MacGyvered Multiproperty Materials Using Nanocarbon and Jam: A Spectroscopic, Electromagnetic and Rheological Investigation

As part of a biopolymer matrix, pectin was investigated to obtain an engineered jam, due to its biodegradability. Only a few examples of pectin-based nanocomposites are present in the literature, and even fewer such bionanocomposites utilize nanocarbon as a filler—mostly for use in food packaging. In the present paper, ecofriendly nanocomposites made from household reagents and displaying multiple properties are presented. In particular, the electrical behavior and viscoelastic properties of a commercial jam were modulated by loading the jam with carbon nanotubes and graphene nanoplates. A new nanocomposite class based on commercial jam was studied, estimating the percolation threshold for each filler. The electrical characterization and the rheological measurements suggest that the behavior above the percolation threshold is influenced by the different morphology—i.e., one-dimensional or two-dimensional—of the fillers. These outcomes encourage further studies on the use of household materials in producing advanced and innovative materials, in order to reduce the environmental impact of new technologies, without giving up advanced devices endowed with different physical properties.

Arylenevinylene Oligomer-Based Heterostructures on Flexible AZO Electrodes

We investigated the optical and electrical properties of flexible single and bi-layer organic heterostructures prepared by vacuum evaporation with a p-type layer of arylenevinylene oligomers, based on carbazole, 3,3′ bis(N hexylcarbazole)vinylbenzene = L13, or triphenylamine, 1,4 bis [4 (N,N’ diphenylamino)phenylvinyl] benzene = L78, and an n-type layer of 5,10,15,20-tetra(4-pyrydil)21H,23H-porphyne = TPyP. Transparent conductor films of Al-doped ZnO (AZO) with high transparency, >90% for wavelengths >400 nm, and low resistivity, between 6.9 × 10−4 Ωcm and 23 × 10−4 Ωcm, were deposited by pulsed laser deposition on flexible substrates of polyethylene terephthalate (PET). The properties of the heterostructures based on oligomers and zinc phthalocyanine (ZnPc) were compared, emphasizing the effect of the surface morphology. The measurements revealed a good absorption in the visible range of the PET/AZO/arylenevinylene oligomer/TPyP heterostructures and a typical injection contact behavior with linear (ZnPc, L78) or non-linear (L13) J-V characteristics in the dark, at voltages <0.4 V. The heterostructure PET/AZO/L78/TPyP/Al showed a current density of ~1 mA/cm2 at a voltage of 0.3 V. The correlation between the roughness exponent, evaluated from the height-height correlation function, grain shape, and electrical behavior was analyzed. Consequently, the oligomer based on triphenylamine could be a promising replacement of donor ZnPc in flexible electronic applications.