Diblock copolymers composed of a side-chain liquid crystalline azobenzene-containing polymethacrylate and poly(tert-butyl acrylate) (PAzoMA-b-PtBA) were prepared using atom-transfer radical polymerization (ATRP). After subsequent selective hydrolysis of PtBA yielding poly(acrylic acid) (PAA), amphiphilic diblock copolymers of PAzoMA-b-PAA were obtained. Aggregation of either PAzoMA or PAA block occurs in solvents selective for one of the blocks. Adding water into dioxane solution of PAzoMA-b-PAA forms micellar aggregates due to the hydrophobic PAzoMA block. Under alternating UV and visible light illumination, reversible changes in micellar aggregates, for both core−shell micelles and vesicles, took place as a result of the reversible trans−cis photoisomerization of azobenzene mesogens in PAzoMA.

The exhausted graphite from spent Li-ion batteries is recycled and reused as a favorable anode for Na/K-ion batteries, and the insights into structural de-/intercalation model are realized.

A full characterization of lipid components is critical for selecting the most suitable microalgae and for downstream processing for biofuel production. This study demonstrates extraction, quantification, and diversity of lipid components from two microalgae of different types. For total lipid quantification, three extraction methods were compared and the method of pre-drying, dry ice-assisted grinding, and sequential solvent extraction gave the highest total lipid recovery. For lipid class composition determination, the photosynthetic Nannochloropsis contained 37.0% polar lipids, 41.1% triacylglycerols, and 12.5% unsaponifiable matter, whereas, the heterotrophic Schizochytrium had much less polar lipids and unsaponifiable matter. Further separation and quantification showed that Nannochloropsis contained more glycolipids (37.1% of total polar lipids) than that in Schizochytrium (14.3%), while Schizochytrium contained much more phospholipids (85.7%) than that in Nannochloropsis (44.7%). The major components in unsaponifiable matter of Nannochloropsis were hydrocarbon and cholesterol (55.8 and 37.7% of the total GC quantifiable matter), which only accounted for 29.3% of total unsaponifiable matter. For Schizochytrium, 15.4% squalene, 28.9% cholesterol, and 43.2% stigmasta-4,7,22-trien-3-ol were found in its GC quantifiable matter, and the total quantified hydrocarbon and sterols accounted for 50.5% of unsaponifiable matter. The lipid compositions of the two types of microalgae are very different, therefore, processing performance, such as lipid extraction and conversion to biodiesel may be different. Similar lipid characterization for other biofuel types of microalgae needs to be made to ensure optimal biofuel processing and fuel quality.

Although sodium ion batteries (SIBs) possess many beneficial features, their rate performance, cycling stability, and safety need improvement for commercial applications. Based on the mechanisms of the sodium ions storage in carbon materials, herein we present a multiple active sites decorated amorphous carbon (MAC) with rich structural defects and heteroatom doping as an anode material for SIBs. The full utilization of fast bonding–debonding processes between the active sites and sodium ions could bring a capacitive strategy to achieve superior sodium storage properties. Consequently, after materials characterization and electrochemical evaluation, the as‐prepared electrode could deliver high rate and long‐life performance. This active‐site‐related design could be extended to other types of electrode materials, thereby contributing to future practical SIB applications.

No abstract

The influence of gold nanoparticles (GNPs) on graphene was studied by Raman spectroscopy. It was found that the contact of GNPs could induce the whole Raman spectrum of graphene to redshift. And the shift of the 2D peak is more obvious than that of the G peak. A model of local strain was brought forward to explain the shift of Raman spectrum, which comes from the charges transfer between the GNPs and graphene. The observation of the Raman shifts helps us to gain more physical insights into the graphene-related systems.

Atomically thin transition metal dichalcogenides (TMDCs) have drawn much interest for their promising applications in electronic, optoelectronic, valleytronic and sensing fields. Controlled growth of large-scale and high-quality TMDC nanostructures is highly desirable but remains challenging. In the present work, large-scale monolayer, bilayer and few-layer MoSe 2 films have been controllably synthesized by ambient pressure chemical vapor deposition (APCVD). Hydrogen flow rate, growth temperature as well as selenium-metal flux ratio have been systematically investigated, which were demonstrated to play a key role in the synthesis of MoSe 2 nanostructures. We have also reported the successful growth of MoSe 2 nanoribbons with controlled width and length on diverse substrates by APCVD with the assistance of sodium chloride and corresponding growth mechanism was proposed. Our findings highlight the prospects for the controlled growth of novel 1D and 2D TMDC nanostructures for nanoelectronic devices and the development of mixed-dimensional heterostructures.

Growing uniform oxides with various thickness on TMDs is one of the biggest challenges to integrate TMDs into complementary metal oxide semiconductor (CMOS) logic circuits. Here, we report a layer-by-layer oxidation of atomically thin MoTe flakes via ozone (O) exposure. The thickness of MoO oxide film could be tuning with atomic-level accuracy simply by varying O exposure time. Additionally, MoO -covered MoTe shows a hole-dominated transport behavior. Our findings point to a simple and effective strategy for growing homogeneous surface oxide film on MoTe, which is promising for several purposes in metal-oxide-semiconductor transistor, ranging from surface passivation to dielectric layers.