradiation, without the need to calculate K Fe2+ ;

[0014] The reason why the absorbance at 520 nm in the absorption spectrum is taken as the baseline absorbance is as follows:

[0015] In the range from the near-infrared band 1300 nm to the ultraviolet band 200 nm, there is an absorbance caused by the interference of the baseline and the emission in each band; the baseline absorption refers to the non-specific absorption caused by the glass matrix itself (such as SiO2 network) and the inevitable trace impurities (such as OH-, trace residual transition metals); the emission includes the non-chemical factors such as environmental light scattering, surface contamination, and test instrument drift; in the prior art, the absorption spectrum of the blank sample is usually taken as the baseline absorbance of the test sample, so as to remove the interference caused by the baseline and the emission, however, the different operation methods and external factors will lead to different baseline absorbances, and the content of Fe 2+ will be deviated; the applicant finds through a large amount of experimental data that the glasses with different contents of Fe 2+ almost all show the lowest absorbance at 520 nm, so the absorbance of Fe 2+ at 520 nm is very low and can be ignored; therefore, we can draw the conclusion that the absorbance at 520 nm = the absorbance caused by the interference + the absorbance of Fe 2+ with very low content; since the present application directly records the absorbance of Fe 2+The absorbance at the characteristic wavelength 1055 nm in the absorption spectrum is not corrected by baseline (although the absorbance of the interference is different at different wavelengths, but it can be ignored), and the iron reduction index can be obtained by the evolution formula of Beer's law (the relationship formula between the iron reduction index and the product of the extinction coefficient of Fe 2+ and the total iron concentration). In summary, by the method of the present application, the blank sample does not need to be tested, the method is simpler, and the technical prejudice that the Fe 2+ concentration in the glass must be accurately obtained by testing the blank sample and performing baseline correction is overcome. Moreover, since the same absorption spectrum is used to remove the interference, rather than the absorption spectrum of the blank sample, the error after removing the interference is smaller.

[0016] The calculation method is as follows: taking the glass with an iron reduction index of 1 as a standard sample, and then substituting =1 into the relationship formula between the iron reduction index and the product of the extinction coefficient of Fe 2+ and the total iron concentration, thereby calculating Fe2+ ; wherein the content of each element in the raw material of the glass with an iron reduction index of 1 is exactly the same as that of the test sample; the glass with an iron reduction index of 1 refers to a glass containing only Fe 2+ , without Fe 3+ , at this time the iron reduction index in the glass is 1;

[0017] After calculating , substitute into the relationship formula between the iron reduction index and the product of the extinction coefficient of Fe 2+ and the total iron concentration, thereby obtaining the calculation formula of the iron reduction index of the test sample, and then the specific value of the iron reduction index can be calculated.

[0018] Compared with the formula of Beer's law, by the formula of the present application, neither the calculation of Fe2+ nor the conversion of is needed to calculate the total iron concentration, which is obtained by dividing the total iron molar amount in the raw material of the glass by the volume of the glass, and the unit is mol / L. However, by the formula of Beer's law in the prior art, both the calculation of and the conversion of to need to know the total iron concentration, and the calculation is complicated.

[0019] As a preferred technical solution:

[0020] The method for testing the change of the iron reduction index in the glass before and after irradiation as described above, the method for preparing the glass with the iron reduction index of 1 is as follows: the raw materials of the glass are placed in an atmosphere furnace with nitrogen or inert gas, heated to the melting temperature of the glass (viscosity less than 10 Pa·s), and kept at the melting temperature until the raw materials of the glass are uniformly melted, then poured into a mold and annealed in an annealing furnace until the internal stress of the glass is eliminated, thereby obtaining the glass with the iron reduction index of 1; the method for preparing the glass with the iron reduction index of 1 is different from the method for preparing the test sample in that: during the preparation of the glass with the iron reduction index of 1, nitrogen or inert gas is introduced into the atmosphere furnace to ensure that there is as little oxygen as possible in the furnace; in addition, a small amount of carbon powder can also be added when the raw materials of the glass are placed to fully react with the residual oxygen in the furnace, but the amount of carbon powder should not be too much, otherwise it will cause Fe 2+ to be reduced to form Fe single element and precipitate; the melting temperature of the glass is selected as a temperature at which the viscosity is less than 10 Pa·s, and the reference is (Glass length: Workability and meltability of glass as a function of glass melt fragility) [J]. Journal of Non-Crystalline Solids, 597 (2022) 121931.

[0021] The method for testing the change of the iron reduction index in the glass before and after irradiation as described above, the measurement range of the spectrophotometer is the wavelength interval containing 200-1300 nm, that is, the near-infrared band is not less than 1300 nm, and the ultraviolet band is not higher than 200 nm.

[0022] The method for testing the change of the iron reduction index in the glass before and after irradiation as described above, before the spectrophotometer determines the glass before and after irradiation, the glass needs to be polished on both sides to a surface roughness Ra≤0.1 μm, and the surface is free of impurities.

[0023] The method for testing the change of the iron reduction index in the glass before and after irradiation as described above, the raw materials of the glass consist of 72 wt% SiO2, 14 wt% Na2O, 13 wt% CaO and 1 wt% FeO.

[0024] The method for testing the change of the iron reduction index in the glass before and after irradiation as described above, when the raw materials of the glass consist of 72 wt% SiO2, 14 wt% Na2O, 13 wt% CaO and 1 wt% FeO, = 7.7057 cm -1 .

[0025] Advantages:

[0026] The method for testing the change of iron reduction index in glass before and after irradiation provided by the application does not need to test a blank sample, is simpler, and overcomes the common understanding in the art that a blank sample must be tested and baseline correction must be performed to accurately obtain the Fe 2+ The technical bias of the concentration, and the use of the same absorption spectrum to remove interference instead of the absorption spectrum of the blank sample, make the error after removing interference smaller. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 Absorption spectra of the glasses I-IV prepared in the application at a thickness of 1 cm;

[0028] Figure 2 Absorption spectra of the glasses I-IV prepared in the application at a thickness of 1 cm, and the Fe 2+ Linear relationship between the absorbance at the characteristic wavelength 1055 nm in the absorption spectrum and the FeO addition amount;

[0029] Figure 3 Absorption spectra of the glasses I-IV prepared in the application at a thickness of 1 cm, and the Fe 2+ Linear relationship between the absorbance at the characteristic wavelength 1055 nm in the absorption spectrum minus the absorbance at 520 nm in the absorption spectrum and the FeO addition amount; in the figure, A 1055 -A 520 represents the Fe 2+ Absorbance at the characteristic wavelength 1055 nm in the absorption spectrum minus the absorbance at 520 nm in the absorption spectrum;

[0030] Figure 4 Absorption spectra of the glasses prepared in Example 1 before and after irradiation;

[0031] Figure 5 Absorption spectra of the glasses prepared in Example 2 before and after irradiation. DETAILED DESCRIPTION

[0032] The application will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the application and not to limit the scope of the application. In addition, it should be understood that those skilled in the art can make various modifications or changes to the application after reading the content taught by the application, and these equivalent forms also fall within the scope of the appended claims of the application.

[0033] In order to verify the absorbance using A 1055 -A 520 The accuracy is better than A 1055 Now, examples are given to prove it, and the specific process is as follows:

[0034] Four glasses with different iron reduction index of 1 were prepared:

[0035] Glass I: The raw materials of the glass were placed in a nitrogen atmosphere furnace, heated to 1450°C (high temperature viscosity of 8 Pa•s) and kept until the raw materials of the glass were uniformly melted, then poured into a mold and annealed in an annealing furnace until the internal stress of the glass was eliminated, the glass was cut and polished on both sides to a surface roughness Ra of 0.1 μm, and the surface was free of impurities, thereby obtaining a glass I with an iron reduction index of 1 and a thickness of 0.303 cm; wherein the raw materials of the glass consisted of 72.98 wt% SiO2, 14 wt% Na2O, 13 wt% CaO and 0.02 wt% FeO;

[0036] Glass II: The raw materials of the glass were placed in a nitrogen atmosphere furnace, heated to 1450°C (high temperature viscosity of 8 Pa•s) and kept until the raw materials of the glass were uniformly melted, then poured into a mold and annealed in an annealing furnace until the internal stress of the glass was eliminated, the glass was cut and polished on both sides to a surface roughness Ra of 0.1 μm, and the surface was free of impurities, thereby obtaining a glass II with an iron reduction index of 1 and a thickness of 0.400 cm; wherein the raw materials of the glass consisted of 72.92 wt% SiO2, 14 wt% Na2O, 13 wt% CaO and 0.08 wt% FeO;

[0037] Glass III: The raw materials of the glass were placed in a nitrogen atmosphere furnace, heated to 1450°C (high temperature viscosity of 8 Pa•s) and kept until the raw materials of the glass were uniformly melted, then poured into a mold and annealed in an annealing furnace until the internal stress of the glass was eliminated, the glass was cut and polished on both sides to a surface roughness Ra of 0.1 μm, and the surface was free of impurities, thereby obtaining a glass III with an iron reduction index of 1 and a thickness of 0.699 cm; wherein the raw materials of the glass consisted of 72.87 wt% SiO2, 14 wt% Na2O, 13 wt% CaO and 0.13 wt% FeO;

[0038] Glass IV: The raw materials of the glass were placed in a nitrogen atmosphere furnace, heated to 1450°C (high temperature viscosity of 8 Pa•s) and kept until the raw materials of the glass were uniformly melted, then poured into a mold and annealed in an annealing furnace until the internal stress of the glass was eliminated, the glass was cut and polished on both sides to a surface roughness Ra of 0.1 μm, and the surface was free of impurities, thereby obtaining a glass IV with an iron reduction index of 1 and a thickness of 1.012 cm; wherein the raw materials of the glass consisted of 72.81 wt% SiO2, 14 wt% Na2O, 13 wt% CaO and 0.19 wt% FeO;

[0039] Under the same conditions of glass components and thickness, theoretically, without considering the influence of external interference, the FeO addition amount and Fe 2+ The absorbance at the characteristic wavelength 1055 nm in the absorption spectrum is linearly related. According to the Beer-Lambert law, the thickness is proportional to the absorbance. Since the thicknesses of the glasses I to IV are different, in order to facilitate the study, the thickness needs to be removed from the interference of the absorbance, and therefore the absorbance in the absorption spectrum of the glasses I to IV needs to be divided by the thickness of the glass, thereby obtaining the absorption spectrum of the glasses I to IV at a thickness of 1 cm as shown in FIG. 2. Figure 1

[0040] In the glass I with a thickness of 1 cm, the Fe 2+ The absorbance at the characteristic wavelength 1055 nm in the absorption spectrum A is 0.1341, and the absorbance at 520 nm in the absorption spectrum is 0.0713.

[0041] In the glass II with a thickness of 1 cm, the Fe 2+ The absorbance at the characteristic wavelength 1055 nm in the absorption spectrum is 0.4469, and the absorbance at 520 nm in the absorption spectrum is 0.0919.

[0042] In the glass III with a thickness of 1 cm, the Fe 2+ The absorbance at the characteristic wavelength 1055 nm in the absorption spectrum is 0.6704, and the absorbance at 520 nm in the absorption spectrum is 0.0791.

[0043] In the glass IV with a thickness of 1 cm, the Fe 2+ The absorbance at the characteristic wavelength 1055 nm in the absorption spectrum is 1.0854, and the absorbance at 520 nm in the absorption spectrum is 0.2224.

[0044] As can be seen from the above, with the increase of the FeO addition amount in the glass raw material formula, the Fe 2+ The absorbance at the characteristic wavelength 1055 nm in the absorption spectrum also increases.

[0045] Subsequently, the FeO addition amount in the glass raw material of the glasses I to IV and the Fe 2+ The absorbance (A 1055 ) at the characteristic wavelength 1055 nm in the absorption spectrum and the FeO addition amount in the glass raw material of the glasses I to IV are fitted, and the results are shown in FIG. 4. Figure 2 As can be seen from the figure, they are linearly related (consistent with the linear equation y=ax+b), and the fitting degree R 2 is 0.9570.

[0046] ​The FeO addition amount in the glass raw materials of the above-mentioned glasses I to IV and the Fe 2+ The absorbance at the characteristic wavelength 1055 nm in the absorption spectrum minus the absorbance at 520 nm in the absorption spectrum (A 1055 -A 520 ) is fitted, and the results are shown in Figure 3 From the figure, it can be seen that they also show a linear relationship, and the fitting degree R 2 is 0.9839;

[0047] As can be seen from the above, the absorbance at 520 nm in the absorption spectrum as the baseline absorbance can maximize the interference caused by the interference of the sample absorption and the emission, so that the fitting degree R 2 is closer to linear fitting, which can effectively reduce the error caused by the test, so as to improve the precision of the test.

[0048] Example 1

[0049] A test method for the change of iron reduction index of glass before and after irradiation, the steps are as follows:

[0050] (1) Prepare a glass with an iron reduction index of 1 (used to simulate the preparation of glass in an oxygen-free environment);

[0051] Place the raw materials of the glass in a nitrogen atmosphere furnace, heat to 1450℃ (high temperature viscosity is 8 Pa•s), and then pour into a mold and anneal in an annealing furnace until the internal stress of the glass is eliminated, that is, a glass with a thickness of 0.404 cm and an iron reduction index of 1 is obtained; wherein the raw materials of the glass consist of 72 wt% SiO2, 14 wt% Na2O, 13 wt% CaO and 1 wt% FeO;

[0052] (2) First, the glass with an iron reduction index of 1 is used as the test glass, and then both sides are polished to a surface roughness Ra of 0.1 μm, and then the absorption spectrum of the test glass before and after irradiation in the wavelength range of 200~1300 nm is measured by a spectrophotometer (as shown in Figure 4 The absorbance of Fe 2+ at the characteristic wavelength 1055 nm in the absorption spectrum is 3.3024, and the absorbance at 520 nm in the absorption spectrum is 0.1893, and the absorbance of Fe 2+ at the characteristic wavelength 1055 nm in the absorption spectrum is 3.2173, and the absorbance at 520 nm in the absorption spectrum is 0.2087; wherein the irradiation type is electron irradiation, the intensity is 10 MeV, and the fluence is 5E14 / cm 2 ;

[0053] (3) Then taking the absorbance at 520 nm in the absorption spectrum as the baseline absorbance, the relationship between the iron reduction index in the glass before and after irradiation and the product of the extinction coefficient of Fe 2+ and the total iron concentration is obtained, and the change rate of the iron reduction index in the glass before and after irradiation is calculated to be reduced by 3.36%; wherein, the relationship formula between the iron reduction index and the product of the extinction coefficient of Fe 2+ and the total iron concentration is: , wherein, is the iron reduction index, dimensionless; is the absorbance of Fe 2+ at the characteristic wavelength 1055 nm in the absorption spectrum, dimensionless; is the absorbance at 520 nm in the absorption spectrum, dimensionless; K Fe2+ is the product of the extinction coefficient of Fe 2+ and the total iron concentration, cm -1 ; L is the thickness of the glass, cm;

[0054] (4) The glass with an iron reduction index of 1 prepared in step (1) is used as a standard sample, and then =1 is substituted into the relationship formula between the iron reduction index and the product of the extinction coefficient of Fe 2+ and the total iron concentration, so that K Fe2+ =7.7057 cm -1 ;

[0055] (5) The absorbance of the glass to be tested obtained in step (2) and K Fe2+ obtained in step (4) are substituted into the relationship formula between the iron reduction index and the product of the extinction coefficient of Fe 2+ and the total iron concentration, and it is known that the iron reduction index in the glass to be tested after irradiation is 0.9664.

[0056] Example 2

[0057] A test method for the change of the iron reduction index in glass before and after irradiation, the steps are as follows:

[0058] (1) Prepare a glass to be tested;

[0059] Place the raw materials of the glass in an atmosphere furnace under an air atmosphere, heat to 1450℃ (high temperature viscosity is 8 Pa•s), and then pour into a mold and anneal in an annealing furnace until the internal stress of the glass is eliminated, thereby obtaining a glass to be tested with a thickness of 0.408 cm; wherein, the raw materials of the glass are composed of 72 wt% SiO2, 14 wt% Na2O, 13 wt% CaO and 1 wt% FeO;

[0060] (2) First, polish both sides of the glass to be tested in step (1) to a surface roughness Ra of 0.1 μm, so that the surface is free of impurities, and then measure the absorption spectrum of the glass to be tested in the wavelength range of 200-1300 nm before and after irradiation by a spectrophotometer (as shown in Figure 5 ; 2+ The absorbance at the characteristic wavelength 1055 nm in the absorption spectrum is 0.5732, and the absorbance at 520 nm in the absorption spectrum is 0.1122. After irradiation of the glass to be tested, the absorbance at the characteristic wavelength 1055 nm in the absorption spectrum is 0.6291, and the absorbance at 520 nm in the absorption spectrum is 0.1051; wherein the irradiation type is electron irradiation, the intensity is 10 MeV, and the fluence is 5E14 / cm 2+ ; 2 ;

[0061] (3) Take the absorbance at 520 nm in the absorption spectrum as the baseline absorbance, obtain the relationship between the iron reduction index in the glass before and after irradiation and the product of the extinction coefficient of Fe 2+ and the total iron concentration, and calculate the change rate of the iron reduction index in the glass before and after irradiation, which increases by 13.67%; wherein the relationship formula between the iron reduction index and the product of the extinction coefficient of Fe 2+ and the total iron concentration is: , wherein, is the iron reduction index, dimensionless; is the absorbance at the characteristic wavelength 1055 nm in the absorption spectrum of Fe 2+ , dimensionless; is the absorbance at 520 nm in the absorption spectrum, dimensionless; K Fe2+ is the product of the extinction coefficient of Fe 2+ and the total iron concentration, cm -1 ; and L is the thickness of the glass, cm.

[0062] (4) Prepare a glass with an iron reduction index of 1;

[0063] Place the glass raw material in a nitrogen atmosphere furnace, heat to 1450°C (high temperature viscosity of 8 Pa•s), and then pour into a mold and anneal in an annealing furnace until the internal stress of the glass is eliminated, thereby obtaining a glass with a thickness of 0.404 cm and an iron reduction index of 1; wherein the glass raw material consists of 72 wt% SiO2, 14 wt% Na2O, 13 wt% CaO, and 1 wt% FeO;

[0064] (5) Polishing both sides of the glass with the iron reduction index of 1 in step (4) to a surface roughness Ra of 0.1 μm, and then measuring the absorption spectrum of the glass to be tested in the wavelength range of 200-1300 nm by a spectrophotometer before and after irradiation, and recording the absorbance of Fe 2+ The absorbance at the characteristic wavelength of 1055 nm in the absorption spectrum is 3.3024, the absorbance at 520 nm in the absorption spectrum is 0.1893, and the thickness of the glass to be tested is 0.404 cm measured by a high-precision thickness measuring tool;

[0065] The glass with the iron reduction index of 1 is used as a standard sample, and then the glass to be tested is irradiated by a laser with a wavelength of 1064 nm and a power density of 0.5 W / cm2 for 30 min. =1 is substituted into the relationship formula of the iron reduction index and the product of the extinction coefficient of Fe 2 + ; Fe2+ =7.7057 cm -1 ;

[0066] (6) The absorbance of the glass to be tested obtained in step (2) and K Fe2+ obtained in step (5) are substituted into the relationship formula of the iron reduction index and the product of the extinction coefficient of Fe 2+ , and it is known that the iron reduction index of the glass to be tested before irradiation is 0.1466 and the iron reduction index of the glass to be tested after irradiation is 0.1667.

[0067] Example 3

[0068] A testing method for the change of the iron reduction index of glass before and after irradiation, comprising the following steps:

[0069] (1) Preparing a glass with an iron reduction index of 1;

[0070] Placing the raw material of the glass in a nitrogen atmosphere furnace, heating to 1550℃ (high temperature viscosity of 9 Pa•s), and then pouring into a mold and annealing in an annealing furnace until the internal stress of the glass is eliminated, thereby obtaining a glass with an iron reduction index of 1 and a thickness of 1.030 cm; wherein the raw material of the glass is composed of 63wt% SiO2, 18wt% Al2O3, 17wt% MgO, 0.15wt% FeO, 0.5wt% B2O3, 0.35wt% ZrO2, and 1.0wt% TiO2;

[0071] ​​(2) First, a glass with an iron reduction index of 1 was used as the glass to be tested. Then, both sides of the glass were polished to a surface roughness Ra of 0.1 μm to ensure that there were no impurities on the surface. Then, the absorption spectra of the glass before and after irradiation in the 200~1300 nm wavelength range were measured by spectrophotometer. Then, the Fe of the glass before irradiation was recorded. 2+ The absorbance at the characteristic wavelength of 1055 nm in the absorption spectrum is 2.4008, and the absorbance at 520 nm in the absorption spectrum is 0.1874. The Fe... 2+ The absorbance at the characteristic wavelength of 1055 nm in the absorption spectrum is 2.3686, and the absorbance at 520 nm in the absorption spectrum is 0.2628; the irradiation type is electron irradiation, the intensity is 1 MeV, and the fluence is 5E14 electrons / cm². 2 ;

[0072] (3) Then, using the absorbance at 520 nm in the absorption spectrum as the baseline absorbance, the iron reduction index and Fe in the glass before and after irradiation were obtained. 2+ The relationship between the extinction coefficient and the product of total iron concentration was used to calculate the rate of change of the iron reduction index in the glass before and after irradiation, which decreased by 4.86%. The iron reduction index was related to the product of Fe... 2+ The formula relating the extinction coefficient to the product of the total iron concentration is: In the formula, The iron reduction index is dimensionless. For Fe 2+ The absorbance at the characteristic wavelength of 1055 nm in the absorption spectrum, dimensionless; K represents the absorbance at 520 nm in the absorption spectrum, which is dimensionless; Fe2+ For Fe 2+ The product of the extinction coefficient and the total iron concentration, cm -1 L represents the glass thickness, in cm.

[0073] (4) Use the glass with an iron reduction index of 1 obtained in step (1) as a standard sample, and then... Substituting 1 into the iron reduction index and Fe 2+ The formula relating the extinction coefficient to the product of the total iron concentration is used to calculate K. Fe2+ =2.1489cm -1 ;

[0074] (5) Combine the absorbance of the glass to be tested obtained in step (2) with the K obtained in step (4). Fe2+ Introducing the iron reduction index and Fe 2+ From the formula relating the extinction coefficient to the total iron concentration, it can be seen that the iron reduction index in the glass to be tested after irradiation is 0.9514.

[0075] Example 4

[0076] A method for testing the change of iron reduction index in glass before and after irradiation, comprising the following steps:

[0077] (1) preparing the glass to be tested;

[0078] Placing the raw materials of the glass in an atmosphere furnace under an air atmosphere, heating to 1550°C (high temperature viscosity of 9 Pa•s), and then pouring into a mold and annealing in an annealing furnace until the internal stress of the glass is eliminated, thereby obtaining the glass to be tested with a thickness of 0.997 cm; wherein the raw materials of the glass are composed of 63wt% SiO2, 18wt% Al2O3, 17wt% MgO, 0.15wt% FeO, 0.5wt% B2O3, 0.35wt% ZrO2, and 1.0wt% TiO2;

[0079] (2) polishing both sides of the glass to be tested in step (1) to a surface roughness Ra of 0.1 μm, then measuring the absorption spectrum of the glass to be tested before and after irradiation in the wavelength range of 200-1300 nm by a spectrophotometer, and then recording the absorbance of Fe 2+ in the absorption spectrum at a characteristic wavelength of 1055 nm is 0.5499, and the absorbance in the absorption spectrum at 520 nm is 0.1059, and the absorbance of Fe 2+ in the absorption spectrum at a characteristic wavelength of 1055 nm is 0.5752, and the absorbance in the absorption spectrum at 520 nm is 0.1093; wherein the irradiation type is electron irradiation, the intensity is 1 MeV, and the fluence is 5E14 / cm 2 ;

[0080] (3) taking the absorbance at 520 nm in the absorption spectrum as the baseline absorbance, obtaining the relationship between the iron reduction index in the glass before and after irradiation and the product of the extinction coefficient of Fe 2+ and the total iron concentration, and calculating the change rate of the iron reduction index in the glass before and after irradiation to be increased by 4.93%; wherein the relationship formula between the iron reduction index and the product of the extinction coefficient of Fe 2+ and the total iron concentration is: , wherein, is the iron reduction index, dimensionless; is the absorbance of Fe 2+ at a characteristic wavelength of 1055 nm in the absorption spectrum, dimensionless; is the absorbance at 520 nm in the absorption spectrum, dimensionless; K Fe2+ is the product of the extinction coefficient of Fe 2+ and the total iron concentration, cm -1L is the thickness of the glass, cm;

[0081] (4) preparing a glass with an iron reduction index of 1;

[0082] The raw materials of the glass are placed in a nitrogen atmosphere furnace, heated to 1550°C (high temperature viscosity of 9 Pa•s), and then poured into a mold and annealed in an annealing furnace until the internal stress of the glass is eliminated, thereby obtaining a glass with an iron reduction index of 1; wherein the raw materials of the glass consist of 63wt% SiO2, 18wt% Al2O3, 17wt% MgO, 0.15wt% FeO, 0.5wt% B2O3, 0.35wt% ZrO2, and 1.0wt% TiO2;

[0083] (5) The glass with an iron reduction index of 1 obtained in step (4) is polished on both sides to a surface roughness Ra of 0.1 μm, and then the absorption spectrum of the glass to be measured before and after irradiation is measured in the wavelength range of 200-1300 nm by a spectrophotometer, and the Fe 2+ The absorbance at 1055 nm in the absorption spectrum is 2.4008, the absorbance at 520 nm in the absorption spectrum is 0.1874, and the thickness of the glass to be measured is 1.030 cm measured by a high-precision thickness measuring tool;

[0084] The above glass with an iron reduction index of 1 is used as a standard sample, and then the =1 is substituted into the relationship formula between the iron reduction index and the product of the extinction coefficient of Fe 2 + Fe2+ =2.1489 cm -1 .

[0085] (6) The absorbance of the glass to be measured obtained in step (2) and the K Fe2+ obtained in step (5) are substituted into the relationship formula between the iron reduction index and the product of the extinction coefficient of Fe 2+ , and it is known that the iron reduction index of the glass to be measured before irradiation is 0.2072, and the iron reduction index of the glass to be measured after irradiation is 0.2175.​

Claims

1. A method for testing the change in the iron reduction index in a glass before and after irradiation, characterized in that, First, the absorption spectrum of the glass before and after irradiation in the wavelength range of 200-1300 nm is determined by a spectrophotometer, and then the Fe 2+ The absorbance at the characteristic wavelength 1055 nm in the absorption spectrum and the absorbance at 520 nm in the absorption spectrum; wherein the composition of the glass comprises iron oxide; The relationship between the iron reduction index in the glass before and after irradiation and the product of the extinction coefficient of Fe 2+ at 520 nm in the absorption spectrum and the total iron concentration was obtained using the absorbance at 520 nm in the absorption spectrum as the baseline absorbance, and the change rate of the iron reduction index in the glass before and after irradiation was calculated; Iron reduction index is the ratio of Fe2+ to total Fe concentration in the glass 2+ concentration to total iron concentration; Iron reduction index and the product of the extinction coefficient of Fe 2+ and total iron concentration: ; in, The iron reduction index is dimensionless. For Fe 2+ The absorbance at the characteristic wavelength of 1055 nm in the absorption spectrum, dimensionless; K represents the absorbance at 520 nm in the absorption spectrum, which is dimensionless; Fe2+ For Fe 2+ The product of the extinction coefficient and the total iron concentration, cm -1 L represents the glass thickness, in cm. The calculation method is as follows: taking the glass with the iron reduction index of 1 as a standard sample, then substituting the iron reduction index of 1 into the relationship formula of the iron reduction index and the product of the extinction coefficient of Fe 2+ Fe2+ ; wherein the content of each element in the raw material of the glass with the iron reduction index of 1 is completely same as that of the test sample.​​ 2. The method for testing the change of iron reduction index in glass before and after irradiation according to claim 1, characterized in that, The method for preparing the glass having the iron reduction index of 1 is as follows: placing raw materials of the glass in an atmosphere furnace into which nitrogen or inert gas is introduced, heating to the melting temperature of the glass, keeping the temperature until the raw materials of the glass are uniformly melted, then pouring into a mold and annealing in an annealing furnace until the internal stress of the glass is eliminated, thereby obtaining the glass having the iron reduction index of 1.

3. The method for testing the change of iron reduction index in glass before and after irradiation according to claim 1, characterized in that, The measurement range of the spectrophotometer is a wavelength interval containing 200-1300 nm.

4. The method for testing the change of iron reduction index in glass before and after irradiation according to claim 1, characterized in that, The raw materials of the glass consist of 72 wt% SiO2, 14 wt% Na2O, 13 wt% CaO and 1 wt% FeO.

5. The method for testing the change of iron reduction index in glass before and after irradiation according to claim 4, characterized in that, When the raw material of the glass consists of 72 wt% Si02, 14 wt% Na20, 13 wt% CaO and 1 wt% FeO, = 7.7057 cm -1 .

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