Plane source blackbody

The present invention relates to a plane source blackbody. The plane source blackbody comprises a panel, a black lacquer layer, and a carbon nanotube array. The panel comprises a first surface and a second surface opposite to the first surface. The black lacquer layer and the carbon nanotube array are located on the first surface. The carbon nanotube array comprises a plurality of carbon nanotubes. Each of the carbon nanotubes comprises a top end and a bottom end. The bottom end of each of the carbon nanotubes is immersed into the black lacquer layer and the top end of each of the carbon nanotubes is exposed out from the black lacquer layer. The plurality of carbon nanotubes are substantially perpendicular to the first surface of the pane.

CROSS-REFERENCE TO RELATED APPLICATIONS

FIELD

The present disclosure relates to a plane source blackbody.

BACKGROUND

With a rapid development of infrared remote sensing technology, the infrared remote sensing technology is widely used in military fields and civilian fields, such as earth exploration, weather forecasting, and environmental monitoring. Known infrared detectors need to be calibrated by a blackbody before they can be used. The higher an effective emissivity of the blackbody, the higher a calibration accuracy of the infrared detector. Used as a standard radiation source, a role of blackbody is increasingly prominent. The blackbody comprises a cavity blackbody and a plane source blackbody. Wherein, the effective emissivity of the plane source blackbody mainly depends on a surface structure of the plane source blackbody and an emissivity of materials on a surface of the plane source blackbody. Therefore, to obtain plane source blackbody with high performance, it is important to use surface materials with high emissivity.

DETAILED DESCRIPTION

The term “substantially” is defined to be essentially conforming to the particular dimension, shape, or other feature which is described, such that the component need not be exactly or strictly conforming to such a feature. The term “include,” when utilized, means “include, but not necessarily limited to”; it specifically indicates open-ended inclusion or membership in the so-described combination, group, series, and the like.

A plane source blackbody is provided according to the present disclosure. The plane source blackbody comprises a panel, a black lacquer layer, and a carbon nanotube array. The panel comprises a first surface and a second surface opposite to the first surface. The black lacquer layer and the carbon nanotube array are located on the first surface of the panel. The carbon nanotube army comprises a plurality of carbon nanotubes. Each of the carbon nanotubes comprises a top end and a bottom end. The bottom end of each of the carbon nanotubes is immersed into the black lacquer, and the top end of each of the carbon nanotubes is exposed out from the black lacquer layer. The plurality of carbon nanotubes are substantially perpendicular to the first surface of the panel.

The panel is made from a material resistant to high temperature and having a high emissivity. The panel can be made from a hard aluminum material, an aluminum alloy material or an oxygen-free copper. In one embodiment, the first surface can be a flat surface. In another embodiment, the first surface can comprise a plurality of grooves.

The black lacquer has high emissivity, such as PYROMARK® 1200 black lacquer having an emissivity of 0.92, NEXTEL® Velvet 811-21 black lacquer having an emissivity of 0.95. A thickness of the black lacquer layer should not be too small or too large. If the thickness of the black lacquer layer is too small, the bottom end of each carbon nanotube cannot be immersed into the black lacquer completely. Therefore, the plurality of carbon nanotubes cannot be contact with the black lacquer tightly and cannot be firmly fixed to the first surface of the panel. On the contrary, if the thickness of the black lacquer layer is too large, the plurality of carbon nanotubes can be embedded into the black lacquer. So a structure of the carbon nanotube array would be destroyed, and the high emissivity of carbon nanotube materials cannot be exhibited. In one embodiment, the thickness of the black lacquer layer is in a range from about 1 micrometer to about 300 micrometers.

The carbon nanotube array comprises a bottom surface and a top surface. The bottom surface is in contact with the first surface of the panel, and the top surface is far away from the first surface of the panel. The plurality of carbon nanotubes extend from the bottom surface to the top surface.

In one embodiment, the top ends of the carbon nanotubes are open ends, and the open ends of the carbon nanotubes are not blocked by catalysts particles or something else.

In another embodiment, the plane source blackbody further comprises a heating element. The heating element is placed on the second surface of the panel. The heating element can comprise a carbon nanotube structure, a first electrode and a second electrode. The first electrode and the second electrode are spaced apart from each other on a surface of the carbon nanotube structure. The carbon nanotube structure comprises at least one carbon nanotube film or at least one carbon nanotube long wire. The carbon nanotube structure comprises a plurality of carbon nanotubes joined end to end and substantially oriented along a same direction. The plurality of carbon nanotubes of the carbon nanotube structure extend from the first electrode toward the second electrode.

Because the carbon nanotube structure is placed on the second surface of the panel, after energized by the first electrode and the second electrode, the carbon nanotube structure can heat the whole plane source blackbody. Therefore, a temperature field on the first surface of the panel can be evenly distributed, and a temperature stability and uniformity of the plane source blackbody can be improved. Since carbon nanotube has low density and light weight, the plane source blackbody using the carbon nanotube structure as the heating element is light and compact. The carbon nanotube structure has low electrical resistance, high electrothermal conversion efficiency and low thermal resistivity. So using the carbon nanotube structure to heat the plane source blackbody has the characteristics of rapid temperature rise, small thermal hysteresis and fast heat exchange rate. Carbon nanotube materials have excellent toughness, thus the plane source blackbody using the carbon nanotube structure as the heating element has a long service life.

Referring to theFIG. 1, a plane source blackbody10is provided according to one embodiment. The plane source blackbody10comprises a panel101. The panel101comprises a first surface102and a second surface103opposite to the first surface102. A black lacquer layer104and a carbon nanotube array105are located on the first surface102of the panel101. The carbon nanotube array105comprises a plurality of carbon nanotubes. Each of the carbon nanotubes comprises a top end and a bottom end. The bottom end of each of the carbon nanotubes is immersed into the black lacquer layer104, and the top end of each of the carbon nanotubes is exposed out from the black lacquer layer104. The plurality of carbon nanotubes are substantially perpendicular to the first surface102of the panel101.

The panel101is made from an aluminum alloy material. The first surface102of the panel101is a flat surface. The black lacquer is NEXTEL® Velvet 811-21 black lacquer. A thickness of the black lacquer layer104is 150 micrometers. The top end of each of the carbon nanotubes is an open end. The plane source blackbody10further comprises a heating element106on the second surface103of the panel101. The heating element106comprises a carbon nanotube structure107, a first electrode108and a second electrode109.

A method for making the plane source blackbody10is provided in one embodiment. The method comprises the following steps:

S11, providing a panel101, wherein the panel101comprises a first surface102and a second surface103opposite to the first surface102;

S12, coating the first surface102with a black lacquer layer104;

S13, placing a carbon nanotube array105on the first surface103.

In the step S11, the panel101is made from an aluminum alloy material. The first surface102of the panel101is a flat surface.

In the step S12, the black lacquer is NEXTEL® Velvet 811-21 black lacquer. A thickness of the black lacquer layer104is 150 micrometers.

In the step S13, the carbon nanotube array105can be placed on the first surface102of the panel101by a method of transfer. The method comprises the following steps:

S131, providing a substrate, wherein a carbon nanotube array is grown on a surface of the substrate;

S132, transferring the carbon nanotube array on the first surface102of the panel101.

In the step S131, The carbon nanotube array is grown by a method of chemical vapor deposition. The carbon nanotube array comprises a plurality of carbon nanotubes105. The ends of the plurality of carbon nanotubes adjacent to the substrate are defined as growth ends, and the ends of the plurality of carbon nanotubes far away from the substrate are defined as top ends.

In the step S132, the substrate is inverted. The top ends of the plurality of carbon nanotubes are in contact with and then are immersed into the black lacquer104located on the first surface102of the panel101. The substrate is pressed slightly, and then the substrate is separated from the panel101and leaving the plurality of carbon nanotubes on the panel101. Thereby, the carbon nanotube array can be transferred on the first surface102of the panel101.

After the plurality of carbon nanotubes105are placed on the first surface102of the panel101, the black lacquer can be solidified through a process of natural drying. Because the black lacquer is of certain viscosity, the plurality of carbon nanotubes105can be tightly fixed on the first surface102of the panel101through the black lacquer layer104and may not easily fall off from the first surface102. Hence, the panel101, the black lacquer layer104and the plurality of carbon nanotubes105become a stable and integrated structure.

Referring to theFIG. 2, a plane source blackbody20is provided according to one embodiment. The plane source blackbody20comprises a panel201. The panel201comprises a first surface202and a second surface203opposite to the first surface202. Wherein, a black lacquer layer204and a carbon nanotube array205are located on the first surface202of the panel201. The carbon nanotube array205comprises a plurality of carbon nanotubes. Each of the carbon nanotubes comprises a top end and a bottom end. The bottom end of each of the carbon nanotubes is immersed into the black lacquer, and the top end of each of the carbon nanotubes is exposed out from the black lacquer layer. The plurality of carbon nanotubes are substantially perpendicular to the first surface202of the panel201. A distribution of the plurality of carbon nanotubes on the first surface202of the panel201forms a pattern.

By “pattern”, it means that the first surface202of the panel201is partially covered by the plurality of carbon nanotubes. A shape and position of the pattern are not limited. The panel201is made from an oxygen-free copper. The first surface202is a flat surface.

A method for making the plane source blackbody20is provided in one embodiment. The method comprises the following steps:

S21, providing a panel201, wherein the panel201comprises a first surface202and a second surface203opposite to the first surface202;

S22, coating the first surface202with a black lacquer layer204;

S23, placing a carbon nanotube array205on a part area of the first surface202.

In the step S21, the panel201is made from an oxygen-free copper. The first surface202is a flat surface.

A specific operation method of the step S22is the same as that of the step S12, and will not be described in detail here.

In the step S23, the carbon nanotube array205are placed on the part area of the first surface202of the panel201via a method of transfer. The method comprises the following steps:

S231, providing a substrate, wherein a patterned carbon nanotube array is grown on a surface of the substrate;

S232, Transferring the patterned carbon nanotube array on the first surface202of the panel201.

In the step S231, a method for making the patterned carbon nanotube array comprises: forming a patterned mask on the surface of the substrate, wherein the patterned mask can make part of the surface of the substrate exposed; depositing a catalyst on the exposed surface of the substrate to obtain a patterned catalyst; growing a patterned carbon nanotube array on the patterned catalyst by the method of chemical vapor deposition.

A specific operation method of the step S232is the same as that of the step S132, and will not be described in detail here.

Referring to theFIG. 3, a plane source blackbody30is provided in one embodiment. The plane source blackbody30comprises a panel301. The panel301comprises a first surface302and a second surface303opposite to the first surface302. Wherein, a black lacquer layer304and a carbon nanotube array305are located on the first surface302of the panel301. The carbon nanotube array305comprises a plurality of carbon nanotubes. Each of the carbon nanotubes comprises a top end and a bottom end. The bottom end of each of the carbon nanotubes is immersed into the black lacquer layer304, and the top end of each of the carbon nanotubes is exposed out from the black lacquer layer304. The plurality of carbon nanotubes are substantially perpendicular to the first surface302of the panel301. The carbon nanotube array305comprises a top surface and a bottom surface opposite to the top surface. The top surface of the carbon nanotube array305is far away from the first surface302of the panel301. A plurality of microstructures are formed on the top surface of the carbon nanotube array305.

In one embodiment, the plurality of microstructures comprises a plurality of micro-grooves306formed on the top surface of the carbon nanotube array305. Each of the micro-grooves306can be an annular micro-groove, a strip micro-groove, or a dot-shaped micro-groove. The plurality of micro-grooves306form concentric circular patterns, stripped patterns, or dotted patterns on the top surface of the carbon nanotube array305. Cross-sectional shapes of the micro-grooves306are not limited, and can be inverted triangles, rectangles, or trapezoids.

It is indicated by existing research that the larger the surface roughness of the panel of the plane source blackbody, the higher the emissivity of the plane source blackbody. In the present disclosure, the plurality of microstructures formed on the top surface of the carbon nanotube array305is equivalent to an increase of the surface roughness of the panel301of the plane source blackbody30, therefore the emissivity of the plane source blackbody30can be further increased.

The panel301is made from an aluminum alloy material. The first surface302is a flat surface.

A method for making the plane source blackbody30is provided in one embodiment. The method comprises the following steps:

S31, providing a panel301, wherein the panel301comprises a first surface302and a second surface303opposite to the first surface302;

S32, coating the first surface302with a black lacquer layer304;

S33, placing a carbon nanotube array305on the first surface302of the panel301;

S34, forming a plurality of micro-grooves306on a top surface of the carbon nanotube array305away from the first surface302of the panel301.

A specific operation method of the step S31, S32and S33is the same as that of the step S11, S12and S13respectively, and will not be described in detail here.

In the step S34, a laser generator is provided to generate a laser beam. The laser beam is used to irradiate the top surface of the carbon nanotube array305to form a plurality of microstructures on the top surface of the carbon nanotube array305. A direction in which the laser beam is incident can be at an angle to the top surface of the carbon nanotube array305. In one embodiment, the angle ranges from about 55 degrees to about 90 degrees.

During the process of laser irradiation, since a high energy of the laser beam can be absorbed by carbon nanotubes which are on the paths of the laser beams, the temperature of the carbon nanotubes become high and the carbon nanotubes can react with the oxygen in the air, and then decompose. Thus, the carbon nanotubes on the paths of the laser beams will be removed. In this way, a plurality of micro-grooves306with predetermined depth and width can be formed on the top surface of the carbon nanotube array305. A scanning path of the laser beam can be set precisely by a computer in advance to form a complex etched pattern on the top surface of the carbon nanotube array.

Referring to theFIG. 4andFIG. 5, a plane source blackbody40is provided in one embodiment. The plane source blackbody40comprises a panel401. The panel401comprises a first surface402and a second surface403opposite to the first surface402. A black lacquer layer404and a carbon nanotube array405are formed on the first surface402of the panel401. The carbon nanotube array405comprises a plurality of carbon nanotubes. Each of the carbon nanotubes comprises a top end and a bottom end. The bottom end of each of the carbon nanotubes is immersed into the black lacquer404, and the top end of each of the carbon nanotubes is exposed out from the black lacquer layer304. The plurality of carbon nanotubes are substantially perpendicular to the first surface402of the panel401.

The panel401is made from a hard aluminum material. The first surface402comprises a plurality of grooves406spaced apart from each other.

The plurality of grooves406are arranged in a matrix manner. Each of the grooves406can be a strip groove, an annular groove, or a dot-shaped groove. Cross-sectional shapes of the grooves406can be rectangles or trapezoids. The grooves406can be formed via a method of casting or etching the panel401. In one embodiment, the grooves406are strip grooves, and cross-sectional shapes of the grooves406are rectangles.

Each of the grooves406comprises a bottom surface407. The bottom surface407is a flat surface. The plurality of carbon nanotubes can be located on the bottom surfaces407of the grooves406and the first surface402of the panel401simultaneously.

Each of the grooves406comprises a side surface408. The side surface408is coated with the black lacquer, or the side surface408is not coated with the black lacquer. In one embodiment, the side surface408is not coated with the black lacquer.

A method for making the plane source blackbody40is provided in one embodiment. The method comprises the following steps:

S41, providing a panel401, wherein the panel comprises a first surface402and a second surface403opposite to the first surface402, and the first surface402comprises a plurality of grooves406spaced apart from each other;

S42, coating bottom surfaces407of the grooves406and the first surface402of the panel401with a black lacquer layer404respectively;

S43, placing a plurality of carbon nanotubes on both the bottom surfaces407of the grooves406and the first surface402of the panel401.

In the step S41, the grooves406are strip grooves. Cross-sectional shapes of the grooves406are rectangles.

In the step S42, the method of coating the black lacquer layer404can be a method of spin coating, spraying or scraping.

In the step S43, the plurality of carbon nanotubes can be placed on both the bottom surfaces407of the grooves406and the first surface402of the panel401via a method of transfer. The method comprises the following steps:

S431, providing a substrate, wherein a surface of the substrate comprises a plurality of protrusions spaced apart from each other, a shape, a size and positions of the protrusions are corresponding designed to matched the shape, the size and the positions of the grooves on the first surface402of the panel401respectively, and a plurality of carbon nanotubes are respectively grown on a top surface of the protrusion and the surface of the substrate, and the plurality of carbon nanotubes are substantially perpendicular to the surface of the substrate;

S432, transferring the plurality of carbon nanotubes to the panel401, wherein the plurality of carbon nanotubes on the top surface of the protrusion of the substrate are transferred to the bottom surface of the groove of the panel, and the plurality of carbon nanotubes on the surface of the substrate are transferred to the first surface402of the panel401.

The blackbody radiation source provided by the present disclosure has the following characteristics.

Firstly, carbon nanotubes are currently the blackest material in the world. Tiny gaps between carbon nanotubes in a carbon nanotube array can prevent an incident light from being reflected off a surface of the array, so the emissivity of the carbon nanotube array is high. The emissivity of the carbon nanotube array is as high as 99.6% according to a measurement, which is far larger than that of known inner surface materials of the blackbody cavity. For example, the emissivity of NEXTEL® Velvet 811-21 black lacquer is 96%.

Secondly, the carbon nanotubes can be prepared conveniently and quickly by a chemical vapor deposition of carbon source gas under high temperature conditions, and the raw materials are cheap and easy to obtain.

Thirdly, the carbon nanotubes have excellent thermal conductivity. So it can improve the temperature uniformity and stability of the plane source blackbody to use the carbon nanotube array as the surface material of the plane source blackbody.

Fourthly, the carbon nanotubes have excellent mechanical properties, so the plane source blackbody using carbon nanotubes will have good stability and may not be easily damaged in harsh environment.

Fifthly, a black lacquer is also located on the surface of the panel. The black lacquer is not only a high emissivity material but also functioned as a glue to keep the plurality of carbon nanotubes fixed on the surface of the panel. Thereby the emissivity of the plane source blackbody is further improved, the stability of the plane source blackbody is further enhanced, and the service life of the plane source blackbody is further prolonged.

It is to be understood that the above-described embodiments are intended to illustrate rather than limit the present disclosure. Variations may be made to the embodiments without departing from the spirit of the present disclosure as claimed. Elements associated with any of the above embodiments are envisioned to be associated with any other embodiments. The above-described embodiments illustrate the scope of the present disclosure but do not restrict the scope of the present disclosure.