阅读说明：本技术 一种提高玻璃纤维热导率的方法 (Method for improving thermal conductivity of glass fiber ) 是由 付继伟 王国辉 陈红波 荀飞 岳勇 高雅 林三春 胡苏珍 于 2020-11-30 设计创作，主要内容包括：本发明涉及一种提高玻璃纤维热导率的方法,采用超临界二氧化碳处理玻璃纤维,使得玻璃纤维表面粗糙度和极性官能团显著增加,随后用化学镀法在玻璃纤维表面制作一层金属镍层,这些工作显著提高了玻璃纤维的热导率,该项技术发明属于化学镀领域,也属于高温热防护技术领域。(The invention relates to a method for improving the thermal conductivity of glass fiber, which adopts supercritical carbon dioxide to treat the glass fiber, so that the surface roughness and polar functional groups of the glass fiber are obviously increased, and then a metal nickel layer is manufactured on the surface of the glass fiber by a chemical plating method, and the work obviously improves the thermal conductivity of the glass fiber.)

1. A method for increasing the thermal conductivity of glass fibers, characterized in that the method comprises the steps of

Firstly, treating the surface of glass fiber by using supercritical carbon dioxide;

secondly, preparing a chemical plating solution;

and thirdly, putting the glass fiber treated in the first step into the chemical plating solution prepared in the second step for treatment to form a metal nickel layer on the surface of the glass fiber, thereby finishing the improvement of the thermal conductivity of the glass fiber.

2. The method of claim 1, wherein the step of increasing the thermal conductivity of the glass fiber comprises:

in the first step, the glass fiber is processed under the conditions of supercritical carbon dioxide: the temperature is 100-150 ℃, the pressure is 100-120 atm, and the time is 30-60 minutes.

3. The method of claim 1, wherein the step of increasing the thermal conductivity of the glass fiber comprises:

in the second step, in the chemical plating solution: 100-200 parts of deionized water, 10-15 parts of main salt, 1-2 parts of a reducing agent, 5-10 parts of a complexing agent, 5-10 parts of a buffering agent and 1-5 parts of an accelerating agent.

4. A method of increasing the thermal conductivity of glass fibers as recited in claim 3, wherein: the main salt is nickel sulfate, nickel chloride, nickel sulfamate or nickel acetate, the reducing agent is sodium hypophosphite, sodium borohydride or alkylamine borane and hydrazine, the complexing agent is sodium citrate or sodium tartrate, the buffering agent is sodium acetate, borax or potassium pyrophosphate, and the accelerator is malonic acid, succinic acid, aminoacetic acid, propionic acid or sodium fluoride.

5. The method of claim 1, wherein the step of increasing the thermal conductivity of the glass fiber comprises:

and in the third step, the glass fiber is treated in the chemical plating solution for 30-60 minutes, and mechanical stirring is adopted during treatment, and the rotating speed is 10-30 revolutions per minute.

Technical Field

The invention relates to a method for improving the thermal conductivity of glass fiber, which adopts supercritical carbon dioxide to treat the glass fiber, so that the surface roughness and polar functional groups of the glass fiber are obviously increased, and then a metal nickel layer is manufactured on the surface of the glass fiber by a chemical plating method, and the work obviously improves the thermal conductivity of the glass fiber.

Background

Glass fibers are inorganic nonmetallic materials with excellent performance, and are various in types, the main components of the glass fibers are silicon dioxide, aluminum oxide, calcium oxide, boron oxide, magnesium oxide, sodium oxide and the like, and the glass fibers can be divided into alkali-free glass fibers (sodium oxide is 0-2 percent, belonging to aluminoborosilicate glass), medium-alkali glass fibers (sodium oxide is 8-12 percent, belonging to boron-containing or boron-free soda-lime silicate glass) and high-alkali glass fibers (sodium oxide is more than 13 percent, belonging to soda-lime silicate glass) according to the content of alkali in the glass. The glass fiber has the advantages of good insulativity, strong heat resistance, good corrosion resistance and high mechanical strength, but has the defects of brittleness and poor wear resistance. The hair-care fiber is made of seven kinds of ores of pyrophyllite, quartz sand, limestone, dolomite, borocalcite and boromagnesite through the processes of high-temperature melting, wire drawing, winding, weaving and the like, wherein the diameter of each monofilament ranges from several micrometers to twenty micrometers, the monofilament is equivalent to 1/20-1/5 of one hair, and each bundle of fiber precursor consists of hundreds of even thousands of monofilaments. Glass fibers are generally used in various fields of national economy, such as reinforcing materials, electrical insulating materials, thermal insulating materials, and circuit boards in composite materials, and among them, glass fibers are widely used in various high-temperature environments because of their high softening points (generally, the softening points are considered to be 500 to 750 ℃). However, the low thermal conductivity of glass fibers (1.09w/m · k) makes it difficult for glass fibers to transfer heat, and increases the thermal conductivity of glass fibers in order to expand the range of applications of glass fibers. However, the surface of the glass fiber is very smooth, and many coating materials cannot form stable interface combination with the surface of the glass fiber, which results in that the coating is difficult to manufacture on the surface of the glass fiber.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the method for improving the thermal conductivity of the glass fiber overcomes the defects of the prior art, and the coating is used for improving the thermal conductivity of the glass fiber.

The technical solution of the invention is as follows:

a method for improving the thermal conductivity of glass fibers comprises the following steps

Firstly, treating the surface of glass fiber by using supercritical carbon dioxide;

secondly, preparing a chemical plating solution;

thirdly, the glass fiber treated in the first step is put into the chemical plating solution prepared in the second step for treatment, and a metal nickel layer is formed on the surface of the glass fiber;

and fourthly, measuring the thickness of the metal nickel layer on the cross section of the glass fiber and the thermal conductivity of the glass fiber after chemical plating.

The proportions in the invention are mass ratios, and the specific process steps are as follows:

the first step is as follows: treating the glass fiber in supercritical carbon dioxide (the temperature is 100-150 ℃, and the pressure is 100-120 atm) for different time (30-60 minutes);

the second step is that: in the chemical plating solution: 100-200 parts of deionized water, 10-15 parts of nickel oxalate as main salt, 1-2 parts of dimethylamine borane as a reducing agent, 5-10 parts of calcium oxalate as a complexing agent, 5-10 parts of sodium persulfate as a buffering agent and 1-5 parts of 2-hydroxypropionic acid as an accelerating agent;

the third step: placing the glass fiber treated by the supercritical carbon dioxide into a chemical plating solution for natural reaction for 30-60 minutes, wherein in order to ensure the whole solution to be uniform, the chemical plating solution is always mechanically stirred and the rotating speed is 10-30 r/min;

the fourth step: the thickness of the metal nickel layer on the cross section of the glass fiber and the thermal conductivity of the glass fiber after chemical plating are measured. In order to prove the advantages of the invention, the common glass fiber is directly put into the chemical plating solution for processing for the same time, and the thickness of the metal nickel layer and the thermal conductivity of the glass fiber after chemical plating are tested. Each data measurement was an average of 10 measurements. The thermal conductivity at 600 ℃, 800 ℃ and 1000 ℃ is measured by adopting a laser method, because the instantaneous heating at 800 ℃ and 1000 ℃ cannot cause the melting of the nickel coating on the surface of the glass fiber measured by adopting a laser pulse method.

On the other hand, as the temperature and pressure of the environment change, the point where any one substance exists in three phases-gas phase, liquid phase, solid phase, and three phases coexist in an equilibrium state is called a three-phase point. The point at which the interface between the liquid and gas phases disappears is called the supercritical point. Supercritical carbon dioxide refers to a fluid with temperature and pressure higher than the critical point of carbon dioxide (the critical temperature is 31.26 ℃, and the critical pressure is 72.9atm), and the supercritical carbon dioxide has many special properties, for example, can react with the surfaces of various substances to form polar groups such as carbonyl, carboxyl, hydroxyl and the like on the surfaces; high impact and etching capability, can etch a plurality of rugged structures on the solid surface, and obviously increases the roughness. In the current work, the glass fibers are first treated with supercritical carbon dioxide, so that the roughness of the surface of the glass fibers is significantly increased, and at the same time, some polar groups are also added, and the increase of the polar groups and the roughness can significantly improve the interface bonding strength between the coating and the glass fibers.

Electroless plating is a deposition process that produces metal by a controlled redox reaction under the catalytic action of the metal. Compared with electroplating, the chemical plating technology has the characteristics of uniform plating layer, small pin holes, no need of direct-current power supply equipment, capability of depositing on a non-conductor, certain special properties and the like. The chemical plating needs the following raw materials: main salts (usually, nickel sulfate, nickel chloride, nickel sulfamate, nickel acetate, etc.), reducing agents (usually, sodium hypophosphite, sodium borohydride, alkylamine borane, hydrazine, etc.), complexing agents (usually, sodium citrate, sodium tartrate, etc.), buffering agents (usually, sodium acetate, borax, potassium pyrophosphate, etc.), accelerators (usually, malonic acid, succinic acid, glycine, propionic acid, sodium fluoride, etc.), etc. are used.

In order to improve the thermal conductivity of the glass fiber, the glass fiber is treated by supercritical carbon dioxide to increase the surface roughness and polar groups of the glass fiber, and then a layer of metallic nickel is plated on the surface of the glass fiber by chemical plating.

Detailed Description

The invention is further illustrated by the following examples, without restricting its application to the examples given.

The method for improving the thermal conductivity of the glass fiber comprises the following steps:

the first step is as follows: treating the glass fiber in supercritical carbon dioxide (the critical temperature is 150 ℃, and the critical pressure is 100-120 atm) for different time periods of 60 minutes;

the second step is that: 100 parts of deionized water, 15 parts of nickel oxalate as main salt, 2 parts of dimethylamino borane as a reducing agent, 10 parts of calcium oxalate as a complexing agent, 10 parts of sodium persulfate as a buffering agent and 5 parts of 2-hydroxypropionic acid as an accelerator;

the third step: placing the glass fiber treated by the supercritical carbon dioxide into a chemical plating solution for natural reaction for 60 minutes, wherein in order to ensure the whole uniformity of the solution, the chemical plating solution is always mechanically stirred and the rotating speed is 30 r/min;

the fourth step: the thickness of the metal nickel layer on the cross section of the glass fiber and the thermal conductivity of the glass fiber after chemical plating are measured. In order to prove the advantages of the invention, the common glass fiber is directly put into the chemical plating solution for treatment for the same time, and the thickness of the metal nickel layer and the thermal conductivity of the glass fiber after chemical plating are tested.

The measurement results show that: the thermal conductivity of the untreated glass fiber at 600 ℃, 800 ℃ and 1000 ℃ was 1.3 kw/c, 1.2 kw/c and 1.0 kw/c, and the diameter of the glass fiber was 15 μm; the thermal conductivity of the glass fiber which is directly chemically plated without being treated by supercritical carbon dioxide at 600 ℃, 800 ℃ and 1000 ℃ is 5.7 kw/DEG C, 4.6 kw/DEG C and 4.1 kw/DEG C, the diameter of the glass fiber is 18 microns, meanwhile, the surface of the glass fiber can be clearly seen to have some exposed places by adopting a scanning electron microscope, and the discontinuous nickel layer has limited improvement range on the thermal conductivity; the thermal conductivities at 600 ℃, 800 ℃ and 1000 ℃ of the glass fiber treated by the method, namely after the chemical plating of the glass fiber treated by the supercritical carbon dioxide are 67.6 kw/DEG C, 59.4 kw/DEG C and 51.1 kw/DEG C respectively, and meanwhile, the diameter of the glass fiber is measured to be 28 microns. The significant improvement in thermal conductivity is due to the formation of a high thermal conductivity nickel layer on the surface of the glass fiber in a thickness close to the diameter of the fiber itself.

Example 2

The first step is as follows: the glass fibers were treated in supercritical carbon dioxide (temperature 100 ℃ C., pressure 100atm) for various times (30 minutes);

the second step is that: 200 parts of deionized water, 10 parts of nickel oxalate as main salt, 1 part of dimethylamino borane as a reducing agent, 5 parts of calcium oxalate as a complexing agent, 5 parts of sodium persulfate as a buffering agent and 1 part of 2-hydroxypropionic acid as an accelerating agent;

the third step: placing the glass fiber treated by the supercritical carbon dioxide into a chemical plating solution for natural reaction for 30 minutes, wherein in order to ensure the whole uniformity of the solution, the chemical plating solution is always mechanically stirred and the rotating speed is 10 r/min;

the fourth step: the thickness of the metal nickel layer on the cross section of the glass fiber and the thermal conductivity of the glass fiber after chemical plating are measured. In order to prove the advantages of the invention, the common glass fiber is directly put into the chemical plating solution for treatment for the same time, and the thickness of the metal nickel layer and the thermal conductivity of the glass fiber after chemical plating are tested.

The measurement results show that: the thermal conductivity of the untreated glass fiber at 600 ℃, 800 ℃ and 1000 ℃ was 1.3 kw/c, 1.2 kw/c and 1.0 kw/c, and the diameter of the glass fiber was 15 μm; the thermal conductivity of the glass fiber which is directly chemically plated without being treated by supercritical carbon dioxide at 600 ℃, 800 ℃ and 1000 ℃ is 5.3 kw/DEG C, 4.9 kw/DEG C and 4.4 kw/DEG C, the diameter of the glass fiber is 18 microns, meanwhile, the surface of the glass fiber can be clearly seen to have some exposed places by adopting a scanning electron microscope, and the discontinuous nickel layer has limited improvement range on the thermal conductivity. The thermal conductivities of the glass fiber after the supercritical carbon dioxide treatment at 600 ℃, 800 ℃ and 1000 ℃ are 53.9 kw/DEG C, 41.2 kw/DEG C and 34.6 kw/DEG C respectively, and meanwhile, the diameter of the glass fiber is measured to be changed to 22 micrometers. The significant improvement in thermal conductivity is due to the formation of a high thermal conductivity nickel layer on the surface of the glass fiber in a thickness close to the diameter of the fiber itself.

Example 3

The first step is as follows: the glass fibers were treated in supercritical carbon dioxide (temperature 110 ℃ C., pressure 105atm) for various times of 55 minutes;

the second step is that: 180 parts of deionized water, 11 parts of nickel oxalate as main salt, 1 part of dimethylamino borane as a reducing agent, 10 parts of calcium oxalate as a complexing agent, 10 parts of sodium persulfate as a buffering agent and 5 parts of 2-hydroxypropionic acid as an accelerator;

the third step: placing the glass fiber treated by the supercritical carbon dioxide into a chemical plating solution for natural reaction for 50 minutes, wherein in order to ensure the whole uniformity of the solution, the chemical plating solution is always mechanically stirred and the rotating speed is 15 r/min;

the fourth step: the thickness of the metal nickel layer on the cross section of the glass fiber and the thermal conductivity of the glass fiber after chemical plating are measured. In order to prove the advantages of the invention, the common glass fiber is directly put into the chemical plating solution for treatment for the same time, and the thickness of the metal nickel layer and the thermal conductivity of the glass fiber after chemical plating are tested.

The measurement results show that: the thermal conductivity of the untreated glass fiber at 600 ℃, 800 ℃ and 1000 ℃ was 1.3 kw/c, 1.2 kw/c and 1.0 kw/c, and the diameter of the glass fiber was 15 μm; the thermal conductivity of the glass fiber which is directly chemically plated without being treated by supercritical carbon dioxide at 600 ℃, 800 ℃ and 1000 ℃ is 6.4 kw/DEG C, 5.7 kw/DEG C and 4.9 kw/DEG C, the diameter of the glass fiber is 18 microns, meanwhile, the surface of the glass fiber can be clearly seen to have some exposed places by adopting a scanning electron microscope, and the discontinuous nickel layer has limited improvement range on the thermal conductivity. The thermal conductivities at 600 ℃, 800 ℃ and 1000 ℃ of the glass fiber after the supercritical carbon dioxide treatment were 57.1 kw/DEG C, 49.3 kw/DEG C and 36.1 kw/DEG C, respectively, and the diameter of the glass fiber was measured to be 24 μm. The significant improvement in thermal conductivity is due to the formation of a high thermal conductivity nickel layer on the surface of the glass fiber in a thickness close to the diameter of the fiber itself.

Example 4

The first step is as follows: the glass fibers were treated in supercritical carbon dioxide (temperature 140 ℃ C., pressure 115atm) for various times of 50 minutes;

the second step is that: 160 parts of deionized water, 13 parts of nickel oxalate as main salt, 1 part of dimethylamino borane as a reducing agent, 7 parts of calcium oxalate as a complexing agent, 9 parts of sodium persulfate as a buffering agent and 4 parts of 2-hydroxypropionic acid as an accelerator;

the third step: placing the glass fiber treated by the supercritical carbon dioxide into a chemical plating solution for natural reaction for 40 minutes, wherein in order to ensure the whole uniformity of the solution, the chemical plating solution is always mechanically stirred and the rotating speed is 20 r/min;

the fourth step: the thickness of the metal nickel layer on the cross section of the glass fiber and the thermal conductivity of the glass fiber after chemical plating are measured. In order to prove the advantages of the invention, the common glass fiber is directly put into the chemical plating solution for treatment for the same time, and the thickness of the metal nickel layer and the thermal conductivity of the glass fiber after chemical plating are tested.

The measurement results show that: the thermal conductivity of the untreated glass fiber at 600 ℃, 800 ℃ and 1000 ℃ was 1.3 kw/c, 1.2 kw/c and 1.0 kw/c, and the diameter of the glass fiber was 15 μm; the thermal conductivity of the glass fiber which is directly chemically plated without being treated by supercritical carbon dioxide at 600 ℃, 800 ℃ and 1000 ℃ is 5.3 kw/DEG C, 4.5 kw/DEG C and 3.9 kw/DEG C, the diameter of the glass fiber is 18 microns, meanwhile, the surface of the glass fiber can be clearly seen to have some exposed places by adopting a scanning electron microscope, and the discontinuous nickel layer has limited improvement range on the thermal conductivity. The thermal conductivities at 600 ℃, 800 ℃ and 1000 ℃ after the chemical plating of the glass fiber treated by the supercritical carbon dioxide were 59.1, kw/DEG C, 50.6 kw/DEG C and 45.8 kw/DEG C, respectively, and the diameter of the glass fiber was measured to be 25 micrometers. The significant improvement in thermal conductivity is due to the formation of a high thermal conductivity nickel layer on the surface of the glass fiber in a thickness close to the diameter of the fiber itself.

Example 5

The first step is as follows: the glass fibers were treated in supercritical carbon dioxide (temperature 120 ℃ C., pressure 120atm) for various times of 45 minutes;

the second step is that: 150 parts of deionized water, 14 parts of nickel oxalate as main salt, 2 parts of dimethylamino borane as a reducing agent, 6 parts of calcium oxalate as a complexing agent, 6 parts of sodium persulfate as a buffering agent and 3 parts of 2-hydroxypropionic acid as an accelerator;

the third step: placing the glass fiber treated by the supercritical carbon dioxide into a chemical plating solution for natural reaction for 35 minutes, wherein in order to ensure the whole uniformity of the solution, the chemical plating solution is always mechanically stirred and the rotating speed is 18 r/min;

the fourth step: the thickness of the metal nickel layer on the cross section of the glass fiber and the thermal conductivity of the glass fiber after chemical plating are measured. In order to prove the advantages of the invention, the common glass fiber is directly put into the chemical plating solution for treatment for the same time, and the thickness of the metal nickel layer and the thermal conductivity of the glass fiber after chemical plating are tested.

The measurement results show that: the thermal conductivity of the untreated glass fiber at 600 ℃, 800 ℃ and 1000 ℃ was 1.3 kw/c, 1.2 kw/c and 1.0 kw/c, and the diameter of the glass fiber was 15 μm; the thermal conductivity of the glass fiber which is directly chemically plated without being treated by supercritical carbon dioxide at 600 ℃, 800 ℃ and 1000 ℃ is 5.7 kw/DEG C, 4.9 kw/DEG C and 4.2 kw/DEG C, the diameter of the glass fiber is 18 microns, meanwhile, the surface of the glass fiber can be clearly seen to have some exposed places by adopting a scanning electron microscope, and the discontinuous nickel layer has limited improvement range on the thermal conductivity. The thermal conductivities at 600 ℃, 800 ℃ and 1000 ℃ after the chemical plating of the glass fiber treated by the supercritical carbon dioxide were 62.5kw/℃ and 53.1kw/℃ and 49.3kw/℃ respectively, and at the same time, the diameter of the glass fiber was measured to be 27 μm. The significant improvement in thermal conductivity is due to the formation of a high thermal conductivity nickel layer on the surface of the glass fiber in a thickness close to the diameter of the fiber itself.

Example 6

The first step is as follows: the glass fibers were treated in supercritical carbon dioxide (temperature 130 ℃ C., pressure 105atm) for various times 38 minutes;

the second step is that: 170 parts of deionized water, 12 parts of nickel oxalate as main salt, 1 part of dimethylamino borane as a reducing agent, 8 parts of calcium oxalate as a complexing agent, 9 parts of sodium persulfate as a buffering agent and 4 parts of 2-hydroxypropionic acid as an accelerator;

the third step: placing the glass fiber treated by the supercritical carbon dioxide into a chemical plating solution for natural reaction for 36 minutes, wherein in order to ensure the whole uniformity of the solution, the chemical plating solution is always mechanically stirred and the rotating speed is 26 r/min;

the fourth step: the thickness of the metal nickel layer on the cross section of the glass fiber and the thermal conductivity of the glass fiber after chemical plating are measured. In order to prove the advantages of the invention, the common glass fiber is directly put into the chemical plating solution for treatment for the same time, and the thickness of the metal nickel layer and the thermal conductivity of the glass fiber after chemical plating are tested.

The measurement results show that: the thermal conductivity of the untreated glass fiber at 600 ℃, 800 ℃ and 1000 ℃ was 1.3 kw/c, 1.2 kw/c and 1.0 kw/c, and the diameter of the glass fiber was 15 μm; the thermal conductivity of the glass fiber which is directly chemically plated without being treated by supercritical carbon dioxide at 600 ℃, 800 ℃ and 1000 ℃ is 6.1 kw/DEG C, 4.7 kw/DEG C and 4.0 kw/DEG C, the diameter of the glass fiber is 18 microns, meanwhile, the surface of the glass fiber can be clearly seen to have some exposed places by adopting a scanning electron microscope, and the discontinuous nickel layer has limited improvement range on the thermal conductivity. The thermal conductivities at 600 ℃, 800 ℃ and 1000 ℃ after the glass fiber is subjected to the chemical plating by the supercritical carbon dioxide treatment are 56.7 kw/DEG C, 42.4 kw/DEG C and 46.8 kw/DEG C, respectively, and the diameter of the glass fiber is measured to be 25 micrometers. The significant improvement in thermal conductivity is due to the formation of a high thermal conductivity nickel layer on the surface of the glass fiber in a thickness close to the diameter of the fiber itself.

To summarize:

as can be seen from the 6 embodiments described above: the thermal conductivity of untreated glass fiber at 600-1000 ℃ is about 1.3-1.0 kw/DEG C, the glass fiber without supercritical carbon dioxide treatment is directly plated by chemical plating, a continuous metal nickel layer cannot be formed, and the thermal conductivity at 600-1000 ℃ is about 6.4-3.9 kw/DEG C, and the thickness of the metal nickel layer is almost kept unchanged, while the technical advantage of the invention is very obvious that the thermal conductivity at 600-1000 ℃ is about 67.6-34.6 kw/DEG C, and the thickness of the nickel layer on the surface of the glass fiber is about 22-28 microns. In the present invention, the thermal conductivity is not greatly related to the thickness of the nickel layer, mainly because electroless plating is a very complicated process, and the compactness of the formed nickel layer is also different, so that the thermal conductivity does not show a linear relationship with the thickness. In addition, the method is simple and easy to implement, and is easy for industrial production and engineering application.