Exploration of highly efficient light conversion agents for agricultural film based on the bay-substituted perylene diimides derivatives

To explore highly efficient yellow-green light conversion agents used for agricultural film, six bay-substituted perylene diimides and their polyvinyl chloride doped films (by 0.5% weight addition) were prepared. The maximum absorption and emission peaks of the luminogens-doped polyvinyl chloride films are located at 581-609 nm and 647-667 nm, respectively. More importantly, the fluorescence quantum yields of PTCDA, t-BuOPTCDA and m-MeOPTCDA are up to 0.88, 0.84 and 0.78 in doping film, respectively. The strengthening solar radiation and outdoor exposure to sunlight last 160 min and two months respectively and the emission intensity of m-MeOPTCDA-doped film displays slight changes and 9% fluctuation in turn. Combined transmittance, compatibility, mechanical properties and thermal stability, m-MeOPTCDA is chosen as the best effective light conversion materials. To better understand the optical properties of the luminogens, molecular configuration optimization, electron cloud density distribution and molecular orbital energy levels were completed by theoretical calculation. Further, the double layer coextrusion film containing m-MeOPTCDA and Triphenyl acrylonitrile is succeed in dual band excitation(350 nm and 580 nm)and emission (430 nm and 651 nm), by optimizing the proportion of m-MeOPTCDA and Triphenyl acrylonitrile, the special light conversion films for different crops will be expected.