One-Step Realization of Layered/Spinel Heterostructures and Na Doping by Sodium Dodecyl Sulfate-Assisted Sol-Gel Method for Li-Ion Batteries.

Li-rich layered oxide cathodes have attracted extensive attention due to their high energy density. However, due to the low initial Coulombic efficiency and the capacity fading and voltage fading during cycling, its practical application is still a great challenge. Here, we report the one-step realization of layered/spinel heterostructures and Na doping by the sodium dodecyl sulfate (SDS)-assisted sol-gel method.

Efficient Structural Regulation Platform for the Controlled Synthesis of LiFePO Cathodes with Shorter Li-Ion Diffusion Paths.

The rate performance of lithium iron phosphate (LiFePO) is mainly limited by its poor electronic conductivity and slow Li-ion diffusion rate. Graphene-based materials are often compounded with LiFePO (LFP) to improve their rate performance, mainly because of their excellent electrical conductivity. Unlike most past composite work focusing on the conductive network between LFP and graphene, in this work, we further developed the functionality of graphene-based materials as nanoparticle carriers, where the nitrogen-doping strategy endows graphene with properties that make it an efficient structural regulation platform during the solvothermal process.

A Promising Solid-State Synthesis of LiMn FePO Cathode for Lithium-ion Batteries.

LiMnFePO (LMFP) is a significant and cost-effective cathode material for Li-ion batteries, with a higher working voltage than LiFePO (LFP) and improved safety features compared to layered oxide cathodes. However, its commercial application faces challenges due to a need for a synthesis process to overcome the low Li-ion diffusion kinetics and complex phase transitions. Herein, a solid-state synthesis process using LFP and nano LiMnFePO (MF73) is proposed.

Thermal behavior and combustion of Al nanoparticles/ MnO-nanorods nanothermites with addition of potassium perchlorate.

To explore the effect of potassium perchlorate (KClO) on Al nanoparticles/MnO-nanorods nanothermite systems, in this paper, Al/MnO nanothermites with different mass fraction of KClO were prepared by electrospray. The samples were characterized by XRD, SEM, TG-DSC analysis. According to the results of TG-DSC, the addition of KClO seemed to cause no direct improvement on their exothermic reactions.

Study on thermal behavior and kinetics of Al/MnO poly(vinylidene fluorine) energetic nanocomposite assembled by electrospray.

To explore the effect of the addition of poly(vinylidene fluorine) (PVDF) to a nanothermite system, an Al/MnO/PVDF energetic nanocomposite was prepared using an electrospray method, Al/MnO nanothermite was prepared as a control group. Then, the energetic nanocomposite and nanothermite were tested and analyzed by XRD, FE-SEM and TG-DSC, and the reaction products were collected. The results show that energetic nanocomposite would have three obvious exothermic peaks in the range of room temperature to 800 °C with a total more than 1700 J g heat release while the control experiment, Al/MnO nanothermite, could be found one exothermic peak with a 1100 J g heat release.

A completely controlled sphere-to-bilayer micellar transition: the molecular mechanism and application on the growth of nanosheets.

The combination of a simple modification of the sample addition method to generate a sort of continuously accumulated external stimulation with only minute increments in amplitude and the introduction of probe molecules (herein aniline) within the micelle allow the direct continuous in situ spectroscopic monitoring of possible micellar transitions. In this way, a sphere-to-ellipsoid and further an ellipsoid-to-bilayer micellar transition of sodium dodecyl sulfate (SDS) induced by camphor sulfuric acid (CSA) is observed to experience four stages in the time sequence: (i) the accumulated protons released from CSA in the hydration layer of the micelle stimulate the rearrangement of SDS micelles; (ii) the micelles transform into ellipsoidal shapes as evidenced by the characteristic chemical shift anisotropy and the corresponding molecular dynamic properties from probe molecules; (iii) further protonation of aniline induces the micelle to turn into lamellar structures; (iv) aniline is freed from the micelle while leaving the SDS bilayers undistorted. Moreover, polyaniline nanosheets incorporating SDS bilayers in sandwich structures, which can display excellent capacitive behavior at relatively high current densities for the fabricated supercapacitors, are prepared from the aniline oriented by the bending energy of the SDS bilayers.

Nucleation of polyaniline nano-/macrotubes from anilinium composed micelles.

A mechanistic study on the nucleation of polyaniline nanotubes (PANI-NT) through template-free method is explored by in situ solution-state (1)H NMR experiments via a careful analysis of the spectral evolution of the major species in the course of the reaction. Before polymerization, aniline and salicylic acid have assembled into loosely packed micelles due to electrostatic interactions and the proton exchange reaction between aniline and anilinium. A three-stage polymerization with a formation, accumulation of aniline dimers, as well as a generation of phenazine-like oligomers is observed, which can be attributed to the monomer transformation from neutral aniline molecules to anilinium cations and the significantly lowered pH in the reaction.

Room-temperature synthesis of self-assembled Sb2S3 films and nanorings via a two-phase approach.

The freestanding Sb(2)S(3) films were easily synthesized at the interface of water and toluene at room temperature, where Na(2)S and (C(2)H(5)OCS(2))(3)Sb (xanthate, O-ethyldithiocarbonate) acted as sulfur and antimony source, respectively. After 3 h of aging, the Sb(2)S(3) films with a flat surface toward organic side and rough surface toward aqueous side were assembled by sheaflike Sb(2)S(3) nanowires. The Sb(2)S(3) nanorings formed by end-to-end connection of the bundled nanowires appeared in the water layer when the reaction time reached 24 h.

Interfacing colloidal graphene oxide sheets with gold nanoparticles.

Aqueous solutions of graphene oxide (GO) and citrate-stabilised gold nanoparticles (AuNPs) are two classic, negatively charged colloids. Using the surface plasmon resonance spectra of AuNPs as a probe, we illustrate how the two like-charged colloids interact with each other and in so doing, reveal the unique solution behaviour of GO. We demonstrate that the electrical double layer of the GO sheets in water plays a key role in controlling the interaction between GO and AuNPs, which displays a one-way gate effect.

Discussion on microcosmic derivation of biological golden section phenomena from DNA geometric structure and snow flower generation.

As a mysterious and most universal mathematical constant, the ratio of golden section exists in biological organism widely either from microstructure to macrostructure or from anatomical structure to functional features, and the DNA is the most universal germ plasm throughout all life world. In this paper, by analyzing the DNA microstructure and generating process of snow flowers, such a fact is disclosed that biological golden section phenomena derives from the DNA structure at the molecular layer based on the complex nonlinear interaction with the inner environments.

Excitation profile of surface-enhanced Raman scattering in graphene-metal nanoparticle based derivatives.

Understanding energy transfer mechanisms in graphene derivatives is strongly motivated by the unusually interesting electronic properties of graphene, which can provide a template for the creation of novel nanostructured derivatives. From a synthetic point of view, it is highly attractive to envision being able to synthesize pristine graphene from precursors such as graphene oxide (GO). While this goal may be challenging over large length-scales, it is possible to generate regions of graphene at the nanoscale, confirmed by Raman spectroscopy or other methods.

Substituent effects on heats of formation, group interactions, and detonation properties of polyazidocubanes.

We have calculated the heats of formation (HOFs) for a series of polyazidocubanes by using the density functional theory (DFT), Hartree-Fock, and MP2 methods with 6-31G* basis set as well as semiempirical methods. The cubane skeleton was chosen for a reference compound, that is, the cubane skeleton was not broken in the process of designing isodesmic reactions. There exists group additivity for the HOF with respect to the azido group.