Slow-release salt-storage snow-melting ice-inhibiting microcapsule and preparation method thereof

Abstract

The invention discloses a slow-release salt-storage snow-melting ice-inhibiting microcapsule and a preparation method thereof, and belongs to the technical field of highway engineering in traffic transportation engineering. During preparation, the sustained-release salt-storing snow-melting ice-inhibiting microcapsule is prepared by taking a high polymer material as a wall material and salt as a core material through a spray drying method, a phase separation method or an interfacial polymerization method. According to the invention, the salt is coated in the polymer wall material, and the wall material has good water blocking capability and can control salt release, so that the release rate of the salt is obviously slowed down, the utilization rate of snow melting and deicing is improved, and the problem of snow accumulation and icing on the road surface in winter is effectively solved.

Description

Technical Field

[0001] This invention relates to the field of highway engineering technology in transportation engineering, and more specifically to a slow-release salt-storing snow-melting and ice-suppressing microcapsule and its preparation method. Background Technology

[0002] Winter road icing and snow disasters plague most parts of northern China. Studies have shown that the road surface adhesion coefficient is 0.6 in dry conditions, only 0.2 in snow-covered conditions, and 0.15 in icy conditions. This reduced adhesion coefficient leads to longer vehicle braking distances, increases the winter traffic accident rate, endangers public safety, severely impacts road traffic flow, and causes significant economic losses.

[0003] To ensure smooth traffic flow and driving safety, avoid or reduce traffic accidents, and improve road capacity and operational efficiency, snow-melting and ice-suppressing technologies are needed to remove snow and ice from roads and alleviate this problem. Salt-retaining asphalt pavement is an active snow-melting and ice-suppressing technology that melts snow and ice on the road surface by releasing salt. It refers to a pavement constructed by replacing some of the aggregate in the asphalt mixture with an anti-icing agent during the mixing process. Under the combined influence of low temperatures, precipitation (rain, snow, ice, freezing rain, etc.), and the presence of voids in the pavement structure, the anti-icing agent in the mixture migrates from the pavement interior to the surface through the voids in the mixture under the combined effects of pumping suction generated by vehicle rolling, capillary pressure, and salt solution concentration gradient, lowering the freezing point of the surface water solution and achieving the effect of snow-melting and ice-suppressing. However, in salt-retaining asphalt pavement, salt is directly mixed with the asphalt mixture before use. During use, it is subject to water erosion, causing the salt in the salt-retaining asphalt pavement to be easily lost, thus compromising its snow-melting and ice-suppressing durability. Summary of the Invention

[0004] To address the above problems, this invention provides a slow-release salt-storing snow-melting and ice-suppressing microcapsule and its preparation method. This invention uses a polymer material as the wall material to encapsulate salt. Due to the good water-blocking ability of the wall material, the release of salt can be controlled, thereby significantly slowing down the release rate of salt, improving the utilization rate of snow and ice melting, and effectively solving the problem of snow and ice accumulation on roads in winter.

[0005] The first objective of this invention is to provide a sustained-release salt-storage snow-melting and ice-suppressing microcapsule, which is prepared by using a polymer material as the wall material and salt as the core material.

[0006] In one embodiment of the present invention, the salt is one of potassium acetate, sodium chloride, calcium chloride, magnesium chloride, and potassium chloride;

[0007] The polymer material is one of gum arabic, gelatin, polyvinyl alcohol, agar, linear starch, polylactic acid, gelatin, fibroin, polylactic acid-polyhydroxyacetic acid, and polycarbonate.

[0008] A second objective of this invention is to provide a method for preparing the above-mentioned sustained-release salt-accumulating snow-melting and ice-suppressing microcapsules, comprising the following steps:

[0009] Salt is dissolved in water, and then encapsulated with wall materials using spray drying, phase separation, or interfacial polymerization to obtain slow-release salt-storing, snow-melting, and ice-suppressing microcapsules.

[0010] In one embodiment of the present invention, the sustained-release salt-storage snow-melting and ice-suppressing microcapsules are prepared by spray drying, including the following steps:

[0011] Salt is dissolved in water to obtain solution A; wall material is dissolved in water and heated and stirred at 90-97℃ to obtain solution B; solution B and solution A are homogenized, dispersed and mixed evenly, and then diluted until the solid content is 10%-20% to obtain solution C; solution C is spray-dried to obtain sustained-release salt-storing, snow-melting and ice-suppressing microcapsules.

[0012] In one embodiment of the present invention, the wall material accounts for 5%-40% of the total mass of the salt and the wall material; the homogenization speed is 8000-12000 rpm, and the homogenization time is 5-15 min;

[0013] The wall material is one of gum arabic, gelatin, polyvinyl alcohol, agar, or amylose.

[0014] The spray drying conditions are: inlet temperature 180-220℃, outlet temperature 80-115℃, and inlet air volume 75-90 m³ / h. 3 / h, feed rate 10-20ml / min, pressure pump 0.15-0.3MPa.

[0015] In one embodiment of the present invention, the sustained-release salt-storage snow-melting and ice-suppressing microcapsules are prepared by phase separation method, including the following steps:

[0016] Dissolve salt in water and stir until homogeneous to obtain solution A; dissolve wall material in organic solvent A and stir to obtain solution B;

[0017] Solution B and solution A are mixed and homogenized to obtain solution D. Solution D is added to organic solvent B and stirred to obtain a complex emulsion containing microcapsules. The complex emulsion containing microcapsules is stirred and solidified to obtain sustained-release salt-snow-melting and ice-suppressing microcapsules.

[0018] In one embodiment of the present invention, the mass ratio of salt to water is 1:3-19; the wall material accounts for 5%-40% of the total mass of salt and wall material; and the mass ratio of wall material to organic solvent A is 1:1-99.

[0019] The homogenization speed is 1000-8000 rpm, and the homogenization time is 5-30 min;

[0020] The mass ratio of organic solvent B to solution D is 1:1-2.5;

[0021] The wall material is one of polylactic acid, gelatin, fibroin, polyvinyl alcohol, polylactic acid-polyhydroxyacetic acid, or polycarbonate;

[0022] Organic solvent A is one of dichloromethane, ethyl acetate, acetonitrile, heptane, chloroform, or acetone;

[0023] Organic solvent B is one of glycerol, ethanol, propylene glycol, ethylene glycol, or dimethicone.

[0024] In one embodiment of the present invention, the sustained-release salt-storage snow-melting and ice-suppressing microcapsules are prepared by interfacial polymerization, including the following steps:

[0025] Dissolve the salt and monomer A in water and stir until homogeneous to obtain solution A. Adjust the pH of solution A to 10-11 to obtain an aqueous solution.

[0026] The emulsifier is added to organic solvent C to obtain an oil phase solution;

[0027] An emulsion is obtained by homogenizing and dispersing the aqueous solution and the oil solution evenly.

[0028] Monomer D was dissolved in organic solvent D to obtain solution E. Solution E was added to an emulsion and stirred until homogeneous to obtain final solution F. Solution F was filtered, washed, and dried to obtain sustained-release salt-snow-melting and ice-suppressing microcapsules.

[0029] In one embodiment of the present invention, the mass ratio of salt to water is 1:3-19;

[0030] The ratio of emulsifier to organic solvent C is 1-3g:100ml. The emulsifier is one of sodium dodecylbenzenesulfonate, sodium alginate, sorbitol, styrene-maleic anhydride, Span 20, Span 40, Span 60, Span 80, Tween 20, Tween 40, Tween 60, and Tween 80.

[0031] The volume ratio of organic solvent C to organic solvent D and water is 2-5:1, and the volume ratio of organic solvent C to organic solvent D is 1-3:1; both organic solvent C and organic solvent D are one of cyclohexane, dichloromethane, carbon tetrachloride, toluene, and chloroform.

[0032] The total amount of monomers A and D accounts for 5%-40% of the total mass of the salt and monomers A and D, and the molar ratio of monomers A and D is 1:1; monomer A is one of ethylenediamine, ethylene glycol, and glycolic acid; monomer D is one of terephthaloyl chloride, toluene diisocyanate, and adipyl chloride.

[0033] The homogenization speed is 1000-8000 rpm, and the homogenization time is 5-30 min.

[0034] In one embodiment of the present invention, a pH adjuster is used to adjust the pH; the pH adjuster is one of sodium hydroxide, potassium hydroxide, sodium bicarbonate, sodium carbonate, and potassium carbonate.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] (1) This invention uses polymer materials as wall materials to encapsulate salt and make snow melting and ice-melting materials. Compared with wet adsorption methods and commercially available anti-freezing agents, the salt release time is longer, the ability to lower the freezing point is stronger, and the effect is more long-lasting.

[0037] (2) The wall material of the snow melting and ice suppressing material prepared by the present invention is a polymer material with good stability and corrosion resistance.

[0038] (3) The preparation method of the present invention is simple, highly controllable, and the raw materials are inexpensive, making it suitable for industrial mass production of snow melting and ice suppressing microcapsule materials. Attached Figure Description

[0039] Figure 1 The graph shows the change in conductivity after complete dissolution of the materials prepared in Examples 1-4;

[0040] Figure 2 The graph shows the change in conductivity of the materials prepared in Examples 3, 14, 26, and Comparative Example 1 after complete dissolution of the Mafilon material. Detailed Implementation

[0041] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] In salt-retaining asphalt pavements, the salt and asphalt mixture is directly mixed and used. During use, the mixture is subject to water erosion, causing the salt content to easily dissipate and compromising the durability for snow melting and ice suppression. Therefore, this invention uses a polymer material to coat the salt. Because the coating material has excellent water-blocking capabilities, it can control salt release, significantly slowing down the salt release rate, improving the utilization rate of snow melting and ice suppression, and effectively solving the problem of snow and ice accumulation on roads in winter.

[0043] Microencapsulation technology refers to the method of encapsulating a target substance (core material) within a dense membrane (wall material) to form microcapsules. The wall material is typically made of natural or synthetic polymers. Microcapsule membranes can alter the appearance and properties of substances, prolong and control the release of substances within the membrane, and improve their storage stability. Microcapsules are classified into impermeable microcapsules and semi-permeable microcapsules based on their encapsulation material. Semi-permeable microcapsules do not require disruption of the wall material during use; small molecules from the core material and environment can freely pass through the wall material, eventually reaching equilibrium, thus achieving sustained and controlled release. This invention employs three methods—spray drying, interfacial polymerization, and phase separation—to prepare release-type salt-storage, snow-melting, and ice-suppressing microcapsules.

[0044] The spray drying method involves first mixing the core material and wall material to form a spray working liquid. Then, the resulting working liquid is diluted with water to a certain concentration. The working liquid is then dispersed into uniform small droplets by the centrifugal action of the atomizer. The droplets are dried by hot air or other gases. The droplets of the core material encapsulated by the wall material will quickly solidify to form microcapsule powder.

[0045] Interfacial polymerization involves the polymerization of two substances with different active groups—oil-soluble monomers such as isocyanates and water-soluble monomers such as polyols—at the interface through a chain extender. This polymerization reaction forms a polymer film (i.e., wall material) with a certain hardness on the surface of the core material droplet, such as polyurea, polyamide, or polyurethane. This process encapsulates the target material in the core material.

[0046] The phase separation method involves dissolving the core material in water and dispersing it in a wall material dissolved in an organic solvent to form a water-in-oil internal emulsion. The internal emulsion is then added to an aqueous solution containing an emulsifier to form a W / O / W multiphase emulsion. A reagent that extracts only the organic solvent is then added and stirred. This reduces the solubility of the wall material and causes precipitation, thus achieving the encapsulation of the core material and preparing microcapsules.

[0047] Example 1

[0048] This embodiment provides a method for preparing sustained-release salt-storing snow-melting and ice-suppressing microcapsules, including the following steps:

[0049] (1) Dissolve 9.5g of sodium chloride in 50g of deionized water and stir thoroughly to obtain solution A;

[0050] (2) Dissolve 0.5g of gelatin in 10g of deionized water, stir thoroughly at 92℃ to dissolve, and cool to room temperature after dissolution to obtain solution B;

[0051] (3) Add solution A to solution B and dilute with water to a solid content of 15%. After homogenizing at 10000 rpm for 10 min, solution C is obtained.

[0052] (4) Spray dry the solution C obtained in step (3), wherein the inlet temperature is 210℃, the outlet temperature is 115℃, and the air volume is 85m³. 3 The feed rate was 15 ml / min, and the pressure pump was 0.2 MPa, to obtain sustained-release salt-snow-melting and ice-suppressing microcapsules.

[0053] Example 2

[0054] This embodiment provides a method for preparing sustained-release salt-storing snow-melting and ice-suppressing microcapsules, including the following steps:

[0055] (1) Dissolve 9g of sodium chloride in 50g of deionized water and stir thoroughly to obtain solution A;

[0056] (2) Dissolve 1g of gelatin in 10g of deionized water, stir thoroughly at 92℃ to dissolve, and cool to room temperature after dissolution to obtain solution B;

[0057] (3) Add solution A to solution B and dilute with water to a solid content of 15%. After homogenizing at 10000 rpm for 10 min, solution C is obtained.

[0058] (4) Spray dry the solution C obtained in step (3), wherein the inlet temperature is 210℃, the outlet temperature is 115℃, and the air volume is 85m³. 3 The feed rate was 15 ml / min, and the pressure pump was 0.2 MPa, to obtain sustained-release salt-snow-melting and ice-suppressing microcapsules.

[0059] Example 3

[0060] This embodiment provides a method for preparing sustained-release salt-storing snow-melting and ice-suppressing microcapsules, including the following steps:

[0061] (1) Dissolve 8g of sodium chloride in 50g of deionized water and stir thoroughly to obtain solution A;

[0062] (2) Dissolve 2g of gelatin in 10g of deionized water, stir thoroughly at 92℃ to dissolve, and cool to room temperature after dissolution to obtain solution B;

[0063] (3) Add solution A to solution B and dilute with water to a solid content of 15%. After homogenizing at 10000 rpm for 10 min, solution C is obtained.

[0064] (4) Spray dry the solution C obtained in step (3), wherein the inlet temperature is 215℃, the outlet temperature is 115℃, and the air volume is 85m³. 3 The feed rate was 15 ml / min, and the pressure pump was 0.2 MPa, to obtain sustained-release salt-snow-melting and ice-suppressing microcapsules.

[0065] Example 4

[0066] (1) Dissolve 6g of sodium chloride in 50g of deionized water and stir thoroughly to obtain solution A;

[0067] (2) Dissolve 4g of gelatin in 10g of deionized water, stir thoroughly at 92℃, and cool to room temperature after dissolution to obtain solution B;

[0068] (3) Add solution A to solution B and dilute with water to a solid content of 15%. After homogenizing at 10000 rpm for 10 min, solution C is obtained.

[0069] (4) Spray dry the solution C obtained in step (3), wherein the inlet temperature is 215℃, the outlet temperature is 115℃, and the air volume is 85m³. 3 The feed rate was 15 ml / min, and the pressure pump was 0.2 MPa, to obtain sustained-release salt-snow-melting and ice-suppressing microcapsules.

[0070] Example 5

[0071] This embodiment provides a method for preparing sustained-release salt-storing snow-melting and ice-suppressing microcapsules, including the following steps:

[0072] (1) Dissolve 8g of sodium chloride in 50g of deionized water and stir thoroughly to obtain solution A;

[0073] (2) Dissolve 2g of agar in 10g of deionized water, stir thoroughly at 92℃, and cool to room temperature after dissolution to obtain solution B;

[0074] (3) Add solution A to solution B and dilute with water to a solid content of 15%. After homogenizing at 10000 rpm for 10 min, solution C is obtained.

[0075] (4) Spray dry the solution C obtained in step (3), wherein the inlet temperature is 215℃, the outlet temperature is 115℃, and the air volume is 85m³. 3 The feed rate was 15 ml / min, and the pressure pump was 0.2 MPa, to obtain sustained-release salt-snow-melting and ice-suppressing microcapsules.

[0076] Example 6

[0077] This embodiment provides a method for preparing sustained-release salt-storing snow-melting and ice-suppressing microcapsules, including the following steps:

[0078] (1) Dissolve 8g of sodium chloride in 50g of deionized water and stir thoroughly to obtain solution A;

[0079] (2) Dissolve 2g of amylose in 10g of deionized water, stir thoroughly at 92℃, and cool to room temperature after dissolution to obtain solution B;

[0080] (3) Add solution A to solution B and dilute with water to a solid content of 15%. After homogenizing at 10000 rpm for 10 min, solution C is obtained.

[0081] (4) Spray dry the solution C obtained in step (3), wherein the inlet temperature is 215℃, the outlet temperature is 115℃, and the air volume is 85m³. 3 The feed rate was 15 ml / min, and the pressure pump was 0.2 MPa, to obtain sustained-release salt-snow-melting and ice-suppressing microcapsules.

[0082] Example 7

[0083] This embodiment provides a method for preparing sustained-release salt-storing snow-melting and ice-suppressing microcapsules, including the following steps:

[0084] (1) Dissolve 8g of sodium chloride in 50g of deionized water and stir thoroughly to obtain solution A;

[0085] (2) Dissolve 2g of polyvinyl alcohol in 10g of deionized water, stir thoroughly at 92℃ to dissolve, and cool to room temperature after dissolution to obtain solution B;

[0086] (3) Add solution A to solution B and dilute with water to a solid content of 15%. After homogenizing at 10000 rpm for 10 min, solution C is obtained.

[0087] (4) Spray dry the solution C obtained in step (3), wherein the inlet temperature is 215℃, the outlet temperature is 115℃, and the air volume is 85m³. 3 The feed rate was 15 ml / min, and the pressure pump was 0.2 MPa, to obtain sustained-release salt-snow-melting and ice-suppressing microcapsules.

[0088] Example 8

[0089] This embodiment provides a method for preparing sustained-release salt-storing snow-melting and ice-suppressing microcapsules, including the following steps:

[0090] (1) Dissolve 9.5g of calcium chloride in 50g of deionized water and stir thoroughly to obtain solution A;

[0091] (2) Dissolve 0.5g of gum arabic in 10g of deionized water, stir thoroughly at 92℃ to dissolve, and then cool to room temperature to obtain solution B;

[0092] (3) Add solution A to solution B and dilute with water to a solid content of 15%. After homogenization at 8000 rpm for 5 min, solution C is obtained.

[0093] (4) Spray dry the solution C obtained in step (3), wherein the inlet temperature is 180℃, the outlet temperature is 80℃, and the air volume is 75m³. 3 The feed rate was 10 ml / min, and the pressure pump was 0.15 MPa, to obtain sustained-release salt-storage snow-melting and ice-suppressing microcapsules.

[0094] Example 9

[0095] This embodiment provides a method for preparing sustained-release salt-storing snow-melting and ice-suppressing microcapsules, including the following steps:

[0096] (1) Dissolve 9.5g of potassium acetate in 50g of deionized water and stir thoroughly to obtain solution A;

[0097] (2) Dissolve 0.5g of agar in 10g of deionized water, stir thoroughly at 92℃ to dissolve, and then cool to room temperature to obtain solution B;

[0098] (3) Add solution A to solution B and dilute with water to a solid content of 15%. After homogenizing at 12000 rpm for 15 min, solution C is obtained.

[0099] (4) Spray dry the solution C obtained in step (3), wherein the inlet temperature is 220℃, the outlet temperature is 100℃, and the air volume is 90m³. 3 The feed rate was 20 ml / min, and the pressure pump was 0.3 MPa, to obtain sustained-release salt-storage snow-melting and ice-suppressing microcapsules.

[0100] Example 10

[0101] This embodiment provides a method for preparing sustained-release salt-storing snow-melting and ice-suppressing microcapsules, including the following steps:

[0102] (1) Dissolve 9.5g of magnesium chloride in 50g of deionized water and stir thoroughly to obtain solution A;

[0103] (2) Dissolve 0.5g of polyvinyl alcohol in 10g of deionized water, stir thoroughly at 90℃ to dissolve, and cool to room temperature after dissolution to obtain solution B;

[0104] (3) Add solution A to solution B and dilute with water to a solid content of 10%. After homogenization at 8000 rpm for 10 min, solution C is obtained.

[0105] (4) Spray dry the solution C obtained in step (3), wherein the inlet temperature is 210℃, the outlet temperature is 115℃, and the air volume is 85m³. 3 The feed rate was 15 ml / min, and the pressure pump was 0.2 MPa, to obtain sustained-release salt-snow-melting and ice-suppressing microcapsules.

[0106] Example 11

[0107] This embodiment provides a method for preparing sustained-release salt-storing snow-melting and ice-suppressing microcapsules, including the following steps:

[0108] (1) Dissolve 9.5g of potassium chloride in 50g of deionized water and stir thoroughly to obtain solution A;

[0109] (2) Dissolve 0.5g of amylose in 10g of deionized water, stir thoroughly at 97℃ to dissolve, and then cool to room temperature to obtain solution B;

[0110] (3) Add solution A to solution B and dilute with water to a solid content of 20%. After homogenizing at 10000 rpm for 10 min, solution C is obtained.

[0111] (4) Spray dry the solution C obtained in step (3), wherein the inlet temperature is 210℃, the outlet temperature is 115℃, and the air volume is 85m³. 3 The feed rate was 15 ml / min, and the pressure pump was 0.2 MPa, to obtain sustained-release salt-snow-melting and ice-suppressing microcapsules.

[0112] Example 12

[0113] (1) Dissolve 9.5g of sodium chloride in 100g of deionized water to obtain a salt solution;

[0114] (2) Add 0.5g of polylactic acid to 40g of dichloromethane to obtain oil phase 1;

[0115] (3) Add the salt solution to the oil phase 1 and homogenize it at 5000 rpm for 10 min to form a uniform water-in-oil emulsion.

[0116] (4) Add the emulsion obtained in step (3) to 60g of propylene glycol and stir to form a complex emulsion containing microcapsules;

[0117] (5) The microcapsule-containing emulsion from step (4) was solidified by magnetic stirring at 200 rpm for 1 hour to obtain the final microcapsules.

[0118] Example 13

[0119] (1) Dissolve 9g of sodium chloride in 100g of deionized water to obtain a salt solution;

[0120] (2) Add 1g of polylactic acid to 40g of dichloromethane to obtain oil phase 1;

[0121] (3) Add the salt solution to the oil phase 1 and homogenize it at 5000 rpm for 10 min to form a uniform water-in-oil emulsion.

[0122] (4) Add the emulsion obtained in step (3) to 60g of propylene glycol and stir to form a complex emulsion containing microcapsules;

[0123] (5) The microcapsule-containing emulsion from step (4) was solidified by magnetic stirring at 200 rpm for 1 hour to obtain the final microcapsules.

[0124] Example 14

[0125] (1) Dissolve 8g of sodium chloride in 100g of deionized water to obtain a salt solution;

[0126] (2) Add 2g of polylactic acid to 40g of dichloromethane to obtain oil phase 1;

[0127] (3) Add the salt solution to the oil phase 1 and homogenize it at 5000 rpm for 10 min to form a uniform water-in-oil emulsion.

[0128] (4) Add the emulsion obtained in step (3) to 60g of propylene glycol and stir to form a complex emulsion containing microcapsules;

[0129] (5) The microcapsule-containing emulsion from step (4) was solidified by magnetic stirring at 200 rpm for 1 hour to obtain the final microcapsules.

[0130] Example 15

[0131] (1) Dissolve 6g of sodium chloride in 100g of deionized water to obtain a salt solution;

[0132] (2) Add 4g of polylactic acid to 40g of dichloromethane to obtain oil phase 1;

[0133] (3) Add the salt solution to the oil phase 1 and homogenize it at 5000 rpm for 10 min to form a uniform water-in-oil emulsion.

[0134] (4) Add the emulsion obtained in step (3) to 60g of propylene glycol and stir to form a complex emulsion containing microcapsules;

[0135] (5) The microcapsule-containing emulsion from step (4) was solidified by magnetic stirring at 200 rpm for 1 hour to obtain the final microcapsules.

[0136] Example 16

[0137] (1) Dissolve 8g of sodium chloride in 100g of deionized water to obtain a salt solution;

[0138] (2) Add 2g of gelatin to 40g of dichloromethane to obtain oil phase 1;

[0139] (3) Add the salt solution to the oil phase 1 and homogenize it at 5000 rpm for 10 min to form a uniform water-in-oil emulsion.

[0140] (4) Add the emulsion obtained in step (3) to 60g of propylene glycol and stir to form a complex emulsion containing microcapsules;

[0141] (5) The microcapsule-containing emulsion from step (4) was solidified by magnetic stirring at 200 rpm for 1 hour to obtain the final microcapsules.

[0142] Example 17

[0143] (1) Dissolve 8g of sodium chloride in 100g of deionized water to obtain a salt solution;

[0144] (2) Add 2g of polyvinyl alcohol to 40g of dichloromethane to obtain oil phase 1;

[0145] (3) Add the salt solution to the oil phase 1 and homogenize it at 5000 rpm for 10 min to form a uniform water-in-oil emulsion.

[0146] (4) Add the emulsion obtained in step (3) to 60g of propylene glycol and stir to form a complex emulsion containing microcapsules;

[0147] (5) The microcapsule-containing emulsion from step (4) was solidified by magnetic stirring at 200 rpm for 1 hour to obtain the final microcapsules.

[0148] Example 18

[0149] (1) Dissolve 8g of sodium chloride in 100g of deionized water to obtain a salt solution;

[0150] (2) Add 2g of fibrin to 40g of dichloromethane to obtain oil phase 1;

[0151] (3) Add the salt solution to the oil phase 1 and homogenize it at 5000 rpm for 10 min to form a uniform water-in-oil emulsion.

[0152] (4) Add the emulsion obtained in step (3) to 60g of propylene glycol and stir to form a complex emulsion containing microcapsules;

[0153] (5) The microcapsule-containing emulsion from step (4) was solidified by magnetic stirring at 200 rpm for 1 hour to obtain the final microcapsules.

[0154] Example 19

[0155] (1) Dissolve 6g of calcium chloride in 27g of deionized water to obtain a salt solution;

[0156] (2) Add 1g of gelatin to 1g of ethyl acetate to obtain oil phase 1;

[0157] (3) Add the salt solution to the oil phase 1 and homogenize and shear at 1000 rpm for 30 min to form a uniform water-in-oil emulsion;

[0158] (4) Add the emulsion obtained in step (3) to 35g of glycerin and stir to form a compound emulsion containing microcapsules;

[0159] (5) The microcapsule-containing emulsion from step (4) was solidified by magnetic stirring at 200 rpm for 1 hour to obtain the final microcapsules.

[0160] Example 20

[0161] (1) Dissolve 6g of potassium chloride in 114g of deionized water to obtain a salt solution;

[0162] (2) Add 4g of fibrin to 396g of heptane to obtain oil phase 1;

[0163] (3) Add the salt solution to the oil phase 1 and homogenize and shear at 8000 rpm for 5 min to form a uniform water-in-oil emulsion;

[0164] (4) Add the emulsion obtained in step (3) to 260g of ethanol and stir to form a complex emulsion containing microcapsules;

[0165] (5) The microcapsule-containing emulsion from step (4) was solidified by magnetic stirring at 200 rpm for 1 hour to obtain the final microcapsules.

[0166] Example 21

[0167] (1) Dissolve 9g of potassium acetate in 100g of deionized water to obtain a salt solution;

[0168] (2) Add 1g of polyvinyl alcohol to 40g of acetonitrile to obtain oil phase 1;

[0169] (3) Add the salt solution to the oil phase 1 and homogenize it at 5000 rpm for 10 min to form a uniform water-in-oil emulsion.

[0170] (4) Add the emulsion obtained in step (3) to 60g of propylene glycol and stir to form a complex emulsion containing microcapsules;

[0171] (5) The microcapsule-containing emulsion from step (4) was solidified by magnetic stirring at 200 rpm for 1 hour to obtain the final microcapsules.

[0172] Example 22

[0173] (1) Dissolve 9g of potassium acetate in 100g of deionized water to obtain a salt solution;

[0174] (2) Add 1g of polylactic acid-polyhydroxyacetic acid to 50g of acetone to obtain oil phase 1;

[0175] (3) Add the salt solution to the oil phase 1 and homogenize it at 6000 rpm for 10 min to form a uniform water-in-oil emulsion.

[0176] (4) Add the emulsion obtained in step (3) to 70g of ethylene glycol and stir to form a double emulsion containing microcapsules;

[0177] (5) The microcapsule-containing emulsion from step (4) was solidified by magnetic stirring at 200 rpm for 1 hour to obtain the final microcapsules.

[0178] Example 23

[0179] (1) Dissolve 9g of potassium acetate in 100g of deionized water to obtain a salt solution;

[0180] (2) Add 1g of polycarbonate to 40g of chloroform to obtain oil phase 1;

[0181] (3) Add the salt solution to the oil phase 1 and homogenize it at 6000 rpm for 10 min to form a uniform water-in-oil emulsion.

[0182] (4) Add the emulsion obtained in step (3) to 60g of dimethicone and stir to form a complex emulsion containing microcapsules;

[0183] (5) The microcapsule-containing emulsion from step (4) was solidified by magnetic stirring at 200 rpm for 1 hour to obtain the final microcapsules.

[0184] Example 24

[0185] (1) Add 9.5g of sodium chloride and 0.1579g of ethylenediamine to 50g of water and dissolve them completely. Then use sodium hydroxide to adjust the pH to 10.5 to form an aqueous phase.

[0186] (2) Add 1g of sodium dodecylbenzenesulfonate to 100ml of chloroform and stir to form an oil phase;

[0187] (3) The aqueous phase in step (1) is slowly added to the oil phase in step (2) and homogenized and sheared at 5000 rpm for 10 min to obtain a stable W / O emulsion.

[0188] (4) Weigh 0.5342 g of terephthaloyl chloride and dissolve it in 50 ml of chloroform to obtain oil phase 2. Slowly add oil phase 2 to W / O emulsion using a peristaltic pump and polymerize for 20 min to obtain a suspension containing microcapsules.

[0189] (5) The suspension was filtered with deionized water, washed 3-5 times, and finally dried in an oven at 60°C for 24 hours to obtain salt-accumulating microcapsule powder.

[0190] Example 25

[0191] (1) Add 9g of sodium chloride and 0.3158g of ethylenediamine to 50g of water and dissolve them completely. Then use sodium hydroxide to adjust the pH to 10.5 to form an aqueous phase.

[0192] (2) Add 1g of sodium dodecylbenzenesulfonate to 100ml of chloroform and stir to form oil phase 1;

[0193] (3) The aqueous phase in step (1) is slowly added to the oil phase in step (2) and homogenized and sheared at 5000 rpm for 10 min to obtain a stable W / O emulsion.

[0194] (4) Weigh 1.0684 g of terephthaloyl chloride and dissolve it in 50 ml of chloroform to obtain oil phase 2. Slowly add oil phase 2 to W / O emulsion using a peristaltic pump and polymerize for 20 min to obtain a suspension containing microcapsules.

[0195] (5) The suspension was filtered with deionized water, washed 3-5 times, and finally dried in an oven at 60°C for 24 hours to obtain salt-accumulating microcapsule powder.

[0196] Example 26

[0197] (1) Add 8g of sodium chloride and 0.6316g of ethylenediamine to 50g of water and dissolve them completely. Then use sodium hydroxide to adjust the pH to 10.5 to form an aqueous phase.

[0198] (2) Add 1g of sodium dodecylbenzenesulfonate to 100ml of chloroform and stir to form oil phase 1;

[0199] (3) The aqueous phase in step (1) is slowly added to the oil phase in step (2) and homogenized and sheared at 5000 rpm for 10 min to obtain a stable W / O emulsion.

[0200] (4) Weigh 2.1368g of terephthaloyl chloride and dissolve it in 50ml of chloroform to obtain oil phase 2. Slowly add oil phase 2 to W / O emulsion using a peristaltic pump and polymerize for 20min to obtain a suspension containing microcapsules.

[0201] (5) The suspension was filtered with deionized water, washed 3-5 times, and finally dried in an oven at 60°C for 24 hours to obtain salt-accumulating microcapsule powder.

[0202] Example 27

[0203] (1) Add 6g of sodium chloride and 1.2632g of ethylenediamine to 50g of water and dissolve them completely. Then use sodium hydroxide to adjust the pH to 10.5 to form an aqueous phase.

[0204] (2) Add 1g of sodium dodecylbenzenesulfonate to 100ml of chloroform and stir to form oil phase 1;

[0205] (3) The aqueous phase in step (1) is slowly added to the oil phase in step (2) and homogenized and sheared at 5000 rpm for 10 min to obtain a stable W / O emulsion.

[0206] (4) Weigh 4.2737 g of terephthaloyl chloride and dissolve it in 50 ml of chloroform to obtain oil phase 2. Slowly add oil phase 2 to W / O emulsion using a peristaltic pump and polymerize for 20 min to obtain a suspension containing microcapsules.

[0207] (5) The suspension was filtered with deionized water, washed 3-5 times, and finally dried in an oven at 60°C for 24 hours to obtain salt-accumulating microcapsule powder.

[0208] Example 28

[0209] (1) Add 8g of sodium chloride and 0.7453g of ethylenediamine to 50g of water and dissolve them completely. Then use sodium hydroxide to adjust the pH to 10.5 to form an aqueous phase.

[0210] (2) Add 1g of sodium dodecylbenzenesulfonate to 100ml of chloroform and stir to form oil phase 1;

[0211] (3) The aqueous phase in step (1) is slowly added to the oil phase in step (2) and homogenized and sheared at 5000 rpm for 10 min to obtain a stable W / O emulsion.

[0212] (4) Weigh 2.1615g of toluene diisocyanate and dissolve it in 50ml of chloroform to obtain oil phase 2. Slowly add oil phase 2 to W / O emulsion using a peristaltic pump and polymerize for 20min to obtain a suspension containing microcapsules.

[0213] (5) The suspension was filtered with deionized water, washed 3-5 times, and finally dried in an oven at 60°C for 24 hours to obtain salt-accumulating microcapsule powder.

[0214] Example 29

[0215] (1) Add 8g of sodium chloride and 0.7059g of ethylenediamine to 50g of water and dissolve them completely. Then use sodium hydroxide to adjust the pH to 10.5 to form an aqueous phase.

[0216] (2) Add 1g of sodium dodecylbenzenesulfonate to 100ml of chloroform and stir to form oil phase 1;

[0217] (3) The aqueous phase in step (1) is slowly added to the oil phase in step (2) and homogenized and sheared at 5000 rpm for 10 min to obtain a stable W / O emulsion.

[0218] (4) Weigh 2.1529g of adipic acid chloride and dissolve it in 50ml of chloroform to obtain oil phase 2. Slowly add oil phase 2 to W / O emulsion using a peristaltic pump and polymerize for 20min to obtain a suspension containing microcapsules.

[0219] (5) The suspension was filtered with deionized water, washed 3-5 times, and finally dried in an oven at 60°C for 24 hours to obtain salt-accumulating microcapsule powder.

[0220] Example 30

[0221] (1) Add 9g of potassium acetate and 0.3803g of ethylene glycol to 27g of water and dissolve them completely. Then use sodium bicarbonate to adjust the pH to 10 to form an aqueous phase.

[0222] (2) Add 1.35g of sodium alginate to 67.5ml of toluene and stir to form oil phase 1;

[0223] (3) Slowly add the aqueous phase from step (1) to the oil phase from step (2) and homogenize and shear at 8000 rpm for 5 min to obtain a stable W / O emulsion.

[0224] (4) Weigh 1.0675g of toluene diisocyanate and dissolve it in 67.5ml of toluene to obtain oil phase 2. Slowly add oil phase 2 to W / O emulsion by peristaltic pump and polymerize for 20min to obtain a suspension containing microcapsules.

[0225] (5) The suspension was filtered with deionized water, washed 3-5 times, and finally dried in an oven at 60°C for 24 hours to obtain salt-accumulating microcapsule powder.

[0226] Example 31

[0227] (1) Add 6g of magnesium chloride and 1.2917g of glycolate to 114g of water and dissolve them completely. Use sodium carbonate to adjust the pH to 11 to form an aqueous phase.

[0228] (2) Add 5.13g of sorbitol to 171ml of dichloromethane and stir to form oil phase 1;

[0229] (3) The aqueous phase in step (1) is slowly added to the oil phase in step (2) and homogenized and sheared at 1000 rpm for 30 min to obtain a stable W / O emulsion.

[0230] (4) Weigh 4.2292g of terephthaloyl chloride and dissolve it in 57ml of dichloromethane to obtain oil phase 2. Slowly add oil phase 2 to W / O emulsion using a peristaltic pump and polymerize for 20min to obtain a suspension containing microcapsules.

[0231] (5) The suspension was filtered with deionized water, washed 3-5 times, and finally dried in an oven at 60°C for 24 hours to obtain salt-accumulating microcapsule powder.

[0232] Example 32

[0233] (1) Add 8g of calcium chloride and 0.7059g of ethylenediamine to 50g of water and dissolve them completely. Then use potassium carbonate to adjust the pH to 10.5 to form an aqueous phase.

[0234] (2) Add 1g Span 20 to 100ml cyclohexane and stir to form oil phase 1;

[0235] (3) The aqueous phase in step (1) is slowly added to the oil phase in step (2) and homogenized and sheared at 5000 rpm for 20 min to obtain a stable W / O emulsion.

[0236] (4) Weigh 2.1529g of adipic acid chloride and dissolve it in 50ml of cyclohexane to obtain oil phase 2. Slowly add oil phase 2 to W / O emulsion using a peristaltic pump and polymerize for 20min to obtain a suspension containing microcapsules.

[0237] (5) The suspension was filtered with deionized water, washed 3-5 times, and finally dried in an oven at 60°C for 24 hours to obtain salt-accumulating microcapsule powder.

[0238] Span 20 can also be replaced with Span 40, Span 60 or Span 80.

[0239] Example 33

[0240] (1) Add 9g of potassium chloride and 0.3229g of glycolate to 50g of water and dissolve them completely. Then use potassium hydroxide to adjust the pH to 10.5 to form an aqueous phase.

[0241] (2) Add 1g of Tween 20 to 100ml of carbon tetrachloride and stir to form oil phase 1;

[0242] (3) The aqueous phase in step (1) is slowly added to the oil phase in step (2) and homogenized and sheared at 5000 rpm for 10 min to obtain a stable W / O emulsion.

[0243] (4) Weigh 1.0573g of terephthaloyl chloride and dissolve it in 50ml of carbon tetrachloride to obtain oil phase 2. Slowly add oil phase 2 to W / O emulsion using a peristaltic pump and polymerize for 20min to obtain a suspension containing microcapsules.

[0244] (5) The suspension was filtered with deionized water, washed 3-5 times, and finally dried in an oven at 60°C for 24 hours to obtain salt-accumulating microcapsule powder.

[0245] Tween 20 can also be replaced with Tween 40, Tween 60 or Tween 80.

[0246] Comparative Example 1

[0247] 16g of sodium chloride was completely dissolved in 200mL of deionized water, 4g of carrier was added, and the mixture was stirred at a constant temperature of 70℃ until it became a paste. The paste was then dried in an oven at 60℃ and pulverized in a universal pulverizer until it could pass through a 0.075mm sieve. This yielded the wet-process sodium chloride carrier material.

[0248] The performance of the sustained-release salt-snow-melting and ice-suppressing microcapsules prepared in this invention will be analyzed below.

[0249] (1) The dissolution test of the slow-release salt-storing snow-melting and ice-suppressing microcapsules in Examples 1-4 was analyzed. 150 mL of deionized water and 1 g of material were added to a dissolution vessel. The temperature of the dissolution apparatus was set to 25 °C, and the mixture was stirred at a low speed of 100 r / min. The conductivity of the solution was continuously measured using a conductivity meter. Generally, the more ions in the solution, the better the ability to transfer electrons, and the higher the conductivity value. Higher conductivity means more snow-melting salt precipitates into the solution. The results are shown in […]. Figure 1 .

[0250] Depend on Figure 1 As can be seen from Examples 1-4, as the wall-core material ratio of the snow-melting and ice-suppressing microcapsules increases from 5% to 40%, the conductivity of complete dissolution increases from 9890 μS·cm. -1 Reduced to 6284 μs·cm -1 The results indicate that the lower the salt content of the snow-melting and ice-suppressing microcapsules, the lower the conductivity upon complete dissolution, and consequently, the weaker the snow-melting and ice-suppressing ability. The unchanged conductivity indicates complete dissolution of the salt in the material. Specifically, as the wall-to-core material ratio increased from 5% to 20%, the dissolution time increased from 80 min to 100 min. However, when the wall material ratio increased from 20% to 40%, the dissolution time remained unchanged at 100 min. This demonstrates that both the wall and core material contents affect the dissolution time, and a longer dissolution time indicates a longer sustained-release time and stronger sustained-release ability. In summary, Example 3, with a wall-to-core ratio of 20%, exhibits better performance and better meets the requirements for road snow and ice melting.

[0251] (2) Analysis of the water permeability test of the slow-release salt-storing snow melting and ice-suppressing microcapsules and some existing snow melting and ice-suppressing materials in the embodiment: at 25°C, several small holes were punched in the bottom of a transparent disposable plastic cup, 20g of sample was spread flat and pressed firmly on the bottom of the cup, and 100mL of deionized water was slowly poured in along the cup wall. The permeation time and the time to complete flow were observed. The chloride ion was measured in the filtrate or supernatant using a chloride ion analyzer. The longer the permeation time and the time to complete flow, the stronger the hydrophobicity of the material and the stronger the slow-release ability. The test results are shown in Table 1.

[0252] Table 1. Water permeability of different materials

[0253]

[0254]

[0255] As shown in Table 1, the permeation time and flow completion time of pure sodium chloride were 5s and 15s, respectively. The permeation time of Comparative Example 1, prepared using wet adsorption, was extended to 40s, and the flow completion time was 5h. Currently, the effective snow-melting and ice-suppressing agent Mafilon has a permeation time of 48h and a flow completion time of 5d. However, the permeation time and flow completion time of sodium chloride coated with the wall material were both increased compared to Mafilon, indicating that water is less likely to permeate through the microcapsule wall material, resulting in a significantly improved sustained-release time and enhanced sustained-release performance. Although Examples 3 and 16 used the same wall material, their preparation methods differed. The permeation time and flow completion time of the material prepared by spray drying in Example 3 were 60h and 8d, respectively, while those of the material prepared by phase separation in Example 1 were 55h and 7d. This shows that the permeation time and flow completion time of the material prepared in Example 1 were longer than those in Example 16, indicating that the microcapsule product prepared by spray drying has better quality and the wall material can better coat the core material. Furthermore, the permeation time and flow completion time of the materials prepared by the interfacial polymerization method in Examples 26, 28, and 29 were 65h and 9d, 65h and 9d, and 64h and 9d, respectively. It can be seen that the dissolution time and flow completion time of the snow melting and ice suppressing microcapsules prepared by the interfacial polymerization method are longer than those prepared by the other two methods, while the sodium chloride concentration is relatively low. This indicates that the microcapsule wall material prepared by this method has stronger hydrophobicity and stronger sustained-release ability.

[0256] (3) The freezing point test of the slow-release salt-storing snow-melting and ice-suppressing microcapsules and some existing snow-melting and ice-suppressing materials in the analysis example was conducted. 10 mL of deionized water was added to each of the three test tubes, and 2 g of sample was added to the water. The test tubes were placed in a low-temperature constant-temperature reaction bath and the temperature was continuously lowered. The freezing point of the solution was measured with a thermometer. The lower the freezing point, the stronger the snow-melting and ice-suppressing ability. The test results are shown in Table 2.

[0257] Table 2 Freezing points of different materials

[0258]

[0259]

[0260] As shown in Table 2, the freezing points of the materials prepared by spray drying in Examples 3, 5, 6, and 7 were -7.34℃, -7.85℃, -7.08℃, and -7.40℃, respectively; the freezing points of the materials prepared by phase separation in Examples 14, 16, 17, and 18 were -5.87℃, -6.14℃, -6.20℃, and -5.98℃, respectively; and the freezing points of the materials prepared by interfacial polymerization in Examples 26, 28, and 29 were -7.46℃, -7.43℃, and -7.38℃, respectively. Among these, the freezing points of the materials prepared in Examples 3 and 16 were -7.31℃ and -6.14℃, respectively. The material prepared in Example 3 using gelatin as the wall material had a lower freezing point and stronger snow-melting and ice-suppressing ability, further demonstrating that the microcapsule wall material prepared by spray drying can better encapsulate the core material than the microcapsules prepared by phase separation. The freezing point of the snow-melting and ice-suppressing microcapsules prepared in the above embodiments is lower than that of Comparative Example 1 and Mafilon, indicating that the snow-melting and ice-suppressing microcapsules prepared in this invention have a stronger ability to lower the freezing point and more effectively suppress snow accumulation and ice formation on road surfaces.

[0261] (4) Dissolution tests were conducted on the slow-release salt-storing snow-melting and ice-suppressing microcapsules and some existing snow-melting and ice-suppressing materials in the analysis examples. Specifically, 150 mL of deionized water and 1 g of material were added to a dissolution vessel. The dissolution apparatus was set to 25°C, and the mixture was stirred at a low speed of 100 r / min. The conductivity of the solution was continuously measured using a conductivity meter. Generally, the more ions in the solution, the better the ability to transfer electrons, and the higher the conductivity value. Higher conductivity means more snow-melting salt is precipitated into the solution. The results are shown in […]. Figure 2 .

[0262] Depend on Figure 2 It can be seen that the conductivity of sodium chloride in Examples 3, 14, 26, Mafilon, and Comparative Example 1 was 8300 μS / cm when completely dissolved. -1 8329μS / cm -1 8312μS / cm -1 8357μS / cm -1 8339μS / cm -1The similar electrical conductivity indicates that the salt content of the materials is basically the same, and the lack of change in electrical conductivity indicates that the salt in the materials has been completely dissolved. Among them, the material prepared by interfacial polymerization in Example 26 has the longest dissolution time of 120 min and the strongest sustained-release ability. The material prepared by spray drying in Example 3 has a dissolution time of 100 min, the material prepared by phase separation in Example 14 has a dissolution time of 90 min, the material prepared by phase separation in Comparative Example 1 has a dissolution time of 30 min, and the material prepared by Mafilon has a dissolution time of 70 min. It can be seen that the snow melting and ice suppressing microcapsules prepared by the three methods have a longer dissolution time than the materials prepared by wet adsorption in Comparative Example 1 and Mafilon. This indicates that the sodium chloride in the snow melting and ice suppressing microcapsules prepared by the present invention has a lower dissolution and diffusion rate in aqueous solution, better sustained-release effect, and stronger snow melting and ice suppressing ability in road use.

[0263] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0264] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A sustained-release salt-absorbing, snow-melting, and ice-suppressing microcapsule, characterized in that, Slow-release salt-storage snow-melting and ice-suppressing microcapsules were prepared using polymer materials as wall materials and salt as core materials.

2. The sustained-release salt-storing, snow-melting, and ice-suppressing microcapsule according to claim 1, characterized in that, The salt is one of potassium acetate, sodium chloride, calcium chloride, magnesium chloride, and potassium chloride. The polymer material is one of gum arabic, gelatin, polyvinyl alcohol, agar, linear starch, polylactic acid, gelatin, fibroin, polylactic acid-polyhydroxyacetic acid, and polycarbonate.

3. A method for preparing the sustained-release salt-storing snow-melting and ice-suppressing microcapsules according to any one of claims 1-2, characterized in that, Includes the following steps: Salt is dissolved in water, and then encapsulated with wall materials using spray drying, phase separation, or interfacial polymerization to obtain slow-release salt-storing, snow-melting, and ice-suppressing microcapsules.

4. The preparation method of the sustained-release salt-storing snow-melting and ice-suppressing microcapsules according to claim 3, characterized in that, The sustained-release salt-storage snow-melting and ice-suppressing microcapsules were prepared by spray drying, including the following steps: Salt is dissolved in water to obtain solution A; wall material is dissolved in water and heated and stirred at 90-97℃ to obtain solution B; solution B and solution A are homogenized, dispersed and mixed evenly, and then diluted until the solid content is 10%-20% to obtain solution C; solution C is spray-dried to obtain sustained-release salt-storing, snow-melting and ice-suppressing microcapsules.

5. The preparation method of the sustained-release salt-storing snow-melting and ice-suppressing microcapsules according to claim 4, characterized in that, The wall material accounts for 5%-40% of the total mass of salt and wall material; the homogenization speed is 8000-12000 rpm, and the homogenization time is 5-15 min; The wall material is one of gum arabic, gelatin, polyvinyl alcohol, agar, or amylose. The spray drying conditions are: inlet temperature 180-220℃, outlet temperature 80-115℃, and inlet air volume 75-90 m³ / h. 3 / h, feed rate 10-20ml / min, pressure pump 0.15-0.3MPa.

6. The preparation method of the sustained-release salt-storing snow-melting and ice-suppressing microcapsules according to claim 3, characterized in that, The sustained-release salt-storage snow-melting and ice-suppressing microcapsules were prepared by phase separation method, including the following steps: Dissolve salt in water and stir until homogeneous to obtain solution A; dissolve wall material in organic solvent A and stir to obtain solution B; Solution B and solution A are mixed and homogenized to obtain solution D. Solution D is added to organic solvent B and stirred to obtain a complex emulsion containing microcapsules. The complex emulsion containing microcapsules is stirred and solidified to obtain sustained-release salt-snow-melting and ice-suppressing microcapsules.

7. The preparation method of the sustained-release salt-storing snow-melting and ice-suppressing microcapsules according to claim 6, characterized in that, The mass ratio of salt to water is 1:3-19; the wall material accounts for 5%-40% of the total mass of salt and wall material; the mass ratio of wall material to organic solvent A is 1:1-99. The homogenization speed is 1000-8000 rpm, and the homogenization time is 5-30 min; The mass ratio of organic solvent B to solution D is 1:1-2.5; The wall material is one of polylactic acid, gelatin, fibroin, polyvinyl alcohol, polylactic acid-polyhydroxyacetic acid, or polycarbonate; Organic solvent A is one of dichloromethane, ethyl acetate, acetonitrile, heptane, chloroform, or acetone; Organic solvent B is one of glycerol, ethanol, propylene glycol, ethylene glycol, or dimethicone.

8. The method for preparing the sustained-release salt-storing snow-melting and ice-suppressing microcapsules according to claim 3, characterized in that, The sustained-release salt-storing snow-melting and ice-suppressing microcapsules were prepared by interfacial polymerization, including the following steps: Dissolve the salt and monomer A in water and stir until homogeneous to obtain solution A. Adjust the pH of solution A to 10-11 to obtain an aqueous solution. The emulsifier is added to organic solvent C to obtain an oil phase solution; An emulsion is obtained by homogenizing and dispersing the aqueous solution and the oil solution evenly. Monomer D was dissolved in organic solvent D to obtain solution E. Solution E was added to an emulsion and stirred until homogeneous to obtain final solution F. Solution F was filtered, washed, and dried to obtain sustained-release salt-snow-melting and ice-suppressing microcapsules.

9. The method for preparing the sustained-release salt-storing snow-melting and ice-suppressing microcapsules according to claim 8, characterized in that, The mass ratio of salt to water is 1:3-19; The ratio of emulsifier to organic solvent C is 1-3g:100ml. The emulsifier is one of sodium dodecylbenzenesulfonate, sodium alginate, sorbitol, styrene-maleic anhydride, Span 20, Span 40, Span 60, Span 80, Tween 20, Tween 40, Tween 60, and Tween 80. The volume ratio of organic solvent C to organic solvent D and water is 2-5:1, and the volume ratio of organic solvent C to organic solvent D is 1-3:1; both organic solvent C and organic solvent D are one of cyclohexane, dichloromethane, carbon tetrachloride, toluene, and chloroform. The total amount of monomers A and D accounts for 5%-40% of the total mass of the salt and monomers A and D, and the molar ratio of monomers A and D is 1:1; monomer A is one of ethylenediamine, ethylene glycol, and glycolic acid; monomer D is one of terephthaloyl chloride, toluene diisocyanate, and adipyl chloride. The homogenization speed is 1000-8000 rpm, and the homogenization time is 5-30 min.

10. The method for preparing the sustained-release salt-storing snow-melting and ice-suppressing microcapsules according to claim 8, characterized in that, pH is adjusted using a pH adjuster; the pH adjuster is one of sodium hydroxide, potassium hydroxide, sodium bicarbonate, sodium carbonate, or potassium carbonate.

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