Recent years, the columnar structure of carbon nanotube array film superhydrophobic materials with great progress, superhydrophobic nano-material with its excellent performance, super-hydrophobic capacity of the appliance industry has increasingly The more widespread application.
1. Solid surface wettability and the main indicators of invasive means that when the liquid and solid surface contact, the liquid can be infiltrated or attached to the solid surface characteristics. Infiltration is one of the important properties of solid surface, the article introduces the liquid water in the solid surface wettability. Contact angle and roll angle is to evaluate the importance of solid surface wettability indicators.
1.1 the so-called contact angle contact angle is the formation of droplets on solid surfaces held at thermodynamic equilibrium angle. Through the liquid - solid - gas junction end of the curve in water droplets and solid determination of the surface out of contact points. According to the infiltration of water level in the solid surface, solid can be divided into hydrophilic and hydrophobic, usually with a water contact angle greater than 150 ° the surface is called super-hydrophobic surface.
1.2 roll angle roll angle can be used as another indicator of surface wettability, refers to a quality of droplets in the critical tilt angle of the surface began to roll. Roll angle of the smaller, solid surface hydrophobicity showed better. Because the Earth's gravity, water droplets in the solid surface tilt downward trend. With the larger solid angle, drop down along the slope direction also contribute to increasing, when the tilt angle increases to a critical point, the water droplets will fall down from the solid surface, then the critical angle is the water roll angle of such a solid surface. Roll angle of the smaller, super-hydrophobic solid surface the better the performance.
2. Columnar structure of carbon nanotube array film superhydrophobic materials for research in the decision of solid surface wettability of the main factors, the chemical nature of the internal and geometry shape is an important and indispensable factor. By changing the solid surface roughness can change their invasive. In recent years people through physical and chemical methods of preparation of a variety of super-hydrophobic material, while the cylindrical structure of carbon nanotube array membrane was bionic (similar to the lotus leaf) closely arranged carbon film prepared on the basis of a new generation of super-hydrophobic material.
2.1 columnar structure of carbon nanotube array membranes according to the literature method of carbon nanotube films "ChemCommun" in the method of preparation, the treated substrate Note: the substrate for the cylindrical array of carbon nanotube films attached to the material, which can be metal (aluminum) or ceramic, etc. into the quartz tube, with iron phthalocyanine (FeC32N8H16, ACROS) as a carbon source and catalyst, in argon and hydrogen (volume ratio 1:1 ) flow atmosphere, with a high temperature tube furnace pyrolysis at 900 15min, the substrate can be cylindrical array of carbon nanotubes on the membrane.
2.2 columnar structure of carbon nanotube arrays feature film morphology and structure of carbon nanotubes films by scanning electron microscopy and transmission electron microscope. X-ray photoelectron spectroscopy study of the chemical composition of carbon nanotube films. Optical contact angle meter at room temperature, the contact angle measurement of film and roll angle, roll angle measurement, the water droplet diameter of about 1.7mm. Scanning electron microscope to the surface morphology of columnar arrays of carbon nanotubes. Large cylindrical array of carbon nanotubes films were stacked bundles, each bundle diameter of carbon nanotubes 3 ~ 6 m, the distance between the carbon nanotube bundles 2 ~ 35 m.
Aligned Carbon Nanotube Films by a cylindrical side view shows that carbon nanotubes perpendicular to the bottom, carbon nanotube bundle height 16 m. The side of a single carbon nanotube bundles to enlarge graph shows that the formation of carbon nanotube bundle tightly arranged, the bottom of the loose, slightly wider large, close the top. Transmission electron microscope found that the microstructure of carbon nanotubes, multi-walled carbon nanotube is a hollow tube, carbon tube diameter 30 ~ 55nm. XPS (X-ray photoelectron spectroscopy) analysis shows that carbon nanotube array composed mainly of carbon nanotubes films the binding energy of C1s peak at about 284.6eV. Table 1 for the tightly arranged carbon nanotubes film (A) and cylindrical carbon nanotube array membrane (B) static contact angle and roll angle measurement results, showing that the water in both surface static contact angle values are very , showing the nature of super-hydrophobic; the columnar structure of carbon nanotube array film roll angle is less than 3 °, water droplets in the film is very easy to roll.
3. Nanomaterials Home Appliances Industry prospects carbon nanotubes because of their special electrical, magnetic, and mechanical properties and has important research value, in the appliance industry and have extensive application prospects.
3.1 superhydrophobic nano-materials in the satellite antenna and other outdoor equipment applications in our winter, especially in cold northern snows, sometimes up to a foot thick snow, the snow will cause many of our lives inconvenience, such as snow on the roof of the satellite receiving antenna on the quality of television programming would be affected, but if the antenna surface with nano-materials, then this problem would not arise. A set of comparative experiments show that the same natural conditions, superhydrophobic materials using nano-antenna above the no snow, but not super-hydrophobic materials with nano-antenna above are filled with snow, apparently watching the quality of the former than the latter much better.
3.2 superhydrophobic nano-materials in the air on the application we all know, air-conditioning cooling in the summer, the indoor heat exchanger there will be a lot of condensation water, the need for specialized outdoor drain discharge, it will consume a certain energy, but also vulnerable to the phenomenon of pipe leakage, resulting in inconvenience. Similarly, the winter heating air conditioning, the outdoor temperature is too low, easily lead to heat exchanger frost, air-conditioning had to frequently stop working to defrost. This not only wastes energy, but also prone to various problems. However, if the heat exchanger surfaces treated with hydrophobic material after that no such phenomenon. Air conditioning heat exchanger surface is superhydrophobic materials handling after the superhydrophobic nano-materials in the role, the condensed water can only be a tiny drop of water (100 m or so) the form of condensation in the heat exchanger above, through the air-conditioned indoor (outdoor) fan air, water droplets will be blown in the form of mist into the atmosphere. Thus the use of such air-conditioning heat exchanger condensate production is not, nor frost. Can effectively maintain the air conditioning and highly efficient operation, without indoor water into the room, can keep indoor humidity, increased comfort, more conducive to human health.
3.3 superhydrophobic nano-materials in the refrigerator (freezer) on the application of the refrigerator is
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