CN104874382A - Preparation method of vermiculite loaded with magnetic nano-materials - Google Patents

Abstract

The invention specifically relates to a preparation method of a vermiculite-loaded magnetic nanometer material, and belongs to the technical field of inorganic material water treatment. In the method of the present invention, the yellowish-brown suspension obtained by mixing FeCl ₃ ?6H ₂ O, NaAc?3H ₂ O, ethylene glycol, ethylenediamine and industrial vermiculite powder is packaged in a polytetrafluoroethylene reactor, and the Reacting at 180-200°C for more than 8 hours, washing the black solid, magnetically separating, drying, and grinding to obtain vermiculite loaded with magnetic nanomaterials. The invention directly carries out magnetic modification on industrial vermiculite through hydrothermal synthesis technology, the operation process is simple and easy to control, the preparation cost is low, the threshold of industrial production is low, and it is easy to industrial large-scale production; the prepared magnetic loaded vermiculite not only has vermiculite The characteristic diffraction peaks of the magnetic nanoparticles have the advantages of superparamagnetism; the prepared loaded magnetic vermiculite has a good effect on some dye pollutants in water.

Description

Preparation method of vermiculite-loaded magnetic nanomaterials

technical field

The invention specifically relates to a preparation method of a vermiculite-loaded magnetic nanometer material, and belongs to the technical field of inorganic material water treatment.

Background technique

Vermiculite belongs to the layered magnesium (or aluminum) silicate mineral of 2:1 type, and the structural unit layer of vermiculite is composed of two silicon-oxygen tetrahedra and one magnesium (or aluminum) oxygen (or hydrogen-oxygen) octahedron. During the formation of vermiculite, due to the phenomenon of isomorphic substitution, such as the substitution of Al ³⁺ and Fe ³⁺ for Si ⁴⁺ in the tetrahedron, permanent negative charges are generated between the vermiculite crystal layers, and these negative charges are generated from the interlayer Exchangeable cations such as Na ⁺ , K ⁺ , Ca ²⁺ , Mg ²⁺ , etc. to balance, due to the exchangeability of interlayer ions, have a larger specific surface area and higher ion exchange capacity, so that vermiculite has a relatively high Strong cation exchange capacity.

Vermiculite is a non-metallic mineral with special properties and wide application. It can obtain significant benefits from the application of vermiculite in heat insulation, heat preservation, light building materials, waste liquid disposal, horticulture, agriculture, feed and other departments. After chemical modification And specially treated vermiculite can show application prospects even in high-tech fields.

Commonly referred to as vermiculite refers to industrial vermiculite, which includes vermiculite of mineralogical significance and regular or irregular interlayer minerals of vermiculite and mica. Vermiculite has good adsorption and ion exchange properties, and is widely used in industry and agriculture. , horticulture, breeding and other aspects have a wide range of applications. However, industrial vermiculite samples generally contain impurities, which affect its reactivity, and its surface hydrophilicity affects its application in composite materials, and vermiculite has the disadvantage of expansibility, so it is very necessary to modify industrial vermiculite of. Commonly used modification methods include acid modification, thermal modification, and organic modification.

Magnetic carrier technology is to uniformly introduce dispersed strong magnetic substances into non-magnetic or weak magnetic particles to enhance the magnetic susceptibility of the matrix material, and then use magnetic separation technology to rapidly separate saturated magnetic complexes from the active system. Therefore, magnetic materials that are easy to collect under an external magnetic field have unique advantages in the separation and recovery process. However, there is no literature on the preparation method of vermiculite-loaded magnetic nanomaterials.

Contents of the invention

This patent provides a large method for preparing vermiculite-loaded magnetic nanomaterials with simple process flow, high removal efficiency and cost savings, so as to better remove pollutants in water.

Technical solutions

A preparation method for vermiculite-loaded magnetic nanomaterials, comprising the following steps:

(1) Dissolve FeCl ₃ ?6H ₂ O and NaAc?3H ₂ O in ethylene glycol, then add ethylenediamine to form a transparent solution, then add industrial vermiculite powder to obtain a yellow-brown suspension;

(2) Seal the suspension in a polytetrafluoroethylene reactor, react at 180-200°C for more than 8 hours, and take a black solid;

(3) The black solid is washed, magnetically separated, dried, and ground to obtain vermiculite loaded with magnetic nanomaterials.

The preparation method of the present invention uses ferric chloride as an iron source, adopts ethylene glycol as a solvent and performs partial solvothermal reduction of ferric ions, and successfully synthesizes iron ferric oxide nanoparticles; uses sodium acetate as a reaction aid, ethylene di Amine is used as encapsulating agent, and ferric oxide with uniform size of nanoparticles can be synthesized by controlling the ratio of ethylenediamine and ferric chloride. Through two-step main reactions in the reaction of synthesizing ferric oxide nanoparticles, possible reactions are as follows:

2Fe ³⁺ +OHCH ₂ CH ₂ OH+2H ⁺ → 2Fe ²⁺ +CH ₃ CHO+2H ₂ O;

2Fe ³⁺ +Fe ²⁺ +8OH ^- → Fe ₃ O ₄ +4H ₂ O.

During the synthesis reaction, nano-ferric oxide is combined with industrial vermiculite powder to form magnetic vermiculite.

In addition, ethylenediamine should be added after the first three reagents are added; otherwise, ferric chloride and sodium acetate cannot be dissolved.

In the above method, FeCl ₃ ?6H ₂ O, ethylene glycol, NaAc?3H ₂ O, ethylenediamine and industrial vermiculite powder participate in the synthesis process of magnetic vermiculite. The change of the amount does not affect the formation of the product, but will affect Properties of the prepared magnetic vermiculite. In order to reduce waste of raw materials and obtain magnetic vermiculite with higher magnetic properties, the dosage ratio of FeCl ₃ ?6H ₂ O, ethylene glycol, NaAc?3H ₂ O, ethylenediamine and industrial vermiculite powder is preferably: 1.0g: 20mL: 3.0g: 10mL: 0.04-1.0g; most preferred: 1.0g: 20mL: 3.0g: 10mL: 1.0g.

In order to shorten the stirring time, the above method preferably dissolves FeCl ₃ ?6H ₂ O in ethylene glycol, and then adds NaAc ?3H ₂ O.

Beneficial effect

(1) The present invention directly performs magnetic modification on industrial vermiculite through hydrothermal synthesis technology, the operation process is simple and easy to control, the preparation cost is low, the threshold for industrial production is low, and it is easy for large-scale industrial production;

(2) No need to use water in the preparation process, only a small amount of organic solvent is needed;

(3) The prepared loaded magnetic vermiculite not only has the characteristic diffraction peaks of vermiculite, but also has the advantages of superparamagnetism of magnetic nanoparticles, and the operation process is convenient and simple, saving material cost and high synthesis efficiency;

(4) The prepared loaded magnetic vermiculite has a good adsorption effect on some dye pollutants in water, such as basic fuchsin and basic royal blue dye, and can realize rapid separation of solid and liquid after the adsorption is completed, making the adsorbent be recycled;

(5) Adding ethylenediamine during the preparation process can significantly improve the adsorption performance and superparamagnetism of the product.

Description of drawings

Fig. 1 is the X-ray diffraction spectrogram of magnetic vermiculite of the present invention and industrial vermiculite, _Fe3O4 contrast; Wherein, AD is successively: Fe3O4, industrial vermiculite, the vermiculite loaded magnetic nanomaterial of embodiment _4-5 The X-ray Diffraction Spectrum.

Detailed ways

Example 1

(1) Dissolve 2.0 g FeCl ₃ ?6H ₂ O in 40 mL of ethylene glycol, add 6.0 g of NaAc?3H ₂ O to form a transparent solution, then add 20 mL of ethylenediamine, add 0.08 g of industrial vermiculite powder, Stir for 30 minutes to get a fully mixed yellow-brown suspension (industrial vermiculite powder is fully dispersed);

(2) Encapsulate the above mixture in a polytetrafluoroethylene reactor, heat and react at 180 °C for 8 h, and cool to room temperature after the reaction is completed;

(3) Wash the obtained black solid several times with distilled water (to remove impurities), magnetically separate, dry, grind, and pass through a 100-mesh sieve to obtain loaded magnetic vermiculite MV1;

At room temperature, add 0.04g MV1 to 25mL 20mg/l basic fuchsin solution, shake for 360min, the adsorption rate reaches 81.2%; add 0.04g MV1 to 25mL 20mg/l basic royal blue solution, shake for 360min, the The rate reached 78.76%.

Example 2

(1) Dissolve 2.0 g FeCl ₃ 6H ₂ O in 40 mL ethylene glycol, add 6.0 g NaAc 3H ₂ O to form a transparent solution, then add 20 mL ethylenediamine, add 0.2 g industrial vermiculite powder, Stir for 30 minutes to obtain a fully mixed yellow-brown suspension;

(2) Encapsulate the above mixture in a polytetrafluoroethylene reactor, heat and react at 190 °C for 8 h, and cool to room temperature after the reaction is completed;

(3) The obtained black solid was washed several times with distilled water, magnetically separated, dried, ground, and passed through a 100-mesh sieve to obtain loaded magnetic vermiculite MV2;

At room temperature, add 0.04g MV2 to 25mL 20mg/l basic fuchsin solution, shake for 360min, the adsorption rate reaches 83.9%; add 0.04g MV2 to 25mL 20mg/l basic royal blue solution, shake for 360min, the adsorption The rate reached 85.1%.

Example 3

(1) Dissolve 2.0 g FeCl ₃ 6H ₂ O in 40 mL ethylene glycol, add 6.0 g NaAc 3H ₂ O to form a transparent solution, then add 20 mL ethylenediamine, add 0.4 g industrial vermiculite powder, stir After 30 minutes, a fully mixed yellow-brown suspension was obtained;

(2) Encapsulate the above mixture in a polytetrafluoroethylene reactor, heat and react at 200 °C for 8 h, and cool to room temperature after the reaction is completed;

(3) The obtained black solid was washed several times with distilled water, magnetically separated, dried, ground, and passed through a 200-mesh sieve to obtain loaded magnetic vermiculite MV3;

At room temperature, add 0.04g MV3 to 25mL 20mg/l basic fuchsin solution, shake for 360min, the adsorption rate reaches 87.84%; add 0.04g MV3 to 25mL 20mg/l basic royal blue solution, shake for 360min, the The rate reached 92.41%.

Example 4

(1) Dissolve 2.0 g FeCl ₃ 6H ₂ O in 40 mL ethylene glycol, add 6.0 g NaAc 3H ₂ O to form a transparent solution, then add 20 mL ethylenediamine, add 0.8 g sodium-based vermiculite powder, Stir for 30 minutes; get a fully mixed yellow-brown suspension;

(2) Encapsulate the above mixture in a polytetrafluoroethylene reactor, heat and react at 200 °C for 8 h, and cool to room temperature after the reaction is completed;

(3) The obtained black solid was washed several times with distilled water, magnetically separated, dried, ground, and passed through a 200-mesh sieve to obtain loaded magnetic vermiculite MV4;

At room temperature, add 0.04g MV4 to 25mL 20mg/l basic fuchsin solution, shake for 150min, the adsorption rate reaches 90.3%; add 0.04g MV4 to 25mL 100mg/l basic royal blue solution, shake for 240min, the rate reached 92.8%

Example 5

(1) Dissolve 2.0 g FeCl ₃ 6H ₂ O in 40 mL ethylene glycol, add 6.0 g NaAc 3H ₂ O to form a transparent solution, then add 20 mL ethylenediamine, add 2.0 g sodium-based vermiculite powder, Stir for 30 minutes; get a fully mixed yellow-brown suspension;

(2) Encapsulate the above mixture in a polytetrafluoroethylene reactor, heat and react at 200 °C for 8 h, and cool to room temperature after the reaction is completed;

(3) The obtained black solid was washed several times with distilled water, magnetically separated, dried, ground, and passed through a 200-mesh sieve to obtain loaded magnetic vermiculite MV5;

At room temperature, add 0.04g MV5 to 25mL 20mg/l basic fuchsin solution, shake for 360min, the adsorption rate reaches 90.3%; add 0.04g MV5 to 25mL 20mg/l basic royal blue solution, shake for 360min, the The rate reached 95.6%.

Example 6

(1) Dissolve 2.0g FeCl3?6H2O in 40mL ethylene glycol, add 6.0gNaAc?3H2O to form a transparent solution, add 0.4g industrial vermiculite powder, and stir for 30 minutes to obtain a fully mixed yellow-brown suspension;

(2) Encapsulate the above mixture in a polytetrafluoroethylene reactor, heat and react at 200°C for 8 hours, and cool to room temperature after the reaction is completed;

(3) The obtained black solid was washed several times with distilled water, magnetically separated, dried, ground, and passed through a 200-mesh sieve to obtain loaded magnetic vermiculite MV6;

At room temperature, add 0.04g MV6 to 25mL 20mg/l basic fuchsin solution, shake for 360min, the adsorption rate reaches 76.43%; add 0.04g MV6 to 25mL 20mg/l basic royal blue solution, shake for 360min, the The rate reached 81.29%.

Comparing the experimental data of Example 3 and Example 6, it can be drawn that, under other conditions being the same, the adsorption performance of the loaded magnetic vermiculite MV3 prepared by adding ethylenediamine during the preparation process is significantly higher than that during the preparation process Adsorption properties of loaded magnetic vermiculite MV6 prepared without ethylenediamine. This shows that ethylenediamine has played a role in improving the adsorption performance of the product in the preparation method of the present invention.

During the experiment, the present invention finds that: with the increase of the amount of vermiculite, the smaller the ratio of Fe to vermiculite (Fe / vermiculite), the weaker the magnetism of the synthesized material. The superparamagnetic properties of MV3 (with the increase of the external magnetic field, the performance of magnetic increase) are stronger than MV6, and the energy consumption in the magnetization process is smaller; therefore, the addition of ethylenediamine can enhance the superparamagnetism of vermiculite-loaded magnetic nanomaterials Energy, reduce energy loss in the process of repeated magnetization.

Claims (4)

1. vermiculite loads a preparation method for magnetic Nano material, comprises the following steps:

(1) by FeCl ₃6H ₂o, NaAc 3H ₂o is dissolved in ethylene glycol, then adds ethylenediamine and forms clear solution, then add Industrial Vermiculite powder, obtain yellowish-brown suspension;

(2) suspension is packaged in polytetrafluoroethylene (PTFE) reactor, under 180-200 DEG C of condition, reacts 8 more than h, get black solid;

(3) black solid is through washing, Magneto separate, oven dry, grinding, obtains the vermiculite loading magnetic Nano material.

2. preparation method according to claim 1, is characterized in that, FeCl ₃6H ₂o, ethylene glycol, NaAc 3H ₂the usage ratio of O, ethylenediamine and Industrial Vermiculite powder is: 1.0g:20mL:3.0g:10mL:0.04-1.0g.

3. preparation method according to claim 2, is characterized in that, FeCl ₃6H ₂o, ethylene glycol, NaAc 3H ₂the usage ratio of O, ethylenediamine and Industrial Vermiculite powder is 1.0g:20mL:3.0g:10mL:1.0g.

4., according to the preparation method of claim 1,2 or 3, it is characterized in that, by FeCl ₃6H ₂o is dissolved in ethylene glycol, then adds NaAc 3H ₂o.