Search

Recently, a composite material made from natural fibers and biodegradable resin, “green composite,” is attracting attention as an alternative composite material for the replacement of glass fiber-reinforced plastics. Plant-based natural fibers such as kenaf and flax have already been used as composite reinforcement materials because they are more environmentally friendly and costless fibers than artificial fibers. A problem of using natural fibers is the fiber waviness, which affects the tensile properties. Fiber waviness is fluctuation in the fiber orientation that is inherent in the sliver morphology of plant-based natural fibers. This study was conducted to clarify the relation between quantified parameters of fiber waviness and a composite’s tensile strength. First, the fiber orientation angles on a flax-sliver-reinforced composite were measured. Then the angle distribution was quantified through spatial autocorrelation analysis methods: Local Moran’s I and Local Geary’s c. Finally, the relation between the resultant tensile strength and quantified parameters was discussed.

Au/TiO2 mesocrystals (Au/TMCs) were synthesized via a template-free solvothermal approach, followed with in situ photoreduction of gold chloride tetrahydrate for deposition of Au nanoparticles (AuNPs). The microstructure and components of the photocatalysts were characterized with various techniques. The results indicated that the AuNPs selectively anchored on the (101) facet of TiO2 mesocrystals (TMCs). More interestingly, the strong interactions occurred between AuNP and TMC support, due to the formation of a close Schottky heterointerface, combined with Ti−O−Au chemical bonds partially formed. Unexpectedly, it was found that the AuNPs typically aligned with their [111] direction, parallelling to the [101] direction of TMC in many cases. Au/TMCs exhibited high selectivity and activity for the transformation of nitroarenes to corresponding azoxyarenes, which could be attributed to not only the plasmonic effect of AuNPs and the unique superstructure of TMC, but also the highly strong interaction between AuNPs and TMCs through the close Schottky heterointerface. [ABSTRACT FROM AUTHOR]