Preparation method of ternary copolymerized oxygen sensing microspheres

Abstract

The invention provides a preparation method of a ternary copolymerized oxygen sensing microsphere, which comprises the following steps: selecting styrene (St), trifluoroethyl methacrylate (TFEMA) and butyl acrylate (BA) with different volume ratios as copolymer monomers, platinum octaethylporphyrin (PtOEP) as an indicator, azodiisobutyronitrile (AIBN) as an initiator and lauryl sodium sulfate (SDS) as an emulsifier, and preparing the ternary copolymerized oxygen sensing microsphere by using a hydrothermal method. The preparation method comprises the following steps: preparing a terpolymer microsphere emulsion with oxygen sensing performance, and then changing the proportion content of styrene (St), trifluoroethyl methacrylate (TFEMA) and butyl acrylate (BA) so as to prepare terpolymer microsphere emulsions with different volume ratios. Finally, the optimal volume ratio of styrene (St) to trifluoroethyl methacrylate (TFEMA) to butyl acrylate (BA) is obtained by testing different properties of the ternary copolymerized oxygen sensing microspheres.

Description

Technical Field

[0001] The invention relates to the technical field of optical sensors, and in particular to a method for preparing ternary copolymerized oxygen sensing microspheres. Background Art

[0002] Oxygen is an element closely related to life, widely present in the atmosphere, water and the earth's crust. It plays an important role in the survival of humans, animals and plants and in the process of social development. It has different applications in different fields. For example, in the field of environmental monitoring, the quality of water is directly reflected in the value of oxygen content. The reduction of oxygen content indicates that the water body is polluted by some organic substances. In clinical medicine, the value of biochemical oxygen demand can reflect the metabolism and growth of microorganisms or some aerobic cells. The detection of oxygen concentration has been widely used in disease diagnosis. A lower oxygen saturation concentration in the blood indicates that the patient may suffer from chronic obstructive pulmonary disease. In the field of food industry, the presence of oxygen will directly affect the taste and shelf life of products such as beer and beverages, so the oxygen content needs to be accurately detected and strictly controlled. Therefore, the study of a new type of oxygen sensing material with high sensitivity, good accuracy and strong stability is of great significance in environmental monitoring, clinical medicine, aquaculture, food industry, marine science and biochemical engineering.

[0003] For example, the patent document with Chinese patent application number 201711367610.5 and announcement date of May 17, 2019, discloses a method for preparing a colorimetric fluorescent microsphere emulsion based on octaethylporphyrin platinum and its application in an optical oxygen sensing microfluidic detection chip. The preparation method is as follows: polydimethylsiloxane, methyl methacrylate, trifluoroethyl methacrylate and butyl acrylate are mixed, octaethylporphyrin platinum and coumarin 6 are added, and then an initiator, an emulsifier and ultrapure water are added, and a miniemulsion polymerization is carried out at a temperature of 55 to 65°C, and then a reflux reaction is carried out after ultrasonic treatment, and a PtOEP / PDMS optical oxygen sensing microfluidic detection chip is prepared by the copolymer emulsion.

[0004] The above-mentioned document is based on the principle that dissolved oxygen can quench the phosphorescence emitted by the indicator octaethylporphyrin platinum, and the colorimetric fluorescent microspheres are prepared. However, since the colorimetric fluorescent microspheres are formed by simply mixing four monomers and stirring them during the preparation process, the formed mixture cannot have a certain induction effect on oxygen, and the oxygen sensitivity needs to be tested in the subsequent detection process, resulting in poor test results. In addition, methyl methacrylate among the four monomers is soluble in water, and is easily affected by different external environments, resulting in inconvenience in use, thereby affecting the detection accuracy of oxygen concentration. Summary of the invention

[0005] The purpose of the present invention is to provide a method for preparing ternary copolymer oxygen sensing microspheres. The prepared copolymer emulsion has the advantages of high sensitivity, short response time, good stability and wide application range, and the Stern-Volmer oxygen content calibration equation of the copolymer emulsion has high linear correlation, so that the oxygen concentration can be accurately measured.

[0006] To achieve the above object, the present invention provides a method for preparing ternary copolymer oxygen sensing microspheres, comprising the following steps: S1 presets the set temperature of the constant temperature water bath, and after reaching the set temperature, connects the circulating water circuit of the reactor, adds an appropriate amount of ultrapure water to the reactor, adjusts the speed of the reactor, and introduces nitrogen into the reactor at the same time; S2 Add 1 mL of 0.0090 g / mL emulsifier sodium dodecyl sulfate (SDS) into the reactor and stir evenly; S3: Initiator azobisisobutyronitrile (AIBN) and indicator octaethylporphyrin platinum (PtOEP) are uniformly dispersed in a ternary monomer mixture formed by mixing three monomers of styrene (St), trifluoroethyl methacrylate (TFEMA) and butyl acrylate (BA) in a volume ratio of 4:8:1-16, and then uniformly mixed by ultrasonication; the mass ratio of indicator octaethylporphyrin platinum (PtOEP) to emulsifier sodium dodecyl sulfate (SDS) is 1:50-150, and the mass ratio of indicator octaethylporphyrin platinum (PtOEP) to initiator azobisisobutyronitrile (AIBN) is 1:80-180; S4: adding the mixed solution in step S3 into a reactor, passing nitrogen, stirring evenly, and then placing the reactor in an ice water bath for ultrasonication; S5: nitrogen is passed through to allow the mixed solution in step S4 to react for 24 h at a preset temperature, thereby obtaining a ternary copolymer oxygen sensing microsphere emulsion; S6 obtained the optimal volume ratio of styrene (St), trifluoroethyl methacrylate (TFEMA) and butyl acrylate (BA) by testing the different properties of ternary copolymer oxygen sensor microspheres, including oxygen measurement sensitivity and accuracy, and stability testing; S7 According to S5, the optimal volume ratio of styrene (St), trifluoroethyl methacrylate (TFEMA) and butyl acrylate (BA) was determined to specify the ternary copolymer oxygen sensing microsphere emulsion.

[0007] In the above setting, styrene (St), trifluoroethyl methacrylate (TFEMA) and butyl acrylate (BA) in different volume ratios were selected as copolymer monomers, octaethylporphyrin platinum (PtOEP) was used as an indicator, azobisisobutyronitrile (AIBN) was used as an initiator, and sodium dodecyl sulfate (SDS) was used as an emulsifier to prepare a ternary copolymer microsphere emulsion with oxygen sensing performance. Styrene plays a cross-linking role. Styrene has a benzene ring, which increases the stability of the polymer. Trifluoroethyl methacrylate makes the formed fluorinated polymer have excellent thermal stability and light stability. In addition, the fluorine atom has a strong affinity to oxygen. The induction effect can effectively enhance the oxygen measurement sensitivity of the material; the strong hydrophobicity of the fluorinated polymer can improve the sensor's ability to resist interference from the external environment, thereby ensuring stability in dealing with the external environment. In addition, during the reaction process, nitrogen is first introduced to prevent the substances produced during the stirring process from reacting with oxygen, thereby ensuring the stability of the stirred product. The optimal volume ratio is determined through performance testing based on the different volume ratios of the three, thereby selecting the volume ratio of the ternary monomer mixture. In this way, the obtained ternary copolymer oxygen sensor microspheres have good oxygen measurement sensitivity and high accuracy, good stability, fast response speed, and a wide range of applications.

[0008] Furthermore, step S1 includes: setting the temperature of the thermostatic water bath to 80° C., adjusting the rotation speed of the reactor to 300-400 rpm, and introducing nitrogen into the reactor for 15 min.

[0009] The above settings can ensure the reliability of stirring and mixing at a certain speed.

[0010] Furthermore, step S2 includes: adding 1 mL of an emulsifier sodium dodecyl sulfate (SDS) with a concentration of 0.0090 g / mL into the reaction kettle, and stirring evenly for 15 min.

[0011] The above setting ensures emulsification and miscibility by adding an emulsifier in the same setting.

[0012] Furthermore, step S4 includes adding the mixed solution in step S3 to the reactor, passing nitrogen for 15 minutes, stirring uniformly at a rotation speed range of 300-400 rpm for 30 minutes, and then placing the reactor in an ice water bath for ultrasonication for 10 minutes.

[0013] The above arrangement ensures the reliability of mixing by first stirring the object at a certain rotation speed and then performing ultrasonic stirring.

[0014] Furthermore, the mass ratio of the ultrapure water to the ternary monomer mixture is 1:(100-200).

[0015] Furthermore, the mass ratio of the indicator platinum octaethylporphyrin (PtOEP) to the ternary monomer mixture is 1:100-300.

[0016] Furthermore, the temperature was set to 80°C. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a flow chart of the working method of the present invention.

[0018] Figure 2 Figure 2 is a particle size diagram of the ternary copolymer oxygen sensing microspheres with different volume ratios in (a) to (f) of the present invention.

[0019] Figure 3 Fluorescence microscope images of ternary copolymer oxygen sensing microspheres with different volume ratios in (a) to (f) of the present invention.

[0020] Figure 4 The zeta potential diagram of the ternary copolymer oxygen sensor microspheres with different volume ratios in the present invention.

[0021] Figure 5 This is a diagram of the quenching ratio of the ternary copolymer oxygen sensing microspheres with different volume ratios in the present invention.

[0022] Figure 6 It is a quenching curve diagram of the luminescence intensity and oxygen content of the ternary copolymer oxygen sensor microspheres with different volume ratios in the present invention.

[0023] Figure 7 It is a Stern-Volmer equation curve diagram of the ternary copolymer oxygen sensing microspheres with different volume ratios in the present invention.

[0024] Figure 8 This is a cyclic stability curve of the ternary copolymer oxygen sensor microspheres in the present invention.

[0025] Fig. 9 This is a photostability curve of the ternary co-polymerized oxygen sensing microspheres of the present invention.

[0026] Fig.10 This is a pH stability curve of the ternary copolymer oxygen sensor microspheres in the present invention. DETAILED DESCRIPTION

[0027] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] like Figure 1 As shown, a method for preparing ternary copolymer oxygen sensing microspheres comprises the following specific steps: S1 presets the set temperature of the constant temperature water bath. After reaching the set temperature, the circulating water circuit of the reactor is connected, and an appropriate amount of ultrapure water is added to the reactor. The speed of the reactor is adjusted to 300-400 rpm, and nitrogen is introduced into the reactor for 15 min. S2 Add 1 mL of 0.0090 g / mL emulsifier sodium dodecyl sulfate (SDS) into the reactor and stir evenly; S3: Initiator azobisisobutyronitrile (AIBN) and indicator octaethylporphyrin platinum (PtOEP) are uniformly dispersed in a ternary monomer mixture formed by mixing three monomers of styrene (St), trifluoroethyl methacrylate (TFEMA) and butyl acrylate (BA) in a volume ratio of 4:8:1-16, and then uniformly mixed by ultrasonication; the mass ratio of indicator octaethylporphyrin platinum (PtOEP) to emulsifier sodium dodecyl sulfate (SDS) is 1:50-150, and the mass ratio of indicator octaethylporphyrin platinum (PtOEP) to initiator azobisisobutyronitrile (AIBN) is 1:80-180; S4: adding the mixed solution in step S3 into a reactor, passing nitrogen, stirring evenly, and then placing the reactor in an ice water bath for ultrasonication; S5: nitrogen is passed through to allow the mixed solution in step S4 to react for 24 h at a preset temperature, thereby obtaining a ternary copolymer oxygen sensing microsphere emulsion; S6 obtained the optimal volume ratio of styrene (St), trifluoroethyl methacrylate (TFEMA) and butyl acrylate (BA) by testing the different properties of ternary copolymer oxygen sensor microspheres, including oxygen measurement sensitivity and accuracy, and stability testing; S7 The optimal volume ratio of styrene (St), trifluoroethyl methacrylate (TFEMA) and butyl acrylate (BA) was obtained according to S5 to specify the ternary tool oxygen sensing microsphere emulsion.

[0029] Example 1.

[0030] A method for preparing ternary copolymer oxygen sensing microspheres comprises the following specific steps: S1 sets the temperature of the thermostatic water bath to 80°C. After reaching the set temperature, connect the circulating water circuit of the reactor, add an appropriate amount of ultrapure water to the reactor, adjust the speed of the reactor to 300-400 rpm, and introduce nitrogen into the reactor for 15 min. S2 Add 1 mL of 0.0090 g / mL emulsifier sodium dodecyl sulfate (SDS) into the reactor and stir evenly for 15 min; S3: 1 mL of initiator azobisisobutyronitrile (AIBN) with a concentration of 0.0090 g / mL and 0.0030 g of indicator platinum octaethylporphyrin (PtOEP) were uniformly dispersed in 0.80 g of a ternary monomer mixture solution formed by mixing three monomers of styrene (St), trifluoroethyl methacrylate (TFEMA) and butyl acrylate (BA) in a volume ratio of 4:8:1-16, and then mixed uniformly by ultrasonication for 2 min; S4: adding the mixed solution in step S3 to the reactor, passing nitrogen for 15 min, stirring evenly at a speed range of 300-400 rpm for 30 min, and then placing the reactor in an ice water bath for ultrasonic treatment for 10 min; S5: nitrogen was passed through for 15 min, and the mixed solution in step S4 was reacted at 80° C. for 24 h, and then a ternary copolymer oxygen sensing microsphere emulsion was prepared; S6 obtained the optimal volume ratio of styrene (St), trifluoroethyl methacrylate (TFEMA) and butyl acrylate (BA) by testing the different properties of ternary copolymer oxygen sensor microspheres. The volume ratio of the three was set to 4:8:1, 4:8:2, 4:8:4, 4:8:8, 4:8:12, and 4:8:16.

[0031] S7 The optimal volume ratio of styrene (St), trifluoroethyl methacrylate (TFEMA) and butyl acrylate (BA) was obtained according to S5 to specify the ternary tool oxygen sensing microsphere emulsion.

[0032] Since the volume ratios of the three monomers of styrene (St), trifluoroethyl methacrylate (TFEMA) and butyl acrylate (BA) in the ternary monomer mixture are different, ternary copolymer oxygen sensing microspheres formed by different volume ratios of styrene (St), trifluoroethyl methacrylate (TFEMA) and butyl acrylate (BA) are obtained. In this embodiment, the different volume ratios of styrene (St), trifluoroethyl methacrylate (TFEMA) and butyl acrylate (BA) include (a) to (f), as follows: (a) Styrene (St): trifluoroethyl methacrylate (TFEMA): butyl acrylate (BA) = 4:8:1, (b) Styrene (St): trifluoroethyl methacrylate (TFEMA): butyl acrylate (BA) = 4:8:2, (c) Styrene (St): trifluoroethyl methacrylate (TFEMA): butyl acrylate (BA) = 4:8:4, (d) Styrene (St): trifluoroethyl methacrylate (TFEMA): butyl acrylate (BA) = 4:8:8, (e) Styrene (St): trifluoroethyl methacrylate (TFEMA): butyl acrylate (BA) = 4:8:12, (f) Styrene (St): trifluoroethyl methacrylate (TFEMA): butyl acrylate (BA) = 4:8:16.

[0033] The different properties of the ternary copolymer oxygen sensing microspheres tested in step S5 are as follows: Test the particle size of the ternary copolymer oxygen sensor microspheres, such as Figure 2 As shown in the figure, the ternary copolymer oxygen sensing microspheres with different volume ratios in (a)~(f) all have a relatively regular spherical structure with a particle size range of 150 nm-180 nm and good monodispersity. Among them, the ternary copolymer oxygen sensing microspheres formed with a volume ratio of styrene (St): trifluoroethyl methacrylate (TFEMA): butyl acrylate (BA) of 4:8:2 in (a) have the largest particle size of 180 nm.

[0034] Test the absolute value of the potential of the ternary copolymer oxygen sensor microspheres, such as Figure 3 As shown in Figure 2, the absolute values ​​of the Zeta potential of the ternary copolymer oxygen sensing microspheres with different volume ratios in (a) to (f) are all above 60 mV, indicating that the ternary copolymer oxygen sensing microspheres with different volume ratios in (a) to (f) have high stability and are not prone to agglomeration or precipitation. Figure 3 It can be seen that the ternary copolymer oxygen sensor microspheres formed by the volume ratio of styrene (St): trifluoroethyl methacrylate (TFEMA): butyl acrylate (BA) of 4:8:4 in (c) have the highest absolute value of Zeta potential, with a Zeta potential value of -74.6 mV. Therefore, the ternary copolymer oxygen sensor microspheres formed by the volume ratio of styrene (St): trifluoroethyl methacrylate (TFEMA): butyl acrylate (BA) of 4:8:4 have the best stability.

[0035] In this embodiment, the particle size and the absolute value of the potential of the ternary copolymer oxygen sensor microspheres are measured by a Zeta potential tester. The Zeta potential tester is a prior art and will not be described in detail here.

[0036] The surface morphology characteristics of the ternary copolymer oxygen sensing microspheres with different volume ratios in (a) to (f) were obtained by scanning electron microscopy (SEM). Figure 2 As shown, the white area represents the luminescent molecules, and it can be seen that the indicator platinum octaethylporphyrin (PtOEP) has been encapsulated into the interior of the ternary copolymer oxygen sensing microspheres, resulting in a larger luminescence intensity. Figure 2It can be seen that the ternary copolymer oxygen sensing microspheres formed with a volume ratio of styrene (St) : trifluoroethyl methacrylate (TFEMA) : butyl acrylate (BA) of 4:8:4 in (c) have the highest luminescence intensity and the best dispersion.

[0037] The quenching ratios of the ternary copolymer oxygen sensing microspheres with different volume ratios in tests (a) to (f) are as follows: Figure 5 As shown, it can be concluded that the quenching ratio of the ternary copolymer oxygen sensing microspheres formed by the volume ratio of styrene (St) : trifluoroethyl methacrylate (TFEMA) : butyl acrylate (BA) in (c) is 4:8:4 is the largest, which is 8.92. Therefore, the sensitivity of the ternary copolymer oxygen sensing microspheres formed by the volume ratio of styrene (St) : trifluoroethyl methacrylate (TFEMA) : butyl acrylate (BA) in (c) is the highest.

[0038] The luminescence intensity curves of the ternary copolymer oxygen sensing microspheres with different volume ratios in tests (a) to (f) under different oxygen volume fraction conditions, such as Figure 6 As shown, it can be concluded that the luminescence intensity of the ternary copolymer oxygen sensor microspheres formed by the volume ratio of styrene (St) : trifluoroethyl methacrylate (TFEMA) : butyl acrylate (BA) of 4:8:4 in (c) decreased to a certain extent with the increase of oxygen content, and the quenching phenomenon was more obvious, indicating that the ternary copolymer oxygen sensor microspheres formed by the volume ratio of styrene (St) : trifluoroethyl methacrylate (TFEMA) : butyl acrylate (BA) of 4:8:4 in (c) have high sensitivity to oxygen molecules.

[0039] The Stern-Volmer linear regression equation was fitted by the least squares method, and the calibration curves between the luminescence intensity and oxygen content of the ternary copolymer oxygen sensor microspheres with different volume ratios in (a) to (f) were obtained by fitting, as shown in Figure 2. Figure 7 As shown, it can be concluded that the Stern-Volmer equation of the ternary copolymer oxygen sensing microspheres formed by the volume ratio of styrene (St): trifluoroethyl methacrylate (TFEMA): butyl acrylate (BA) of 4:8:4 in (c) has the highest linear correlation and the best test accuracy.

[0040] Combined with the particle size, potential absolute value, luminescence intensity and quenching ratio of the above-mentioned ternary copolymer oxygen sensor microspheres, it was concluded that the optimal volume ratio of styrene (St), trifluoroethyl methacrylate (TFEMA) and butyl acrylate (BA) in the preparation of ternary copolymer oxygen sensor microspheres is 4:8:4, which is the volume ratio of styrene (St), trifluoroethyl methacrylate (TFEMA) and butyl acrylate (BA) in (c).

[0041] After obtaining the optimal volume ratio of styrene (St), trifluoroethyl methacrylate (TFEMA) and butyl acrylate (BA), the cyclic stability curve of the ternary copolymer oxygen sensing microspheres with a volume ratio of styrene (St): trifluoroethyl methacrylate (TFEMA): butyl acrylate (BA) of 4:8:4 in test (c) was shown. Figure 8 As shown, it can be concluded that after 4 alternating cycle tests, the luminescence intensity retention rate of the ternary copolymer oxygen sensing microspheres in (c) is about 99.2%, which has good reproducibility; at the same time, the response speed is also fast, and the quenching time and recovery time are 14 s and 220 s respectively, which meets the application requirements.

[0042] The photostability of the ternary copolymer oxygen sensing microspheres with a volume ratio of styrene (St): trifluoroethyl methacrylate (TFEMA): butyl acrylate (BA) of 4:8:4 in test (c) was tested. Fig. 9 As shown in (c), after continuous irradiation of the excitation light source for 3 h, the luminescence intensity attenuation ratio of the ternary copolymer oxygen sensor microspheres with different volume ratios was about 0.04%, showing good photostability, indicating that the ternary copolymer oxygen sensor microspheres effectively protected the indicator octaethylporphyrin platinum (PtOEP), overcame the photobleaching problem, and exhibited good light resistance.

[0043] In test (c), the sensitivity of the ternary copolymer oxygen sensing microspheres with a volume ratio of styrene (St): trifluoroethyl methacrylate (TFEMA): butyl acrylate (BA) of 4:8:4 in buffer solutions with different pH values ​​was tested. In this embodiment, the pH values ​​of the different buffer solutions were pH=2, pH=4, pH=7, pH=10, and pH=12, respectively. Fig.10 As shown in (c), the ternary copolymer oxygen sensing microspheres with different volume ratios showed high sensitivity in acid-base buffer solutions with different pH values, the maximum quenching ratio remained basically consistent, and the maximum error value was ±0.02, indicating that it had good acid-base stability and was applicable in the range of pH=2-12. Therefore, when the external solvent environment changed, it still had good sensitivity to oxygen molecules and the response ability remained basically consistent.

[0044] Example 2.

[0045] In the preparation method of the ternary copolymer oxygen sensing microspheres of this embodiment, the mass ratio of the ultrapure water to the ternary monomer mixture is 1:100, the mass ratio of the indicator octaethylporphyrin platinum (PtOEP) to the ternary monomer mixture is 1:100, the mass ratio of the indicator octaethylporphyrin platinum (PtOEP) to the emulsifier sodium dodecyl sulfate (SDS) is 1:50, and the mass ratio of the indicator octaethylporphyrin platinum (PtOEP) to the initiator azobisisobutyronitrile (AIBN) is 1:80.

[0046] Example 3.

[0047] In the preparation method of the ternary copolymer oxygen sensing microspheres of this embodiment, the mass ratio of the ultrapure water to the ternary monomer mixture is 1:150, the mass ratio of the indicator octaethylporphyrin platinum (PtOEP) to the ternary monomer mixture is 1:200, the mass ratio of the indicator octaethylporphyrin platinum (PtOEP) to the emulsifier sodium dodecyl sulfate (SDS) is 1:100, and the mass ratio of the indicator octaethylporphyrin platinum (PtOEP) to the initiator azobisisobutyronitrile (AIBN) is 1:130.

[0048] Example 4.

[0049] In the preparation method of the ternary copolymer oxygen sensing microspheres of this embodiment, the mass ratio of the ultrapure water to the ternary monomer mixture is 1:200, the mass ratio of the indicator octaethylporphyrin platinum (PtOEP) to the ternary monomer mixture is 1:300, the mass ratio of the indicator octaethylporphyrin platinum (PtOEP) to the emulsifier sodium dodecyl sulfate (SDS) is 1:150, and the mass ratio of the indicator octaethylporphyrin platinum (PtOEP) to the initiator azobisisobutyronitrile (AIBN) is 1:180.

[0050] The working principle of the present invention is as follows: styrene (St), trifluoroethyl methacrylate (TFEMA) and butyl acrylate (BA) in different volume ratios are selected as copolymer monomers, octaethylporphyrin platinum (PtOEP) is used as an indicator, azobisisobutyronitrile (AIBN) is used as an initiator, and sodium dodecyl sulfate (SDS) is used as an emulsifier to prepare a ternary copolymer microsphere emulsion with oxygen sensing performance, and then the proportion content of styrene (St), trifluoroethyl methacrylate (TFEMA) and butyl acrylate (BA) is changed to prepare ternary copolymer microsphere emulsions with different volume ratios, and finally the optimal volume ratio of styrene (St), trifluoroethyl methacrylate (TFEMA) and butyl acrylate (BA) is obtained by testing the different properties of the ternary copolymer oxygen sensing microspheres.

Claims

1. A method for preparing ternary copolymer oxygen sensor microspheres, characterized in that: The following steps are involved: S1 presets the set temperature of the constant temperature water bath. After reaching the set temperature, the circulating water circuit of the reactor is connected, and an appropriate amount of ultrapure water is added to the reactor. The speed of the reactor is adjusted to 300-400 rpm, and nitrogen is introduced into the reactor for 15 minutes. S2 Add 1 mL of 0.0090 g / mL emulsifier sodium dodecyl sulfate (SDS) into the reactor and stir evenly; S3: Initiator azobisisobutyronitrile (AIBN) and indicator octaethylporphyrin platinum (PtOEP) are uniformly dispersed in a ternary monomer mixture formed by mixing three monomers of styrene (St), trifluoroethyl methacrylate (TFEMA) and butyl acrylate (BA) in a volume ratio of 4:8:1-16, and then uniformly mixed by ultrasonication; the mass ratio of indicator octaethylporphyrin platinum (PtOEP) to emulsifier sodium dodecyl sulfate (SDS) is 1:50-150, and the mass ratio of indicator octaethylporphyrin platinum (PtOEP) to initiator azobisisobutyronitrile (AIBN) is 1:80-180; S4: adding the mixed solution in step S3 into a reactor, passing nitrogen, stirring evenly, and then placing the reactor in an ice water bath for ultrasonication; S5: nitrogen is passed through to allow the mixed solution in step S4 to react for 24 h at a preset temperature, thereby obtaining a ternary copolymer oxygen sensing microsphere emulsion; S6 obtained the optimal volume ratio of styrene (St), trifluoroethyl methacrylate (TFEMA) and butyl acrylate (BA) by testing the different properties of ternary copolymer oxygen sensor microspheres, including oxygen measurement sensitivity and accuracy, and stability testing; S7 The optimal volume ratio of styrene (St), trifluoroethyl methacrylate (TFEMA) and butyl acrylate (BA) was obtained according to S5 to specify the ternary tool oxygen sensing microsphere emulsion.

2. The method for preparing ternary copolymer oxygen sensing microspheres according to claim 1, characterized in that: Step S2 includes: adding 1 mL of an emulsifier sodium dodecyl sulfate (SDS) with a concentration of 0.0090 g / mL into a reaction kettle, and stirring evenly for 15 minutes.

3. The method for preparing the ternary copolymer oxygen sensing microspheres according to claim 1, characterized in that: Step S4 includes adding the mixed solution in step S3 to the reactor, passing nitrogen for 15 minutes, stirring uniformly at a rotation speed range of 300-400 rpm for 30 minutes, and then placing the reactor in an ice water bath for ultrasonication for 10 minutes.

4. The method for preparing ternary copolymer oxygen sensing microspheres according to claim 1, characterized in that: The mass ratio of the ultrapure water to the ternary monomer mixed liquid is 1:(100-200).

5. The method for preparing ternary copolymer oxygen sensing microspheres according to claim 1, characterized in that: The mass ratio of the indicator platinum octaethylporphyrin (PtOEP) to the ternary monomer mixed solution is 1:100-300.

6. The method for preparing ternary copolymer oxygen sensing microspheres according to claim 1, characterized in that: Set the temperature to 80°C.

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