The influence of single layer MoS2 flake on the propagated surface plasmons of silver nanowire

We demonstrate the enhancement of both excitation and transmission efficiency of the propagated surface plasmon (SP) of Ag nanowire (Ag NW) in hybrid Ag-MoS2 structure by contrasting the SP propagation of the same Ag NW on different substrates including silicon substrate, monolayer MoS2, or partially overlapping the Ag NW on MoS2 flake. The simulation results indicate that with the assistance of MoS2, the leaky radiation of the hybrid plasmonic modes of the H1 and H2 can be prominently suppressed by the high refractive index dielectric layer of the MoS2, which provides an optical barrier blocking the leaky radiation, resulting in the reduced propagation loss. Our work provides a feasible and effective method to enhance the SP propagation length.

Films Based on Mater-Bi® Compatibilized with Pine Resin Derivatives: Optical, Barrier, and Disintegration Properties

Mater-Bi® NF866 (MB) was blended with gum rosin and two pentaerythritol esters of gum rosin (labeled as LF and UT), as additives, to produce biobased and compostable films for food packaging or agricultural mulch films. The films were prepared by blending MB with 5, 10, and 15 wt.% of each additive. The obtained films were characterized by optical, colorimetric, wettability, and oxygen barrier properties. Moreover, the additives and the MB-based films were disintegrated under composting conditions and the effect of each additive on the biodegradation rate was studied. All films were homogeneous and optically transparent. The color of the films tended to yellow tones due to the addition of pine resin derivatives. All the formulated films presented a complete UV-transmittance blocking effect in the UVA and UVB region, and those with 5 wt.% of pine resin derivatives increased the MB hydrophobicity. Low amounts of resins tend to maintain the oxygen transmission rate (OTR) values of the neat MB, due to its good solubilizing and compatibilizing effects. The disintegration under composting conditions test revealed that gum rosin completely disintegrates in about 90 days, while UT degrades 80% and LF degrades 5%, over 180 days of incubation. As expected, the same tendency was obtained for the disintegration of the studied films, although Mater-Bi® reach 28% of disintegrability over the 180 days of the composting test.

Low-Density Polyethylene Films Carrying ferula asafoetida Extract for Active Food Packaging: Thermal, Mechanical, Optical, Barrier, and Antifungal Properties

The physical, thermal, mechanical, optical, microstructural, and barrier properties of low-density polyethylene films (LDPE) containing ferula asafoetida leaf and gum extracts were investigated. Results showed a reduction in elasticity and tensile strength with increasing extract concentration in the polymer matrix. The melting temperature and enthalpy increased with increasing concentration of extracts. The films containing extracts had lower L∗ and a∗ and higher b∗ indices. The films containing leaf extract had more barrier potential to UV than the gum extracts. The oxygen permeability in films containing 5% of leaf and gum extracts increased by 2.3 and 2.1 times, respectively. The morphology of the active films was similar to bubble swollen islands, which was more pronounced at higher concentrations of gum and leaf extracts. FTIR results confirmed some chemical interactions of ferula extracts with the polymer matrix. At the end of day 14th, the growth rate of Aspergillus niger and Saccharomyces cerevisea in the presence of the PE-Gum-5 reduced more than PE-Leaf-5 (3.7 and 2.4 logarithmic cycles, respectively) compared to the first day. Our findings showed that active LDPE films have desire thermo-mechanical and barrier properties for food packaging.

Planar waveguides produced by implanting Si and C ions in rutile

Planar waveguides were generated in samples of rutile crystal (TiO2) by bombarding with two typesof ion: silicon and carbon. Rutile is used because of its anisotropic properties, particularly its birefrin-gence. The guide is generated due to damage caused by the ions in the crystal which change its index ofrefraction. Three parameters were used: the implantation ion energy, the implantation uence, and theorientation of the crystallographic planes. The refractive index prole of the irradiated sample was cal-culated and together with the value of the optical barrier the comparison was made between the dierentwaveguides generated.