Synthesis and Antibacterial Testing of Silver/Poly (Ether Amide) Composite Nanofibers with Ultralow Silver Content

Antimicrobial materials have attracted much attention all over the world. Herein, a new kind of antimicrobial material, poly (ether amide) (PebaxⓇ) nanofibers containing Ag nanoparticles, was prepared by electrospinning method. The Ag/PebaxⓇ composites were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), differential scanning calorimetry (DSC), and thermogravimetric analyzer (TGA) measurements. The antimicrobial properties of Ag/PebaxⓇ composites against Escherichia coli (E. coli; ATCC25922 and avirulent) and Staphylococcus aureus (S. aureus; ATCC6538 and avirulent) were evaluated by membrane adhering method. It was found that the Ag content played an important part in the antimicrobial ability of Ag/PebaxⓇ composites. When the mass ratio of AgNO3 to PebaxⓇ in the precursor was 0.15‰, the inhibition rate can reach >99.9% and antimicrobial activity against E. coli and S. aureus was 5.8 and 5.6, respectively, exceeding the antimicrobial testing standards JIS Z 2801. The above results indicated that the Ag/PebaxⓇ composite was a promising antimicrobial material that can be used in many applications

TiEV: The Tongji Intelligent Electric Vehicle in the Intelligent Vehicle Future Challenge of China

TiEV is an autonomous driving platform implemented by Tongji University of China. The vehicle is drive-by-wire and is fully powered by electricity. We devised the software system of TiEV from scratch, which is capable of driving the vehicle autonomously in urban paths as well as on fast express roads. We describe our whole system, especially novel modules of probabilistic perception fusion, incremental mapping, the 1st and the 2nd planning and the overall safety concern. TiEV finished 2016 and 2017 Intelligent Vehicle Future Challenge of China held at Changshu. We show our experiences on the development of autonomous vehicles and future trends

Multinuclear Iridium Complex Encapsulated by Oligocarbazole Dendrons for Enhanced Nondoped Device Efficiency

A dendritic multinuclear Ir complex, namely Cz–3IrB–IrG, has been designed and synthesized by introducing the second-generation oligocarbazole dendrons into its periphery. Because of the characteristic encapsulation, the intermolecular interactions could be effectively alleviated to prevent the unwanted triplet–triplet annihilation stemmed from the outer blue Ir complexes. Compared with 3IrB–IrG in the absence of dendrons, the film photoluminescence quantum yield of Cz–3IrB–IrG is greatly increased from 0.46 to 0.82 together with a small blue-shifted emission from 524 to 520 nm. On the basis of Cz–3IrB–IrG as the emitting layer alone, the nondoped device realizes a promising luminous efficiency of 40.9 cd/A (12.0%), much higher than that of 3IrB–IrG (32.6 cd/A, 9.7%). The obtained improvement clearly indicates that further dendronization toward multinuclear Ir complex will provide an alternative strategy to construct highly efficient phosphors used for nondoped phosphorescent organic light-emitting diodes

Plasmonic Nanostructure for Enhanced Light Absorption in Ultrathin Silicon Solar Cells

The performances of thin film solar cells are considerably limited by the low light absorption. Plasmonic nanostructures have been introduced in the thin film solar cells as a possible solution around this issue in recent years. Here, we propose a solar cell design, in which an ultrathin Si film covered by a periodic array of Ag strips is placed on a metallic nanograting substrate. The simulation results demonstrate that the designed structure gives rise to 170% light absorption enhancement over the full solar spectrum with respect to the bared Si thin film. The excited multiple resonant modes, including optical waveguide modes within the Si layer, localized surface plasmon resonance (LSPR) of Ag stripes, and surface plasmon polaritons (SPP) arising from the bottom grating, and the coupling effect between LSPR and SPP modes through an optimization of the array periods are considered to contribute to the significant absorption enhancement. This plasmonic solar cell design paves a promising way to increase light absorption for thin film solar cell applications

A binary solvent mixture-induced aggregation of a carbazole dendrimer host toward enhancing the performance of solution-processed blue electrophosphorescent devices

The emissive layer morphology strongly correlates with the charge transport and light-emitting performance of solution-processed phosphor-doped organic light-emitting diodes (PhOLEDs). Herein, morphology manipulation of the solution-processed emissive layer comprising of carbazole dendrimer (H2) host:blue phosphor (FIrpic) guest is realized via processing of the solvent and its influence on charge transport and light-emitting properties is investigated. The formation of H2 aggregates within its amorphous matrix processed with the toluene:p-xylene solvent mixture distinctively improves the hole and electron transport within the emissive layer, helping to lower the driving voltages and improve the light-emitting efficiency. However, excess aggregation of H2 would result in non-uniform dispersion of the FIrpic guest within the H2 host, leading to non-complete host-to-guest energy transfer and decreased electroluminescence performance. Through manipulation of the aggregates within the H2 host by varying the solvent mixture ratio, the trade off between charge transport and energy transfer is realized. Finally, the solution-processed blue PhOLED with optimized emissive layer morphology processed with toluene:p-xylene (9:1) solvent mixture achieves a high light-emitting efficiency of 27.8 cd A-1, corresponding to 25% enhancement compared to 22.2 cd A-1 of the control device processed with commonly used toluene solvent

Achieving Deep-Blue Thermally Activated Delayed Fluorescence in Nondoped Organic Light-Emitting Diodes through a Spiro-Blocking Strategy

A deep-blue thermally activated delayed fluorescence (TADF) emitter TXADO-spiro-DMACF has been reported for nondoped organic light-emitting diodes (OLEDs) by integrating an appropriate blocking unit with the donor (D)–acceptor (A)–donor (D)-type TADF emitter via a spiro linkage. Benefiting from the characteristic perpendicular arrangement, the intermolecular interactions are expected to be weakened to some degree. As a result, TXADO-spiro-DMACF shows a very small bathochromic shift of 8 nm associated with a narrowed full width at half maximum of 54 nm on going from solution to the film. The corresponding nondoped device successfully achieves a bright deep-blue emission, revealing Commission Internationale de l’Eclairage coordinates of (0.16, 0.09) and a peak external quantum efficiency of 5.3% (5.3 cd/A, 5.9 lm/W). The results clearly indicate that spiro-blocking is a promising strategy to develop deep-blue TADF emitters capable of nondoped OLEDs

High-Energy-Level Blue Phosphor for Solution-Processed White Organic Light-Emitting Diodes with Efficiency Comparable to Fluorescent Tubes

Summary: A high-energy-level blue phosphor FIr-p-OC8 has been developed for solution-processed white organic light-emitting diodes (WOLEDs) with comparable fluorescent tube efficiency. Benefiting from the electron-donating nature of the introduced alkoxy, FIr-p-OC8 shows not only efficient blue light but also elevated highest occupied molecular orbital/lowest unoccupied molecular orbital levels to well match the dendritic host H2. Consequently, the hole scattering between FIr-p-OC8 and H2 can be prevented to favor the direct exciton formation on the blue phosphor, leading to reduced driving voltage and thus improved power efficiency. By exploiting this approach, a maximum power efficiency of 68.5 lm W−1 is achieved for FIr-p-OC8-based white devices, slightly declining to 47.0 lm W−1 at a practical luminance of 1,000 cd m−2. This efficiency can be further raised to 96.3 lm W−1 @ 1,000 cd m−2 when a half-sphere is applied to increase light out-coupling. We believe that our results can compete with commercial fluorescent tubes, representing an important progress in solution-processed WOLEDs. : Organometallic Chemistry; Inorganic Materials; Optoelectronics Subject Areas: Organometallic Chemistry, Inorganic Materials, Optoelectronic