Two-step crystallization process based on a low-Pb-content seed layer is proposed to form PZT films by the chemical solution deposition. The first crystallization step was performed after the deposition from precursor solutions with 0 and 5 wt% Pb excess, which provides a low nucleation rate and the strong perovskite (111) orientation. The bulk film was obtained from solutions with a 30 wt% Pb excess, which ensures a high growth rate and eliminates formation of pyrochlore residuals. Some films with a fixed Pb excess were prepared for comparison. It is shown that the low-Pb-content seed layer can sufficiently enhance the texture of perovskite (111) grains thus providing the highest polarization magnitudes as compared to films prepared with the fixed Pb content. The lead content and the crystallization of the seed layer are found to affect the grain-boundary conduction, which, in turn, influences the polarization dependence of transient currents.

To determine the spray forming process parameters of 7075/Al–Si bimetallic gradient composite plate with two gas atomizers, a calculation model of the plate has been established by using the finite element software ANSYS. The effects of different motion trajectory, advance speed, swing cycle and spray center distance on shape, and silicon distribution of deposited plate have been simulated by the APDL programming language. The results show that a smooth and uniform surface is obtained when motion trajectory is in a regular jaggies mode. The deposited plate varies from platform to stepped shape with a center distance increasing from 20 mm to 50 mm; meanwhile, the width of the transition zone decreases gradually. As the period increases to 8 s, the silicon distribution of each layer presents a jagged fluctuation. Both the thickness of the deposited plate and the width of the transition zone decrease as the advance speed increases, except the silicon distribution. Finally, the modeling and simulation of the co-spray formed 7075/Al–Si bimetallic gradient composite plate are validated by experimental investigations and the simulation results are in good agreement with the actual results.

Comparative studies between doped conducting polymers and electrochemical deposited organometallic compounds reveals the interplay between crystalline-amorphous phases with significant contributions to the internal quantum efficiency in the OLED devices. The coexistence of the amorphous and crystalline phase in the electrodeposited film is revealed by the minor micro-crystal products which are present in the amorphous phase in thin films, while the many micro-crystals are randomly distributed in the thick films. Concerning the doped conducting polymers, the level of doping induces crystalline effects as a result of the π–π stacking between molecules, due to the Forester energy transfer processes in which the transfer rate is increased with decreasing of the distances between neighboring molecules. The crystallization processes change the emission properties of the active layers both for the luminance level and all over color, ranging from yellow to red in the case of IrQ(ppy)2 compounds.

A novel approach based on the preceramic paper method was used for the fabrication of Ti3SiC2-based material. Elemental powders of Ti, TiC, Si, C, and organic additives were used as starting materials. The Rapid Köthen process was used to fabricate the preceramic papers. The high-loaded green body of preceramic papers was heat-treated up to varying temperatures of 1300, 1400, 1500, and 1600 °C for 1 h in an Ar atmosphere. By using an excess amount of Si powder in the basic composition, the amount of Ti3SiC2 in the sintered specimen could be increased while the amount of TiC could be reduced. X-ray analysis showed that the paper-derived sample with the basic powder composition 3Ti/3TiC/3Si/C was a single phase within the resolution limit of the instrument used. The high purity of Ti3SiC2 can be explained by the partial formation of amorphous C which could not be detected by X-ray diffraction. Scanning electron microscopy analysis of fracture surfaces showed the characteristic lamellar structure of the paper-derived MAX phase.

Nickel oxide-based materials have attracted significant interest for a variety of energy conversion applications although many of their structures remain unresolved. In this study, Density Functional Theory+U (DFT+U) and hybrid DFT calculations are used to analyze the properties of crystalline nickel oxyhydroxide (β-NiOOH) with hydrogen (H) vacancies. Hydrogen vacancies are found to lower the band gap without creating states inside the band gap. Inter-layer crossing is a possible transport pathway, while intra-layer transport is inhibited. Bulk modulus is not influenced by H vacancies in the crystal. β-NiOOH with H vacancies exhibits good electronic properties, essential for solid electrolytes and anodes in solid oxide fuel cells.

Due to the increasingly severe environmental pollution problems, the development of semiconductor photocatalysts is being extensively carried out because they have exhibited high activities for the degradation of many organic and inorganic pollutants. In this study, waxberry-like Ni11(HPO3)8(OH)6 microball photocatalysts with a diameter of 10–20 μm have been successfully synthesized via a solvothermal route by using NiSO4 as a Ni-source and NaH2PO2 as a P-source in a mixture of ethylene glycol and water under the optimized conditions with a Ni:P molar ratio of 1:2 at 200 °C for 16 h. The as-prepared photocatalysts were characterized by powder X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray analysis, Brunauer–Emmett–Teller N2 adsorption, zeta potential, ultraviolet-visible (UV–vis) absorption, and photocatalysis tests. The decolourization of organic dyes, methylene blue and rhodamine B, under ultraviolet light over the as-prepared products reveals an excellent photocatalytic performance due to the good absorption for ultraviolet light.

Twinned silicon carbide (SiC) nanowires (NWs) reinforced Si3N4–SiOC composites were successfully fabricated through a joint process of three-dimensional printing (3DP), direct nitridation, and polymer infiltration and pyrolysis (PIP). 3DP and PIP were both addictive manufacturing processes, enabling the near net shape fabrication and microstructure designing of Si3N4–SiOC. With the increase of the PIP cycle number, the pores of Si3N4 were mostly filled with polymer-derived ceramics-silicon oxycarbide (containing SiC NWs and free carbons), which led to the increase of electrical conductivity of Si3N4–SiOC composites. With the increase of SiOC ceramics, the electromagnetic interference shielding effectiveness of Si3N4–SiOC composites increased from 2 dB to 35 dB, in which the absorption shielding effectiveness increased to 27 dB. The flexural strength of Si3N4–SiOC composites reached 63 MPa when the content of SiOC ceramics was 50.1 wt%. It is indicated that Si3N4–SiOC ceramics are a promising electromagnetic shielding and structural material.

In the quest for high real in-line transmittances for transparent polycrystalline alumina (PCA), we need defect free processing. One of the biggest advances in producing high density defect free ceramics over recent years has been the advent of spark plasma sintering (SPS) or pulsed electric current sintering. The production of PCA with high transmittances >60% has been demonstrated, but the mechanisms behind this fast, pressure aided sintering method are still much debated. Here, we investigate the sintering of doped α-alumina powders using traditional and pulsed electric current dilatometry. We demonstrate that at the final sintering stage, there is no major difference in the sintering mechanisms between conventional sintering and SPS sintering. High densification rates occurring in SPS are shown to be related to powder reorientation at the very early sintering stage and viscous-flow dominated densification in the intermediate sintering cycle. This paper clarifies what parameters in the processing–sintering domain have to be improved for even higher real in-line transmittances for PCA.

Among the most abundant biopolymers in the biosphere, lignin represents an untapped opportunity to create novel bioproducts. In this article, we discuss possibilities to synthesize nano- and microparticles by harnessing lignin’s inherent tendency to associate and to develop new material compositions and functions by controlling its capacity to assemble into supramolecular structures. Because lignin is biodegradable, antimicrobial, antioxidative, and carbon neutral, inexpensive industrial lignin streams could generate value-added particulate materials that preserve the structure, composition, and colloidal features inherent to this macromolecule. We present available routes for synthesis or isolation of lignin particles, including antisolvent and aerosol processing. Metallic and polymeric lignin particle hybrids for magnetic, antibacterial, catalytic, photonic, and other applications are also discussed. Overall, the facile formation of nano- and microparticles from lignins is expected to open new pathways toward future material development.

Agricultural soils are among the depositories of engineered nanomaterials (ENMs). Soil exposure to ENMs occurs through the intentional use of nano-agrochemicals, as well as through incidental contamination from industrial-waste release, irrigation with wastewater or gray water, amendment with ENMs-loaded sludge (soil conditioning to stimulate plant growth), or atmospheric fallouts. Concerns about ENM interactions with plants raise two questions. (1) Are ENMs taken up from soil by plants? (2) If they are taken up, do they remain in the nanoform within plant tissues? Experiments with crop plants have demonstrated that some ENMs such as TiO2 are taken up by roots and translocated to aboveground tissues, including fruits, without biotransformation. CeO2 ENM is also taken up by the roots; however, although most of it remains as ENM, it releases cerium ions that are incorporated into organic compounds. CeO2 ENM has been shown to be translocated from roots to seeds in soybean grown in soil amended with such ENM. On the other hand, ZnO ENM is transformed at the soil/root interface, leading to tissue Zn enrichment. Overall, most ENMs are taken up by plants with either low or no transformation, and accumulate in tissues.