In the field of greenhouse cultivation, whether it is a film greenhouse, a solar greenhouse or a glass greenhouse, there is a common understanding of covering materials, which is diffuse reflection (scattering) materials. Diffuse reflective film is, diffuse reflective coating is, and diffuse reflective glass is too.

So what is diffuse reflection?

When light strikes a solid surface, reflection and scattering occur. When specular reflection occurs, the reflection angle is equal to the incident angle and the light is not absorbed. When the light beam is incident on the powdery crystal surface layer, part of the light is specularly reflected on each crystal grain surface of the surface layer; the other part of the light is refracted into the interior of the surface crystal grains, is partially absorbed, and then emitted to the internal grain interface, where it is reflected again. , refraction absorption.

This is repeated many times, and is finally reflected in all directions by the surface layer of the powder. This radiation is called diffuse reflected light. By simultaneously detecting the specular reflected light and diffuse reflected light of a solid powder sample, the diffuse reflectance spectrum can be obtained.

The difference between UV-visible spectrophotometer and UV-visible diffuse reflection: the former uses transmission mode and the sample is a solution, while the latter uses diffuse reflection mode and the sample is mostly solid. Although the transmission method has the advantages of good reproducibility, high accuracy, and easy operation, it is not suitable for some insoluble substances, opaque substances, and substances that cannot be made into single crystals. The diffuse reflectance method can directly measure the spectrum of a solid substance without changing its state.

What are the factors that affect diffuse reflectance spectrum?

(1) Particle size: The absorbance decreases as the particle size decreases.

(2) Smoothness of the sample surface: As the surface smoothness increases, the specular reflection increases and the apparent absorbance decreases.

(3) The sample is damp or has moisture: The presence of moisture leads to a reduction in scattering ability and an increase in apparent absorbance. In addition, the chemical reaction between water molecules and the sample or the formation of hydrogen bonds will cause changes in the spectrum.

(4) The particle size of the adsorbent or diluent: As the particle size of the adsorbent or diluent increases, the band tends to broaden. Therefore, it is necessary to fully consider eliminating interfering factors as much as possible during sample preparation and sample preparation.

In the field of glass greenhouse cultivation, diffuse reflective (scattering) glass ensures that crops are not damaged by too much light. At the same time, no light is lost by using diffuse reflective (scattering) glass. Ultimately, these factors combine to create less stress on the crop, with cooler plant wax temperatures in the upper leaf layers and warmer leaf texture in the lower leaf layers.

Crops grown in a comfortable environment will grow better. Due to the better climate in the greenhouse, with direct sunlight and higher temperatures (i.e. without constant stress on the plants), crops are no longer in a "remaining state". The plant remains comfortable, continues to photosynthesize, and continues to grow. This new greenhouse climate environment also requires new carbon dioxide dosing methods, improved fertilizer strategies, and improved indoor shielding and ventilation systems. If these growth parameters are also well controlled, diffuse reflective (scattering) glass can be even more useful.

Diffuse reflective (scattering) glass can not only adjust the intensity of light entering the greenhouse according to different light intensity, but also reduce the leaf surface temperature, keeping plants in a growing state throughout the day, and effectively shortening the growth and maturity cycle of crops.

Among the many covering materials with diffuse reflection (scattering) effect in agriculture, diffuse reflection (scattering) glass has the best effect. It not only has high strength, but also does not have to worry about wear and tear. Whether it is a diffuse reflection (scattering) coating or a thin film, other factors exist more or less, such as low durability and short life.