阅读说明：本技术 一种硫酸钡纤维及其制备方法 (Barium sulfate fiber and preparation method thereof ) 是由 朱英杰 吴进 于 2020-07-21 设计创作，主要内容包括：本发明公开一种硫酸钡纤维及其制备方法。所述硫酸钡纤维由硫酸钡纳米棒沿长度方向平行排列组装而成；所述硫酸钡纤维的长度大于5微米,直径为0.1~5微米。(The invention discloses a barium sulfate fiber and a preparation method thereof. The barium sulfate fiber is formed by assembling barium sulfate nanorods in parallel along the length direction; the length of the barium sulfate fiber is more than 5 micrometers, and the diameter of the barium sulfate fiber is 0.1-5 micrometers.)

1. The barium sulfate fiber is characterized in that the barium sulfate fiber is formed by assembling barium sulfate nanorods in parallel along the length direction; the length of the barium sulfate fiber is more than 5 micrometers, and the diameter of the barium sulfate fiber is 0.1-5 micrometers.

2. The barium sulfate fiber of claim 1, wherein the barium sulfate nanorods have a diameter of 5 to 100 nm and a length of 50 to 500 nm.

3. The method for producing barium sulfate fibers according to claim 1 or 2, characterized by comprising: (1) oleate is used as a reactant and an emulsifier, water-soluble barium salt is used as a barium source, water is used as a solvent, and barium oleate precursor suspension is generated through reaction;

(2) adding a water-soluble sulfate aqueous solution into the barium oleate precursor suspension to obtain a barium sulfate precursor suspension;

(3) and carrying out hydrothermal treatment on the barium sulfate precursor suspension, separating and drying to obtain the barium sulfate fiber.

4. The method according to claim 3, wherein the temperature of the hydrothermal treatment is 120 to 240 ℃ and the time of the hydrothermal treatment is 10 to 72 hours.

5. The method according to claim 3 or 4, wherein the concentration of the oleate salt and the concentration of the water-soluble barium salt in the step (1) are 0.01 to 2 mol/l and 0.01 to 2 mol/l, respectively.

6. The production method according to any one of claims 3 to 5, characterized in that the oleate is selected from at least one of sodium oleate, potassium oleate, ammonium oleate; the water-soluble barium salt is selected from barium chloride and/or barium nitrate.

7. The method according to any one of claims 3 to 6, wherein the concentration of the water-soluble sulfate in the step (2) is 0.01 to 6 mol/liter.

8. The production method according to any one of claims 3 to 7, wherein the water-soluble sulfate is at least one selected from the group consisting of sodium sulfate, potassium sulfate, and ammonium sulfate.

Technical Field

The invention belongs to the field of inorganic fibers, and particularly relates to a barium sulfate fiber with a nano assembly structure and a preparation method thereof.

Background

Inorganic fibers generally have high temperature resistance and are ideal raw materials for preparing products and coatings with flame retardance, fire resistance, heat insulation and the like. The common inorganic high-temperature resistant fibers mainly comprise silicon oxide, aluminum silicate, asbestos and the like, but the inorganic fibers are usually prepared by a melting and spinning method, have larger diameters (generally larger than 10 microns), lack functional groups on the surfaces of the fibers and have weaker bonding force among the fibers. Therefore, products prepared from the composite material are rough and have low mechanical strength, and therefore, the composite material is mainly applied to the field of industrial heat insulation. In addition, some inorganic fibers, such as asbestos fibers, are not biologically safe and have potential risk of disease.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a barium sulfate fiber with a nano assembly structure and a preparation method thereof, wherein the barium sulfate fiber is non-toxic and odorless, has very stable chemical property, is insoluble in most of acid and alkali, and has high temperature resistance and excellent fire resistance (the melting point is about 1580 ℃, and the decomposition temperature is about 1400 ℃).

In a first aspect, the present invention provides a barium sulfate fiber. The barium sulfate fiber is formed by assembling barium sulfate nanorods in parallel along the length direction; the length of the barium sulfate fiber is more than 5 micrometers, and the diameter of the barium sulfate fiber is 0.1-5 micrometers.

Preferably, the barium sulfate nanorod has a diameter of 5-100 nm and a length of 50-500 nm.

The barium sulfate fiber prepared by the invention is assembled by barium sulfate nano rods which are orderly arranged along the length direction. Thus, the smallest structural unit of the barium sulfate fiber of the present invention is the aforementioned nanorods, which are 3 to 4 orders of magnitude smaller in size than conventional inorganic refractory fibers (generally without finer assembled structures). The barium sulfate fiber has better flexibility, and the barium sulfate fiber can be further assembled and connected to form a longer barium sulfate fiber. The barium sulfate fiber provided by the invention has good flexibility, high temperature resistance and corrosion resistance, and has good application prospect in the field of special high temperature resistant fiber products.

In a second aspect, the present invention provides a method for preparing barium sulfate fiber. The preparation method comprises the following steps:

(1) oleate is used as a reactant and an emulsifier, water-soluble barium salt is used as a barium source, water is used as a solvent, and barium oleate precursor suspension is generated through reaction;

(2) adding a water-soluble sulfate aqueous solution into the barium oleate precursor suspension to obtain a barium sulfate precursor suspension;

(3) and carrying out hydrothermal treatment on the barium sulfate precursor suspension, separating and drying to obtain the barium sulfate fiber.

Preferably, the temperature of the hydrothermal treatment is 120-240 ℃, and the time of the hydrothermal treatment is 10-72 hours.

Preferably, in the step (1), the concentration of the oleate is 0.01-2 mol/L, and the concentration of the water-soluble barium salt is 0.01-2 mol/L. Preferably, the oleate is selected from at least one of sodium oleate, potassium oleate, ammonium oleate; the water-soluble barium salt is selected from barium chloride and/or barium nitrate.

Preferably, in the step (2), the concentration of the water-soluble sulfate is 0.01 to 6 mol/L. Preferably, the water-soluble sulfate is selected from at least one of sodium sulfate, potassium sulfate, and ammonium sulfate.

Preferably, the temperature of the hydrothermal treatment is 160-200 ℃, and the time of the hydrothermal treatment is 36-48 hours.

Drawings

FIGS. 1 and 2 are scanning electron micrographs, respectively, of the barium sulfate fiber prepared in example 1 on different scales;

FIG. 3 is a transmission electron micrograph of a barium sulfate fiber prepared according to example 1 of the present invention;

FIG. 4 is a transmission electron micrograph of the ends of barium sulfate fibers prepared in example 1 of the present invention;

FIG. 5 is an X-ray diffraction spectrum and a standard diffraction spectrum of barium sulfate of the barium sulfate fiber prepared in example 1 of the present invention;

FIG. 6 is a scanning electron micrograph of barium sulfate fibers prepared in example 2 of the present invention;

FIG. 7 is a digital photograph of barium sulfate fiber inorganic refractory paper prepared in example 13 of the present invention;

FIG. 8 is a Scanning Electron Microscope (SEM) photograph of the lower surface of the barium sulfate fiber inorganic refractory paper prepared in example 13 of the present invention; wherein the surface of the attaching substrate is a lower surface, the surface far away from the substrate is an upper surface, and the weaving pattern in the figure is an indentation of the weaving substrate in the paper making process;

FIG. 9 is a Scanning Electron Microscope (SEM) photograph of the side of the barium sulfate fiber inorganic refractory paper prepared in example 13 of the present invention;

FIG. 10 is a photograph of the barium sulfate fiber inorganic refractory paper prepared in example 13 of the present invention burned on a flame of an alcohol burner.

Detailed Description

The present invention is further illustrated by the following examples, which are to be understood as merely illustrative of, and not restrictive on, the present invention.

The following is an exemplary description of the method of making the barium sulfate fiber of the present invention.

Oleate is used as a reactant and an emulsifier, water-soluble barium salt is used as a barium source, water is used as a solvent, and barium oleate precursor suspension is obtained through chemical reaction. The water-soluble barium salt may be at least one selected from barium chloride and barium nitrate. The oleate can be at least one selected from sodium oleate, potassium oleate and ammonium oleate. The method selects water as a reaction solvent, has low cost and environmental protection, and is beneficial to large-scale production. In the barium oleate precursor suspension, the concentration of oleate is 0.01-2 mol/L, preferably 0.1-1 mol/L; the concentration of the water-soluble barium salt is 0.01 to 2 mol/L, preferably 0.03 to 1 mol/L.

And then adding the water-soluble sulfate into the barium oleate precursor suspension to obtain the barium sulfate precursor suspension. The water-soluble sulfate may be at least one selected from sodium sulfate, potassium sulfate and ammonium sulfate. The concentration of the water-soluble sulfate is 0.01 to 6 mol/L, preferably 0.1 to 1 mol/L.

And (3) placing the obtained barium sulfate precursor suspension into a reaction kettle, sealing, carrying out hydrothermal treatment, separating, and washing with ethanol and water to obtain the barium sulfate fiber. The temperature of the hydrothermal treatment is 120-240 ℃, and preferably 160-200 ℃. When the temperature of the hydrothermal treatment is lower than 120 ℃ or higher than 240 ℃, the ideal barium sulfate fiber cannot be obtained. Specifically, when the hydrothermal treatment temperature is lower than 120 ℃, the length of the barium sulfate nanorod is short, which is not beneficial to obtaining barium sulfate nanorod which is directionally arranged along the length direction to obtain barium sulfate fiber; when the heat treatment temperature is higher than 240 ℃, the diameter of the barium sulfate nano rod is larger, and the barium sulfate nano rod is not beneficial to obtaining barium sulfate fiber by directional arrangement along the length direction. The time of the hydrothermal treatment is 10-72 hours, preferably 36-48 hours. When the time of the hydrothermal treatment is less than 10 hours, the length of the obtained barium sulfate nano rod is short, which is not beneficial to obtaining barium sulfate fiber by directionally arranging the barium sulfate nano rod along the length direction. When the hydrothermal treatment time is more than 72 hours, energy waste and cost increase are caused.

The barium sulfate fiber obtained by the preparation method has a nano assembly structure and is formed by parallelly arranging and assembling barium sulfate nano rods with the diameters of 5-100 nanometers and the lengths of 50-500 nanometers. In some embodiments, the barium sulfate fiber is assembled by barium sulfate nanorods arranged in parallel along the length direction.

Compared with the prior art, the invention has the following effects:

the barium sulfate fiber prepared by the invention has the length of more than 5 micrometers and the diameter of 0.1-5 micrometers, is much thinner than the traditional inorganic high-temperature resistant fiber, and two-dimensional and three-dimensional products formed by the barium sulfate fiber have higher density and smoothness, and are beneficial to improving the mechanical strength and the writing and printing performances of the products.

The present invention is further illustrated by, but is not limited to, the following examples.