Novel alkali-resistant diamond-silica gel hybrid chromatographic filler and preparation process thereof

Abstract

The invention provides a novel alkali-resistant diamond-silica gel hybrid chromatographic packing preparation technology and a preparation process. The preparation method comprises the following steps: preparing hybrid gel of a siloxane network from organosilane and other silane, and treating nano-diamond by using a FeSO4 solution and hydrogen peroxide to obtain hydroxylated nano-diamond; then the hydroxylated nano-diamond, the hybrid gel and polyethylene glycol 400 are prepared into diamond-hybrid silica gel; and finally, treating with an alkaline solution, washing and drying to finally obtain the diamond-hybrid silica gel filler. Organosilane and other silane are mixed and hydrolyzed to form a silicon-oxygen-silicon (Si-O-Si) skeleton to enhance the stability and surface reactivity of silica gel, then added hydroxylated diamond nanoparticles and Si-OH form hydrogen bonds, and the hydrogen bonds are subjected to a dehydration condensation reaction and are uniformly doped into the silica gel skeleton. The strength, alkali resistance and durability of the chromatographic packing are greatly improved, and the preparation process is simple to operate, good in reproducibility and easy for large-scale production.

Description

Technical Field

[0001] The invention relates to the technical field related to chromatographic fillers, and in particular to a diamond-silica gel hybrid chromatographic filler preparation technology filler and a preparation process. Background Art

[0002] Chromatography is an analytical method that separates substances based on the difference in the distribution of substances between two phases. Since the advent of chromatography in the early 20th century, it has been widely used in many fields such as chemistry, life sciences, and environmental monitoring. In the process of chromatographic analysis, chromatographic fillers (usually solid or porous materials) play the role of separation media, and their performance is directly related to the efficiency of chromatographic separation and the accuracy of the final analysis results.

[0003] Traditional chromatographic fillers are usually silica gel or polymer materials, which are physically or chemically modified to improve their separation effect. Silica gel, as a commonly used chromatographic filler, has a porous structure, and its abundant pores can provide a large number of adsorption sites for sample molecules. However, the surface properties of unmodified silica gel are relatively simple, and the selectivity may not be ideal when separating complex mixtures.

[0004] Hybrid chromatographic filler is a new type of chromatographic filler. It is formed by hybridizing materials of different properties (such as inorganic materials and organic materials) through methods such as chemical synthesis. This filler combines the advantages of multiple materials and can provide better performance for chromatographic separation. Hybrid chromatographic fillers combine the advantages of inorganic materials and organic materials, usually have good mechanical stability and thermal stability, can withstand high pressure and a wide temperature range, and can be used stably under a variety of chromatographic conditions. Hybrid chromatographic fillers combine reverse phase, normal phase and hydrophilic action modes, are compatible with extreme pH and complex matrices, and are suitable for biological separation, drug analysis and multifunctional detection. However, existing hybrid chromatographic fillers have problems such as low stability and unsatisfactory lifespan. The inventors of the present invention have found that by adding an appropriate amount of hydroxy diamond nanoparticles to the surface of silica gel filler, a new type of diamond-silica gel chromatographic filler with good stability can be obtained, thereby effectively increasing the reproducibility, stability and lifespan of the chromatographic filler.

[0005] However, hybrid chromatographic fillers have some shortcomings, such as the degree of compositeness of different materials, which cannot be evenly dispersed and stably embedded in the silica gel skeleton; the particle size and dispersion cannot be controlled, and the pore structure cannot be precisely controlled, so that it cannot maintain a good size and distribution; while improving acid and alkali resistance and mechanical strength, how to ensure that the filler has sufficient silanol-modified binding sites, etc., which seriously restrict the application and development of hybrid chromatographic fillers. Summary of the invention

[0006] In view of the above shortcomings, the present invention aims to provide a novel alkali-resistant diamond-silica gel hybrid chromatographic filler preparation technology and preparation process. The present invention provides a novel diamond-silica gel hybrid chromatographic filler, comprising: diamond nanoparticles and silane bonded to the surface of the diamond nanoparticles, characterized in that: the silane is obtained by hydrolyzing a mixture of an organic silane and other silanes, wherein the chemical structure of the organic silane is:

[0007]

[0008] Wherein R1 is a C1-6 alkyl group, and X1 is a reactive group, preferably chlorine, methoxy and ethoxy.

[0009] The other silanes are selected from one or more of bis(triethoxysilyl)methane, 1,2-bis(triethoxysilyl)ethane, 1,2-bis(triethoxysilyl)propane, 1,2-bis(triethoxysilyl)butane, 1,2-bis(triethoxysilyl)pentane, 1,2-bis(triethoxysilyl)hexane, and 1,2-bis(triethoxysilyl)heptane.

[0010] The present invention also provides a method for preparing the above-mentioned silica gel chromatographic filler, comprising the following steps:

[0011] Step 1: adding organic silane and other silanes to a first organic solvent, stirring and heating to react, and then drying to obtain a hybrid gel of a siloxane network;

[0012] Step 2: Add FeSO 4 and distilled water, stir to dissolve, adjust the solution pH to 2-3, then add nanodiamond, stir to mix, and add 30% H 2 O 2 , heating reaction, cooling and drying to obtain hydroxylated nanodiamond.

[0013] Step 3: Add the hydroxylated nanodiamond, hybrid gel and polyethylene glycol 400 into a second organic solvent, stir and heat to react, and then filter and extract to obtain diamond-hybrid silica gel.

[0014] Step 4: Wash the diamond-hybrid silica gel with pure water or ethanol to remove surface impurities, add it to the alkaline solution, stir and heat to react, then add the acid solution until it is neutral, filter, wash the filtered solid with pure water or ethanol several times, and dry to obtain the diamond-hybrid silica gel filler.

[0015] Furthermore, in step 1, the molar ratio of the organosilane to the other silane is 1:0.1 to 2.0, preferably 1:0.5 to 1.0. The mass volume ratio of the total mass of the organosilane and the other silane to the first organic solvent is 1:2 to 10. The first organic solvent includes but is not limited to one or more of acetone and tetrahydrofuran.

[0016] Furthermore, the reaction in step 1 is a stirring reflux reaction, and the organic silane and other silanes are stirred and refluxed for 6 to 24 hours, and then filtered by vacuum filtration to separate the hybrid gel of the siloxane network from the acetone solution.

[0017] Further, step 2 is to hydroxylate the nanodiamond using the Fenton reagent reflux method: take FeSO 4 , add distilled water to dissolve completely, adjust the pH of the solution to 2-3 with concentrated sulfuric acid, add nanodiamonds into the solution, stir and mix, and add 30% H 2 O 2 , the temperature is 70℃~90℃, reflux reaction is carried out for 2~6h, the reaction solution is cooled to room temperature and the nanodiamond is repeatedly washed by centrifugation with deionized water until the pH is close to neutral, and finally vacuum dried or freeze-dried to obtain hydroxylated nanodiamond.

[0018] Further, in step 2, nanodiamond and FeSO 4 The mass molar ratio of FeSO is 1:0.3~0.4; 4 and H 2 O 2 The molar ratio is 1:10-15; the particle size of nano-diamond is 1-10nm.

[0019] Furthermore, in step three, the mass ratio of hydroxylated nanodiamond to hybrid gel is 1:0.1-2; the mass volume ratio of hydroxylated nanodiamond to polyethylene glycol 400 is 1:0.3-1; the mass volume ratio of the total mass of hydroxylated nanodiamond and hybrid gel to the second organic solvent is 1:2-10.

[0020] Furthermore, in step 3, the second organic solvent is a non-polar solvent, which may be benzene, n-hexane, etc. or a combination thereof. The reaction is a stirring reflux reaction, the reaction time is 2 to 24 hours, and the reaction temperature is 80°C to 150°C. Before the reaction, ultrasound can be applied for 10 to 15 minutes to make it evenly dispersed. After the reaction is completed, it is washed with toluene, tetrahydrofuran aqueous solution, methanol and acetonitrile in turn and filtered under reduced pressure to remove other unreacted solubles such as the porogen and the second solvent.

[0021] Furthermore, in step 4, the mass volume ratio of diamond-hybrid silica gel to alkaline solution is 1:5-15, and the alkaline solution includes but is not limited to 0.5-5 mol / L sodium hydroxide solution or ammonia water; the acid solution is 0.1-2 mol / L hydrochloric acid solution or 10%-30% sulfuric acid solution.

[0022] The beneficial effects of the present invention are as follows: 1. The present invention adopts organic silane and other silanes to form a silicon-oxygen-silicon (Si-O-Si) skeleton by mixed hydrolysis to enhance the stability and surface reactivity of silica gel, and then the hydroxylated diamond nanoparticles are added to form hydrogen bonds with Si-OH and dehydration condensation reaction to be uniformly incorporated into the silica gel skeleton, thereby greatly improving the strength, alkali resistance and durability of the chromatographic filler; 2. By adding an appropriate amount of porogen (polyethylene glycol 400, etc.) and performing alkaline pore expansion treatment, the silica gel microspheres finally obtained have a pore size of 5 μm, which is suitable for efficient separation and analysis of complex samples; 3. The preparation process provided by the present invention is simple to operate, has good reproducibility, and is easy to mass produce; 4. The new diamond-silica gel hybrid chromatographic filler provided by the present invention is characterized to be superior to similar products. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The reaction equation prepared in Example 1; DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] Example 1

[0026] 1. Preparation of Hybrid Gel

[0027] Add 1.0 g of methyltrimethoxysilane, 2.5 g of bis(triethoxysilyl)methane and 35 ml of acetone to the reaction bottle, stir and heat to reflux, keep reflux and react for 24 hours, cool to room temperature, filter and obtain a hybrid gel of the siloxane network.

[0028] 2. Preparation of Hydroxylated Nanodiamonds

[0029] Add 60.8 g FeSO into the reaction flask. 4 Add 250 ml of distilled water, stir until completely dissolved, adjust the pH of the solution to about 2-3 with concentrated sulfuric acid, add 1.0 g of nanodiamond with a particle size of 10 nm, stir and mix, and drop 680.2 g of 30% H 2 O 2 After the dripping, the temperature is raised to about 90°C, kept warm for 2 hours, then cooled to room temperature, filtered, and the filtered solid is washed with deionized water until the pH of the filtrate is close to neutral. After drying, hydroxylated nanodiamonds are obtained.

[0030] 3. Preparation of Diamond-Hybrid Silica Gel

[0031] Add 1.0 g of hydroxylated diamond nanoparticles, 2.0 g of hybrid gel, 1.0 ml of polyethylene glycol 400 (porogen), and 30 ml of benzene into a reaction bottle, stir and heat to reflux, reflux for 2 hours, cool to room temperature, filter, wash the filtered solid with toluene, tetrahydrofuran aqueous solution, methanol and acetonitrile in turn, and dry to obtain diamond-hybrid silica gel.

[0032] 4. Preparation of Diamond-Hybrid Silica Filler

[0033] In a reaction flask, add 1.0g of diamond-hybrid silica gel and 15ml of 5mol / L sodium hydroxide solution, stir and heat to 90℃, and keep warm for 1 hour. After the reaction is completed, cool to room temperature, add 1mol / L hydrochloric acid solution dropwise, adjust the pH to neutral, filter, wash the filtered solid with deionized water and ethanol several times until the pH value of the washing liquid is close to neutral, and dry to obtain diamond-hybrid silica gel filler.

[0034] Example 2

[0035] 1. Preparation of Hybrid Gel

[0036] Add 1.0 g of propyltrichlorosilane, 0.2 g of 1,2-bis(triethoxysilyl)ethane and 3 ml of tetrahydrofuran to the reaction bottle, stir and heat to reflux, keep reflux and react for 6 hours, cool to room temperature, filter and obtain a hybrid gel of siloxane network.

[0037] 2. Preparation of Hydroxylated Nanodiamonds

[0038] Add 45.6 g FeSO into the reaction flask. 4 Add 200 ml of distilled water, stir until completely dissolved, adjust the pH of the solution to about 2-3 with concentrated sulfuric acid, add 1.0 g of nanodiamond with a particle size of 1 nm, stir and mix, and drop 340.1 g of 30% H 2 O 2 After the dripping, the temperature is raised to about 70°C, kept warm for 6 hours, then cooled to room temperature, filtered, and the filtered solid is washed with deionized water until the pH of the filtrate is close to neutral. After drying, hydroxylated nanodiamonds are obtained.

[0039] 3. Preparation of Diamond-Hybrid Silica Gel

[0040] Add 1.0 g of hydroxylated diamond nanoparticles, 0.1 g of hybrid gel, 0.3 ml of polyethylene glycol 400 (porogen), and 5 ml of benzene into a reaction bottle, stir and heat to reflux, reflux for 24 hours, cool to room temperature, filter, wash the filtered solid with toluene, tetrahydrofuran aqueous solution, methanol, and acetonitrile in turn, and dry to obtain diamond-hybrid silica gel.

[0041] 4. Preparation of Diamond-Hybrid Silica Filler

[0042] In a reaction flask, add 1.0g of diamond-hybrid silica gel and 5ml of 0.5mol / L sodium hydroxide solution, stir and heat to 60℃, and keep warm for 4 hours. After the reaction is completed, cool to room temperature, add 0.1mol / L hydrochloric acid solution dropwise, adjust the pH to neutral, filter, wash the solid with deionized water and ethanol several times until the pH value of the washing liquid is close to neutral, and dry to obtain diamond-hybrid silica gel filler.

[0043] Example 3

[0044] 1. Preparation of Hybrid Gel

[0045] Add 1.0 g of n-pentyltrimethoxysilane, 1.1 g of 1,2-bis(triethoxysilyl)hexane and 10 ml of tetrahydrofuran into the reaction bottle, stir and heat to reflux, keep reflux and react for 12 hours, cool to room temperature, filter and obtain a hybrid gel of siloxane network.

[0046] 2. Preparation of Hydroxylated Nanodiamonds

[0047] Add 53.2 g FeSO into the reaction flask. 4 Add 250 ml of distilled water, stir until completely dissolved, adjust the pH of the solution to about 2-3 with concentrated sulfuric acid, add 1.0 g of nanodiamond with a particle size of 5 nm, stir and mix, and drop 396.8 g of 30% H 2 O 2 After the dripping, the temperature is raised to about 80°C, kept warm for 5 hours, then cooled to room temperature, filtered, and the filtered solid is washed with deionized water until the pH of the filtrate is close to neutral. After drying, hydroxylated nanodiamonds are obtained.

[0048] 3. Preparation of Diamond-Hybrid Silica Gel

[0049] Add 1.0 g of hydroxylated diamond nanoparticles, 1.0 g of hybrid gel, 0.6 ml of polyethylene glycol 400 (porogen), and 10 ml of benzene into a reaction bottle, stir and heat to reflux, reflux for 12 hours, cool to room temperature, filter, wash the filtered solid with toluene, tetrahydrofuran aqueous solution, methanol and acetonitrile in turn, and dry to obtain diamond-hybrid silica gel.

[0050] 4. Preparation of Diamond-Hybrid Silica Filler

[0051] In a reaction bottle, add 1.0g diamond-hybrid silica gel and 10ml ammonia water (28%-29%), stir and heat to 80℃, keep warm and react for 2 hours. After the reaction is completed, cool to room temperature, add 10% sulfuric acid solution dropwise, adjust the pH to neutral, filter, wash the filtered solid with deionized water and ethanol several times until the pH value of the washing liquid is close to neutral, and dry to obtain diamond-hybrid silica gel filler.

[0052] Example 4

[0053] 1. Preparation of Hybrid Gels

[0054] Add 1.0 g of n-butyltriethoxysilane, 3.3 g of 1,2-bis(triethoxysilyl)propane, 20 ml of acetone and 15 ml of tetrahydrofuran to the reaction bottle, stir and heat to reflux, keep reflux and react for 10 hours, cool to room temperature, filter and obtain a hybrid gel of siloxane network.

[0055] 2. Preparation of Hydroxylated Nanodiamonds

[0056] Add 60.8 g FeSO into the reaction flask. 4 Add 300 ml of distilled water, stir until completely dissolved, adjust the pH of the solution to about 2-3 with concentrated sulfuric acid, add 1.0 g of nanodiamond with a particle size of 8 nm, stir and mix, and drop 453.5 g of 30% H 2 O 2 After the dripping, the temperature is raised to about 90°C, kept warm for 2 hours, then cooled to room temperature, filtered, and the filtered solid is washed with deionized water until the pH of the filtrate is close to neutral. After drying, hydroxylated nanodiamonds are obtained.

[0057] 3. Preparation of Diamond-Hybrid Silica Gel

[0058] Add 1.0 g of hydroxylated diamond nanoparticles, 1.5 g of hybrid gel, 0.8 ml of polyethylene glycol 400 (porogen), 10 ml of benzene and 15 ml of n-hexane into a reaction bottle, stir and heat to reflux, reflux for 20 hours, cool to room temperature, filter, wash the filtered solid with toluene, tetrahydrofuran aqueous solution, methanol and acetonitrile in turn, and dry to obtain diamond-hybrid silica gel.

[0059] 4. Preparation of Diamond-Hybrid Silica Filler

[0060] In a reaction flask, add 1.0g of diamond-hybrid silica gel and 15ml of 2mol / L sodium hydroxide solution, stir and heat to 70°C, and keep warm for 3 hours. After the reaction is completed, cool to room temperature, add 30% sulfuric acid solution dropwise, adjust the pH to neutral, filter, wash the filtered solid with deionized water and ethanol several times until the pH value of the washing liquid is close to neutral, and dry to obtain diamond-hybrid silica gel filler.

[0061] Example 5

[0062] 1. Preparation of Hybrid Gels

[0063] Add 1.0 g of methyltrichlorosilane, 2.3 g of 1,2-bis(triethoxysilyl)heptane and 10 ml of acetone to the reaction bottle, stir and heat to reflux, keep reflux and react for 6 hours, cool to room temperature, filter and obtain a hybrid gel of siloxane network.

[0064] 2. Preparation of Hydroxylated Nanodiamonds

[0065] Add 45.6 g FeSO into the reaction flask. 4 Add 200 ml of distilled water, stir until completely dissolved, adjust the pH of the solution to about 2-3 with concentrated sulfuric acid, add 1.0 g of nanodiamond with a particle size of 3 nm, stir and mix, and drop 408.1 g of 30% H 2 O 2 After the dripping, the temperature is raised to about 70°C, kept warm for 5 hours, then cooled to room temperature, filtered, and the filtered solid is washed with deionized water until the pH of the filtrate is close to neutral. After drying, hydroxylated nanodiamonds are obtained.

[0066] 3. Preparation of Diamond-Hybrid Silica Gel

[0067] Add 1.0 g of hydroxylated diamond nanoparticles, 0.5 g of hybrid gel, 1.0 ml of polyethylene glycol 400 (porogen), and 10 ml of benzene into a reaction bottle, stir and heat to reflux, reflux for 5 hours, cool to room temperature, filter, wash the filtered solid with toluene, tetrahydrofuran aqueous solution, methanol, and acetonitrile in turn, and dry to obtain diamond-hybrid silica gel.

[0068] 4. Preparation of Diamond-Hybrid Silica Filler

[0069] In a reaction bottle, add 1.0g diamond-hybrid silica gel and 5ml ammonia water (28%-29%), stir and heat to 60℃, keep warm and react for 2 hours. After the reaction is completed, cool to room temperature, add 2mol / L hydrochloric acid solution, adjust the pH to neutral, filter, wash the solid with deionized water and ethanol several times until the pH value of the washing liquid is close to neutral, and dry to obtain diamond-hybrid silica gel filler.

[0070] Example 6

[0071] 1. Preparation of Hybrid Gel

[0072] Add 1.0 g of ethyltrimethoxysilane, 2.6 g of 1,2-bis(triethoxysilyl)pentane and 35 ml of tetrahydrofuran to the reaction bottle, stir and heat to reflux, keep reflux and react for 15 hours, cool to room temperature, filter and obtain a hybrid gel of siloxane network.

[0073] 2. Preparation of Hydroxylated Nanodiamonds

[0074] Add 45.6 g FeSO into the reaction flask. 4 Add 250 ml of distilled water, stir until completely dissolved, adjust the pH of the solution to about 2-3 with concentrated sulfuric acid, add 1.0 g of nanodiamond with a particle size of 10 nm, stir and mix, and drop 476.1 g of 30% H 2 O 2After the dripping, the temperature is raised to about 80°C, kept warm for 3 hours, then cooled to room temperature, filtered, and the filtered solid is washed with deionized water until the pH of the filtrate is close to neutral. After drying, hydroxylated nanodiamonds are obtained.

[0075] 3. Preparation of Diamond-Hybrid Silica Gel

[0076] Add 1.0 g of hydroxylated diamond nanoparticles, 1.0 g of hybrid gel, 0.5 ml of polyethylene glycol 400 (porogen), and 20 ml of n-hexane into a reaction bottle, heat to reflux with stirring, reflux for 10 hours, cool to room temperature, filter, wash the filtered solid with toluene, tetrahydrofuran aqueous solution, methanol, and acetonitrile in turn, and dry to obtain diamond-hybrid silica gel.

[0077] 4. Preparation of Diamond-Hybrid Silica Filler

[0078] In a reaction flask, add 1.0g of diamond-hybrid silica gel and 8ml of 1.5mol / L sodium hydroxide solution, stir and heat to 90°C, and keep warm for 2 hours. After the reaction is completed, cool to room temperature, add 20% sulfuric acid solution dropwise, adjust the pH to neutral, filter, wash the filtered solid with deionized water and ethanol several times until the pH value of the washing liquid is close to neutral, and dry to obtain diamond-hybrid silica gel filler.

[0079] Example 7

[0080] 1. Preparation of Hybrid Gel

[0081] Add 1.0 g of n-hexyltrichlorosilane, 0.8 g of 1,2-bis(triethoxysilyl)propane and 10 ml of acetone to the reaction bottle, stir and heat to reflux, keep reflux and react for 20 hours, cool to room temperature, filter and obtain a hybrid gel of siloxane network.

[0082] 2. Preparation of Hydroxylated Nanodiamonds

[0083] Add 60.8 g FeSO into the reaction flask. 4 and 300 ml of distilled water, stir until completely dissolved, adjust the pH of the solution to about 2-3 with concentrated sulfuric acid, add 1.0 g of nanodiamond with a particle size of 5 nm, stir and mix, and drop 453.5 g of 30% H 2 O 2 After the dripping, the temperature is raised to about 80°C, kept warm for 4 hours, then cooled to room temperature, filtered, and the filtered solid is washed with deionized water until the pH of the filtrate is close to neutral. After drying, hydroxylated nanodiamonds are obtained.

[0084] 3. Preparation of Diamond-Hybrid Silica Gel

[0085] Add 1.0 g of hydroxylated diamond nanoparticles, 1.5 g of hybrid gel, 0.8 ml of polyethylene glycol 400 (porogen), and 10 ml of n-hexane into a reaction bottle, stir and heat to reflux, reflux for 8 hours, cool to room temperature, filter, wash the filtered solid with toluene, tetrahydrofuran aqueous solution, methanol, and acetonitrile in turn, and dry to obtain diamond-hybrid silica gel.

[0086] 4. Preparation of Diamond-Hybrid Silica Filler

[0087] In a reaction flask, add 1.0g of diamond-hybrid silica gel and 15ml of 1mol / L sodium hydroxide solution, stir and heat to 90℃, and keep warm for 4 hours. After the reaction is completed, cool to room temperature, add 1.5mol / L hydrochloric acid solution dropwise, adjust the pH to neutral, filter, wash the filtered solid with deionized water and ethanol several times until the pH value of the washing liquid is close to neutral, and dry to obtain diamond-hybrid silica gel filler.

[0088] Example 8

[0089] 1. Preparation of Hybrid Gel

[0090] Add 1.0 g of propyltriethoxysilane, 0.8 g of bis(triethoxysilyl)methane and 5 ml of tetrahydrofuran into the reaction bottle, heat to reflux with stirring, keep the reflux reaction for 12 hours, cool to room temperature, filter and obtain a hybrid gel of the siloxane network.

[0091] 2. Preparation of Hydroxylated Nanodiamonds

[0092] Add 45.6FeSO into the reaction flask 4 Add 250 ml of distilled water, stir until completely dissolved, adjust the pH of the solution to about 2-3 with concentrated sulfuric acid, add 1.0 g of nanodiamond with a particle size of 8 nm, stir and mix, and drop 340.1 g of 30% H 2 O 2 After the dripping, the temperature is raised to about 90°C, kept warm for 3 hours, then cooled to room temperature, filtered, and the filtered solid is washed with deionized water until the pH of the filtrate is close to neutral. After drying, hydroxylated nanodiamonds are obtained.

[0093] 3. Preparation of Diamond-Hybrid Silica Gel

[0094] Add 1.0 g of hydroxylated diamond nanoparticles, 2.0 g of hybrid gel, 1.0 ml of polyethylene glycol 400 (porogen), and 25 ml of benzene into a reaction bottle, stir and heat to reflux, reflux for 16 hours, cool to room temperature, filter, wash the filtered solid with toluene, tetrahydrofuran aqueous solution, methanol, and acetonitrile in turn, and dry to obtain diamond-hybrid silica gel.

[0095] 4. Preparation of Diamond-Hybrid Silica Filler

[0096] In a reaction bottle, add 1.0g diamond-hybrid silica gel and 10ml 3mol / L sodium hydroxide solution, stir and heat to 70℃, keep warm and react for 4 hours. After the reaction is completed, cool to room temperature, add 20% sulfuric acid solution dropwise, adjust the pH to neutral, filter, wash the filtered solid with deionized water and ethanol several times until the pH value of the washing liquid is close to neutral, and dry to obtain diamond-hybrid silica gel filler.

[0097] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A diamond-silica gel hybrid chromatographic filler, comprising diamond nanoparticles and silane bonded to the surface of the diamond nanoparticles, characterized in that: Silane is obtained by the hydrolysis of organic silane and other silanes. The general chemical structure of organic silane is: Wherein R1 is a C1-6 alkyl group, X1 is a reactive group, preferably chlorine, methoxy and ethoxy; The other silanes are selected from one or more of bis(triethoxysilyl)methane, 1,2-bis(triethoxysilyl)ethane, 1,2-bis(triethoxysilyl)propane, 1,2-bis(triethoxysilyl)butane, 1,2-bis(triethoxysilyl)pentane, 1,2-bis(triethoxysilyl)hexane, and 1,2-bis(triethoxysilyl)heptane.

2. A method for preparing the diamond-silica gel hybrid chromatographic filler according to claim 1, characterized in that: The following steps are involved: Step 1: neutralize other silanes in the organosilane, add a first organic solvent, stir and heat to react, and then treat and dry to obtain a hybrid gel of a siloxane network; Step 2: Stir FeSO4 and distilled water to dissolve, adjust the solution pH to 2-3, then add nanodiamond, stir and mix, add 30% H2O2 dropwise while stirring, heat to react, cool and dry to obtain hydroxylated nanodiamond. Step 3: Add the hydroxylated nanodiamond, hybrid gel and polyethylene glycol 400 into a second organic solvent, stir and heat to react, and then filter and extract to obtain diamond-hybrid silica gel. Step 4: Wash the diamond-hybrid silica gel with pure water or ethanol to remove surface impurities, add it to the alkaline solution, stir and heat to react, then add the acid solution until it is neutral, filter, wash the filtered solid with pure water or ethanol several times, and dry to obtain the diamond-hybrid silica gel filler.

3. The method for preparing the diamond-silica gel hybrid chromatographic filler according to claim 2, characterized in that: Step 3: Before heating the reaction, ultrasonicate for 10 to 15 minutes to evenly disperse the reaction materials.

4. The method for preparing the diamond-silica gel hybrid chromatographic filler according to claim 2 or 3, characterized in that: In step 1, the molar ratio of the organosilane and other silanes is 1:0.1-2.0, preferably 1:0.5-1.0; the mass volume ratio of the total mass of the organosilane and other silanes to the first organic solvent is 1:2-10.

5. The method for preparing the diamond-silica gel hybrid chromatographic filler according to claim 4, characterized in that: In step 2, the mass molar ratio of nano-diamond to FeSO4 is 1:0.3-0.4; the molar ratio of FeSO4 to H2O2 is 1:10-15; and the particle size of nano-diamond is 1-10 nm.

6. The method for preparing the diamond-silica gel hybrid chromatographic filler according to claim 5, characterized in that: In step three, the mass ratio of hydroxylated nanodiamond to hybrid gel is 1:0.1-2; the mass volume ratio of hydroxylated nanodiamond to polyethylene glycol 400 is 1:0.3-1; the mass volume ratio of the total mass of hydroxylated nanodiamond and hybrid gel to the second organic solvent is 1:2-10.

7. The method for preparing the diamond-silica gel hybrid chromatographic filler according to claim 6, characterized in that: In step 4, the mass volume ratio of diamond-hybrid silica gel to alkaline solution is 1:5-15.

8. The method for preparing the diamond-silica gel hybrid chromatographic filler according to claim 3 or 7, characterized in that: In step 1, the first organic solvent is one or both of acetone and tetrahydrofuran; in step 3, the second organic solvent is one or both of benzene and n-hexane; in step 4, the alkaline solution is sodium hydroxide solution or ammonia solution; in step 4, the acid solution is hydrochloric acid solution or sulfuric acid solution.

9. The method for preparing the diamond-silica gel hybrid chromatographic filler according to claim 8, characterized in that: The concentration of the sodium hydroxide solution is 0.5-5 mol / L; the concentration of the hydrochloric acid solution is 0.1-2 mol / L; and the concentration of the sulfuric acid solution is 10%-30%.

10. The method for preparing the diamond-silica gel hybrid chromatographic filler according to claim 9, characterized in that: The reaction in step 1 is a reflux reaction, and the reaction time is 6 to 24 hours; the reaction temperature in step 2 is 70 to 90° C., and the reaction time is 2 to 6 hours; the reaction in step 3 is a reflux reaction, and the reaction time is 2 to 24 hours; the reaction temperature in step 4 is 60 to 90° C., and the reaction time is 1 to 4 hours.

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