No abstract

No abstract

Chemically modified natural fibers were introduced into a commercial biodegradable poly(butylene adipate-co-terephthalate) (PBAT) matrix to obtain composite materials in a mini-extruder. Influence of the fiber introduction on thermal and mechanical properties of the composites were studied. A decrease of the crystallinity degree of the composites was observed upon addition of the hydrolyzed-fibers, but the addition of the acetylated ones resulted in the opposite behavior. Thermal stability of the matrix was not affected by introduction of the treated fibers. However, an improvement of mechanical properties of the composites was found by means of dynamic mechanical thermal analysis and tensile tests, particularly for those containing acetylated fibers. Scanning electron micrographs of cryofractured surfaces of the composites showed stronger adhesion of the acetylated fibers to the PBAT matrix. No interfacial gaps or signs of the fiber pullout from the matrix were observed.

The radiofrequency magnetron sputtering codeposition is a versatile technique to obtain Er-doped glass films, i.e., optical materials characterized by the emission of an intense photoluminescence signal at λ = 1.54 μm, the most exploited wavelength for optical telecommunications through fiberglass. After the optimization of this radiative emission in the Er:SiO2 systems, strong sensitizing effects in Cu-doped Er:SiO2 glass systems were evidenced and investigated. Experimental findings suggested that the main energy-transfer mechanism in the metal-doped Er:SiO2 system could be related only to the very small size (less than 1−2 nm) of the doping aggregates and not dependent on their composition