Studies On The Spectral Extinction For Organic Materials

Information of photosensitive components of a organic material could be recorded in the transmission spectra.Studies of spectral extinction properties of organic materials are of great significance to the interdisciplinary subjects of biophysics,such as organic solar cells,photosynthesis and plant plants.The current thesis carried out reseach on the spectral extinction properties of 58 kinds of organic materials,such as leaves,petals,sunscreen,plexiglass and fresh-keeping films by using the German RAMSES series spectrometer with applying theory and measurement methods of spectral extinction.Extinction characteristics of these organic materials were obtained for the first time.It was found that the extinction spectrums of all tested plant leaves showed obvious peaks and valleys: the absorption in green plants was stable in the blue indigo light,in the spectral region between 455-492 nm.It was the strongest in the red light with central wavelength of 676 nm,and was the weakest in the green light around 553 nm.No extinction was shown in the long wave of beyond 750 nm.For the purple plants,the absorption was stable for the wavelength between the blue indigo light to the green light of wave band 455-577 nm,the valley of extinction spectrum appeared at wavelength of 639 nm,and the peak appeared at 676 nm.Leaves with different life cycle have different spectral extinction characteristics: although the transmission spectrum intensity of young leaves and adult leaves is different,they share high correlation in their spectral shapes.The characteristics of spectral extinction of fallen leaves in wave band of 317-553 nm and 636-950 nm are similar to those of green leaves,but showed obvious distinction in 552-636 nm due to the difference in plant pigment contents.Petals in different colors show different spectral extinction characteristics.The white petals absorbed light in wave band of 317-455 nm,the yellow petals absorbed light in 317-553 nm,and the red petals absorbed light in 317-676 nm.The study in spectral extinction of sunscreen showed that all sunscreens tested absorbed ultraviolet B and reduced the intensity of ultraviolet A without absorbing visible and infrared light.The transmittance of the tested conductive glass reached more than 81% in the visible light area,and was less than 75% in the ultraviolet and infrared light areas.The transmittance of the tested fresh-keeping film was higher than 91% in the whole solar spectrum region,and the transmissivity increases with the increase of wavelength.The high consistency between curve of linear attenuation coefficient and the curve of Rayleigh scattering showed that scattering played a leading role in the spectral extinction.The tested fresh-keeping film has poor photosensitivity and showed no extinction.Researches on the spectral extinction is still in its infancy in biophysics.The current research explored the spectral extinction characteristics of different tested organic materials in a macro level,which may help to provide the pioneer macro level research results for the targeted micro level research for future research work.