Solution Of Tetrabutylammonium Chloride Research Articles

Antioxidative 2D Bismuth Selenide via Halide Passivation for Enhanced Device Stability.

The topological insulator 2D Bi2Se3 is promising for electronic devices due to its unique electronic properties; however, it is challenging to prepare antioxidative nanosheets since Bi2Se3 is prone to oxidation. Surface passivation using ligand agents after Bi2Se3 exfoliation works well to protect the surface, but the process is time-consuming and technically challenging; a passivation agent that is stable under a highly biased potential is significant for in situ passivation of the Bi2Se3 surface. In this work, the roles of halide anions (Cl-, Br-, and I-) in respect of the chemical properties of synthetic Bi2Se3 nanosheets during electrochemical intercalated exfoliation were investigated to determine the antioxidation capacity. It was found that Bi2Se3 nanosheets prepared in a solution of tetrabutylammonium chloride (TBA+ and Cl-) have the best oxidation resistance via the surface bonding of Bi with Cl, which promotes obtaining better device stability. This work paves an avenue for adjusting the components of the electrolyte to further promote the stability of 2D Bi2Se3-nanosheet-based electronic devices.

Solid-State Electrochemistry of Organic Macrocycles and Mofs; Application to Organic Electronics and Energy Storage

Solid-state electrochemistry is a powerful tool to control the electronic properties of organic materials through charge/carrier injections. In contrast to the numerous studies on organic polymers, its application to small molecules has been limited, because most of them become soluble into solvents after redox reactions. In this perspective, the organic macrocycles and MOFs are promising materials due to their structural robustness. We will discuss the following three topics 1. Electric-double-layer field-effect transistors of organic macrocycles. Electric-double-layers (EDLs), formed at solid-electrolyte interfaces, induce extremely large electric fields. This results in a high charge carrier accumulation in the solid, much more effectively than solid dielectric materials. We investigated the EDL thin-film transisotrs of porphyrazines and octathio[8]circulene (sulflower) with gate dielectrics of ionic liquids, which have attracted much attention due to their wide electrochemical windows, low vapor pressures, etc. We revealed the factors, controlling the mobility and threshold voltage in these types of FETs. 2. Electrochemical doping to nano-porous single crystals of Li-phthalocyanine (LiPc). The crystal structure of a neutral π radical, LiPc in the x from, consists of 1D stacking chains of LiPc and nano-channels parallel to them. We found that the LiPc crystals were electrochemically oxidized in an acetonitrile solution of tetrabutyl ammonium chloride (TBA·Cl), exhibiting a crystal-to-crystal transformation to LiPc·Cl x (0<x<0.5). The crystal structures of the LiPc·Cl x series were successfully solved and refined by the X-ray single-crystal analysis, and the obtained structures clearly indicated the presence of the Cl−ions in the 1D channels and a systematic structural change in the π stacking chain of LiPc. 3. Synthesis and solid-state electrochemistry of a redox-active MOF, Cu(2,7-AQDC), toward high-capacity lithium battery. We synthesized a microporous redox-active MOF, Cu(2,7-AQDC) (2,7-H2AQDC=2,7-anthraquinonedicarboxylic acid), and utilized it as a cathode active material in lithium batteries. With a voltage window of 4.0-1.7 V, both metal clusters and anthraquinone groups in the ligands were found to exhibit reversible redox activity. By controlling the voltage window of operation, extremely high recyclability of batteries was achieved.

The behaviour of dyes at oil/water interfaces

The adsorption of ionic dyes, the builder effect, and the interaction between ionic dyes and surface active agents were investigated by using the electrocapillarity at oil/water interfaces. The oil phase was the solution of tetra-butylammonium chloride, sodium cetylsulphate, cetylpyridinium chloride or stearylamine in methylisobutylketone, and the water phase contained various dyes in addition to the inorganic electrolyte. The interfacial tension decreased over the anodic (or cathodic) polarization range, when anionic (or cationic) dyes were added to the water phase, thus indicating the dye adsorption at the interface. The interfacial excess of dye ions was found to increase linearly with the cubic roots of dye concentration and of ionic strength of the water phase. The counterion binding took place at the oil/water interface between anionic (or cationic) dyes and positive (or negative) head groups of surface active agent ions adsorbed at the interface. It was found that the equilibrium constants of binding between anionic dyes and cationic surface active agents at the oil/water interface were of the same order of magnitude as, and a little larger than, those obtained at the water bulk phase.

The electrocapillary adsorption of surface active agents at oil/water interfaces

The adsorption of surface active agents, and the builder effect, were investigated by using the electro-capillarity at oil/water interfaces. The oil phase was the solution of tetrabutylammonium chloride in methylisobutylketone, and the aqueous phase contained the surface active agent in addition to the inorganic electrolyte. The interfacial tension decreased over the anodic (or cathodic) polarization range, when an anionic (or cationic) surface active agent was added to the aqueous phase, thus indicating the adsorption of this material at the interface. It was found that, in agreement with the theoretical deduction, linear relations held between the interfacial excess of surface active agent and the cubic root of its concentration, as well as of ionic strength, of the aqueous phase. For alkylsulphate anions of various chain lengths, the free energy of desorption was estimated from the above linear relation to be ca. 750 cal mole−1 for each methylene group.

The Adsorption of Surface Active Agents at Oil-Water Interfaces Considered from the Electrocapillarity

The adsorbability of surface active agents at oil-water interfaces and the influence of various norganic electrolyte on it were investigated by making electrocapillary curves. The oil phase was the solution of tetrabutylammonium chloride in methylisobutylketone, and the aqueous phase contained anionic, cationic or nonionic surface active agents in addition to the inorganic electrolyte. It was found that the interfacial tension decreased over the anodic or cathodic polarization range, depending upon whether the surface active agent was anionic or cationic. This decrease was strongly influenced by the kind and concentration of the electolyte in the aqueous phase.Linear relations held between the interfacial excess of the surface active agent and the cubic root of surface active agent concentration of the aqueous phase, as well as between the former and the cubic root of the ionic strength of the aqueous phase. These were in good agreement with Davies' equation derived theoretically. For alkylsulphate ions of various chain length, the free energy of desorption was calculated to be ca. 750 cal mol-1 for each -CH2- group.