A–Ar–A-type small molecule (SM) of Py-2DTOBT and Py-2DTOBTPh with an Ar(A–D)2 framework were synthesized, in which 2,7-pyrene (Py) and alkoxyl-substituted benzothiadiazole (OBT) were, respectively, used as the central aryl (Ar) and arm acceptor (A), while 3-phenanthrene (Ph) was used as a terminal donor (D) in Py-2DTOBTPh. By comparison with the parent SM of Py-2DTBT, where 2,7-pyrene (Py) and benzothiadiazole (BT) were used as the central aryl (Ar) and arm acceptor (A), the effects of non-covalent interactions and the terminal group on optical, electrochemical, and photovoltaic properties were investigated. The gradually improved photovoltaic performances were observed among Py-2DTBT, Py-2DTOBT, and Py-2DTOBTPh based organic solar cells. A power conversion efficiency (PCE) of 2.83% was obtained in the Py-2DTOBTPh/PC71BM-based device, which is a 53% improvement related to that of Py-2DTOBT and three times enhanced related to that of Py-2DTBT(Py-2DTOBT:PCE of 1.86%, Py-2DTBT:PCE of 0.74%).

Here, we develop and characterize high thermal conductivity/high thermal shock-resistant bulk Ce-doped Al2O3 and propose it as a new phosphor converting capping layer for high-powered/high-brightness solid-state white lighting (SSWL). The bulk, dense Ce:Al2O3 ceramics have a 0.5 at.% Ce:Al concentration (significantly higher than the equilibrium solubility limit) and were produced using a simultaneous solid-state reactive current activated pressure-assisted densification (CAPAD) approach. Ce:Al2O3 exhibits a broadband emission from 400 to 600 nm, which encompasses the entire blue and green portions of the visible spectrum when pumped with ultraviolet (UV) light that is now commercially available in UV light–emitting devices and laser diodes (LD). These broadband phosphors can be used in the commonly used scheme of mixing with other UV-converting capping layers that emit red light to produce white light. Alternatively, they can be used in a novel composite down-converter approach that ensures improved thermal–mechanical properties of the converting phosphor capping layer. In this configuration, Ce:Al2O3 is used with proven phosphor conversion materials such as Ce:YAG as an active encapsulant or as a capping layer to produce SSWL with an improved bandwidth in the blue portion of the visible spectrum. To study the effect of crystallinity on the Ce photoluminescent (PL) emission, we synthesize Ce:YAG ceramics using high-pressure CAPAD at moderate temperatures to obtain varying crystallinity (amorphous through fully crystalline). We investigate the PL characteristics of Ce:Al2O3 and Ce:YAG from 295 to 4 K, revealing unique crystal field effects from the matrix on the Ce dopants. The unique PL properties in conjunction with the superior thermal–mechanical properties of Ce:Al2O3 can be used in high-powered/high-brightness–integrated devices based on high-efficiency UV-LD that do not suffer efficiency droop at high drive currents to pump the solid-state capping phosphors.

High-temperature (1500 °C) interactions of promising environmental-barrier coating (EBC) ceramics in the rare-earth (RE) pyrosilicate system, Yb(2-x)YxSi2O7 (x = 0, 0.2, 1, or 2), with three different calcia–magnesia–aluminosiliate (CMAS) glass compositions, are explored. Only the Ca/Si ratio is varied in the CMAS: 0.76, 0.44, or 0.10. Interaction between the highest Ca/Si CMAS and the EBC ceramic with the lowest x (=0, Yb2Si2O7) promotes no reaction but the formation of “blister” cracks. In contrast, the highest x (=2, Y2Si2O7) promotes the formation of an apatite reaction product, but no “blister” cracks. Observationally, it is found that a decrease in the CMAS Ca/Si ratio (0.76–0.10) and a decrease in Y-content decreases the propensity for reaction crystallization (apatite formation) and “blister” cracks. These results are rationalized based on the relative affinities between Ca2+ in the CMAS and Y3+ or Yb3+ in the EBC ceramics, suggesting a way to tune the CMAS interactions in RE pyrosilicate solid solutions.

TiAl alloys are potential structural high-temperature structural materials at a service temperature of ~900 °C, while poor ductility at room temperature and high creep rate at the elevated temperature limits the applications. To improve the room-temperature and high-temperature mechanical properties of Ti–44Al–5Nb–3Cr–1.5Zr, Mo and B were introduced into this system and Ti–44Al–5Nb–3Cr–1.5Zr–xMo–yB alloys were proposed. And then, we, respectively, studied the microstructures and mechanical properties of Ti–44Al–5Nb–3Cr–1.5Zr–xMo–0B and Ti–44Al–5Nb–3Cr–1.5Zr–1Mo–yB to elucidate the role for the addition of Mo and B. It is found that Mo can increase the fraction of B2 phase in the alloys and the microstructures of the alloys are greatly refined by the addition of B. The compression test results indicate that Mo has a positive influence on the high-temperature compressive properties of TiAl-based alloys, whereas B addition can improve their room-temperature compressive properties of Ti–44Al–5Nb–3Cr–1.5Zr–1Mo–yB alloys; the morphology of borides in each sample should be the structural origin for these phenomena.

Selective laser melting (SLM) is a state-of-the-art technology in the additive manufacturing field. This study focuses on the influence of scanning speed on the fabrication of Ti6Al4V samples produced by SLM. This article contributes to the effect of SLM scanning speed parameters on micropores, surface morphology, and roughness. The detailed characterizations for the parts produced by the SLM process are evaluated. An SLM scanning speed of 695, 775, or 853 mm/s was selected. The findings show that a high quality of surface morphology and microstructure is obtained at a scanning speed of 775 mm/s. In addition, the maximum surface roughness values for both upper and side surfaces are approximately 0.460 µm and 0.592 µm, respectively. Furthermore, surface defect characteristics regarding the speed mechanism parameter for the SLM system are also discussed, and the challenges to the part quality, and potential for numerous industries (e.g., aerospace, automotive, and biomedical), creating microstructures, are observed.

During the detection of industrial hazardous gases, like formaldehyde (HCHO), the selectivity is still a challenging issue. Herein, an alternative HCHO chemosensor that based on the tin oxide nanoparticles is proposed, which was obtained through a facile hydrothermal method. Gas sensing performances showed that the optimal working temperature located at only 180 °C, the response value of 79 via 50 ppm HCHO was much higher than that of 35 at 230 °C. However, the compromised test temperature was selected as 230 °C, taking into account the faster response/recovery speeds than 180 °C, named 20/23versus 53/60 s, respectively. The response (35) of the SnO2 nanoparticles-based sensor to 50 ppm of HCHO is about 400% higher than that of bulk SnO2 sensor (9), especially when the gas concentration is 1 ppm, SnO2 nanoparticles also has a higher sensitivity which may possibly result from more exposed active sites and small size effect for nanoparticles than for bulk ones. The gas sensor based on SnO2 nanoparticles can be utilized as a promising candidate for practical low-temperature detectors of HCHO due to its higher gas response, excellent response–recovery properties, and perfect selectivity.

We deposit films of tin–calcium sulfide by atomic layer deposition (ALD) and demonstrate the metastability of this material. Rough and spiky films are obtained by using Sn and Ca precursors with different ligands, whereas compact and smooth films are obtained when the two metal sources share the same ligands. Compositional and quartz crystal microbalance results indicate that part of the underlaying SnS film is replaced and/or removed during the CaS ALD cycle during the ternary film deposition, possibly via a temperature-dependent cation exchange mechanism. The crystal structure transforms from orthorhombic to cubic as the calcium content increases. Furthermore, resistivity increases with calcium content in the alloy films, whereas optical band gap only depends weakly on Ca content. After annealing at 400 °C in an H2S environment, the cubic alloy film undergoes a phase transition into the orthorhombic phase and its resistivity also decreases. Both phenomena could be explained by phase separation of the metastable alloy.

The structural, vibrational, and optoelectronic properties of sol–gel synthesized Zn1−x(Al0.5Si0.5)xO nanoparticles were investigated. The X-ray diffraction studies of the samples confirmed the hexagonal wurtzite phase with the space group P63mc. No significant changes were observed in the lattice parameters. The increase in the intensity of $E_{{\rm{high}}}^2$ Raman mode observed at 438 cm−1 indicates a decrease in the crystallite size. The reduction in the deep-level emission band with the introduction of Al/Si indicates a decrease in intrinsic defects for the codoped sample. A unique electron paramagnetic resonance signal at g= 1.96 follows the same trend as the green luminescence, and its evolution was shown to probe the oxygen vacancy concentrations. I–V characteristics curve confirm the increase in the conductivity for the codoped samples. To evaluate the role of surface defects, ultraviolet photoresponse behavior as a function of time was also studied, and an increase in the photocurrent was observed. The slow decay and rise in the photocurrent are because of multiple trapping by interstitial defects. A relatively faster response time was observed with the substitution of Al/Si. It has been observed that prepared nanomaterials are suitable for optoelectronic devices.

Electrophoretic deposition consisting of bioglass (BG)–chitosan (CS)–iron oxide nanoparticles (Fe3O4 NPs) on the Ti–13Nb–13Zr substrate was described. The bioactive coating was embedded in a CS matrix. The Fe3O4 NPs collected using the co-precipitation method varied at three different levels (1, 3, and 5 wt%) in the BG coating. The formulated coatings exhibited a hydrophilic character due to higher surface roughness values. The pull-off tape test was performed to check the adhesion strength of coatings. The composite coatings displayed adhesion strength of 5B class. The corrosion behavior was evaluated in Ringer's solution by the electrochemical test. The corrosion results showed that the composite coatings were more impressive as compared to pure BG and Fe3O4 coatings. The hemocompatibility results showed a hemolytic ratio (<5%), which validates them as favorable blood compatible nature of the deposited coatings. The findings exhibited that the BG–Fe3O4–CS coating can be widely employed as a favorable material for orthopedic applications.

Integrating LiMn2O4(LMO) and different carbon materials to build a mixed cathode system can provide fast transport channels to improve the conduction of both electrons and ions. In this paper, our work studied in situ low-temperature hydrothermal synthesis of LMO nanocomposites based on graphene oxide (GO)/carbon nanotubes (CNTs) hydrogel. Compared with the pure LMO nanoparticles, GO/CNTs/LMO (GCLMO) composites greatly improved electrochemical performance in specific capacity, cycle performance and rate ability. The electrochemical test results showed that the specific capacitance of GCLMO nanocomposites reached 396 F/g at the current density of 0.5 A/g, which was much higher than 221 F/g of pure LMO. Even at the current density of 10 A/g, the specific capacitance was still as high as 309 F/g. Besides, after 2000 cycles, the specific capacitance retention of the composite was 93%. Electrochemical data showed that GCLMO composite is an ideal cathode material for supercapacitors.

Interactions between smooth muscle cells (SMCs) and biomaterials must not result in phenotype changes as this may generate uncontrolled multiplication processes and occlusions in vascular grafts. The aim of this study was to relate the hydrolytic stability and biocompatibility of polyurethanes (PUs) on SMCs. A higher polycaprolactone (PCL) concentration was found to improve the hydrolytic stability of the material and the adhesion of SMCs. A material with 5% polyethylene glycol, 90% PCL, and 5% pentaerythritol presented high cell viability and adhesion, suggesting a contractile phenotype in SMCs depending on the morphology. Nevertheless, all PUs retained their elastic modulus over 120 days, similar to the collagen of native arteries (~10 MPa). Furthermore, aortic SMCs did not present toxicity (viability over 80%) and demonstrated adherence without any abnormal cell multiplication processes, which is ideal for the function to be fulfiled in situ in the vascular grafts.