Quenching of chlorophyll fluorescence induced by silver nanoparticles

The interaction between chlorophyll (Chl) and silver nanoparticles (AgNPs) was evaluated by analyzing the optical behavior of Chl molecules surrounded by different concentrations of AgNPs (10, 60, and 100 nm of diameter). UV–Vis absorption, steady state and time-resolved fluorescence measurements were performed for Chl in the presence and absence of these nanoparticles. AgNPs strongly suppressed the Chl fluorescence intensity at 678 nm. The Stern-Volmer constant (KSV) showed that fluorescence suppression is driven by the dynamic quenching process. In particular, KSV was nanoparticle size-dependent with an exponential decrease as a function of the nanoparticle diameter. Finally, changes in the Chl fluorescence lifetime in the presence of nanoparticles demonstrated that the fluorescence quenching may be induced by the excited electron transfer from the Chl molecules to the metal nanoparticles

Study of the Mechanical Properties of Nano Silver Nitrate Filled Polypropylene Composites

In this investigation, the mechanical properties of silver nitrate nanoparticles filled polypropylene composite is evaluated. The silver nitrate particles are added to the matrix by 1, 3, 5, and 10% by weight. The composite is prepared by adding the filler to polypropylene under heat and mix the mixture by mechanical stirrer. Then after the test samples are prepared under hot press. The tensile tests are carried out. The tensile strength, yield stress, tensile modulus, and the percentage of elongation to break are obtained and evaluated. The results show that the elastic modulus of the composite is in increase while tensile strength, rupture strength, and the percentage of elongation to break is in decrease with the increase in the content of silver nitrate particle fillers. The morphology, structure, and size of the silver nitrate particles are evaluated by scanning electron microscope