阅读说明：本技术 一种金属纳米颗粒-聚合物复合材料及其制备方法与应用 (Metal nanoparticle-polymer composite material and preparation method and application thereof ) 是由 顾佳俊 刘庆雷 董昌林 袁洋 张荻 于 2019-10-21 设计创作，主要内容包括：本发明提供了一种金属纳米颗粒-聚合物复合材料及其制备方法与应用,涉及复合材料领域；所述复合材料包括固态基体和填充体,填充体包括粒径范围为5-99纳米的金属纳米颗粒,相邻金属纳米颗粒距离1-200纳米；固态基体内具有孔径为2-500纳米的孔隙,固态基体包括聚合物纤维材料,填充体分散填充于固态基体内部的孔隙中,孔隙用于分散填充体,阻止填充体团聚；通过在固态基体的内部孔隙中制备金属种子,然后放入金属纳米颗粒生长溶液中生长得到金属纳米颗粒-聚合物复合材料；该材料光吸收强,光热转换效率高,对太阳光谱300-2500nm波段的平均吸收率可达97％,可大面积制备,可应用于包括光热转换、太阳能海水淡化等领域。(The invention provides a metal nanoparticle-polymer composite material and a preparation method and application thereof, relating to the field of composite materials; the composite material comprises a solid matrix and a filler, wherein the filler comprises metal nano-particles with the particle size range of 5-99 nanometers, and the distance between adjacent metal nano-particles is 1-200 nanometers; the solid matrix is internally provided with pores with the pore diameter of 2-500 nanometers, the solid matrix comprises polymer fiber materials, the filling bodies are dispersed and filled in the pores in the solid matrix, and the pores are used for dispersing the filling bodies and preventing the filling bodies from agglomerating; preparing metal seeds in internal pores of a solid matrix, and then putting the metal seeds into a metal nanoparticle growth solution for growth to obtain a metal nanoparticle-polymer composite material; the material has strong light absorption and high photo-thermal conversion efficiency, has an average absorption rate of 97% to the solar spectrum of 300-2500nm, can be prepared in a large area, and can be applied to the fields of photo-thermal conversion, solar seawater desalination and the like.)

1. A metal nanoparticle-polymer composite comprising a solid matrix and a filler, wherein the filler comprises metal nanoparticles, the metal nanoparticles have a particle size in the range of 5 to 99 nm, and the distance between adjacent metal nanoparticles is in the range of 1 to 200 nm; the solid matrix comprises a polymer fiber material, the polymer fiber material is composed of polymer fibers, and pores of 2-500 nanometers are formed in the polymer fibers; the filler is dispersed and filled in pores in the solid matrix, and the pores are used for dispersing the filler and preventing the filler from agglomerating.

2. The metal nanoparticle-polymer composite material according to claim 1, wherein the material of the metal nanoparticle comprises one or more of gold, silver, palladium, platinum, rhodium, ruthenium, osmium, iridium, copper, zinc, chromium, molybdenum, tungsten, titanium, zirconium, niobium, cobalt, iron, and nickel.

3. The metal nanoparticle-polymer composite material of claim 1, wherein the material of the metal nanoparticle comprises one of gold, silver, copper and nickel, and the average absorption rate of the metal nanoparticle-polymer composite material to the solar spectrum in the wavelength region of 300-2500nm is greater than or equal to ninety percent.

4. The metal nanoparticle-polymer composite of claim 1, wherein the metal nanoparticles are nickel nanoparticles, and the average absorption rate of the metal nanoparticle-polymer composite is greater than or equal to ninety-seven percent in the solar spectrum in the wavelength region of 300-2500 nm.

5. The metal nanoparticle-polymer composite of claim 1, wherein the polymer fiber material comprises a natural fiber material and a synthetic porous fiber material; the natural fiber material comprises a cellulose material, a chitin material and a silk fiber material; the cellulose material comprises one of wet strength paper, printing paper, filter paper, dust-free paper, mirror wiping paper and cotton cloth.

6. A method for preparing a metal nanoparticle-polymer composite according to any one of claims 1 to 5, comprising the following steps of growing metal nanoparticles:

preparing metal seeds in the internal pores of the solid matrix; putting the solid matrix containing the metal seeds into a metal nanoparticle growth solution, and growing for 3-20 minutes to obtain a metal nanoparticle-polymer composite material;

the metal nanoparticle growth solution comprises a metal main salt solution, a complexing agent, a reducing agent and a pH regulator; the metal seeds comprise metal ion seeds and metal simple substance seeds.

7. The method of claim 6, wherein the metal ion seed comprises Sn ²⁺、Pd ²⁺The metal elementary substance seeds comprise one or more of elementary substance Au, elementary substance Ag, elementary substance Pd, elementary substance Pt, elementary substance Cu and elementary substance Ni.

8. The method for preparing a metal nanoparticle-polymer composite according to claim 6,

the preparation of the metal ion seeds in the internal pores of the solid matrix specifically comprises: cleaning the solid matrix, and then putting the solid matrix into a metal ion seed solution to be soaked for 3-5 hours to obtain metal ion seeds in the internal pores of the solid matrix; the metal ion seed solution comprises one of a tin dichloride solution, a palladium dichloride solution and a diammine palladium dichloride solution;

the preparation of the metal elementary seeds in the internal pores of the solid matrix specifically comprises: cleaning the solid matrix, putting the solid matrix into a metal simple substance seed salt solution, soaking for 3-5 hours, cleaning, and then putting the solid matrix into a seed reducing agent for 2-4 minutes to obtain metal simple substance seeds in the internal pores of the solid matrix; the metal elementary substance seed salt solution comprises one of a chloroauric acid solution, a silver nitrate solution, a palladium dichloride solution, a chloroplatinic acid solution, a copper sulfate solution and a nickel sulfate solution; the seed reducing agent comprises one or more of sodium borohydride solution, hydrazine hydrate solution and dimethylamino borane solution.

9. The method for preparing a metal nanoparticle-polymer composite according to claim 6,

the metal main salt solution comprises one of chloroauric acid solution, silver nitrate solution, copper sulfate solution and nickel sulfate solution;

the complexing agent comprises one or more of tartaric acid, sodium chloride, ammonia water, potassium sodium tartrate, sodium citrate and lactic acid;

the reducing agent comprises one or more of ethanol, potassium sodium tartrate, formaldehyde and dimethylamino borane;

the pH regulator comprises one or more of sodium hydroxide and ammonia water.

10. The application of the metal nanoparticle-polymer composite material as claimed in any one of claims 1 to 5, wherein the average absorption rate of the metal nanoparticle-polymer composite material to the solar spectrum in the wavelength region of 300-2500nm is greater than or equal to 90%, and the metal nanoparticle-polymer composite material has high-efficiency photothermal conversion effect and is used for photothermal conversion and solar seawater desalination; the efficiency of photothermal water evaporation of the metal nanoparticle-polymer composite material is greater than or equal to 75%; the efficiency of the metal nanoparticle-polymer composite material for solar seawater desalination is 46.9-65.8%.

Technical Field

The invention relates to the field of composite materials, in particular to a metal nanoparticle-polymer composite material and a preparation method and application thereof.

Background

Solar energy is inexhaustible clean energy and is expected to replace fossil energy which is exhausted. There are many methods of utilizing solar energy, such as solar cells, solar water heaters, focused solar power generation, solar seawater desalination, photocatalysis, and the like.

In any method using solar energy, sunlight is absorbed in the first step. For the full wave band of the solar spectrum, the utilization efficiency of solar energy can be effectively improved by efficient absorption. To this end, scientists have proposed and studied various methods of improving the light absorption rate, including designing a broadband superstructure, exciting plasmon resonance enhanced absorption, and anti-reflection fine nanostructure array. The full-wave band of sunlight means light in all wavelength ranges of the industry standard solar spectrum (Air Mass 1.5G), which ranges from 300 nm to 2500 nm.

Although these methods of increasing light absorption can increase bandwidth and reduce reflection, it is still difficult to achieve full-band absorption of the solar spectrum, and even with few materials available, these materials suffer from complicated preparation processes and difficult large-scale application. Although plasmon resonance can collect incident light and enhance light absorption, plasmon resonance absorption is resonance absorption in nature, and the bandwidth is very narrow, so that a fine and complex structure needs to be designed to improve the bandwidth to achieve the purpose of full-spectrum absorption.

Metals are generally considered to have a specular reflection effect on light, but when the size of the metal is close to the wavelength of light, i.e., becomes nanoparticles, the specular reflection will disappear but the scattering will still be large, and when the size of the metal nanoparticles is less than 40 nanometers, both the reflection and scattering losses will disappear. Therefore, controlling the size and distribution state of the metal nanoparticles can significantly affect their absorption characteristics for light. In fact, there is a certain requirement for the regulation of the size and distribution state of metal nanoparticles not only in optical absorption but also in the fields of catalysis, energy storage, and the like.

In the existing research, nanoparticles are attached to the surface of a material, the problem of nanoparticle agglomeration cannot be substantially solved, and the nanoparticles are mixed in a plasmon composite film reported by Ting Xu et al in 2019, and are subjected to suction filtration to form a light absorption composite material (Nanoscale,2019,11, 437-443). The nano particles are deposited on the surface of the nano material, the nano material plays a certain role in dispersion, but the distribution state of the nano particles is still difficult to control in the preparation process of the composite material, and the nano particles cannot be guaranteed not to agglomerate. In addition, during the use of the composite materials, the nano particles on the surfaces of the fibers are completely exposed outside, so that the nano particles are easy to fall off and agglomerate; when metal nanoparticles are loaded on a polymer material, common polymer materials comprise a polyethyleneimine/polyvinyl alcohol nanofiber membrane, a polyacrylic acid/polyvinyl alcohol electrostatic spinning nanofiber membrane and the like, and at present, no research on directly embedding nanoparticles in the polymer material exists.

Disclosure of Invention

In view of the shortcomings of the prior art, it is an object of the present invention to provide a metal nanoparticle-polymer composite; the second purpose of the invention is to provide a preparation method of the metal nanoparticle-polymer composite material; the third purpose of the invention is to provide an application of the metal nanoparticle-polymer composite material.

In order to realize the first purpose of the invention, the invention provides the following technical scheme that the metal nanoparticle-polymer composite material comprises a solid matrix and a filler, wherein the filler comprises metal nanoparticles, the particle size range of the metal nanoparticles is 5-99 nanometers, and the distance between every two adjacent metal nanoparticles is 1-200 nanometers; the solid matrix comprises a polymer fiber material, the polymer fiber material is composed of polymer fibers, and pores of 2-500 nanometers are formed in the polymer fibers; the filler is dispersed and filled in pores in the solid matrix, and the pores are used for dispersing the filler and preventing the filler from agglomerating.

The pores are long and narrow pores with the diameter of 2-50 nanometers and the length of 50-500 nanometers.

More preferably, the metal nanoparticles have a particle size in the range of 10-25 nm.

More preferably, the metal nanoparticles have a particle size in the range of 14 to 25 nanometers.

The metal nanoparticles may form a dispersed, non-agglomerated distribution on the polymer surface, or may be absent, but the metal nanoparticles may not form a continuous film on the polymer surface. The particle size of the metal nanoparticles is obtained by measuring the length and width of the minimum external rectangle of the metal nanoparticles in a transmission electron microscope and then opening a root number.

Preferably, the material of the metal nanoparticles comprises one or more of gold, silver, palladium, platinum, rhodium, ruthenium, osmium, iridium, copper, zinc, chromium, molybdenum, tungsten, titanium, zirconium, niobium, cobalt, iron and nickel.

Preferably, the shape of the metal nanoparticle includes one or more of a spherical shape, an ellipsoidal shape, a square shape, a rod shape, a star shape, and an irregular shape.

Preferably, the material of the metal nanoparticles comprises one of gold, silver, copper and nickel, and the average absorption rate of the metal nanoparticle-polymer composite material to the solar spectrum in the 300-2500nm band is greater than or equal to ninety percent.

Preferably, the metal nanoparticles are nickel nanoparticles, and the average absorption rate of the metal nanoparticle-polymer composite material to the solar spectrum in the wavelength band of 300-2500nm is greater than or equal to ninety-seven percent.

Preferably, the polymer fiber material comprises a natural fiber material and a synthetic porous fiber material; the natural fiber material comprises a cellulose material, a chitin material and a silk fiber material; the cellulose material comprises one of wet strength paper, printing paper, filter paper, dust-free paper, mirror wiping paper and cotton cloth.

More preferably, the polymer fiber material is one of wet strength paper and cotton cloth, which is common in life, easy to obtain and low in price.

In order to achieve the second object of the present invention, the present invention provides the following technical solutions: a preparation method of a metal nanoparticle-polymer composite material specifically comprises the following steps of growing metal nanoparticles: preparing metal seeds in the internal pores of the solid matrix; putting the solid matrix containing the metal seeds into a metal nanoparticle growth solution, and growing for 3-20 minutes to obtain a metal nanoparticle-polymer composite material; the metal nanoparticle growth solution comprises a metal main salt solution, a complexing agent, a reducing agent and a pH regulator; the metal seeds comprise metal ion seeds and metal simple substance seeds.

The metal seeds are directly reduced or catalytically reduced into corresponding metal nanoparticles in a metal nanoparticle growth solution, and are nucleation sites for the growth of the metal nanoparticles.

Preferably, the metal ion seed comprises Sn ²⁺、Pd ²⁺The metal elementary substance seeds comprise one or more of elementary substance Au, elementary substance Ag, elementary substance Pd, elementary substance Pt, elementary substance Cu and elementary substance Ni.

When the metal ions are used as seeds, the interaction of complexation or electrostatic attraction between the matrix and the metal ions is required, so that the seed ions can be adsorbed; when the metal simple substance is used as a seed, the gold simple substance can be used as a seed for growth of all metals, and other metal simple substance seeds can grow metal nanoparticles with the same material as the seed, so that the self-catalytic reduction effect is achieved (for example, nickel metal nanoparticles grow from nickel seeds, and silver metal nanoparticles grow from silver seeds); in the embodiment, the gold is taken as an example, and other metal ion seeds or metal elemental seeds are also within the protection scope of the present invention.

Preferably, the preparation of the metal ion seeds in the internal pores of the solid matrix comprises in particular: cleaning the solid matrix, and then putting the solid matrix into a metal ion seed solution to be soaked for 3-5 hours to obtain metal ion seeds in the internal pores of the solid matrix; the metal ion seed solution comprises one of a tin dichloride solution, a palladium dichloride solution and a diammine palladium dichloride solution; the preparation of the metal elementary seeds in the internal pores of the solid matrix specifically comprises: cleaning the solid matrix, putting the solid matrix into a metal simple substance seed salt solution, soaking for 3-5 hours, cleaning, and then putting the solid matrix into a seed reducing agent for 2-4 minutes to obtain metal simple substance seeds in the internal pores of the solid matrix; the metal elementary substance seed salt solution comprises one of a chloroauric acid solution, a silver nitrate solution, a palladium dichloride solution, a chloroplatinic acid solution, a copper sulfate solution and a nickel sulfate solution; the seed reducing agent comprises one or more of sodium borohydride solution, hydrazine hydrate solution and dimethylamino borane solution.

More preferably, the preparation of the metal ion seeds in the internal pores of the solid matrix comprises in particular: and cleaning the solid matrix, and then putting the solid matrix into a metal salt solution to soak for 4 hours to obtain metal ion seeds in the internal pores of the solid matrix.

More preferably, the preparation of elemental metal seeds in the internal pores of the solid matrix comprises in particular: cleaning the solid matrix, putting the solid matrix into a metal salt solution, soaking for 4 hours, cleaning, and then putting the solid matrix into a reducing agent for 3 minutes to obtain metal simple substance seeds in the internal pores of the solid matrix.

Preferably, the metal main salt solution comprises one of a chloroauric acid solution, a silver nitrate solution, a copper sulfate solution and a nickel sulfate solution; the complexing agent comprises one or more of tartaric acid, sodium chloride, ammonia water, potassium sodium tartrate, sodium citrate and lactic acid; the reducing agent comprises one or more of ethanol, potassium sodium tartrate, formaldehyde and dimethylamino borane; the pH regulator comprises one or more of sodium hydroxide and ammonia water.

In order to achieve the third objective of the present invention, the present invention provides the following technical solutions: the application of the metal nanoparticle-polymer composite material has the advantages that the average absorption rate of the metal nanoparticle-polymer composite material to the solar spectrum of 300-2500nm is more than or equal to 90%, the metal nanoparticle-polymer composite material has a high-efficiency photothermal conversion effect and is used for photothermal conversion and solar seawater desalination; the efficiency of photothermal water evaporation of the metal nanoparticle-polymer composite material is greater than or equal to 75%; the efficiency of the metal nanoparticle-polymer composite material for solar seawater desalination is 46.9-65.8%

Preferably, the average absorption rate of the metal nanoparticle-polymer composite material to the solar spectrum in the wavelength region of 300-.

In summary, compared with the prior art, the invention has the following beneficial effects:

(1) the metal nanoparticle-polymer composite material provided by the invention can control the size of metal nanoparticles through pores in the polymer, prevent agglomeration among the metal nanoparticles, and also can prevent agglomeration of the metal nanoparticles in the use process of the composite material and prevent falling-off of the metal nanoparticles, so that the optical reflection and optical scattering of the material are minimized;

(2) according to the metal nanoparticle-polymer composite material provided by the invention, metal nanoparticles can be densely distributed in a polymer matrix without agglomeration, so that optical reflection and optical scattering of the metal nanoparticles are reduced, the full-band optical absorption rate of solar spectrum (97.1%) is improved, the water steaming efficiency is high (75%), and the solar seawater desalination efficiency is high (46.9% -65.8%);

(3) the preparation process of the metal nanoparticle-polymer composite material provided by the invention is carried out in an aqueous solution, the preparation method is simple, and large-scale preparation can be realized; the material cost is low, and the method has a practical application prospect.

Drawings

Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments with reference to the following drawings:

FIG. 1 is a scanning electron micrograph of the small-magnification nickel nanoparticle-wet strength paper composite material of example 4;

FIG. 2 is a scanning electron microscope image of the high-multiple nickel nanoparticle-wet strength paper composite material in example 4;

FIG. 3 is a scanning electron micrograph of a small-magnification nickel nanoparticle-cotton composite material in example 5;

FIG. 4 is a scanning electron micrograph of a high-magnification nickel nanoparticle-cotton composite material in example 5;

FIG. 5 is a transmission electron micrograph of the gold nanoparticle-wet strength paper composite of example 1;

FIG. 6 is a transmission electron micrograph of the silver nanoparticle-wet strength paper composite of example 2;

FIG. 7 is a transmission electron micrograph of the copper nanoparticle-wet strength paper composite of example 3;

FIG. 8 is a transmission electron micrograph of the nickel nanoparticle-wet strength paper composite of example 4;

FIG. 9 is a transmission electron micrograph of a nickel nanoparticle-cotton composite of example 5;

FIG. 10 is an optical absorption diagram of five metal nanoparticle-polymer composites of examples 1-5;

FIG. 11 is a graph showing the results of photothermal conversion effect tests on nickel nanoparticle-wet strength paper composites and gold nanoparticle-wet strength paper composites;

FIG. 12 is a schematic view of the experimental apparatus for photo-thermal water evaporation in example 4 and comparative example 1;

FIG. 13 is a graph of water mass versus time for a nickel nanoparticle-wet strength paper composite in a photothermal water evaporation test;

FIG. 14 is a graph of evaporation rate and enhancement factor for a nickel nanoparticle-wet strength paper composite in a photothermal water evaporation test;

FIG. 15 is a drawing of an experimental apparatus for desalinating outdoor seawater in example 6 and a schematic view thereof;

FIG. 16 is a water production efficiency chart of sea water desalination and sewage purification in example 6;

FIG. 17 is a transmission electron micrograph of a nickel nanoparticle-wet strength paper composite grown for 0.5 minutes in comparative example 2;

FIG. 18 is a transmission electron micrograph of a nickel nanoparticle-wet strength paper composite grown for 20.5 minutes in comparative example 3;

FIG. 19 is a graph comparing the optical absorption of the nickel nanoparticle-wet strength paper composites of example 4, comparative example 2, and comparative example 3;

FIG. 20 is a transmission electron microscope image of the nickel nanoparticle-polyester fiber composite material in comparative example 4;

FIG. 21 is a scanning electron microscope image of the nickel nanoparticle-bacterial cellulose composite material in comparative example 6;

fig. 22 is a schematic structural view of the metal nanoparticle-polymer composite in examples 1-5.

Detailed Description

The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. The present invention will be described in detail with reference to the following specific examples:

the particle size of the metal nanoparticles is obtained by measuring the length and width of the minimum external rectangle of the metal nanoparticles in a transmission electron microscope and then opening a root number. The following examples select four typical metal materials: gold, silver, copper and nickel and two common polymeric materials: wet strength paper and cotton cloth to illustrate the technical characteristics of the metal nanoparticle-polymer composite provided by the present invention. In addition, the metal nano-particle-polymer composite material provided by the invention is subjected to optical absorption and photothermal conversion effect test and analysis, and outdoor solar seawater desalination and sewage treatment test.

When the metal ions are used as seeds, the matrix and the metal ions are required to have complexation or electrostatic attraction interaction, so that the matrix can adsorb the seed ions; when the metal simple substance is used as a seed, the gold simple substance can be used as a seed for growth of all metals, and other metal simple substance seeds can grow metal nanoparticles with the same material as the seed, so that the self-catalytic reduction effect is achieved (for example, nickel metal nanoparticles grow from nickel seeds, and silver metal nanoparticles grow from silver seeds); in the embodiment, the gold is taken as an example, and other metal ion seeds or metal elemental seeds are also within the protection scope of the present invention.

Wherein the average absorption rate α of the solar spectrum band of 300-2500nm _sThe calculating method of (2):

wherein E _solarThe standard solar spectrum of AM 1.5G, α (lambda) is the absorption spectrum measured by UV-Vis-NIR spectroscopy (i.e., the absorption spectra measured in FIGS. 10 and 19).