Ferroelectric nanofibers with an embedded optically nonlinear benzothiazole derivative

We report measurements of the molecular first hyperpolarizability, thermal stability, photophysical, piezoelectric and ferroelectric properties of a benzothiazole derivative bearing an arylthiophene π-conjugated bridge both in solution and when embedded into a poly (L-lactic acid) (PLLA) matrix in the form of electrospun fibers with an average diameter of roughly 500 nm. The embedded nanocrystalline phenylthienyl-benzothiazole derivative, with crystal sizes of about 1.4 nm resulted in a good piezoelectric response from these functionalized electrospun fibers, indicative of a polar crystalline structure.Fundação para a Ciência e a Tecnologia (FCT

Magnetically Activated Flexible Thermoelectric Switches Based on Interconnected Nanowire Networks

The use of the spin degree of freedom in thermoelectric conversion offers new functionalities for electronic devices powered by waste heat and a promising solution for sustainable technologies. Here, thermocouples formed from two dissimilar arrays of interconnected magnetic nanowires embedded in a polymer film are used to realize flexible thermoelectric switches providing optimal magnetic-field-induced control of the sign and magnitude of the thermopower. By finetuning the composition of the homogeneous and multilayered nanowires forming the thermocouple legs, an ideal on/off ratio in the switching of the thermoelectric output voltage, or a simple sign reversal can be achieved in the presence of a magnetic field. This work paves the way for flexible spin-caloritronics devices exploiting residual thermal energy for the development of thermally activated sensors and logic devices

Electrokinetic desalination of glazed ceramic tiles

Electrokinetic desalination is a method where an applied electric DC field is the driving force for removal of salts from porous building materials. In the present paper, the method is tested in laboratory scale for desalination of single ceramic tiles. In a model system, where a tile was contaminated with NaCl during submersion and ubsequently desalinated by the method, the desalination was completed in that the high and problematic initial Clconcentration was reduced to an unproblematic concentration. Further conductivity measurements showed a very low conductivity in the tile after treatment, indicating that supply of ions from the poultice at the electrodes into the tile was limited. Electroosmotic transport of water was seen when low ionic content was reached. Experiments were also conducted with XVIII-century tiles, which had been removed from Palacio Centeno (Lisbon) during renovation due to damage of the glazing from the presence of salts. These tiles were severely contaminated with both chlorides and nitrates, and one of the tiles also contained sulphates though at a low concentration. The charge transfer was too low in the experiments to obtain full desalination, but promising results were obtained as significant decreases ([81% Cl-, *59% NO3 - and *22% SO4 2-) were seen.info:eu-repo/semantics/publishedVersio