Discovery of Structural Complexity through Self-Assembly of Molecules Containing Rodlike Components

Hierarchical structures are important for transferring and amplifying molecular functions to macroscopic properties of materials. In this regard, rodlike molecules have emerged as one of the most promising molecular building blocks to construct functional materials. Although the self-assembly of conventional molecules containing rodlike components generally results in nematic or layered smectic phases, due to the preferred parallel arrangements of rodlike components, extensive efforts have revealed that rational molecular design provides a versatile platform to engineer rich self-assembled structures. Herein, first successes achieved in polyphilic liquid crystals and rod–coil block systems are summarized. Special attention is paid to recent progress in the conjugation of rodlike building blocks with other molecular building blocks through the molecular Lego approach. Rod-based giant surfactants, sphere–rod conjugates, and dendritic rodlike molecules are covered. Future perspectives of the self-assembly of molecules containing rodlike components are also provided.     

Low-temperature plasma enhanced atomic layer deposition of large area HfS_2 nanocrystal thin films

Hafnium disulfide(HfS2) is a promising two-dimensional material for scaling electronic devices due to its higher carrier mobility, in which the combination of two-dimensional materials with traditional semiconductors in the framework of CMOS-compatible technology is necessary. We reported on the deposition of HfS2 nanocrystals by remote plasma enhanced atomic layer deposition at low temperature using Hf(N(CH3)(C2H5))4 and H2S as the reaction precursors. Selflimiting reaction behavior was observed at the deposition temperatures ranging from 150℃ to 350℃, and the film thickness increased linearly with the growth cycles. The uniform HfS2 nanocrystal thin films were obtained with the size of nanocrystal grain up to 27 nm. It was demonstrated that higher deposition temperature could enlarge the grain size and improve the HfS2 crystallinity, while causing crystallization of the mixed HfO2 above 450℃. These results suggested that atomic layer deposition is a low-temperature route to synthesize high quality HfS2 nanocrystals for electronic device or electrochemical applications.     

Electrodeposition of Sn powders with pyramid chain and dendrite structures in deep eutectic solvent: roles of current density and SnCl2 concentration

Journal of Solid State Electrochemistry - Tin (Sn) powders with pyramid chain and dendrite structures are successfully prepared by electrodeposition in choline chloride-ethylene glycol deep...     

Microstructural Classification and Reconstruction of the Computational Geometry of Steamed Bread Using Descriptor-Based Approach

Transport in Porous Media - Microstructures affect the properties of food products; accurate and relatively less complex microstructural representations are thus needed for modelling of transport...     

Deposition of Vertically Aligned Ag/Ag2S Nanoflakes on EGaIn Particles for Humidity Sensing

Liquid metals, which possess both good electrical conductivity and liquid-like processability, have drawn much attention recently. They are also capable of acting as synthesis templates to guide the deposition of other functional materials. Herein, through an in-situ galvanic replacement reaction assisted by ultrasonication, core–shell EGaIn/Ag particles composed of EGaIn cores and vertically aligned Ag nanoflakes as shells were prepared; they were further sulfurized to yield ternary EGaIn/Ag/Ag₂S core–shell composite particles. A humidity sensor based on EGaIn/Ag/Ag₂S particles showed much higher sensing response than EGaIn and EGaIn/Ag. Such superior performance could be attributed to the n-type semiconducting character of Ag₂S allowing it to receive electrons from water molecules at low humidity, and its highly hydrophilic surface allowing it to absorb more water molecules at higher humidity so as to enable the formation of ion-conductive paths.     

疫情背景下微积分“课程思政”的教学探索与实践

结合当前的疫情,采用画龙点睛式、隐性渗透式等教学方式,多角度、全方位把“思政”元素融入到微积分教学之中,通过调查问卷评估了课程思政教学效果,为高校微积分课程的“课程思政”改革提供一种思路.     

Domino Cross Dehydrogenative Coupling of 2‐Aryl Acetals with Ketones Using DDQ as Oxidant and Reactant Precursor

A novel domino cross dehydrogenative coupling of 2‐aryl acetals with unmodified ketones has been developed, using DDQ as both the oxidant and reactant precursor.     

3D hierarchical MnO2 aerogels with superhydrophobicity for selective oil–water separation

Inorganic nanowire aerogel with low density, high specific surface area and high porosity has received increasing attention in the field of materials physics and chemistry because of not only the unique structural and physical features of metallic oxide but also low cost, environmental friendliness and earth abundant of precursor materials. In this work, MnO₂ nanowire aerogels (MNA) with ultralow density, and stable 3D hierarchical structures was successfully fabricated by freeze‐drying processes using MnO₂ nanowire as building blocks. The length of MnO₂ nanowires exceeds 100 μm, making it easier to cross‐link and self‐assemble into a 3D network of aerogels, and the acid and alkali resistance of MnO₂ enables it to adapt to extreme environments. Simultaneously, the monodispersed MnO₂ nanowire was prepared by the hydrothermal method, followed by acid treatment. To obtain superhydrophobic properties and achieve selective oil adsorption, the surfaces of nanowire aerogels were grafted the hydrophobic groups with low surface energy via vapor deposition. It is indicated that the obtained 3D hierarchical MNA show both superhydrophobic and super‐lipophilic properties simultaneously with a high‐water contact angle of 156°  ±  2° and an oil contact angle of 0°. And the MNA exhibited a high oil adsorption capacity of 85–140 g/g, thereby indicating its potential applications in oil/water separation. More importantly, the resulting MNA can be recycled ten cycles without loss of oil absorption capacity (more than 120 g/g). The results presented in this work demonstrate that the as‐prepared nanowire aerogel may find applications in chemical separation and environmental remediation for large‐scale absorption of oils from water.     

Investigation of U(VI), Th(IV), and Eu(III) ions’ sorption behavior onto silica gel modified with anhydride

Journal of Radioanalytical and Nuclear Chemistry - Modification of silica gel by butanedioic anhydride (SiO2–BDAH) results in efficient adsorbents for removal of U(VI), Th(IV), and Eu(III)...