Langleycurrie6132

Although static electric fields have been effective in controlling ice nucleation, the highest freezing temperature (Tf) of water that can be achieved in an electric field (E) is still uncertain. We performed a systematic study of the effect of an electric field on water freezing by varying the thickness of a dielectric layer and the voltage across it in an electrowetting system. Results show that Tf first increases sharply with E and then reaches saturation at -3.5 °C after a critical value E of 6 × 106 V/m. Using classical heterogeneous nucleation theory, it is revealed that this behavior is due to saturation in the contact angle of the ice embryo with the underlying substrate. #link# Finally, we show that it is possible to overcome this freezing saturation by controlling the uniformity of the electric field using carbon nanotubes. We achieve a Tf of -0.6 °C using carbon nanotube-based electrodes with an E of 3 × 107 V/m. This work sheds new light on the control of ice nucleation and has the potential to impact many applications ranging from food freezing to ice production.Conventional field-effect transistors (FETs) have long been considered a fundamental electronic component for a diverse range of devices. However, nanoelectronic circuits based on FETs are not energy efficient because they require a large supply voltage for switching applications. To reduce the supply voltage in standard FETs, which is hampered by the 60 mV/decade limit established by the subthreshold swing (SS), a new class of FETs have been designed, tunnel FETs (TFETs). A TFET utilizes charge-carrier transportation in device channels using quantum mechanical based band-to-band tunneling despite of conventional thermal injection. The TFETs fabricated with thin semiconducting film or nanowires can attain a 100-fold power drop compared to complementary metal-oxide-semiconductor (CMOS) transistors. As a result, the use of TFETs and CMOS technology together could ameliorate integrated circuits for low-power devices. selleck screening library of two-dimensional (2D) materials with a diverse range of electronic properties has also opened new gateways for condensed matter physics, nanotechnology, and material science, thus potentially improving TFET-based devices in terms of device design and performance. In this review, state-of-art TFET devices exhibiting different semiconducting channels and geometries are comprehensively reviewed followed by a brief discussion of the challenges that remain for the development of high-performance devices. Lastly, future prospects are presented for the improvement of device design and the working efficiency of TFETs.Solution-processing technique of two-dimensional (2D) materials requires the knowledge of the dielectric effects on mutual interaction of each component and the layer structure variation. This research uses the magnetic dipole (MD) transition of intentionally doped Eu3+, which is dependent on the dielectric environments, as an optical probe to study the dielectric effects on the colloidal charge-bearing [Ca1.8Eu0.1Na0.1Nb3O10]- perovskite nanosheets (NSs) in various solvents. Results reveal that the solvent molecules with longer alkyl chain could more easily impact the ligands on the surface of the NSs, leading to a weaker interaction between the ligands and the NSs as well as less distortion of Eu3+ site (Ca2+ site) at the inner layer of the NSs. The large-sized ligands would impede the stacking of the NSs, while H+ would make the H+-modified NSs restack more easily. With the assistance of density functional theory (DFT) simulation, it is found that the ligands or the dielectric solvents could distort or relax the surface covalent polyhedra [NbO6]7- to a larger extent than the inner polyhedra. Small-sized ligands and a large thickness with more atomic layers of the NSs can resist structural variation caused by solvents. The acquired knowledge in this research benefits the understanding of the solution-processing technique for industrial application of 2D materials.Digital inkjet printing of textiles possesses great advantages like high efficiency and flexible production, but the challenges like the risk of causing serious environmental problems due to the large usage of dyes and chemicals still remain a matter of concern. In response to this problem, herein, a novel kind of reactive dye@copolymer nanosphere was prepared through the adsorption of C. I. Reactive Red 218 dyes (RR218) onto cationic poly(styrene-butyl acrylate-vinylbenzyl trimethylammonium chloride) (PSBV) nanospheres and applied in inkjet printing on woven cotton fabric. Results show that the prepared RR218@PSBV nanospheres possessed homogeneous size and good stability for ink preparation. In comparison with the original RR218 solution, the color depth of RR218@PSBV-printed fabric increased by 1.4 times and the dye residues in the printing effluent were reduced by about 45%. Meanwhile, the consumptions of sodium carbonate and urea in conventional inkjet printing were reduced by about 3.3 and 22.8 mg/cm2, respectively, and the printing process was simplified with 30% energy saving. Furthermore, the mechanism of the color enhancement by nanospheres was revealed by the calculation of absorption and scattering coefficients based on the Kubelka-Munk function. This work provides a potential application of dye@polymer nanospheres to promote the optimization of the textile inkjet printing technique and alleviates the environmental impact of conventional textile coloration.The electronic structures and core-level spectra of chlorogallium phthalocyanine (ClGaPc) molecules of different thicknesses (submonolayer to multilayer) adsorbed on a polycrystalline Au substrate and a highly oriented pyrolytic graphite (HOPG) substrate, before and after thermal annealing, were investigated using photoelectron spectroscopic techniques for better understanding the charge-transfer properties. The energy-level diagrams (ELDs) of the ClGaPc thin films are found to evolve with film thickness, substrate nature, and thermal annealing. The interfacial dipole moment in the active Au substrate and the molecular dipole moment in the inactive HOPG substrate mainly dictate the ELD. Annealed monolayer films on both the substrates seem to adopt a similar well-ordered Cl-up orientated molecular organization, which is quite interesting, as it certainly indicates a substrate-nature-independent energy minimum configuration. The strong interaction of the active Au substrate gives rise to additional charge transfer and state transfer (of Ga) as evident from the formation of a former lowest unoccupied molecular orbital (F-LUMO) level in the highest occupied molecular orbital (HOMO) region and a low binding energy peak in the Ga 2p3/2 core level.