The effect of GF/PP matrix interfacial properties on the weldline strength in short glass fiber reinforced polypropylene

The strength of GF/PP injection molded parts is reduced by the existence of a weldline. In this paper, the effect of molecular weight of matrix PP, GF content, GF surface treatment, GF shape (diameter and chopped strand length), MAH-PP content and interfacial properties on the weldline strength in GF/PP has been studied. Since the fibers orient vertically to the flow direction, effective reinforcement cannot be obtained at the weldline. Such fiber direction at the weldline cannot be controlled by the molecular weight of matrix, GF content and GF shapes. On the other hand, strength of the weld specimens increases when the amount of silane coupling agents and the MAH-PP content increase. Therefore, it is suggested that the weldline strength is affected by the strength of interfacial adhesion between GF and matrix.     

The photosensitive effect of Ce on the precipitation of Ag nanoparticles induced by femtosecond laser in silicate glass

This paper studies the photosensitive effect of cerium oxide on the precipitation of Ag nanoparticles after femtosecond laser irradiating into silicate glass and successive annealing. Spectroscopy analysis and diffraction efficiency measurements show that the introduction of cerium oxide may increase the concentration of Ag atoms in the femtosecond laser-irradiated regions resulting from the photoreduction reaction Ce³⁺ + Ag⁺ \to Ce³⁺ + Ag⁰ via multiphoton excitation. These results promote the aggregation of Ag nanoparticles during the annealing process. It is also found that different concentrations of cerium oxide may influence the Ag nanoparticle precipitation in the corresponding glass.