Defect Engineering and Anisotropic Modulation of Ionic Transport in Perovskite Solid Electrolyte LixLa(1−x)/3NbO3

Solid electrolytes, such as perovskite Li_3xLa_2/1−xTiO₃, Li_xLa_(1−x)/3NbO₃ and garnet Li₇La₃Zr₂O₁₂ ceramic oxides, have attracted extensive attention in lithium-ion battery research due to their good chemical stability and the improvability of their ionic conductivity with great potential in solid electrolyte battery applications. These solid oxides eliminate safety issues and cycling instability, which are common challenges in the current commercial lithium-ion batteries based on organic liquid electrolytes. However, in practical applications, structural disorders such as point defects and grain boundaries play a dominating role in the ionic transport of these solid electrolytes, where defect engineering to tailor or improve the ionic conductive property is still seldom reported. Here, we demonstrate a defect engineering approach to alter the ionic conductive channels in Li_xLa_(1−x)/3NbO₃ (x = 0.1~0.13) electrolytes based on the rearrangements of La sites through a quenching process. The changes in the occupancy and interstitial defects of La ions lead to anisotropic modulation of ionic conductivity with the increase in quenching temperatures. Our trial in this work on the defect engineering of quenched electrolytes will offer opportunities to optimize ionic conductivity and benefit the solid electrolyte battery applications.     

Resveratrol,EGCG and Vitamins Modulate Activated T Lymphocytes

Vitamins and bioactives, which are constituents of the food chain, modulate T lymphocyte proliferation and differentiation, antibody production, and prevent inflammation and autoimmunity. We investigated the effects of vitamins (vitamin A (VA), D (VD), E (VE)) and bioactives (i.e., resveratrol (Res), epigallocatechin-3-gallate (EGCG)) on the adaptive immune response, as well as their synergistic or antagonistic interactions. Freshly isolated T lymphocytes from healthy individuals were activated with anti-CD3/CD28 antibodies for 4–5 days in the presence of bioactives and were analyzed by cytofluorometry. Interleukins, cytokines, and chemokines were measured by multiple ELISA. Gene expression was measured by quantitative RT-PCR. Res and EGCG increased CD4 surface intensity. EGCG led to an increased proportion of CD8⁺ lymphocytes. Anti-CD3/CD28 activation induced exuberant secretion of interleukins and cytokines by T lymphocyte subsets. VD strongly enhanced T_h2 cytokines (e.g., IL-5, IL-13), whereas Res and EGCG favored secretion of T_h1 cytokines (e.g., IL-2, INF-γ). Res and VD mutually influenced cytokine production, but VD dominated the cytokine secretion pattern. The substances changed gene expression of interleukins and cytokines in a similar way as they did secretion. Collectively, VD strongly modulated cytokine and interleukin production and favored T_h2 functions. Resveratrol and EGCG promoted the T_h1 response. VA and VE had only a marginal effect, but they altered both T_h1 and T_h2 response. In vivo, bioactives might therefore interact with vitamins and support the outcome and extent of the adaptive immune response.     

Formulation of Environmentally Safe Graffiti Remover Containing Esterified Plant Oils and Sugar Surfactant

The removal of graffiti or over-painting requires special attention in order to not induce the surface destruction but to also address all of the important eco-compatibility concerns. Because of the necessity to avoid the use of volatile and toxic petroleum-based solvents that are common in cleaning formulations, much attention has recently been paid to the design of a variety of sustainable formulations that are based on biodegradable raw materials. In the present contribution we propose a new approach to graffiti cleaning formulations that are composed of newly synthesized green solvents such as esterified plant oils, i.e., rapeseed oil (RO), sunflower oil (SO), or used cooking oil (UCO), ethyl lactate (EL), and alkylpolyglucosides (APGs) as surfactants. Oil PEG-8 ester solvents were synthesized through the direct esterification/transesterification of these oils using monobutyltin(IV) tris(2-ethylhexanoate) and titanium(IV) butoxide catalysts under mild process conditions. The most efficient formulations, determined by optimization through the response surface methodology (RSM) was more effective in comparison to the reference solvents such as the so-called Nitro solvent (denoting a mixture of toluene and acetone) and petroleum ether. Additionally, the optimal product was found to be effective in removing graffiti from glass, metal, or sandstone surfaces under open-field conditions in the city of Wrocław. The performed studies could be an invaluable tool for developing future green formulations for graffiti removal.     

枝晶簇四方相钛酸钡的制备及其电场响应性能的研究

为了提高BaTiO3粒子在含水复合弹性体中的电场响应能力,本文采用简单的水热合成法,在不引入任何表面活性剂的情况下,仅通过对反应温度和溶液pH值的调控获得了新颖形貌的钛酸钡粒子。通过借助X射线衍射(XRD)、拉曼光谱(Raman)、扫描电子显微镜(SEM)及接触角(Contact Angle)测量等手段对粒子的微观结构和表面特性进行表征发现:该粒子为高纯四方相枝晶簇结构,具有良好的亲水性,而且在含水复合弹性体中对电场具有优良的响应能力。     

Ultrafast Excited State Dynamics of t~rans-4-Aminoazobenzene Studied by Femtosecond Transient Absorption Spectroscopy

The ultrafast excited state dynamics of trans-4-aminoazobenzene （trans-4-AAB） in ethanol was investigated by femtosecond transient absorption spectroscopy. After being excited to the S2 state by 400 nm, trans-4-AAB decays from the S2 state to the hot S1 state by internal conversion with time constant of -70 fs. The photoisomerization through inversion mechanism on the S1 potential energy surface and the internal conversion from the S1 state to the hot So state are observed, respectively. The average timescale of these two decay pathways is -0.7 ps. And the vibrational cooling of the hot So state of cis- and trans-4- AAB occur with time constants of -4 and N13 ps, respectively. Furthermore, the ultrafast intersystem crossing process are also observed. The timescale of intersystem crossing from the S2 state to the T4 state is about 480 ps while from the S1 state to the T2 state is -180 ps.     

Photocrosslinking of copolymers of vinyloxyethyl methacrylate–styrene initiated by sulfonium salts. I. Transient species formed on photolysis of sulfonium salt

Benzyl cation was detected by transient absorption spectroscopy with a spectroscopic multichannel analyzer on pulse excitation (fourth harmonic of Nd:YAG laser, 266 nm; 10 ns fwhm) of benzyl(4-hydroxyphenyl) methylsulfonium hexafluoroantimonate(BSS) in 1,2-dichloroethane (EDC). The benzyl cation was long-lived (lifetime, 59 ms) at room temperature and quenched by a vinyl ether compound. The formation of the benzyl cation as active species on photolysis of BSS is in contrast to the formation of Brønsted acids in other sulfonium salts so far reported. © 1992 John Wiley & Sons, Inc.     

以离子水合能解释离子选择电极响应机理

用相继切换不同浓度I^-试液的活度阶梯法研究了碘化银基离子选择电极（I^--ISE）的瞬时响应。随电位变化的离子水合自由能△Gh(I^-）显示出|△Gh（I^-）|越小，正活度阶民位跃迁越快而负活度阶梯电位变化越慢。将－△Gh(I^-）看作I（H2O）n^-与I^--ISE表面反应的活化能解释了这个现象。比起传统电位法，活度阶梯法的主要优点是ISEs响应非常快并且更灵敏，有可能实现小体积试液的快速分析。     

A new dodecylsulfate-selective supported liquid membrane electrode based on its N-cetylpyridinium ion-pair

A supported liquid and a poly(vinyl chloride) (PVC)-based membrane selective for dodecylsulfate (DS⁻) ion are described. The active element is a membrane containing a dissolved ion association complex of DS⁻ with cetylpyridinium (CP⁺) cation. The supported liquid membrane electrode (acetophenone as solvent) showed a Nernstian response towards the DS⁻ anion over the concentration range of sodium dodecylsulfate (SDS) from 8.3×10⁻³ to 1.0×10⁻⁶ mol dm⁻³ at 25 °C. The proposed electrode also showed a super-Nernstian potential response (108±2 mV decade⁻¹) at low concentrations (1.0×10⁻⁹ to 1.0×10⁻⁶ mol dm⁻³). Moreover, this electrode showed good selectivity and precision (R.S.D.?2.0%), and was usable within the pH range 4.0-6.8. The proposed electrode revealed a lower limit of detection of 6.3×10⁻⁷ mol dm⁻³ and improved selectivity in comparison with the some previously reported DS⁻ ion selective electrodes. The isothermal temperature coefficient of this electrode amounted to −0.001 V °C⁻¹. The liquid membrane electrode may find application in the direct determination of SDS by the standard addition method at pH 5.0, and in the physicochemical studies of surfactant solutions.     

Determination of Pesticide Residues in Fruit and Vegetables by High-Performance Liquid Chromatography–Tandem Mass Spectrometry with Multivariate Response Surface Methodology

Multivariate response surface methodology optimization using Placket–Burman and Box–Behnken designs were respectively used for the screening and optimization of significant factors for liquid chromatography–tandem mass spectrometry. Consequently, the optimized instrument successfully improved the sample preparation protocol and the method was validated. However, modified QuEChERS dispersive solid phase extraction coupled with ionic liquid-based dispersive liquid–liquid microextraction were used for the determination of multi-pesticide residues in fruit and vegetable samples. The analysed samples were jackfruit, strawberries, cucumber, pears, and carrots. The resulting linearity range (5–400?µg/kg) and regression coefficient (>0.99) results were satisfactory. The 94.2 and 95.8% accuracy (89–138%) and precision (0–25%) results were satisfactory and within the recommended ranges (≤20%) and (70–120%), respectively. The limits of detection (0.01–0.54?µg/kg) and quantitation (0.03–1.79?µg/kg) were excellent. The matrix effects (≤?87%) for all analysed samples were not significant. The estimated measurement uncertainties (≤27%) were within the acceptable range (≤50%). Justifiably, the response surface methodology optimized instrument and sample treatment techniques were reliable and convenient for multi-pesticide residue determination in various fruits and vegetables.     

Optimization of cadmium adsorption from aqueous solutions by functionalized graphene and the reversible magnetic recovery of the adsorbent using response surface methodology

Novel functionalized graphene adsorbent was prepared and characterized using different techniques. The prepared adsorbent was applied for the removal of cadmium ions from aqueous solution. A response surface methodology was used to evaluate the simple and combined effects of the various parameters, including adsorbent dosage, pH, and initial concentration. Under the optimal conditions, the cadmium removal performance of 70% was achieved. A good agreement between experimental and predicted data in this study was observed. The experimental results revealed of cadmium adsorption with high linearity follow Langmuir isotherm model with maximum adsorption capacity of 502 mg g^?1, and the adsorption data fitted well into pseudo‐second order model. Thermodynamic studies showed that adsorption process has exothermic and spontaneous nature. The recommended optimum conditions are: cadmium concentration of 970 mg L^?1, adsorbent dosage of 1 g L^?1, pH of 6.18, and T = 25 °C. The magnetic recovery of the adsorbent was performed using a magnetic surfactant to form a noncovalent magnetic functionalized graphene. After magnetic recovery of the adsorbent both components (adsorbent and magnetic surfactant) were recycled by tuning the surface charges through changing the pH of the solution. Desorption behavior studied using HNO₃ solution indicated that the adsorbent had the potential for reusability.