Theoretical Investigation on Photophysical Properties of Triphenylamine and Coumarin Dyes

Organic molecules with donor and acceptor configures are widely used in optoelectronic materials. Triphenylamine dyes (TPCTh and TPCRh) are investigated via density functional theory (DFT) and time-dependent DFT. Some microscopic parameters related to light absorption and photoelectric formation are calculated to interpret the experimental performance in dye-sensitized solar cells (DSSCS). Considering that coumarin derivatives (Dye 10 and Dye 11) have good donor and acceptor structures, they also have a COOH group used as an anchoring group to connect with semiconductors. Thus, the two dyes’ photophysical and photoelectric properties are analyzed to estimate the performance and application in DSSCs

Comparative Biology of <i>Daphniopsis tibetana</i> from Different Habitats under Seawater Acclimation

In this paper, we used experimental ecology methods and third-generation transcriptome sequencing to see the differences in growth, development, and reproduction of three strains of Daphniopsis tibetana Sars, 1903 from different locations in Tibet (Lake Namukacuo, NMKC; Lake Pengcuo, PC; and Lake Zigetangcuo, ZGTC). We also wanted to determine if the genes had changed after seawater-domesticated D. tibetana was reared in a laboratory. The results showed that at 15–16 ppt salinity and 15 ± 0.5 °C, the NMKC strain exhibited the highest survival rate of 26 d, and the ZGTC strain had the lowest survival rate at 53 days of culture. The body length was observed in NMKC (153.6 ± 12.1%), followed by PC (136.4 ± 16.1%), and then ZGTC (86.2 ± 7.6%). Combined, wild-type and seawater-acclimated D. tibetana produced 7252 DEGs, of which 4146 were up-regulated and 3106 were down-regulated. DEGs were subjected to gene ontology enrichment analysis. The DEGs were mainly enriched in single-organism localization, transporter activity, macromolecule localization, and organic substance transport. The Kyoto Encyclopedia of Genes and Genomes enrichment analysis was also performed and revealed that the RNA transport, protein digestion and absorption, and protein processing in the endoplasmic reticulum pathways were highly enriched. The data mined can provide a reference for follow-up research

Key technical problems of the application of DIW process of ceramic materials in ceramic-based diamond tools

The direct ink writing (DIW) technology of slurry is a 3D printing technology based on slurry extrusion. It has the advantages of low energy consumption, low cost, fast printing speed and no structural design restrictions. On the basis of summarizing the advantages of the application of DIW technology to ceramic-based diamond tools, key steps in the application process, such as the raw material selection, the slurry preparation, the printing suitability, the degreasing and the sintering process, are discussed and the powder agglomeration problem that needs to be given attention to in the slurry preparation process is pointed out. At the same time, some research examples of DIW manufacturing process are analyzed. Finally, it points out the key problems that should be solved in DIW manufacturing ceramic-based diamond tools

Photoresist-enabled assembly of BN/graphene/BN heterostructure and fabrication of one-dimensional contact electrode

A poly(methyl methacrylate) (PMMA) substrate is easily soluble in acetone and cannot withstand high temperatures, thereby restricting the application of graphene or boron nitride (BN) on it. Furthermore, the assembly mechanism of a BN/graphene/BN heterostructure directly determines the performance of a device. In this paper, we report the single-spin photoresist stacking transfer assembly (SPSTA) of a BN/graphene/BN heterostructure on a PMMA substrate using a photoresist as a support layer. The photoresist served as a protective layer for the retained BN/graphene/BN heterostructure. The excess BN/graphene/BN heterostructure was etched away by oxygen plasma, following which a metal was evaporated on the photoresist surface. As metal is impervious to light, the excellent light transmittance of the PMMA substrate could be utilized. After the photoresist was denatured by ultraviolet light exposure on the back of the substrate, it was dissolved by a sodium hydroxide (NaOH) solution, and a one-dimensional contact of the BN/graphene/BN heterostructure and metal was achieved. Finally, through different testing methods, we found that the SPSTA of the BN/graphene/BN heterostructure yields a smooth morphology and high electrical conductivity with a uniform sheet resistance. We examined the air failure of the BN/graphene/BN heterostructure and found that its SPSTA was stable. Our study realized the transfer of two-dimensional (2D) materials on PMMA substrates for the first time, overcame the membrane surface pollution caused by the traditional BN/graphene/BN heterostructure assembly process, realized the fabrication of BN/graphene/BN heterostructure devices on PMMA substrates for the first time, and offers important insights for the application of graphene and BN or other 2D materials on PMMA substrates

Niflumic Anion Intercalated Layered Double Hydroxides with Mechano-Induced and Solvent-Responsive Luminescence

Stimuli-responsive luminescent materials play an important role in fluorescent switches, optical storage devices and smart sensors. In this work, we report a mechano-induced and solvent stimuli-responsive luminescent change by the assembly of a typical aggregation-induced-emissive (AIE) molecule, niflumic acid (NFC), into the interlayer region of Zn–Al-layered double hydroxides (LDHs) with heptanesulfonate (HPS) as a cointercalation guest. The structure, chemical composition, and thermostability of the as-prepared NFC-HPS/LDHs composites were characterized by X-ray diffraction, elemental analysis, and thermogravimetry and differential thermal analysis (TG-DTA). Fluorescence spectra demonstrate that the sample with 5% NFC initial molar percentage, with respect to the interlayer guests, exhibits the optimal luminescent intensity. The NFC-HPS/LDH (5%) sample also exhibits the most obvious luminescent mechano-response with a 16 nm blue-shift and increase in the fluorescent intensity after grinding, while the pristine NFC solid shows little to no mechano-responsive behavior. Moreover, the NFC-HPS/LDH (5%) also presents reversible luminescent response to different volatile organic compounds (VOCs) (such as tetrahydrofuran, methanol, acetone, toluene, and chloroform). Therefore, this work not only gives a detailed description on the dual stimuli (mechanics and solvent)-responsive luminescence for future sensor applications but also supplies a deep understanding of the optical properties of the new AIE molecule within the confined LDH layers

Layered Dinitrostilbene-Based Molecular Solids with Tunable Micro/Nanostructures and the Reversible Fluorescent Response to Explosives

The ability to modulate and control the fluorescence properties of molecular solids at the micro/nanoscale is important to develop high-performance optoelectronic materials and sensors. Here we report the tunable one-photon and two-photon fluorescence as well as micro/nanostructures of dinitrostilbene-based (DNS) chromophore by the formation of layered multicomponent crystals with guanidinium cation (GD) through hydrogen-bonding assembly. The as-prepared GD₂DNS bulk crystal shows a red-shift emission as well as enhanced photoluminescence quantum yield and fluorescence lifetime compared with those of the Na₂DNS sample, which is related to the structural transfer of DNS from staggered arrangement to parallel fashion within the crystal. Periodic density functional theoretical calculations further show that the introduction of different cationic units can modify the frontier orbital distribution and electronic structure of DNS anions within the multicomponent crystals. Moreover, one-dimensional GD₂DNS nanobelts with well-aligned orientation can be further obtained by a combined ultrasound and coprecipitation method. The GD₂DNS nanobelts undergo a blue-shift fluorescence compared with its bulk crystal, and exhibit alternated photoresponse (such as emission wavelength and intensity) upon interaction with different nitroaromatic explosives (trinitrotoluene, picric acid and m-dinitrobenzen). Therefore, this work gives a facile bottom-up self-assembly rout to prepare organic multicomponent materials with tunable fluorescence properties and micro/nanostructures, which can be potentially used as luminescence detector for nitroaromatic explosives

Layered Dinitrostilbene-Based Molecular Solids with Tunable Micro/Nanostructures and the Reversible Fluorescent Response to Explosives

The ability to modulate and control the fluorescence properties of molecular solids at the micro/nanoscale is important to develop high-performance optoelectronic materials and sensors. Here we report the tunable one-photon and two-photon fluorescence as well as micro/nanostructures of dinitrostilbene-based (DNS) chromophore by the formation of layered multicomponent crystals with guanidinium cation (GD) through hydrogen-bonding assembly. The as-prepared GD₂DNS bulk crystal shows a red-shift emission as well as enhanced photoluminescence quantum yield and fluorescence lifetime compared with those of the Na₂DNS sample, which is related to the structural transfer of DNS from staggered arrangement to parallel fashion within the crystal. Periodic density functional theoretical calculations further show that the introduction of different cationic units can modify the frontier orbital distribution and electronic structure of DNS anions within the multicomponent crystals. Moreover, one-dimensional GD₂DNS nanobelts with well-aligned orientation can be further obtained by a combined ultrasound and coprecipitation method. The GD₂DNS nanobelts undergo a blue-shift fluorescence compared with its bulk crystal, and exhibit alternated photoresponse (such as emission wavelength and intensity) upon interaction with different nitroaromatic explosives (trinitrotoluene, picric acid and m-dinitrobenzen). Therefore, this work gives a facile bottom-up self-assembly rout to prepare organic multicomponent materials with tunable fluorescence properties and micro/nanostructures, which can be potentially used as luminescence detector for nitroaromatic explosives

Layered Dinitrostilbene-Based Molecular Solids with Tunable Micro/Nanostructures and the Reversible Fluorescent Response to Explosives

The ability to modulate and control the fluorescence properties of molecular solids at the micro/nanoscale is important to develop high-performance optoelectronic materials and sensors. Here we report the tunable one-photon and two-photon fluorescence as well as micro/nanostructures of dinitrostilbene-based (DNS) chromophore by the formation of layered multicomponent crystals with guanidinium cation (GD) through hydrogen-bonding assembly. The as-prepared GD₂DNS bulk crystal shows a red-shift emission as well as enhanced photoluminescence quantum yield and fluorescence lifetime compared with those of the Na₂DNS sample, which is related to the structural transfer of DNS from staggered arrangement to parallel fashion within the crystal. Periodic density functional theoretical calculations further show that the introduction of different cationic units can modify the frontier orbital distribution and electronic structure of DNS anions within the multicomponent crystals. Moreover, one-dimensional GD₂DNS nanobelts with well-aligned orientation can be further obtained by a combined ultrasound and coprecipitation method. The GD₂DNS nanobelts undergo a blue-shift fluorescence compared with its bulk crystal, and exhibit alternated photoresponse (such as emission wavelength and intensity) upon interaction with different nitroaromatic explosives (trinitrotoluene, picric acid and m-dinitrobenzen). Therefore, this work gives a facile bottom-up self-assembly rout to prepare organic multicomponent materials with tunable fluorescence properties and micro/nanostructures, which can be potentially used as luminescence detector for nitroaromatic explosives