Dye-Sensitized Commercial TiO2 for the Construction of Robust Nanocoatings with the Enhanced Transmittance and Visible-Light-Activated Photocatalytic Self-Cleaning Properties.

TiO2-based nanocoatings exhibit great promise in practical applications owing to their superior photocatalytic property. However, because of the wide band gap of TiO2, its photocatalytic capacity is only limited in the ultraviolet range. Herein, we designed and constructed robust SiO2@TiO2 composite nanocoatings with improved transmittance and visible-light-activated photocatalytic self-cleaning properties. Sulfonated cobalt(II) phthalocyanine (CoPcTs) was used as an organic dye to sensitize commercial TiO2 nanoparticles (Degussa P25) to form CoPcTs-P25 for visible-light photocatalysis. CoPcTs-P25 and small-sized solid silica nanoparticles (SSNs) were utilized as two building blocks, and acid-catalyzed silica sol (ACSS) was used as a binder to fabricate the nanocoatings via a simple dip-coating method without requiring any post-processing. By tuning the mass ratios of SSNs to CoPcTs-P25, the nanocoating with the optimized property showed the highest transmittance of ca. 97.0% at the wavelength of 566 nm, higher photocatalytic activity of degrading the organic pollutants than N-TiO2-based nanocoatings, high mechanical firmness of 3H level in pencil hardness test and 4A level in tape adhesion test, and good weather resistance. In short, the dye-sensitized commercial P25 TiO2 nanoparticles should be a promising building block for low-cost and easy preparation of robust nanocoatings with enhanced transmittance and visible-light-activated photocatalytic self-cleaning properties.

Excellent Electroluminescent Property of Eu3+-Induced Polystyrene-co-poly(acrylic acid) Aggregates (EIPAs) in Polymeric Light-Emitting Diodes.

Eu3+-induced polystyrene-co-poly(acrylic acid) aggregates (EIPAs) were synthesized using a self-assembly approach, and their structures and photophysical characteristics were examined to achieve effective monochromatic red emission in polymer light-emitting diodes (PLEDs). By adjusting the monomer ratio in RAFT polymerization, the size of Eu3+-induced block copolymer nanoaggregates can be regulated, thereby modulating the luminescence intensity. High-performance bilayer polymer light-emitting devices were fabricated using poly(9,9-dioctylfluorene) (PFO) and 2-(tert-butylphenyl)-5-biphenylyl-1,3,4-oxadiazole (PBD) as the host matrix, with EIPAs as the guest dopant. The devices exhibited narrow red emission at 615 nm with a full width at half-maximum (fwhm) of 15 nm across doping concentrations of 1, 3, 5, and 10 wt %. At a doping concentration of 3 wt %, the device achieved a maximum brightness of 1864.48 cd/m2 at 193.82 mA/cm2 and an external quantum efficiency of 3.20% at a current density of 3.5 mA/cm2. These results indicate that incorporating polystyrene-co-poly(acrylic acid) with Eu3+ complexes enhances the excitation and emission intensity, as well as the structural stability of the emitting layer in PLEDs, thereby improving the device performance.

Synthesis of Polyethylene Terephthalate (PET) with High Crystallization and Mechanical Properties via Functionalized Graphene Oxide as Nucleation Agent.

In this work, a novel functionalized graphene oxide nucleating agent (GITP) was successfully synthesized using a silane coupling agent (IPTES), and polymer block (ITP) to efficiently improve the crystallization and mechanical performance of PET. To comprehensively investigate the effect of functionalized GO on PET properties, PET/GITP nanocomposites were prepared by introducing GITP into the PET matrix using the melt blending method. The results indicate that PET/GITP exhibits better thermal stability and crystallization properties compared with pure PET, increasing the melting temperature from 244.1 °C to 257.1 °C as well as reducing its crystallization half-time from 595 s to 201 s. Moreover, the crystallization temperature of PET/GITP nanocomposites was increased from 185.1 °C to 207.5 °C and the tensile strength was increased from 50.69 MPa to 66.8 MPa. This study provides an effective strategy for functionalized GO as a nucleating agent with which to improve the crystalline and mechanical properties of PET polyester.

Berberine exerts neuroprotective activities against cerebral ischemia/reperfusion injury through up-regulating PPAR-γ to suppress NF-κB-mediated pyroptosis.

OBJECTIVE: Berberine (BBR) is an anti-inflammatory alkaloid compound extracted from herbs. The purpose of this study is to probe the possible effect and the mechanism of BBR against cerebral ischemia/reperfusion (I/R) injury. METHODS: In vitro oxygen and glucose deprivation (OGD) model was established on neurons from rat hippocampus, which was then subjected to BBR, IVA337 (PPAR-γ agonist), or GW9662 (PPAR-γ antagonist) treatment, to identify their effects on neuronal pyroptosis. MTT assay was utilized to determine cell survival rates, TUNEL staining for observation of ß-tubulin and MAP2 expressions, qRT-PCR for detection of mRNA expression of PPAR-γ, Western blot for assessment of protein expressions of PPAR-γ and pyroptosis-related proteins (AIM2, NLPR3, ASC, cleaved-Caspase-1, GSDMD, and GSDMD-N), and ELISA for examination of IL-18 and IL-1ß expressions. RESULTS: OGD modeling induced neuron pyroptosis, as evidenced by increased expression levels of pyroptosis-related proteins as well as IL-1ß and IL-18, and elevated cell apoptosis rate. In addition, OGD exposure led to PPAR-γ up-regulation and NF-κB activation. Overexpression of PPAR-γ ameliorated cell pyroptosis, while knockdown of PPAR-γ intensified neuron pyroptosis that could be reversed by BBR. Furthermore, either BBR could block the activation of NF-κB signaling pathway through PPAR-γ. CONCLUSION: BBR protects rats from cerebral I/R injury by up-regulating PPAR-γ to restrain NF-κB-mediated pyroptosis.