Photonic crystal humidity sensor and preparation method thereof

A technology of humidity sensor and photonic crystal, which is applied in the direction of color/spectral characteristic measurement, etc., can solve the problems of complicated method, difficult to prepare large-size photonic crystal humidity sensor, complicated steps, etc., and achieve the effect of simple and convenient use method.

Inactive Publication Date: 2011-12-07
UNIV OF SCI & TECH OF CHINA
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, this photonic crystal humidity sensor needs to first prepare a photonic crystal template constructed of polystyrene methyl methacrylate acrylic acid copolyme

Method used

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  • Photonic crystal humidity sensor and preparation method thereof
  • Photonic crystal humidity sensor and preparation method thereof
  • Photonic crystal humidity sensor and preparation method thereof

Examples

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preparation example Construction

[0043] The present invention also provides a method for preparing the photonic crystal humidity sensor, which includes the following steps:

[0044] a) Mix acrylamide monomer, N,N'-methylene bis(acrylamide), persulfate and superparamagnetic carbon-coated ferroferric oxide colloidal nanoparticles in ethylene glycol. Get a mixed solution;

[0045] b) Add N,N,N',N'-tetramethylethylenediamine to the mixed solution obtained in step a), and react under the action of an external uniform magnetic field to obtain a photonic crystal humidity sensor.

[0046] The present invention uses acrylamide monomer, N,N'-methylenebis(acrylamide), persulfate and superparamagnetic carbon-coated ferroferric oxide colloidal nanoparticles as raw materials. Under the catalysis of N',N'-tetramethylethylenediamine, acrylamide monomer, N,N'-methylenebis(acrylamide), and persulfate react to form polyacrylamide gel. At the same time, super The paramagnetic carbon-coated ferroferric oxide colloidal nanoparticles se...

Embodiment 1

[0068] Dissolve 0.3g of ferrocene in 30mL of acetone, add 1.5mL of hydrogen peroxide aqueous solution with a mass concentration of 30% dropwise after ultrasonic dispersion. After magnetic stirring at a speed of 1000r / min for 30min, a mixed solution is obtained; the mixing is easy Transfer to a 40mL autoclave, seal and heat to 200°C, keep for 72h, and cool to room temperature to obtain black powder; wash the black powder with acetone and ethanol 3 times, and dry it in a vacuum oven at 40°C for 6 hours to obtain super smooth Magnetic carbon-coated ferroferric oxide colloidal nanoparticles.

[0069] X-ray diffraction analysis was performed on the superparamagnetic carbon-coated ferroferric oxide colloidal nanoparticles, the results are shown in figure 1 , figure 1 This is the X-ray diffraction pattern of the superparamagnetic carbon-coated ferroferric oxide colloidal nanoparticles prepared in the embodiment of the present invention, which is represented by figure 1 It can be seen tha...

Embodiment 2

[0077] Dissolve 1.5g of acrylamide monomer, 0.05g of N,N'-methylenebis(acrylamide) and 0.02g of ammonium persulfate in 15mL of ethylene glycol, stir it evenly, add 0.04g of the prepared in Example 1 Superparamagnetic carbon-coated colloidal nanoparticles of ferroferric oxide are sonicated in an ice water bath at 0°C for 10 minutes to obtain a mixed solution;

[0078] Put 1.5mL of the mixed solution into a 5mL beaker, apply a uniform magnetic field of 0.1T under the beaker, and then add 20μL of N,N,N′,N′-tetramethylethylenediamine into the container, React for 30 seconds to obtain a photonic crystal humidity sensor.

[0079] Put the photonic crystal humidity sensor into a closed environment with different stable relative humidity values ​​to observe the color of the photonic crystal humidity sensor, see Figure 7 with Figure 8 , Figure 7 Is the color of the photonic crystal humidity sensor provided by the embodiment of the present invention under different relative humidity, Figu...

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Abstract

The invention provides a photonic crystal humidity sensor comprising: a substrate which is polyacrylamide gel; a photonic crystal material cured in the substrate, wherein the photonic crystal material is superparamagnetic carbon-coated ferroferric oxide colloidal nanoparticles. The invention also provides a preparation method of the photonic crystal humidity sensor. In the photonic crystal humidity sensor provided by the invention, the polyacrylamide gel has strong water swelling performance, and has different absorptivity under different relative humidity; when ambient relative humidity changes, the absorptivity of the polyacrylamide gel changes, and thus the expansion rate of the polyacrylamide changes; therefore, the band gap of the photonic forbidden band of the photonic crystal material cured in the polyacrylamide gel changes, and finally the photonic crystal humidity sensor shows different colors with the change of the humidity.

Description

Technical field [0001] The invention belongs to the technical field of humidity sensors, and particularly relates to a photonic crystal humidity sensor and a preparation method thereof. Background technique [0002] Humidity sensor is a sensor that can sense the water vapor content in the gas and convert it into a usable output signal. It has a wide range of applications in agricultural production, weather forecasting, environmental protection, food storage and cultural relic protection. [0003] The prior art discloses a variety of humidity sensors, which are mainly classified into two types: resistive humidity sensors and capacitive humidity sensors. Among them, the resistive sensor is covered with a film made of moisture-sensitive material on the substrate. When water vapor in the air is adsorbed on the moisture-sensitive film, the resistivity and resistance value of the sensor change, thereby measuring humidity; The type humidity sensor is made of polymer film capacitors. When...

Claims

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Application Information

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IPC IPC(8): G01N21/29
Inventor 陈乾旺胡海波王辉
Owner UNIV OF SCI & TECH OF CHINA
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