Maskless Preparation of Spatially-Resolved Plasmonic Nanoparticles on Polydimethylsiloxane via In Situ Fluoride-Assisted Synthesis

Here, a fluoride-assisted route for the controlled in-situ synthesis of metal nanoparticles (NPs) (i.e., AgNPs, AuNPs) on polydimethylsiloxane (PDMS) is reported. The size and coverage of the NPs on the PDMS surface are modulated with time and over space during the synthetic process, leveraging the improved yield (10×) and faster kinetics (100×) of NP formation in the presence of F⁻ ions, compared to fluoride-free approaches. This enables the maskless preparation of both linear and step gradients and patterns of NPs in 1D and 2D on the PDMS surface. As an application in flexible plasmonics/photonics, continuous and step-wise spatial modulations of the plasmonic features of PDMS slabs with 1D and 2D AgNP gradients on the surface are demonstrated. An excellent spatially resolved tuning of key optical parameters, namely, optical density from zero to 5 and extinction ratio up to 100 dB, is achieved with AgNP gradients prepared in AgF solution for 12 minutes; the performance are comparable to those of commercial dielectric/interference filters. When used as a rejection filter in optical fluorescence microscopy, the AgNP-PDMS slabs are able to reject the excitation laser at 405 nm and retain the green fluorescence of microbeads (100 µm) used as test cases.     

The Structure,Preparation, Characterization,and Intercalation Mechanism of Layered Hydroxides Intercalated with Guest Anions

Since the intercalation of anions into layered hydroxides (LHs) has a great impact not only on their nucleation and growth but also on their structure, composition, and size, the intercalation chemistry of LHs has aroused the strong interest of researchers. However, the progress in the fundamental understanding of LHs intercalated with guest anions have not been paralleled by a concomitant development of the preparation and performance improvement of such materials. Considering the guidance of a timely in-depth review for scientists in this area, a systematic introduction about the development that is made on the above-mentioned issues is highly needed but yet missing so far. Herein, recent advances in understanding the chemical composition and structure of LHs intercalated with guest anions are systematically summarized. Meanwhile, typical and emerging bottom-up synthesis methods of LHs intercalated with anions are reviewed, and the potential impact of external reaction parameters on the intercalation of anions into LHs are discussed . Besides, different analytical characterization techniques employed in the examination of guest anion-intercalated LHs are deliberated upon. Finally, although progress is slow in exploring the intercalation mechanism, as many examples as possible are included in this review and inferred the possible intercalation mechanism.     

Study of the factors determining the mobility of ions in the polypyrrole films doped with aromatic sulfonate anions

The electrochemical redox behavior of the polypyrrole (PPy) films doped with benzenesulfonate (BS), p-toluenesulfonate (pTS) and naphtalene-1,5-disulfonate (NDS) was investigated by cyclic voltammetry, the chemical composition of the films was determined by XDS, the surface morphology was characterized by AFM, and the interactions between pyrrole oligomers and the anions were modeled with quantum chemical methods. It is the first detailed comparative study of the properties of these interesting systems with two complementing interactions (electrostatic and aromatic stacking). It was shown than these relatively similar aromatic sulfonate anions have rather different behavior in PPy films. The results showed that the redoxactivity of polypyrrole films doped with sulfonate ions increases in the sequence pTS < BS < NDS. The comparison of voltammograms measured in the presence of different anions with PPy films synthesized in the same solution show that the PPy/pTS films have the most densely packed and the PPy/NDS films the least densely packed structure of the three. The mobility of ions in these films is mainly determined by the packing of the films, which in turn partly depends on the interactions between the dopant-anion and polymer chains.     

Hydrogen‐Terminated Si Nanowires as Label‐Free Colorimetric Sensors in the Ultrasensitive and Highly Selective Detection of Fluoride Anions in Pure Water Phase

The detection of anions in pure water phase with colorimetric sensor is a long standing challenge. As one of the most important anions, F^– is associated with nerve gases and the refinement of uranium for nuclear weapons. However, limited by its anions nature, few of the reported colorimetric sensors can successfully applied to detect F^–1 in pure water phase. This work designs a colorimetric sensor for F^–1 pure water phase detection by taking the advantages of the strong specific binding between F and Si, as well as the color‐changing property of H‐terminated Si nanowires (SiNWs). The sensor demonstrates ultra‐sensitivity, high selectivity, and good stability. The results reveal particular interest for the development of new type aqueous phase anions sensors with SiNWs.     

Reductive ethylation in ethereal solvents

Organic compounds, in particular anthracene and naphthalene, and two coals have been reductively ethylated in tetrahydrofuran (THF) and diglyme using alkali metals to form anions and ethyl iodide to produce ethylates. Product distributions were sensitive to experimental conditions. The rate of anion formation was controlled by their rate of desorption, probably as contact ion pairs, from the alkali metal surface. The enthalpy of formation of a solvated contact ion pair was ≈500 kJ mole^?1 mainly due to dipole-solvent interaction. 18-crown-6 ether was used to diagnose that, when treated with potassium in THF, anthracepe gave solvated contact ion pairs and probably di-anions whose reactions were characterized by the formation of ethyldihydroanthracene. Naphthalene under identical conditions gave loosely solvated mono-anions which reacted by electron transfer to give diethyldihydronaphthalene. With other alkali metals anthracene and naphthalene gave similar product distributions. The behaviour of other polynuclear aromatic hydrocarbons and of two coals was classified in the same way. It is suggested that when coals are readily solubilized by reductive alkylation mono-alkyldihydro products will predominate.     

负离子远红外功能整理剂及其在纺织业中的应用

负离子功能整理剂及用于家居的整理织物，会持续发生负离子，中和空气中正离子，起到净化空气、促进血液循环、抗菌除臭、远红外蓄热等作用．探讨了负离子远红外整理剂的制备及在纺织上的应用．     

离子色谱法测定大白口蘑、绒柄牛肝菌和皱盖疣柄牛肝菌中阴离子含量

采用超声波辅助提取-离子色谱法测定大白口蘑、绒柄牛肝菌和皱盖疣柄牛肝菌3种食用菌中F－、Cl－、NO2、NO3、PO4五种阴离子含量。结果表明：3种样品中,离子含量均表现为NO3＞PO4＞F－＞Cl－,且NO2均未检测出;同一种离子在不同样品中的含量各有差异。本研究为食用菌中阴离子含量的监测提供参考,同时对其他物种的安全监督具有指导意义。     

DFT study of coinage metal-hydrogen associations as hydrogen storage materials stabilized by weakly coordinating anions

Density Functional Theory (DFT) calculations were employed to study a series of coinage metal-hydrogen associations formulated as [M(Η₂)_n][A] (M = Cu^I, Ag^I or Au^I, n = 1–5). The [M(Η₂)_n][A] salts utilize both their anions and cations for H₂ storage. The [M(Η₂)_n]⁺ cations could be stabilized in the solid state by voluminous counter-anions, i.e. the [(H₃B) (BH₂NH₂)₅(NH₂)]^-, [B(CNBH₃)₃]^- and [B₁₂H₁₂]^- anions. The estimated bond dissociation energies (BDEs) of the M···(η²-H₂) bonds are 5–17, 4–11 and 1–26 kcal/mol for the [Cu(Η₂)₄]⁺, [Ag (Η₂)₄]⁺ and [Au (Η₂)₄]⁺ cationic species respectively, while the fifth H₂ molecule is estimated to be very loosely associated to the metal center. Four H₂ molecules could be exploited from the [Cu(Η₂)_n][A] and [Ag (Η₂)_n][A] molecules in addition to the amount of H₂ stored in the anion [A]^-. Among the [M(Η₂)_n][A] salts optimal gravimetric, kinetic and thermodynamic properties and relatively low cost, are predicted for [Cu(Η₂)_n][(H₃B) (BH₂NH₂)₅(NH₂)].     

Tiered Electron Anions in Multiple Voids of LaScSi and Their Applications to Ammonia Synthesis

Electrides—compounds in which electrons localized in interstitial spaces periodically serve as anions—have attracted broad attention for their exotic properties, such as extraordinary electron‐donating ability. In our efforts to expand this small family of phases, LaScSi emerges as a promising candidate. Its electron count is 2e^? f.u.^?1 in excess of that expected from the Zintl concept, while its structure offers interstitial spaces that can accommodate these extra electrons. Herein, this potential is explored through density functional theory (DFT) calculations and property measurements on LaScSi. DFT calculations (validated by heat capacity and electrical transport measurements) reveal electron density peaks at two symmetry‐distinct interstitial sites. Importantly, this electride‐like character is combined with chemical stability in air and water, an advantage for catalysis. Ru‐loaded LaScSi shows outstanding catalytic activity for ammonia synthesis, with a turnover frequency (0.1 s^?1 at 0.1 MPa, 400 °C) an order of magnitude higher than those of oxide‐based Ru catalysts, e.g., Ru/MgO. As with other electrides, LaScSi's ability to reversibly store hydrogen prevents the hydrogen poisoning of Ru surfaces. The better performance of LaScSi, however, hints at the importance of the high concentration (>1.6 × 10²² cm^?3) and tiered nature of its anionic electrons, which offers guidance toward new catalysts.     

影响掺杂聚吡咯(PPy)导电性能的因素

综述了对掺杂聚吡咯的导电能力影响因素的研究成果。主要就溶剂、掺杂离子、合成温度对聚吡咯电导率的影响进行了深入的讨论。通过对各类试验结果和讨论的综合分析 ,以找出其一般性的规律 ,并依据得出的结论提出一些有望改善聚吡咯导电能力的措施