Polystyrene microsphere turbidity liquid and preparation method thereof, turbidity calibration liquid

Abstract

The present invention provides a polystyrene microsphere turbidity liquid, a preparation method thereof, and a turbidity calibration liquid. The polystyrene microsphere turbidity liquid comprises surface-modified polystyrene microspheres, which have cross-linked polystyrene microspheres as cores, fluorine-containing acrylate copolymers as shells, and the surface of the fluorine-containing acrylate copolymers contains hydrophilic ammonium groups. The high light-resistance stability of the fluorine-containing ester coated on the surface of the polystyrene microspheres is utilized to avoid aging, oxidation, and yellowing of the polystyrene microspheres, thereby improving the stability of the polystyrene microspheres. The organic ammonium ions on the surface of the fluorine-containing acrylate give the polystyrene microspheres a positive charge and an antibacterial function, thereby preventing the polystyrene microsphere turbidity liquid from producing sticky bacteria during long-term storage, thereby preventing the turbidity liquid microspheres from settling due to the generation of sticky bacteria, having a positive charge, generating repulsion, and having good hydrophilicity to reduce aggregation and sedimentation, thereby ensuring the stability of the polystyrene microsphere turbidity liquid. The polystyrene microsphere turbidity liquid does not contain irritating substances and toxic substances, and therefore has high safety.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, and in particular to a polystyrene microsphere turbidity liquid and a preparation method thereof, and a turbidity calibration liquid. Background Art

[0002] Turbidity calibration fluid is usually prepared from high turbidity substances and is used to calibrate and calibrate turbidimeters. Turbidity is an important indicator for measuring water clarity and is widely used in water quality monitoring, environmental protection and other fields. Turbidity calibration fluid is a substance used to calibrate and calibrate turbidimeters. Its accuracy and reliability are crucial to ensure the accuracy of water quality monitoring.

[0003] At present, the Formazine standard solution prepared by the method specified in the international standard ISO 7072 "Measurement of Turbidity of Water Quality" is widely used internationally. my country currently uses the Formazine turbidity standard material with a standard value of 400NTU developed by the National Standard Material Research Center. The Formazine turbidity standard solution is a milky white suspension generated by the reaction of hydrazine sulfate aqueous solution and hexamethylenetetramine aqueous solution at a certain temperature. The Formazine turbidity standard solution has the problems of needing to be protected from light, stored in a refrigerated environment, and has harsh transportation and use conditions, is easily degraded, and has poor stability. Its synthetic raw materials, hydrazine sulfate, are highly toxic, and hexamethylenetetramine is carcinogenic, which are very harmful to the human body. In addition, Formazine has the following shortcomings as a turbidity measurement standard: (1) The suspended particles are irregular in shape, and the particle size and distribution are difficult to control; (2) Formazine is an uneven suspension system. Due to the large particle size and fast sedimentation rate, the particles will settle after being placed for a period of time, resulting in a huge concentration difference; (3) Formazine is an unstable suspension system and needs to be shaken when used. The turbidity value is significantly affected by human factors; (4) The value is prone to change during storage and the stability is poor, especially at low turbidity (≤100NTU), the repeatability is poor and the stability is extremely poor. It must be prepared before use.

[0004] Polystyrene density 1.05g / cm 3 , which is very close to water, and the polystyrene microspheres settle slowly. However, there are still some problems. The microspheres aggregate and settle for a long time, resulting in a decrease in turbidity value. When the concentration is high, the light absorption of the microspheres becomes non-negligible, making it difficult to approach 4000NTU, and the calibration error of high turbidity is large. Summary of the invention

[0005] The purpose of the present invention is to provide a polystyrene microsphere turbidity liquid with good stability and safety and a preparation method thereof, as well as a turbidity calibration liquid prepared using the polystyrene microsphere turbidity liquid. The polystyrene microspheres are stabilized by the technology of the present invention and can be used for calibration in the full turbidity range for a long time, greatly reducing the calibration cost.

[0006] In order to solve the above technical problems, the present invention provides a polystyrene microsphere turbidity liquid, comprising surface-modified polystyrene microspheres, wherein the surface-modified polystyrene microspheres have cross-linked polystyrene microspheres as cores and fluorinated acrylate copolymers as shells, and the fluorinated acrylate copolymers have hydrophilic ammonium groups on their surfaces.

[0007] In one embodiment, the particle size of the surface modified polystyrene microspheres is 400-800 nm.

[0008] In one embodiment, the feed ratio for synthesizing the surface modified polystyrene microspheres is, by weight, 100 parts of styrene, 1 to 10 parts of a cross-linking monomer, 0.01 to 5 parts of a hydrophilic monomer, 1 to 10 parts of a fluorine-containing acrylate, 0.5 to 5 parts of an initiator and 2000 to 20000 parts of deionized water.

[0009] In one embodiment, the fluorine-containing acrylate includes at least one of perfluoroalkyl acrylate, perfluoroalkyl (meth)acrylate, partially fluorinated alkyl acrylate, and partially fluorinated alkyl (meth)acrylate.

[0010] In one embodiment, the hydrophilic monomer includes at least one of methacryloyloxyethyltrimethylammonium chloride and (3-acrylamidopropyl)trimethylammonium chloride.

[0011] In one embodiment, the molecular formula of the cross-linking monomer includes at least two unsaturated double bonds;

[0012] The cross-linking monomer includes at least one of styrene, ethylene glycol diacrylate, trimethylolpropane triacrylate, glycerol triacrylate, and pentaerythritol triacrylate; and / or,

[0013] The initiator includes at least one of potassium persulfate and ammonium persulfate.

[0014] The present invention also provides a method for preparing a polystyrene microsphere turbidity liquid, comprising the following steps:

[0015] In parts by weight, 100 parts of styrene, 1 to 10 parts of a crosslinking monomer, 0.01 to 5 parts of a hydrophilic monomer, 1 to 10 parts of a fluorine-containing acrylate, 0.5 to 5 parts of an initiator and 2000 to 20000 parts of deionized water are weighed; the fluorine-containing acrylate comprises at least one of perfluoroalkyl acrylate, perfluoroalkyl (meth)acrylate, partially fluorinated alkyl acrylate and partially fluorinated alkyl (meth)acrylate;

[0016] 0.01 to 0.5 parts of the hydrophilic monomer, the styrene, the initiator and the deionized water are mixed to obtain a first mixed solution, a protective gas is introduced into the first mixed solution, and the mixture is reacted at 70 to 80° C. for 6 to 8 hours under stirring conditions to obtain a first prepolymer mixed solution; the first prepolymer mixed solution contains hydrophilic polystyrene microspheres;

[0017] Adding the crosslinking monomer, the remaining hydrophilic monomer and the fluorine-containing acrylate to the first prepolymer mixture, and continuing to react at 70-80° C. for 18-24 hours under protective gas and stirring;

[0018] After the reaction was completed, the mixture was cooled to room temperature to obtain a polystyrene microsphere turbidity solution.

[0019] In one embodiment, the styrene is purified by a basic alumina column and then mixed with the hydrophilic monomer;

[0020] The cross-linking monomer is purified by a basic alumina column and then added to the first prepolymer mixture;

[0021] The fluorine-containing acrylate is purified by a basic alumina column and then added to the first prepolymerization mixed liquid; and / or the protective gas includes nitrogen or argon.

[0022] The present invention also provides a turbidity calibration solution, which is prepared by diluting the polystyrene microsphere turbidity solution as described above or the polystyrene microsphere turbidity solution prepared above with deionized water to obtain a turbidity calibration solution with a turbidity of 1-4000 NTU.

[0023] In one embodiment, the polystyrene microsphere turbidity solution is diluted with deionized water at a ratio of 30 to 30,000.

[0024] It can be seen from the above technical solution that the advantages and positive effects of the present invention are:

[0025] The polystyrene microsphere turbidity liquid of the present invention utilizes the high light resistance stability of the fluorinated acrylate coated on the surface of the polystyrene microspheres to avoid the aging, oxidation and yellowing of the polystyrene microspheres, improve the stability of the polystyrene microspheres, and make the turbidity reach 4000NTU. The organic ammonium ions on the surface of the fluorinated acrylate make the polystyrene microspheres have a positive charge and have an antibacterial function, thereby preventing the polystyrene microsphere turbidity liquid from producing sticky bacteria during long-term storage and causing the turbidity liquid microspheres to settle. The positive charge produces repulsion, and the good hydrophilicity reduces aggregation and sedimentation, thereby ensuring the stability of the polystyrene microsphere turbidity liquid. The polystyrene microsphere turbidity liquid does not contain irritating substances and toxic substances, so it is highly safe.

[0026] The preparation method of the present invention is simple, easy to operate, and worthy of being vigorously promoted. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic flow chart of the method for preparing the polystyrene microsphere turbidity liquid in the present invention.

[0028] Figure 2 It is a comparison chart of the long-term stability of the embodiment of the present invention and comparative examples 1 and 2. DETAILED DESCRIPTION

[0029] Although the present invention can be easily embodied in different forms of embodiments, only some of the specific embodiments are shown in the drawings and will be described in detail in this specification. It should be understood that this description should be regarded as an exemplary illustration of the principles of the invention and is not intended to limit the invention to that described herein.

[0030] Thus, a feature indicated in this specification will be used to illustrate one of the features of an embodiment of the present invention, rather than implying that each embodiment of the present invention must have the described feature. In addition, it should be noted that this specification describes many features. Although some features can be combined together to illustrate possible system designs, these features can also be used in other combinations that are not explicitly described. Thus, unless otherwise stated, the described combinations are not intended to be limiting.

[0031] In the embodiments shown in the drawings, the indications of directions (such as up, down, left, right, front and back) used to explain the structure and movement of various elements of the present invention are not absolute but relative. These descriptions are appropriate when these elements are in the positions shown in the drawings. If the description of the positions of these elements changes, the indications of these directions also change accordingly.

[0032] In conjunction with the accompanying drawings, some embodiments of the present application are described in detail below. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0033] The invention provides a polystyrene microsphere turbidity liquid, which meets the accuracy requirements, has good stability, is harmless to human health, and has a convenient and simple preparation process.

[0034] The polystyrene microsphere turbidity liquid comprises surface-modified polystyrene microspheres, wherein the surface-modified polystyrene microspheres have cross-linked polystyrene microspheres as cores and fluorine-containing acrylate copolymers as shells, and the surface of the fluorine-containing acrylate copolymers contains hydrophilic ammonium groups.

[0035] The particle size of the surface modified polystyrene microspheres is 400-800 nm.

[0036] Specifically, in parts by weight, the feed ratio for synthesizing surface modified polystyrene microspheres is 100 parts of styrene, 1 to 10 parts of crosslinking monomers, 0.01 to 5 parts of hydrophilic monomers, 1 to 10 parts of fluorine-containing acrylates, 0.5 to 5 parts of initiators and 2000 to 20000 parts of deionized water.

[0037] Styrene, crosslinking monomer, hydrophilic monomer, fluorine-containing acrylate and initiator react together to form the surface-modified polystyrene microspheres with polystyrene microspheres as cores and fluorine-containing acrylate as shells.

[0038] Specifically, the structural formula of styrene is

[0039] The crosslinking monomer contains at least two unsaturated double bonds in its molecular formula.

[0040] The cross-linking monomer includes at least one of styrene, ethylene glycol diacrylate, trimethylolpropane triacrylate, glycerol triacrylate, and pentaerythritol triacrylate. That is, the cross-linking monomer can be any one of styrene, ethylene glycol diacrylate, trimethylolpropane triacrylate, glycerol triacrylate, and pentaerythritol triacrylate, or any two, or any three, or other monomers, which are selected according to actual needs.

[0041] The cross-linking monomer can make the particles of polystyrene microspheres relatively stable and prevent aggregation between the particles.

[0042] The initiator includes at least one of potassium persulfate and ammonium persulfate. That is, the initiator can be any one of potassium persulfate and ammonium persulfate or a mixture of the two.

[0043] The sulfate groups after the initiator splits are adsorbed around the polymer, and the electrostatic repulsion keeps the system stable.

[0044] The hydrophilic monomer includes at least one of methacryloyloxyethyl trimethyl ammonium chloride and (3-acrylamide propyl) trimethyl ammonium chloride. That is, the hydrophilic monomer can be any one of methacryloyloxyethyl trimethyl ammonium chloride and (3-acrylamide propyl) trimethyl ammonium chloride or a mixture of the two.

[0045] The structural formula of methacryloyloxyethyl trimethylammonium chloride is

[0046] The structural formula of (3-acrylamidopropyl)trimethylammonium chloride is

[0047] The fluorine-containing acrylate includes at least one of perfluoroalkyl acrylate, perfluoroalkyl (meth)acrylate, partially fluorinated alkyl acrylate, and partially fluorinated alkyl (meth)acrylate. That is, the fluorine-containing acrylate can be any one of perfluoroalkyl acrylate, perfluoroalkyl (meth)acrylate, partially fluorinated alkyl acrylate, and partially fluorinated alkyl (meth)acrylate, or any two of them, or any three or more of them.

[0048] Perfluoroalkyl acrylate and perfluoroalkyl (meth)acrylate refer to alkyl groups in which all hydrogen atoms are replaced by fluorine atoms. Partially fluorinated alkyl acrylate and partially fluorinated alkyl (meth)acrylate refer to alkyl groups in which part of hydrogen atoms are replaced by fluorine atoms.

[0049] The perfluoroalkyl acrylate is exemplified by perfluoroundecyl acrylate.

[0050] The structural formula of perfluoroundecyl acrylate is

[0051] Perfluoroalkyl (meth)acrylates are exemplified by perfluoroalkylethyl methacrylate, hexafluorobutyl methacrylate, trifluoroethyl methacrylate, and 2,2,3,3,3-pentafluoropropyl methacrylate.

[0052] The structural formula of perfluoroalkylethyl methacrylate is

[0053] The structural formula of hexafluorobutyl methacrylate is

[0054] The structural formula of trifluoroethyl methacrylate is

[0055] The structural formula of 2,2,3,3,3-pentafluoropropyl methacrylate is

[0056] The partially fluorinated alkyl acrylates are exemplified by 2,2,3,4,4,4-hexafluorobutyl acrylate and 1,1,1,3,3,3-hexafluoroisopropyl acrylate.

[0057] The structural formula of 2,2,3,4,4,4-hexafluorobutyl acrylate is

[0058] The structural formula of 1,1,1,3,3,3-hexafluoroisopropyl acrylate is

[0059] The partially fluorinated alkyl (meth)acrylate is exemplified by 2,2,3,3-tetrafluoropropyl acrylate.

[0060] The structural formula of 2,2,3,3-tetrafluoropropyl acrylate is

[0061] The structural formulas of fluorinated acrylate and hydrophilic monomer both contain carbon-carbon double bonds, and both are monomers that can be copolymerized into high molecular weight. Fluorinated acrylate is on the surface of styrene balls due to its lipophilicity and hydrophobicity. It can wrap the styrene microspheres. The hydrophilic monomer contains organic ammonium ions, which are positively charged and have good hydrophilicity. One end of the hydrophilic monomer is bonded to the fluorinated acrylate, and the other end forms a hydrogen bond with the water molecule, so that the hydrophilic ammonium ion group modifies the surface of the polystyrene microspheres.

[0062] Among them, the fluoroacrylate monomer has good compatibility with styrene resin and poor compatibility with water. Therefore, the fluoroacrylate monomer is first grafted onto the surface of the styrene prepolymer, and there is a cross-linking monomer to form a chemical bond to cross-link and solidify the core-shell. The hydrophilic group ammonium ion combines with the styrene molecule to form a long arm, which is always on the outermost layer.

[0063] The high light resistance stability of the fluorinated ammonium salt coated on the surface of the polystyrene microspheres is utilized to avoid the phenomenon that the polystyrene microspheres absorb light and cause oxidation and yellowing, and the absorption of light makes it difficult for the turbidity to reach 4000NTU, thereby improving the stability of the polystyrene microspheres. The organic ammonium ions on the surface of the fluorinated acrylate have antibacterial functions, thereby preventing the polystyrene microsphere turbidity liquid from producing sticky bacteria and causing the turbidity liquid to settle and have poor transparency after long-term storage, thereby ensuring the stability of the polystyrene microsphere turbidity liquid. The organic ammonium ions provide positive charges, so that the polystyrene microspheres are all positively charged, which repels each other from the polystyrene microspheres, thereby reducing the sedimentation caused by agglomeration.

[0064] See also Figure 1 The present invention also provides a method for preparing a polystyrene microsphere turbidity liquid, comprising the following steps:

[0065] S1. In parts by weight, weigh 100 parts of styrene, 1 to 10 parts of a cross-linking monomer, 0.01 to 5 parts of a hydrophilic monomer, 1 to 10 parts of a fluorine-containing acrylate, 0.5 to 5 parts of an initiator and 2000 to 20000 parts of deionized water; the fluorine-containing acrylate comprises at least one of perfluoroalkyl acrylate, perfluoroalkyl (meth)acrylate, partially fluorinated alkyl acrylate and partially fluorinated alkyl (meth)acrylate.

[0066] Specifically, the styrene, the crosslinking monomer, the hydrophilic monomer, the fluorine-containing acrylate and the initiator can all be referred to the above description.

[0067] S2. 0.01-0.5 parts of a hydrophilic monomer, styrene, an initiator and deionized water are mixed to obtain a first mixed solution, protective gas is introduced into the first mixed solution, and the mixture is reacted at 70-80° C. for 6-8 hours under stirring to obtain a first prepolymer mixed solution.

[0068] Specifically, the protective gas includes nitrogen or argon.

[0069] In this step, the first prepolymerization mixed liquid contains hydrophilic polystyrene microspheres.

[0070] S3. Add the crosslinking monomer, the remaining hydrophilic monomer and the fluorine-containing acrylate to the first prepolymer mixture, and continue to react at 70-80° C. for 18-24 hours under the condition of protective gas and stirring.

[0071] Specifically, in this step, an emulsion polymerization reaction occurs and a milky white liquid is obtained.

[0072] S4. After the reaction is completed, cool to room temperature to obtain a polystyrene microsphere turbidity solution.

[0073] Preferably, before performing step S2, ie before performing the reaction, styrene is purified by passing through a basic alumina column and then mixed with the hydrophilic monomer.

[0074] Before the reaction, the cross-linking monomer is purified by a basic alumina column and then added to the first prepolymerization mixture.

[0075] Before the reaction, the fluorinated acrylate is purified by a basic alumina column and then added to the first prepolymerization mixture.

[0076] The present invention also provides a turbidity calibration solution, which is prepared by diluting the polystyrene microsphere turbidity solution with deionized water to obtain a turbidity calibration solution with a turbidity of 1-4000 NTU.

[0077] Specifically, the polystyrene microsphere turbidity liquid is diluted with water in a ratio of 30 to 30,000. The dilution here may be a weight ratio of the polystyrene microsphere turbidity liquid to water of 30 to 30,000.

[0078] The turbidity calibration solution of the present application is obtained by diluting the polystyrene microsphere turbidity solution, and the high light resistance stability of the fluorinated acrylate coated on the surface of the polystyrene microsphere is utilized to avoid the polystyrene microsphere from oxidizing and yellowing due to light exposure, thereby improving the stability of the polystyrene microsphere. The fluorinated ammonium salt includes organic ammonium ions, which have antibacterial function, thereby avoiding the phenomenon that the polystyrene microsphere turbidity solution produces sticky bacteria during long-term storage, resulting in the sedimentation of the turbidity solution and poor transparency, thereby ensuring the stability of the polystyrene microsphere turbidity solution.

[0079] Polystyrene microsphere turbidity liquid does not contain irritating and toxic substances, so it is highly safe.

[0080] The inventors of the present application have achieved the stability and safety of the polystyrene microsphere turbidity liquid by strictly designing the content of each component and the parameters in each step. The method is described below through various embodiments.

[0081] Example 1

[0082] The polystyrene microsphere turbidity liquid comprises surface-modified polystyrene microspheres, wherein the surface-modified polystyrene microspheres have polystyrene microspheres as cores and fluorine-containing acrylate copolymers as shells, and the surface of the fluorine-containing acrylate copolymers contains hydrophilic ammonium groups.

[0083] The polystyrene microsphere turbidity liquid includes, by weight, 100 parts of styrene, 0.01 parts of hydrophilic monomer methacryloyloxyethyl trimethyl ammonium chloride, 1 part of cross-linking monomer styrene, 1 part of perfluoroalkyl acrylate, 0.5 parts of initiator potassium persulfate and 2000 parts of deionized water.

[0084] The preparation method of polystyrene microsphere turbidity liquid comprises the following steps:

[0085] S11. In parts by weight, weigh 100 parts of styrene, 0.01 parts of hydrophilic monomer methacryloyloxyethyl trimethylammonium chloride, 1 part of crosslinking monomer styrene, 1 part of perfluoroalkyl acrylate, 0.5 parts of initiator potassium persulfate and 2000 parts of deionized water.

[0086] S12, mixing styrene, 0.01 parts of a hydrophilic monomer, an initiator and water to obtain a first mixed solution, introducing protective nitrogen gas into the first mixed solution, and reacting at 70° C. for 8 hours under stirring to obtain a first prepolymer mixed solution.

[0087] Specifically, before the reaction in this step, styrene is purified by a basic alumina column and then mixed with the hydrophilic monomer.

[0088] S13, adding crosslinking monomer styrene and 1 part of perfluoroalkyl acrylate to the first prepolymer mixture, and continuing to react at 80° C. for 24 hours under protective gas and stirring conditions.

[0089] S14. After the reaction is completed, cool to room temperature to obtain a polystyrene microsphere turbidity solution.

[0090] Example 2

[0091] The polystyrene microsphere turbidity liquid comprises surface-modified polystyrene microspheres, wherein the surface-modified polystyrene microspheres have polystyrene microspheres as cores and fluorine-containing acrylate copolymers as shells, and the surface of the fluorine-containing acrylate copolymers contains hydrophilic ammonium groups.

[0092] The polystyrene microsphere turbidity liquid includes, by weight, 100 parts of styrene, 2 parts of hydrophilic monomer (3-acrylamidopropyl) trimethylammonium chloride, 2 parts of cross-linking monomer ethylene glycol diacrylate, 2 parts of (meth) acrylate perfluoroalkyl ester, 2 parts of initiator ammonium persulfate and 20,000 parts of deionized water.

[0093] The preparation method of polystyrene microsphere turbidity liquid comprises the following steps:

[0094] S21. In parts by weight, weigh 100 parts of styrene, 2 parts of hydrophilic monomer (3-acrylamidopropyl)trimethylammonium chloride, 2 parts of cross-linking monomer ethylene glycol diacrylate, 2 parts of perfluoroalkyl (meth)acrylate, 2 parts of initiator ammonium persulfate and 20,000 parts of deionized water.

[0095] S22, mixing styrene, 0.5 parts of a hydrophilic monomer, an initiator and water to obtain a first mixed solution, introducing protective nitrogen gas into the first mixed solution, and reacting at 70° C. for 8 hours under stirring to obtain a first prepolymer mixed solution.

[0096] Specifically, before the reaction in this step, styrene is purified by a basic alumina column and then mixed with the hydrophilic monomer.

[0097] S23, adding 2 parts of cross-linking monomer ethylene glycol diacrylate, 1.5 parts of hydrophilic monomer and 2 parts of perfluoroalkyl (meth)acrylate to the first prepolymer mixture, and continuing to react at 80° C. for 24 hours under protective gas and stirring.

[0098] S24. After the reaction is completed, cool to room temperature to obtain a polystyrene microsphere turbidity solution.

[0099] Example 3

[0100] The polystyrene microsphere turbidity liquid comprises surface-modified polystyrene microspheres, wherein the surface-modified polystyrene microspheres have polystyrene microspheres as cores and fluorine-containing acrylate copolymers as shells, and the surface of the fluorine-containing acrylate copolymers contains hydrophilic ammonium groups.

[0101] The polystyrene microsphere turbidity liquid comprises, by weight, 100 parts of styrene, 3 parts of hydrophilic monomer methacryloyloxyethyl trimethylammonium chloride, 3 parts of crosslinking monomer trimethylolpropane triacrylate, 3 parts of partially fluorinated alkyl acrylate, 3 parts of initiator potassium persulfate and 10,000 parts of deionized water.

[0102] The preparation method of polystyrene microsphere turbidity liquid comprises the following steps:

[0103] S31. In parts by weight, weigh 100 parts of styrene, 3 parts of hydrophilic monomer methacryloyloxyethyl trimethylammonium chloride, 3 parts of crosslinking monomer trimethylolpropane triacrylate, 3 parts of partially fluorinated alkyl acrylate, 3 parts of initiator potassium persulfate and 10,000 parts of deionized water.

[0104] S32, mixing styrene, 0.2 parts of hydrophilic monomer, initiator and water to obtain a first mixed solution, introducing protective nitrogen gas into the first mixed solution, and reacting at 80° C. for 6 hours under stirring to obtain a first prepolymer mixed solution.

[0105] Specifically, before the reaction in this step, styrene is purified by a basic alumina column and then mixed with the hydrophilic monomer.

[0106] S33, adding a crosslinking monomer, 2.8 parts of a hydrophilic monomer and 3 parts of a fluorine-containing acrylate to the first prepolymer mixture, and continuing to react at 70° C. for 18 hours under protective gas and stirring.

[0107] S34. After the reaction is completed, cool to room temperature to obtain a polystyrene microsphere turbidity solution.

[0108] Example 4

[0109] The polystyrene microsphere turbidity liquid comprises surface-modified polystyrene microspheres, wherein the surface-modified polystyrene microspheres have polystyrene microspheres as cores and fluorine-containing acrylate copolymers as shells, and the surface of the fluorine-containing acrylate copolymers contains hydrophilic ammonium groups.

[0110] The polystyrene microsphere turbidity liquid comprises, by weight, 100 parts of styrene, 4 parts of hydrophilic monomer methacryloyloxyethyl trimethylammonium chloride, 4 parts of cross-linking monomer glycerol triacrylate, 4 parts of (meth)acrylic acid partially fluorinated alkyl ester, 4 parts of initiator potassium persulfate and 5000 parts of deionized water.

[0111] The preparation method of polystyrene microsphere turbidity liquid comprises the following steps:

[0112] S41. In parts by weight, weigh 100 parts of styrene, 4 parts of hydrophilic monomer methacryloyloxyethyl trimethylammonium chloride, 4 parts of cross-linking monomer glycerol triacrylate, 4 parts of (meth)acrylic acid partially fluorinated alkyl ester, 4 parts of initiator potassium persulfate and 5000 parts of deionized water.

[0113] S42, mixing styrene, 0.2 parts of hydrophilic monomer, initiator and water to obtain a first mixed solution, introducing protective nitrogen gas into the first mixed solution, and reacting at 75° C. for 8 hours under stirring to obtain a first prepolymer mixed solution.

[0114] Specifically, before the reaction in this step, styrene is purified by a basic alumina column and then mixed with the hydrophilic monomer.

[0115] S43, adding a cross-linking monomer, 3.8 parts of a hydrophilic monomer and a fluorine-containing acrylate to the first prepolymer mixture, and continuing to react at 80° C. for 20 hours under protective gas and stirring.

[0116] S44. After the reaction is completed, cool to room temperature to obtain a polystyrene microsphere turbidity solution.

[0117] Example 5

[0118] The polystyrene microsphere turbidity liquid comprises surface-modified polystyrene microspheres, wherein the surface-modified polystyrene microspheres have polystyrene microspheres as cores and fluorine-containing acrylate copolymers as shells, and the surface of the fluorine-containing acrylate copolymers contains hydrophilic ammonium groups.

[0119] The polystyrene microsphere turbidity liquid includes, by weight, 100 parts of styrene, 5 parts of hydrophilic monomer methacryloyloxyethyl trimethyl ammonium chloride, 10 parts of crosslinking monomer pentaerythritol triacrylate, 10 parts of perfluoroalkyl acrylate, 5 parts of initiator ammonium persulfate and 15,000 parts of deionized water.

[0120] The preparation method of polystyrene microsphere turbidity liquid comprises the following steps:

[0121] S51, in parts by weight, 100 parts of styrene, 5 parts of hydrophilic monomer methacryloyloxyethyl trimethyl ammonium chloride, 10 parts of crosslinking monomer pentaerythritol triacrylate, 10 parts of perfluoroalkyl acrylate, 5 parts of initiator ammonium persulfate and 15,000 parts of deionized water.

[0122] S52, mixing styrene, 0.5 parts of a hydrophilic monomer, an initiator and water to obtain a first mixed solution, introducing nitrogen as a protective gas into the first mixed solution, and reacting at 75° C. for 8 hours under stirring to obtain a first prepolymer mixed solution.

[0123] Specifically, before the reaction in this step, styrene is purified by a basic alumina column and then mixed with the hydrophilic monomer.

[0124] S53, adding a cross-linking monomer, 4.5 parts of a hydrophilic monomer and a fluorine-containing acrylate to the first prepolymer mixture, and continuing to react at 80° C. for 20 hours under protective gas and stirring.

[0125] S54. After the reaction is completed, cool to room temperature to obtain a polystyrene microsphere turbidity solution.

[0126] Example 6

[0127] The polystyrene microsphere turbidity liquid comprises surface-modified polystyrene microspheres, wherein the surface-modified polystyrene microspheres have polystyrene microspheres as cores and fluorine-containing acrylate copolymers as shells, and the surface of the fluorine-containing acrylate copolymers contains hydrophilic ammonium groups.

[0128] The polystyrene microsphere turbidity liquid includes, by weight, 100 parts of styrene, 1 part of a hydrophilic monomer methacryloyloxyethyl trimethyl ammonium chloride, 3 parts of a cross-linking monomer styrene, 3 parts of a cross-linking monomer ethylene glycol diacrylate, 1 part of a perfluoroalkyl acrylate, 5 parts of a partially fluorinated alkyl acrylate, 3 parts of an initiator ammonium persulfate, and 12,000 parts of deionized water.

[0129] The preparation method of polystyrene microsphere turbidity liquid comprises the following steps:

[0130] S61. In parts by weight, weigh 100 parts of styrene, 1 part of hydrophilic monomer methacryloyloxyethyl trimethylammonium chloride, 3 parts of cross-linking monomer styrene, 3 parts of cross-linking monomer ethylene glycol diacrylate, 1 part of perfluoroalkyl acrylate, 5 parts of partially fluorinated alkyl acrylate, 3 parts of initiator ammonium persulfate and 12,000 parts of deionized water.

[0131] S62, mixing styrene, 0.25 parts of hydrophilic monomer, initiator and water to obtain a first mixed solution, introducing protective nitrogen gas into the first mixed solution, and reacting at 75° C. for 8 hours under stirring to obtain a first prepolymer mixed solution.

[0132] Specifically, before the reaction in this step, styrene is purified by a basic alumina column and then mixed with the hydrophilic monomer.

[0133] S63, adding a crosslinking monomer, 0.75 parts of a hydrophilic monomer and a fluorine-containing acrylate to the first prepolymer mixture, and continuing to react at 80° C. for 20 hours under protective gas and stirring.

[0134] S64. After the reaction is completed, cool to room temperature to obtain a polystyrene microsphere turbidity solution.

[0135] Comparative Example 1

[0136] The polystyrene microsphere turbidity liquid comprises surface-modified polystyrene microspheres, wherein the surface-modified polystyrene microspheres have polystyrene microspheres as cores and fluorine-containing acrylate as shells.

[0137] The polystyrene microsphere turbidity liquid comprises, by weight, 100 parts of styrene, 2 parts of cross-linking monomer glycerol triacrylate, 2 parts of perfluoroalkyl acrylate, 2 parts of initiator potassium persulfate and 5000 parts of deionized water.

[0138] The preparation method of polystyrene microsphere turbidity liquid comprises the following steps:

[0139] S71. In parts by weight, weigh 100 parts of styrene, 2 parts of cross-linking monomer glyceryl triacrylate, 2 parts of initiator potassium persulfate and 5000 parts of deionized water.

[0140] S72, mixing styrene, an initiator and water to obtain a first mixed liquid, introducing protective gas nitrogen into the first mixed liquid, and reacting at 75° C. for 8 hours under stirring conditions to obtain a first prepolymer mixed liquid.

[0141] Specifically, before the reaction in this step, styrene is purified by a basic alumina column and then mixed with the hydrophilic monomer.

[0142] S73, adding a cross-linking monomer to the first prepolymer mixture, and continuing to react at 80° C. for 20 hours under protective gas and stirring conditions.

[0143] S74. After the reaction is completed, cool to room temperature to obtain a polystyrene microsphere turbidity solution.

[0144] Comparative Example 2

[0145] The formazine produced by Guangjian (Guangzhou) Testing Technology Co., Ltd. has a turbidity of 4000NTU.

[0146] The stability of the polystyrene microsphere turbidity solutions of Examples 1 to 6 and Comparative Examples 1 to 2 was tested respectively, and the results are shown in Table 1.

[0147] Among them, the stability detection method is as follows: continuous testing, turbidity fluctuates due to periodic changes in temperature, and turbidity is recorded at different times.

[0148] Table 1 Stability

[0149]

[0150] Figure 2 The long-term stability comparison diagram of Examples 1 to 6 and Comparative Examples 1 and 2 is shown. Figure 2 It can be seen that the turbidity fluctuation of the polystyrene microsphere turbidity liquid in this embodiment is 3006 at a maximum value of 1h at constant temperature, 2993 at a minimum value, and fluctuates by 0.2%. The turbidity standard liquid is required to fluctuate by 0.2% within 1h. It meets the requirements. After being prepared into 3000NTU, Examples 1 to 6 dropped to 2960NTU after a few days, Comparative Example 1 dropped to 2920NTU after a few days, and Comparative Example 2 dropped to 2900NTU after a few days. The stability of Examples 1-6 is obviously better than Comparative Example 1 and Comparative Example 2.

[0151] Since Examples 1-6 contain hydrophilic ammonium ions, the turbidity remains stable.

[0152] Comparative Example 1 does not contain hydrophilic ammonium ions, settles quickly, and the turbidity decreases quickly.

[0153] Comparative Example 1 does not contain a hydrophilic monomer, so that the surface of the polystyrene microspheres has no charge, resulting in no electrostatic repulsion between the polystyrene microspheres, and the polystyrene microspheres are easily combined and precipitated. Comparative Example 1 does not contain fluoroacrylate, which makes it easy to turn yellow. When used as a high turbidity liquid calibration liquid above 3000 NTU, the turbidity decreases significantly due to yellowing absorption, that is, it is unstable as a high turbidity calibration liquid.

[0154] Comparative Example 2 is commercially available formazin, which is unstable and easily aggregates and settles. Therefore, the long-term stability of Examples 1 to 6 is better than that of formazin.

[0155] In addition, the storage conditions of the formazin standard solution are harsh. It needs to be stored at 4-8°C and needs to be restored to room temperature when used, which makes the waiting time long and the efficiency low. Therefore, the diluted solution is prepared immediately after use, otherwise flocculent precipitation is very likely to occur and cannot be used again. During the test, the amount of formazin standard solution used is large and the price is high, which makes the test cost high. In addition, formazin has certain biological toxicity, and the wastewater after the test should not be discharged directly, which will cause environmental pollution.

[0156] Therefore, the turbidity liquid in the present application not only has good stability, but also has low cost, high safety and is environmentally friendly.

[0157] Although the present invention has been described with reference to several typical embodiments, it should be understood that the terms used are illustrative and exemplary, rather than restrictive. Since the present invention can be embodied in a variety of forms without departing from the spirit or essence of the invention, it should be understood that the above embodiments are not limited to any of the foregoing details, but should be interpreted broadly within the spirit and scope defined by the appended claims, so all changes and modifications falling within the scope of the claims or their equivalents should be covered by the appended claims.

Claims

1. A polystyrene microsphere turbidity liquid, characterized in that: The surface-modified polystyrene microspheres are composed of cross-linked polystyrene microspheres as cores and fluorinated acrylate copolymers as shells; and the surface of the fluorinated acrylate copolymers contains hydrophilic ammonium groups.

2. The polystyrene microsphere turbidity liquid according to claim 1, characterized in that: The particle size of the surface modified polystyrene microspheres is 400-800nm.

3. The polystyrene microsphere turbidity liquid according to claim 1, characterized in that: The material ratio for synthesizing the surface modified polystyrene microspheres is, by weight, 100 parts of styrene, 1 to 10 parts of crosslinking monomers, 0.01 to 5 parts of hydrophilic monomers, 1 to 10 parts of fluorine-containing acrylates, 0.5 to 5 parts of initiators and 2,000 to 20,000 parts of deionized water.

4. The polystyrene microsphere turbidity liquid according to claim 3, characterized in that: The fluorine-containing acrylate includes at least one of perfluoroalkyl (meth)acrylate and partially fluorine-substituted alkyl (meth)acrylate.

5. The polystyrene microsphere turbidity liquid according to claim 3, characterized in that: The hydrophilic monomer includes at least one of methacryloyloxyethyltrimethylammonium chloride and (3-acrylamidopropyl)trimethylammonium chloride.

6. The polystyrene microsphere turbidity liquid according to claim 3, characterized in that: The cross-linking monomer contains at least two unsaturated double bonds in its molecule; The cross-linking monomer includes at least one of styrene, ethylene glycol diacrylate, trimethylolpropane triacrylate, glycerol triacrylate, and pentaerythritol triacrylate; and / or, The initiator includes at least one of potassium persulfate and ammonium persulfate.

7. A method for preparing a polystyrene microsphere turbidity liquid, characterized in that: The following steps are involved: In parts by weight, 100 parts of styrene, 1 to 10 parts of a crosslinking monomer, 0.01 to 5 parts of a hydrophilic monomer, 1 to 10 parts of a fluorine-containing acrylate, 0.5 to 5 parts of an initiator and 2000 to 20000 parts of deionized water are weighed; the fluorine-containing acrylate comprises at least one of perfluoroalkyl acrylate, perfluoroalkyl (meth)acrylate, partially fluorinated alkyl acrylate and partially fluorinated alkyl (meth)acrylate; the hydrophilic monomer comprises at least one of methacryloyloxyethyl trimethylammonium chloride and (3-acrylamidopropyl) trimethylammonium chloride; 0.01 to 0.5 parts of the hydrophilic monomer, the styrene, the initiator and the deionized water are mixed to obtain a first mixed solution, a protective gas is introduced into the first mixed solution, and the mixture is reacted at 70 to 80° C. for 6 to 8 hours under stirring conditions to obtain a first prepolymer mixed solution; the first prepolymer mixed solution contains hydrophilic polystyrene microspheres; Adding the crosslinking monomer, the remaining hydrophilic monomer and the fluorine-containing acrylate to the first prepolymer mixture, and continuing to react at 70-80° C. for 18-24 hours under protective gas and stirring; After the reaction was completed, the mixture was cooled to room temperature to obtain a polystyrene microsphere turbidity solution.

8. The method for preparing a polystyrene microsphere turbidity liquid according to claim 7, characterized in that: The styrene is purified by a basic alumina column and then mixed with the hydrophilic monomer; The cross-linking monomer is purified by a basic alumina column and then added to the first prepolymer mixture; The fluorine-containing acrylate is purified by a basic alumina column and then added to the first prepolymerization mixture; and / or, The protective gas includes nitrogen or argon.

9. A turbidity calibration solution, characterized in that: The polystyrene microsphere turbidity solution according to any one of claims 1 to 6 or the polystyrene microsphere turbidity solution prepared according to claims 7 to 8 is diluted with deionized water to obtain a turbidity calibration solution with a turbidity of 1 to 4000 NTU.

10. The turbidity calibration solution according to claim 9, characterized in that: The polystyrene microsphere turbidity solution is diluted with deionized water in a ratio of 30 to 30,000.

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