CN110357758B

CN110357758B - Reticular porous NiO/Al nano energetic material and preparation method thereof

Info

Publication number: CN110357758B
Application number: CN201910729927.1A
Authority: CN
Inventors: 矫淑杰
Original assignee: Harbin Institute of Technology
Current assignee: Harbin Institute of Technology
Priority date: 2019-08-08
Filing date: 2019-08-08
Publication date: 2021-07-27
Anticipated expiration: 2039-08-08
Also published as: CN110357758A

Abstract

A reticular porous NiO/Al nano energetic material and a preparation method thereof belong to the technical field of nano energetic materials. The invention solves the technical problems of complex preparation method and high cost of the existing preparation method. The method comprises the following steps: step one, respectively ultrasonically dispersing reticular porous NiO powder and Al powder in an organic solvent; and step two, mixing, continuing ultrasonic dispersion, centrifuging, and drying to obtain the reticular porous NiO/Al nano energetic material. The reticular porous NiO powder can be prepared by a hydrothermal method. The Al particles are dispersed in the NiO grid structure, so that the contact distance between NiO and Al can be effectively reduced, the mass transfer distance can be reduced, the contact area between the NiO oxidant and Al can be effectively increased, and the aggregation of a large number of aluminum particles can be effectively avoided due to the net porous structure of NiO, so that the combustion efficiency is improved.

Description

Reticular porous NiO/Al nano energetic material and preparation method thereof

Technical Field

The invention belongs to the technical field of nano energetic materials; in particular to a reticular porous NiO/Al nano energetic material and a preparation method thereof.

Background

Based on the principle of thermite reaction, aluminum and oxide with strong oxidizability can form thermite energetic materials, have the characteristics of high mass density and high energy density, and are widely applied to the fields of welding, metallurgy and military. The traditional aluminothermic energetic material has slow reaction speed, and the application of the energetic material is limited. The nano energetic material mixes the nano Al particles and the nano or micro oxide, increases the contact area between the nano Al particles and the nano or micro oxide, greatly improves the reaction speed and the combustion speed, improves the heat release, and simultaneously has simple preparation and reduced cost.

However, some problems to be solved are also brought, for example, the aluminum particles have small size, high activity and poor stability, and the particles are easy to agglomerate, so that the probability of contacting with the oxidant is reduced, and the agglomerated aluminum particles also cause the activity to be reduced, and finally the efficiency of the nano energetic material is reduced.

Therefore, the existing thermite energetic material needs to overcome the agglomeration of nano particles and improve the contact area of the oxidant and aluminum particles, thereby realizing high-efficiency thermite reaction.

The prior art is as follows: patent application No.: 201110413255.7, entitled three-dimensional ordered macroporous metal oxide based nano energetic material and preparation method thereof, the patent adopts micro-colloidal spheres as a template to prepare three-dimensional ordered macroporous oxide as an oxidant to form the nano energetic material with nano active metal particles, the method can form a porous structure, but the preparation method is complex, the micro-colloidal spheres need to be prepared and assembled firstly, then metal oxide precursor liquid is prepared to fill gaps among the micro-colloidal spheres, the micro-colloidal spheres are removed to obtain macroporous metal oxide, and finally the macroporous metal oxide is assembled with the metal particles. The patent application numbers are: 201710655753.X, entitled Al/CuO/porous graphene nano composite energetic material and a preparation method thereof, which utilizes porous graphene to assemble CuO and Al, so that the CuO and the Al are adsorbed on the graphene, the method can avoid the aggregation of Al particles, and increase the contact between Al and CuO to a certain extent, but the graphene material is introduced in the process, and the graphene does not participate in aluminothermic reaction, thereby increasing the experimental steps and difficulty, and increasing the cost. The title is as follows: in the paper, porous NiO and Al are used for forming an energy-containing material of an thermite, the porous NiO is also used as a template, a precursor solution of NiO is coated at the gap of a microcapsule ball, the microcapsule ball is removed to form the porous NiO, and then a layer of Al film is sputtered on the porous NiO by a magnetron sputtering method to form the NiO/Al nano energy-containing material.

Disclosure of Invention

The invention aims to solve the technical problems of complex preparation method and high cost of the existing preparation method; and provides a reticular porous NiO/Al nano energetic material and a preparation method thereof.

The reticular porous NiO/Al nano energetic material is formed by assembling reticular porous NiO powder and Al powder; the method specifically comprises the following steps:

step one, respectively ultrasonically dispersing reticular porous NiO powder and Al powder in an organic solvent;

and step two, mixing, continuing ultrasonic dispersion, centrifuging, and drying to obtain the reticular porous NiO/Al nano energetic material.

Further defined, the Al powder has a purity of 99% by mass and a particle diameter of 30nm to 50 nm.

Further limiting, the ultrasonic dispersion time in the step one is controlled to be 20min-30 min.

Further, in the first step, the organic solvent is isopropanol. Further limiting, in the second step, the ratio of Al: NiO is mixed in a mass ratio of (1:5) - (1: 1).

Further limiting, in the second step, ultrasonic dispersion is carried out for 30min-60 min.

Further defined, in step two, drying was carried out at 60 ℃ for 6 hours.

Further limited, the reticular porous NiO powder is prepared by a hydrothermal method, and the preparation steps are as follows:

step 1, preparing a nickel nitrate aqueous solution, then adding hexamethylenetetramine, and uniformly mixing, wherein the molar ratio of the nickel nitrate solution to the hexamethylenetetramine is (1:1) - (4: 1);

step 2, pouring the mixture into a hydrothermal reaction kettle, sealing the hydrothermal reaction kettle, and putting the hydrothermal reaction kettle into an oven to heat the hydrothermal reaction kettle for 6 to 12 hours at the temperature of between 80 and 120 ℃;

step 3, after the reaction is finished, taking out the hydrothermal reaction kettle after the temperature of the hydrothermal reaction kettle is reduced to the room temperature, and carrying out centrifugation, washing and drying on the hydrothermal reaction kettle;

and 4, heating at 230-500 ℃ for 2-6 hours to obtain the reticular porous NiO powder.

The invention relates to a nano energetic material which is composed of a reticular porous NiO serving as an oxidant and aluminum nano particles.

NiO is an oxidizing agent with excellent performance, and can be subjected to thermite reaction with Al according to the following reaction:

2Al+3NiO→Al₂O₃+3Ni+ΔH

the NiO is in a net-shaped porous structure, the Al particles are dispersed in the NiO net structure, the contact distance between the NiO and the Al can be effectively reduced, the mass transfer distance can be reduced, the contact area between the NiO oxidant and the Al can be effectively increased, and the net-shaped porous structure of the NiO can effectively avoid the aggregation of a large number of aluminum particles and improve the combustion efficiency. The method has the advantages of simple preparation method, convenient operation and low cost.

The reticular porous NiO can form a porous structure only by synthesizing the reticular porous NiO by a material chemical method without a template in the preparation process, and can be assembled with Al particles, so that the Al particles are prevented from being aggregated, the contact area of the reticular porous NiO and the Al particles is increased, the combustion speed is effectively improved, other substances such as graphene and the like do not need to enter, vacuum coating equipment such as magnetron sputtering, atomic beam deposition and the like is not needed, the preparation method is simple, and the cost is low.

Drawings

FIG. 1 is a scanning electron microscope top view of the reticulated porous NiO;

FIG. 2 is a scanning electron microscope top view of the NiO/Al nano energetic material;

FIG. 3 is a DSC curve of NiO/Al nano energetic material.

Detailed Description

Example 1: the raw material of the reticular porous NiO in the embodiment is prepared by a hydrothermal method, and the method comprises the following specific steps:

step 1, preparing a nickel nitrate aqueous solution with the concentration of 0.06mol/L, then adding hexamethylenetetramine, and uniformly mixing to obtain a mixed solution, wherein the concentration of nickel nitrate in the mixed solution is 0.06mol/L, the concentration of hexamethylenetetramine is 0.06mol/L, and the volume of water is 30 mL;

step 2, putting the mixed solution into a hydrothermal kettle, sealing, and putting into an oven to heat for 9 hours at 90 ℃;

step 3, after the reaction is finished, taking out the reaction kettle after the temperature of the reaction kettle is reduced to room temperature, centrifuging, washing with deionized water, and drying at 150 ℃ for 30min to obtain nickel hydroxide powder;

and 4, heating the nickel hydroxide powder at 250 ℃ for 2 hours to obtain the nickel oxide powder, wherein the nickel oxide powder has a reticular porous structure (see figure 1).

Example 2: the preparation of the NiO/Al nano energetic material in this example specifically includes the following steps:

step one, 0.25g of nano aluminum powder is ultrasonically dispersed in 50mL of isopropanol, 1g of the reticular porous NiO powder prepared in the embodiment 1 is ultrasonically dispersed in 50mL of isopropanol, and the ultrasonic dispersion time is 20 min;

and step two, mixing the solution obtained in the step one, continuing ultrasonic dispersion for 60min, centrifuging, and drying at 60 ℃ for 6 hours to obtain the NiO/Al nano energetic material, wherein the figure is 2.

As can be seen from fig. 2, the Al particles were dispersed in the porous NiO, and no agglomeration phenomenon was observed.

The DSC curve of the NiO/Al nano energetic material is shown in FIG. 3, and it can be known from FIG. 3 that the NiO/Al nano energetic material has a larger exothermic peak between 500 ℃ and 700 ℃.

Claims

1. A reticular porous NiO/Al nano energetic material is characterized in that the energetic material is formed by assembling reticular porous NiO powder and Al powder;

the energetic material is prepared by the following steps:

step one, respectively ultrasonically dispersing reticular porous NiO powder and Al powder in isopropanol;

step two, mixing, continuing ultrasonic dispersion, centrifuging and drying to obtain the reticular porous NiO/Al nano energetic material;

wherein the Al powder has the mass purity of 99 percent and the particle size of 30nm-50 nm;

in the second step, Al: NiO is mixed according to the mass ratio of (1:5) - (1: 1);

ultrasonic dispersion is carried out for 30min-60min in the second step;

the reticular porous NiO powder prepared by the step one is prepared by a hydrothermal method, and the preparation method specifically comprises the following steps:

2. The method for preparing the reticular porous NiO/Al nano energetic material according to claim 1, wherein the ultrasonic dispersion time in the step one is controlled within 20min-30 min.

3. The method for preparing the reticular porous NiO/Al nano energetic material according to claim 1, characterized in that the drying is carried out for 6 hours at 60 ℃ in the second step.