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a New forms of hybrid multiaxial nanocomposites with enhanced mechanical and stab resisting properties are presented. This study is motivated by the lack of knowledge in the study of the multiaxial fabric nanocomposites with two modified thermoplastic matrices for antiballistic protection. Introduction of 5 wt.% silica nanoparticles in the composite of polyurethane/p-aramid/poly (vinyl butyral) leads to significant improvement in mechanical properties, and the addition of silane as a coupling agents and glutaraldehyde as a crosslinking agents yielded maximal values of storage modulus, tensile modulus and anti-stabbing properties for hybrid nanocomposites. Ballistic resistance testing and penetration depth of the hybrid nanocomposites were visualized using image analysis. Copyright

address: Dusica B. Stojanovic duca@tmf.bg.ac.rs † Footnotes relaƟng to the Ɵtle and/or authors should appear here. Electronic Supplementary Information (ESI) available: Results of DSC analysis of ultrasonic treatment of PEO films. Nanoindentation measurements of composite films and keratin-PEO blend with different content ratio. Discussion of FTIR spectra of composite films. FESEM images of composite films. Optical images of keratin-PEO blend with different content ratio. SeePolyethylene oxide (PEO) functionalized graphene (f-G) was prepared by ultrasonication of pristine graphene in PEO aqueous solution. Feasible sonication protocol of PEO degradation and graphene functionalization enabled fabrication of solvent casted nanocomposites. Additionally, the steps to form new bio-nanocomposite films have been described, taking the advantage of the combination of graphene, PEO and keratin fibers from poultry feather waste, to design the aforementioned bio-nanocomposite films, which allow extraordinary properties that would have promising applications as eventual packaging materials and enable bio-waste keratin to be converted to added-value material. Compared to neat PEO, addition of only 0.3 wt.% f-G provided increase of 92 % of storage modulus. These findings are similar to the nanoindentation results, which yielded the increases for reduced modulus of same composition for about 92 %. Nanoindentation testing shows that the incorporation of 0.3 wt.% f-G increased reduces modulus and hardness of keratin-PEO blend for about 155 and 99 %, respectively.

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The study presents a novel method for the protection of Grubbs’ catalyst, by incorporation in polystyrene fibres via electrospinning technique. Epoxy-glass fibre composite with embedded self-healing agents (polystyrene fibres with Grubbs’ and microcapsules with dicyclopentadiene) was processed. Fibres retained pale purple colour during processing, revealing that fibres provided good protection of the catalyst from the amine hardener. The influence of self-healing agents’ content and thermal treatment on self-healing efficiency was investigated. Fourier transform infrared spectroscopy revealed that a polydicyclopentadiene formed at the healed interface. Thermal analysis revealed that ‘bleed’ at the healing sites from different samples had similar concentration of polydicyclopentadiene, indicating that the same amount of the catalyst has been provided to dicyclopentadiene for polymerization. This finding lead to assumption that electrospun polymer fibres enabled good dispersion of the catalyst in the composites. The low energy impact tests of the samples showed a recovery of 90% after 24 h at room temperature and up to 111% after repeated heating cycles.

It is well known that alumina possesses good mechanical and chemical properties. Nanofibers having α-alumina structure was used as reinforcement for metal, polymer and ceramic matrix composites. In this study, three series of nanofibers were prepared. The first series was made from 10 % water solution of the aluminium chloride hydroxide/polyvinyl alcohol with a mass ratio of 5:1. The other two series were made with the addition of 1 wt.% of MgCl 2 or 1 wt.% of FeCl 3 regarding the aluminium chloride hydroxide content. Nanofibers were prepared using the electrospinning technique and they were characterized by the TGA/DTA, XRD and FESEM methods. It was proven that addition of FeCl 3 into the initial spinning solution lowers the temperature for the corundum structure formation while the addition of MgCl 2 results if the formation of mixed oxides that eases the sintering process.

Chitosan based films have found an increasing implementation in variety of topics among which as drug delivery carriers, in packaging industry and as water puritication filters. Therefore, in order to achieve mechanical integrity of such films while preserving processability and biocompatibility, chitosan based films are fabricated in forms of blends with polyethylene oxide (PEO). Nanoindentation study is undertaken in order to investigate nanomechanical properties and surface morphology of chitosan films in blends with various content of PEO. Results of differential scanning calorimetry, water uptake and nanoindentation revealed that films with 80/20 blend ratio of chitosan/PEO showed the optimal values of reduced modulus and hardness. It appears that the incorporation of synthetic PEO in chitosan films could lower the manufacturing cost while preserving the mechanical integrity of the films. [Projekat Ministarstva nauke Republike Srbije, br. EUREKA E!5851