Preparation method of nano calcium tungstate
Technical Field
The invention belongs to the technical field of inorganic nano material preparation, and relates to a preparation method of a calcium tungstate nano material.
Technical Field
Calcium tungstate is an important inorganic functional material, and is an effective luminescent material under the excitation of X rays, electron beams and ultraviolet rays due to the special crystal structure and energy band structure of the calcium tungstate, so that the calcium tungstate has very wide application in the fields of fluorescent and photoelectronic display devices, luminescent coatings, optical fiber devices, biological materials and the like. At present, the main methods for preparing calcium tungstate materials include hydrothermal/solvothermal methods (CN 102701282B), microemulsion methods (CN 1958884 a), ultrasonic chemistry methods (CN 106365203B), microwave radiation methods (CN 102718262B), etc., most of the synthetic products are nanowires, micro-blocks or micro-spheres, etc., and there is still a large space for improving and optimizing the morphology control and controllable synthesis of calcium tungstate nanomaterials.
In the last decade, mechanochemical reaction methods have attracted great research interest due to the characteristics of no or little solvent, high yield, little pollution, short time consumption, low energy consumption, simple operation and equipment, easy industrialization and the like, and have become a new way for developing green chemistry and technology. So far, no literature report is available for preparing the nano calcium tungstate material by adopting a mechanochemical method.
Disclosure of Invention
The invention aims to provide a preparation method of nano calcium tungstate, which is characterized in that common tungstate and calcium chloride are used as raw materials, a mechanochemical reaction method is adopted to obtain materials, and the materials are washed, filtered and dried to obtain the nano calcium tungstate with uniform size and good dispersibility.
The invention is realized by the following technical scheme.
A preparation method of nano calcium tungstate is characterized by comprising the following steps:
(1) weighing tungstate and calcium chloride according to a stoichiometric ratio;
(2) putting the reactant weighed in the step (1) into a ball mill for ball milling for 1-3 hours, and taking out a ball milling product and a grinding ball;
(3) and (3) washing, filtering and drying the ball-milled product obtained in the step (2) to obtain the nano calcium tungstate.
More specifically, the calcium chloride in the step (1) is calcium chloride dihydrate or anhydrous calcium chloride.
More specifically, the tungstate in the step (1) is one or more of alkali metal tungstate, ammonium paratungstate and ammonium metatungstate.
More specifically, the ball mill in the step (2) is a planetary ball mill, a stirring mill, a roller ball mill or a vibration mill.
More specifically, the material of the ball milling pot in the step (2) is yttrium zirconium oxide ceramic, stainless steel, agate, corundum, tungsten carbide, polytetrafluoroethylene or nylon, and the material of the grinding ball is yttrium zirconium oxide ceramic, stainless steel, agate, corundum or tungsten carbide.
More specifically, the drying in the step (3) is drying for 1-4 hours in an air-blast drying oven at 40-100 ℃.
The main advantages of the invention are: (1) the product calcium tungstate has small granularity, good dispersibility and uniform size; (2) the invention takes common tungstate and calcium chloride as raw materials, prepares the nano calcium tungstate by a mechanochemical method, has the characteristics of low equipment requirement, high synthesis yield and no additive, has green and environment-friendly synthesis process and low preparation cost, and is very suitable for industrial production.
Drawings
Figure 1 XRD pattern of sample of example 1.
FIG. 2 SEM photograph of the sample of example 1.
Detailed Description
The invention will be further illustrated by the following examples.
A preparation method of nano calcium tungstate is characterized by comprising the following steps:
(1) weighing tungstate and calcium chloride according to the stoichiometric ratio of the reaction formula; the calcium chloride is calcium chloride dihydrate or anhydrous calcium chloride; the tungstate is one or more of alkali metal tungstate, ammonium paratungstate and ammonium metatungstate.
(2) Putting the reactant weighed in the step (1) into a ball mill for ball milling for 1-3 hours, and taking out a ball milling product and a grinding ball; the ball mill is a planetary ball mill, a stirring mill, a roller ball mill or a vibration mill; the material of the ball milling tank is yttrium zirconium oxide ceramic, stainless steel, agate, corundum, tungsten carbide, polytetrafluoroethylene or nylon, and the material of the grinding ball is yttrium zirconium oxide ceramic, stainless steel, agate, corundum or tungsten carbide.
(3) Washing, filtering and drying the ball-milled product obtained in the step (2), wherein the drying is carried out for 1-4 hours in a forced air drying oven at the temperature of 40-100 ℃; thus obtaining the nano calcium tungstate.
Example 1
Accurately weighing 15g of sodium tungstate dihydrate and 10g of calcium chloride dihydrate, placing the sodium tungstate dihydrate and the calcium chloride dihydrate in a 250ml of polytetrafluoroethylene ball milling tank, wherein the grinding ball is made of corundum, carrying out ball milling for 3 hours by using a planetary ball mill, taking out a ball milling product and the grinding ball, washing the ball milling product for three times, filtering, and drying in a 60 ℃ air-blast drying oven for 2 hours to obtain the nano calcium tungstate powder. XRD analysis of the sample was performed, and the results are shown in FIG. 1, XRD pattern and CaWO4The JCDPS number is matched with 85-0443, which shows that calcium tungstate powder is obtained; SEM analysis is carried out on the sample, and the result is shown in figure 2, and the calcium tungstate powder is uniformly dispersed and has no obvious agglomeration phenomenon.
In the above embodiment of the invention, the ball milling pot is made of polytetrafluoroethylene, or yttrium zirconium oxide ceramic, stainless steel, agate, corundum, tungsten carbide, nylon and other materials, and has good wear resistance and no pollution to products. Similarly, the material of the grinding ball can also be yttrium zirconium oxide ceramic, stainless steel, agate, tungsten carbide and the like.
The ball mill in the present invention may be a stirring mill, a tumbling mill or a vibration mill.
The above examples are only partial embodiments of the present invention, and those skilled in the art can make routine changes based on the spirit of the present invention, and also fall into the protection scope of the present invention.