Open type nano calcium sulfate tubular whisker and preparation method thereof

Abstract

The invention discloses an open type nano calcium sulfate tubular whisker and a preparation method thereof, and relates to the field of inorganic non-metallic material modification. The method specifically comprises the following steps: respectively adding a calcium chloride solution and a sodium sulfate solution into a container, and sequentially adding n-butyl alcohol, cyclohexane and polyoxyethylene lauryl ether to form a micelle solution; adding polyoxyethylene lauryl ether into the sodium oleate solution to form a solution; and mixing the two micelle solutions, then adding a sodium oleate mixed solution, fully stirring, then adding acetone, fully stirring, separating and drying to obtain the open type nano calcium sulfate tubular whisker. Two reversed-phase micelle solutions are prepared, effective collision occurs to generate whiskers, crystal nucleuses grow into tubular structures in micelles, and after sodium oleate is added, the nano calcium sulfate tubular whiskers are in an open state. The prepared nano calcium sulfate tubular whisker is used as an adsorption and purification material in an aqueous solution containing heavy metals, and has extremely high adsorption rate.

Description

Technical Field

[0002] The invention belongs to the field of inorganic non-metallic material modification, and particularly relates to an open-type nano calcium sulfate tubular whisker and a preparation method thereof. Background Art

[0004] Calcium sulfate whiskers are an inorganic, non-metallic material with excellent performance and low cost. They offer superior mechanical properties, good compatibility, good regeneration, are environmentally friendly and non-toxic, and have low manufacturing costs. They are primarily used as reinforcing components in composite materials, friction materials, environmental engineering filtration, asphalt modification, and to improve the adhesion, insulation, and temperature resistance of coatings and paints. Calcium sulfate whiskers are also used as filtration and adsorption purification materials, and have significant market potential. However, drawbacks such as low affinity for heavy metal pollutants, low adsorption efficiency, and unstable properties have limited their application in environmental fields. Summary of the Invention

[0006] Based on this, the present invention provides an open-type nano calcium sulfate tubular whisker. The whisker has a hollow open structure. In addition to having the high temperature resistance, heat insulation and high reinforcement functions of general calcium sulfate whiskers, it can also be used as an adsorption and purification material, and has an extremely high adsorption rate for toxic and harmful metals such as mercury, cadmium, chromium, lead and arsenic in aqueous solutions.

[0007] To achieve the above object, the technical solution adopted by the present invention is:

[0008] A method for preparing open-type nano calcium sulfate tubular whiskers comprises the following steps:

[0009] Step 1: Add a 1% calcium chloride solution into a container, and then add n-butanol, cyclohexane, and lauryl alcohol polyoxyethylene ether in sequence, stirring at high speed to form a clear and transparent micellar solution;

[0010] Step 2: Add a 1% sodium sulfate solution into the container, and then add n-butanol, cyclohexane, and lauryl alcohol polyoxyethylene ether in sequence, stirring at high speed to form a clear and transparent micellar solution;

[0011] Step 3: Add 0.1% sodium oleate solution into the container, add lauryl alcohol polyoxyethylene ether, and stir at high speed to form a clear and transparent solution;

[0012] Step 4: Mix the two solutions prepared in step 1 and step 2, stir for 2 minutes, then add the solution prepared in step 3, and stir thoroughly for 10-15 minutes;

[0013] Step 5: Add acetone to the solution prepared in step 4, stir thoroughly for 10-15 minutes, then separate the material by centrifugal separator, wash the separated product with acetone and distilled water in sequence, and finally dry it in a dryer to obtain open-type nano calcium sulfate tubular whiskers.

[0014] Furthermore, in the first step, the mass ratio of water, calcium chloride, n-butanol, cyclohexane and lauryl alcohol polyoxyethylene ether is: 99-109: 1-5: 1-5: 1-5: 8-10.

[0015] Furthermore, in the second step, the mass ratio of water, sodium sulfate, n-butanol, cyclohexane and lauryl alcohol polyoxyethylene ether is: 99-109: 1-5: 1-5: 1-5: 8-10.

[0016] Furthermore, in the third step, the mass ratio of water, sodium oleate and lauryl alcohol polyoxyethylene ether is: 99.9-110:0.1-0.3:10-12.

[0017] Furthermore, in the fourth step, the mass ratio of the three solutions in the first step, the second step and the third step is 10:10:1.

[0018] Furthermore, in the fifth step, acetone accounts for 0.5% of the mixed solution.

[0019] Furthermore, the nano calcium sulfate tubular whiskers prepared by the preparation method are used as an adsorption purification material in an aqueous solution containing heavy metals.

[0020] Furthermore, the heavy metal is mercury, cadmium, chromium, lead or arsenic.

[0021] Description of the main raw materials used:

[0022] Calcium chloride: anhydrous calcium chloride;

[0023] Sodium sulfate: anhydrous sodium sulfate;

[0024] n-Butanol: solvent;

[0025] Cyclohexane: solvent;

[0026] Lauryl alcohol polyoxyethylene ether: solvent, emulsifier;

[0027] Sodium oleate: whisker stabilizer;

[0028] Acetone: Demulsifier.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1. The first and second steps of the preparation method of the present invention prepare two reverse micelle solutions. When the two reverse micelle solutions are mixed, the micelles can effectively collide, and the micelles that effectively collide combine, and the inorganic ion Ca 2+ With SO4 2- The permeation and bonding can produce crystal nuclei, which further grow into whiskers. Within the micelles, the nuclei further grow along the inner wall, forming tubular structures, thus forming whisker nanotubes. The addition of sodium oleate prevents the nanotube ends from sealing, leaving the calcium sulfate nanotube whiskers open.

[0031] 2. The nano calcium sulfate tubular whiskers prepared by the present invention are in an open state and can be used as an adsorption and purification material in aqueous solutions containing heavy metals to adsorb the heavy metals therein, with an adsorption rate of up to 87%-100%. DETAILED DESCRIPTION

[0033] The technical solutions and effects of the present invention are further described below in conjunction with specific embodiments, but the protection scope of the present invention is not limited thereto.

[0034] Example 1

[0035] The preparation method of the open-type nano calcium sulfate tubular whiskers of the present embodiment comprises the following steps:

[0036] Step 1: Add 100 kg of 1% calcium chloride solution into a container, then add 1 kg of n-butanol, 1 kg of cyclohexane, and 8 kg of lauryl alcohol polyoxyethylene ether in sequence, and stir at 300 rpm for 5 minutes to form a clear and transparent micellar solution.

[0037] Step 2: Add 100 kg of 1% sodium sulfate solution into the container, and then add 1 kg of n-butanol, 1 kg of cyclohexane, and 8 kg of lauryl alcohol polyoxyethylene ether in sequence, and stir at 300 rpm for 5 minutes to form a clear and transparent micellar solution.

[0038] Step 3: Add 100 kg of sodium oleate solution with a mass concentration of 0.1% into the container, add 10 kg of lauryl alcohol polyoxyethylene ether, and stir at 300 rpm for 5 minutes to form a clear and transparent solution.

[0039] Step 4: Mix 10 kg of the solution prepared in step 1 and 10 kg of the solution prepared in step 2, stir for 2 minutes, then add 1 kg of the solution prepared in step 3, and stir thoroughly for 15 minutes.

[0040] Step 5: Take 99.5 kg of the solution prepared in step 4, add 0.5 kg of acetone, stir thoroughly for 15 minutes, then separate the material by centrifuge, wash the separated product with acetone and distilled water in turn, and finally dry it in a dryer.

[0041] Example 1 Adsorption efficiency comparison test: 1000 grams of the product prepared in Example 1 of the present invention and 1000 grams of ordinary calcium sulfate whiskers (the ordinary calcium sulfate whiskers used in the present invention are calcium sulfate whiskers with a diameter of 0.1-10 μm and a length of 10-1000 μm produced by our company using a normal pressure acidification method) were respectively added to 1000 ml of an aqueous solution with an initial concentration of 0.1 mg / L of mercury, cadmium, chromium, lead, and arsenic. The mixture was fully stirred for 3 minutes, allowed to stand for 10 minutes, and then filtered. The removal rates of mercury, cadmium, chromium, lead, and arsenic in the filtered aqueous solution and the removal rate using ordinary calcium sulfate whiskers are compared as shown in Table 1 below.

[0042] Table 1 Comparison of heavy metal adsorption efficiency between Example 1 and ordinary calcium sulfate whisker products

[0043]

[0044] Example 2

[0045] Same as Example 1, except that:

[0046] Step 1: Add 109 kg of 1% calcium chloride solution into a container, then add 5 kg of n-butanol, 5 kg of cyclohexane, and 10 kg of lauryl alcohol polyoxyethylene ether in sequence, and stir at 300 rpm for 5 minutes to form a clear and transparent micellar solution.

[0047] Step 2: Add 109 kg of 1% sodium sulfate solution into the container, and then add 5 kg of n-butanol, 5 kg of cyclohexane, and 10 kg of lauryl alcohol polyoxyethylene ether in sequence, and stir at 300 rpm for 5 minutes to form a clear and transparent micellar solution.

[0048] Step 3: Add 110 kg of sodium oleate solution with a mass concentration of 0.1% into the container, add 12 kg of lauryl alcohol polyoxyethylene ether, and stir at 300 rpm for 5 minutes to form a clear and transparent solution.

[0049] Example 2 Adsorption efficiency comparison test: 1000 grams of the product prepared in Example 2 of the present invention and 1000 grams of ordinary calcium sulfate whiskers (the ordinary calcium sulfate whiskers used in the present invention are calcium sulfate whiskers with a diameter of 0.1-10 μm and a length of 10-1000 μm produced by our company using a normal pressure acidification method) were respectively added to 1000 ml of an aqueous solution with an initial concentration of 0.1 mg / L of mercury, cadmium, chromium, lead and arsenic. The mixture was fully stirred for 3 minutes, allowed to stand for 10 minutes, and then filtered. The removal rates of mercury, cadmium, chromium, lead and arsenic in the filtered aqueous solution and the removal rate using ordinary calcium sulfate whiskers are compared as shown in Table 2 below.

[0050] Table 2 Comparison of heavy metal adsorption efficiency between Example 2 and ordinary calcium sulfate whisker products

[0051]

[0052] Example 3

[0053] Same as Example 1, except that:

[0054] Step 1: Add 104 kg of 1% calcium chloride solution into a container, followed by 3 kg of n-butanol, 3 kg of cyclohexane, and 9 kg of lauryl alcohol polyoxyethylene ether. Stir at 300 rpm for 5 minutes to form a clear micellar solution.

[0055] Step 2: Add 104 kg of 1% sodium sulfate solution into the container, and then add 3 kg of n-butanol, 3 kg of cyclohexane, and 9 kg of lauryl alcohol polyoxyethylene ether in sequence. Stir at 300 rpm for 5 minutes to form a clear micellar solution.

[0056] Step 3: Add 105 kg of sodium oleate solution with a mass concentration of 0.1% into the container, add 11 kg of lauryl alcohol polyoxyethylene ether, and stir at 300 rpm for 5 minutes to form a clear and transparent solution.

[0057] Example 3 Adsorption efficiency comparison test: 1000 grams of the product prepared in Example 3 of the present invention and 1000 grams of ordinary calcium sulfate whiskers (the ordinary calcium sulfate whiskers used in the present invention are calcium sulfate whiskers with a diameter of 0.1-10 μm and a length of 10-1000 μm produced by our company using a normal pressure acidification method) were respectively added to 1000 ml of an aqueous solution with an initial concentration of 0.1 mg / L of mercury, cadmium, chromium, lead, and arsenic. The mixture was fully stirred for 3 minutes, allowed to stand for 10 minutes, and then filtered. The removal rates of mercury, cadmium, chromium, lead, and arsenic in the filtered aqueous solution and the removal rate using ordinary calcium sulfate whiskers are compared as shown in Table 3 below.

[0058] Table 3 Comparison of heavy metal adsorption efficiency between Example 3 and ordinary calcium sulfate whisker products

[0059]

[0060] As can be seen from Table 1-Table 3, the calcium sulfate whisker prepared by the embodiment of the present invention 1-embodiment 3 is much higher than currently commercially available common calcium sulfate whisker to the heavy metal removal rate in the aqueous solution, this is because the calcium sulfate whisker prepared by preparation method of the present invention is a hollow structure, compares common calcium sulfate whisker, and specific surface area increases, and adsorption capacity significantly improves. In addition, the nano calcium sulfate tubular whisker prepared by the present invention is an open state, can be used as adsorption purification material adsorption heavy metal wherein in the aqueous solution containing heavy metal, and adsorption rate is up to 87%-100%.

[0061] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing an open-type nano calcium sulfate tubular whisker, characterized in that: The preparation method comprises the following steps: Step 1: Add a 1% calcium chloride solution into a container, and then add n-butanol, cyclohexane, and lauryl alcohol polyoxyethylene ether in sequence, and stir at high speed to form a clear and transparent micellar solution; Step 2: Add a sodium sulfate solution with a mass concentration of 1% into the container, and then add n-butanol, cyclohexane, and lauryl alcohol polyoxyethylene ether in sequence, and stir at high speed to form a clear and transparent micellar solution; Step 3: Add a sodium oleate solution with a mass concentration of 0.1% into a container, add lauryl alcohol polyoxyethylene ether, and stir at high speed to form a clear and transparent solution; Step 4: Mix the two solutions prepared in step 1 and step 2, stir for 2 minutes, then add the solution prepared in step 3, and stir and mix thoroughly for 10-15 minutes; Step 5: Add acetone to the solution prepared in step 4, stir thoroughly for 10-15 minutes, then separate the material by centrifuge, wash the separated product with acetone and distilled water in turn, and finally dry it with a dryer.

2. The preparation method of open type nano calcium sulfate tubular whisker according to claim 1, wherein In the first step, the mass ratio of water, calcium chloride, n-butanol, cyclohexane and lauryl alcohol polyoxyethylene ether is 99-109: 1-5: 1-5: 1-5: 8-10.

3. The preparation method of open type nano calcium sulfate tubular whisker according to claim 1, wherein In the second step, the mass ratio of water, sodium sulfate, n-butanol, cyclohexane and lauryl alcohol polyoxyethylene ether is: 99-109: 1-5: 1-5: 1-5: 8-10.

4. The preparation method of open type nano calcium sulfate tubular whisker according to claim 1, characterized in that, In the third step, the mass ratio of water, sodium oleate and lauryl alcohol polyoxyethylene ether is 99.9-110: 0.1-0.3: 10-12.

5. The preparation method of open type nano calcium sulfate tubular whisker according to claim 1, characterized in that, In the fourth step, the mass ratio of the three solutions in the first step, the second step and the third step is 10:10:

1.

6. The preparation method of open type nano calcium sulfate tubular whisker according to claim 1, characterized in that, In the fifth step, acetone accounts for 0.5% of the mixed solution.

7. The preparation method of open type nano calcium sulfate tubular whisker according to claim 1, characterized in that, The nano calcium sulfate tubular whiskers prepared by the preparation method are used as adsorption and purification materials in aqueous solutions containing heavy metals.

8. The preparation method of open type nano calcium sulfate tubular whisker according to claim 7, characterized in that, The heavy metal is mercury, cadmium, chromium, lead or arsenic.

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