Preparation of Polyaniline/Au0 Nanocomposites Modified Electrode and Application for Hydrazine Detection

The PANI/Au₀ nanocomposite films were successfully prepared on glassy carbon electrode (GCE) using a simple alternate adsorption of water soluble polyaniline (PANI) and . The growth of the films was monitored by UV? Vis spectroscopy and cyclic voltammetry. was in‐situ reduced in the film due to the redox interaction between PANI and , without extra reductant. The ultrafine Au nanoparticles with the size of 2–4 nm were observed by transmission electron spectroscopy. The existence of zero‐valence Au nanocrystals (Au₀) was confirmed by X‐ray photoelectron spectroscopy, X‐ray Diffraction and FTIR. PANI in the nano‐structured PANI/Au₀ composite films displayed a good redox activity in neutral pH solution. The as‐obtained PANI/Au₀/GCE presents an excellent electrocatalytic activity to hydrazine oxidation, and the mechanism of hydrazine oxidation was studied. The calibration curve on (PANI/Au₀)₅/GCE was obtained in the concentration range of 0.01–6 mM with the detection limit of 1 µM (S/N>3). The modified electrode has a great potential for hydrazine sensor application due to its ease of fabrication, good reproducibility and high stability.     

Preparation of Fe−Co−LDH/MXene modified electrode for sensitive determination of arsenic (III) in aquatic system

3-dimensional (3D) Fe−Co−LDH/MXene composite was synthesized by in-situ synthesis and assembly of Fe−Co−LDH rod around MXene under hydrothermal condition. Due to the unique 3D configuration and good conductivity, the obtained Fe−Co−LDH/MXene modified glassy carbon electrode (Fe−Co−LDH/MXene/GCE) showed excellent electrochemical activity for As(III) detection. Via square-wave anodic stripping voltammetry, the response current on Fe−Co−LDH/MXene/GCE had good linear relationship with As(III) concentrations (1∼1000 ppt) with superior sensitivity (0.22 μA ppt⁻¹ cm⁻²) and low detection limit (0.9 ppt). The mechanism of As(III) adsorption was demonstrated. The electrode showed excellent anti-interference ability. Real water sample analysis demonstrated the Fe−Co−LDH/MXene/GCE was deployable in aqua-system.     

In situ growth of LiMn2O4 on graphene oxide for efficient lithium extraction by capacitive deionization

Journal of Solid State Electrochemistry - Selective extraction of lithium from brines has attracted significant interests with the rapid development of lithium battery industry. LiMn2O4 (LMO) is a...     

Large-scale fabrication of two-dimensional spider-web-like gelatin nano-nets via electro-netting

For the first time, two-dimensional (2D) gelatin nano-nets are fabricated by regulating the solution properties and several process parameters during electrospinning/electro-netting. The spider-web-like nano-nets that comprise interlinked one-dimensional (1D) ultrathin nanowires (10-35 nm) are stacked layer-by-layer and widely distributed in the three-dimensional (3D) porous membranes. The final morphology of the gelatin nano-nets, including nanowire diameter, area density and pore-width of the nano-nets, is highly dependent on the solution concentration, salt concentration, kinds of solvents, applied voltage, ambient temperature and relative humidity (RH). The occurrence of rapid phase separation on the splitting-film and the formation of hydrogen bond among gelatin molecules during electro-netting are proposed as the possible mechanisms for the formation of these spider-web-like nano-nets.     

Amino‐Containing Ultrafine Organosilica‐Nanoparticle‐Modified Au Electrode for the Determination of Cu(II) Ions

Using 3‐Aminopropyltriethoxysilane(APTES) as a single silica source, an amino‐rich ultrafine organosilica‐nanoparticle‐modified Au electrode was fabricated, following the formation of (3‐mercaptopropyl)‐trimethoxysilane (MPTS) monolayer on Au surface (MPTS/Au). With cetyltrimethylammonium bromide as an additive, APTES‐based gel particles on the electrode have a narrow particle size distribution of 4–7 nm and “crystal‐like” structure. AFM and electrochemical characterization confirmed the successful grafting of APTES nanoparticles on MPTS/Au. The APTES/MPTS/Au electrode is highly sensitive for the detection of copper(II) ions with a detection limit as low as 1.6×10^?12 mol L^?1 (S/N>3) by square wave voltammetry. The current is linear to copper(II) concentration between 1.6×10^?12 and 6.25×10^?10 mol L^?1.     

Preparation of Au Nanoparticles Decorated Polyaniline Nanotube and Its Catalytic Oxidation to Ascorbic Acid

With sulfonated electrospun polystyrene fiber as a template, uniform polyaniline(PANI) nanotubes were fabricated via polymerization of aniline followed by template removal. Au nanoparticles(Au_nano) were decorated on the PANI nanotube successfully via auto-reduction of HAuCl₄ on the PANI nanotube. The morphology of the nanotubes was characterized by means of scanning electron microscopy(SEM) and transmittance electron microscopy(TEM). By varying precursor concentration and incubation time, Au_nano-PANI with different size of Au_nano was obtained conveniently. Glassy carbon electrode modified with the Au_nano decorated PANI nanotubes (Au_nano-PANI/GCE) was prepared and used seccessfully for the catalytic oxidation of ascorbic acid(AA). The results of differential pulse voltammetry indicate that there is a good linear relationship between the peak currents and the concentrations of AA in the range of 5-3000 μmol/L, with the limit of detection of 1 μmol/L(S/N>3). There is no mutual interference between AA and dopamine. The electrode has been successfully applied in the detection of AA in vitamin C tablet sample.     

分子筛在真空低温下水汽吸附脱附性实验研究

空间遥感仪器红外通道的信号衰减,入轨初期的主要原因是由于材料释放的水汽在低温光学窗口表面沉积,导致红外透射率降低所致。主动吸附是控制低温沉积污染的措施之一。分子筛对包括水汽在内的多种污染物具有良好的吸附作用,可以作为控制污染物的吸附材料。目前对于分子筛吸附特性的研究集中在常压环境。通过试验测试了13x型分子筛在高真空低温环境下,对水汽的吸附特性。     

A Zn2GeO4-ethylenediamine hybrid nanoribbon membrane as a recyclable adsorbent for the highly efficient removal of heavy metals from contaminated water

Zn(2)GeO(4)-ethylenediamine (ZGO-EDA) hybrid nanoribbons have been synthesized on a large-scale and directly assembled to membranes, which exhibit an excellent recyclability, high selectivity, and good thermal stability for highly efficient removal of heavy metal ions, i.e., Pb(2+), Cd(2+), Co(2+), and Cu(2+), from contaminated water.     

STUDY ON MULTICHANNEL PASSIVE MILLIMETER-WAVE RADIOMETER IMAGING AND SUPERRESOLUTION

Multichannel passive millimeter-wave (PMMW) imaging systems have advantage in operating speed, however traditional data processing methods for single channel systems are not applicable for such kind of system. This paper describes an 8-mm multichannel PMMW imaging system, points out the specific problems encountered in multichannel systems, and proposes an experimental multichannel calibration approach in microwave unreflected chamber. In the last superresolution algorithms considering imaging process and some related issues are discussed. The imaging result shows the proposed processing approaches are effective.     

黏弹性对介观液珠聚并的影响——液珠-细丝-液珠聚并现象及其分析

在四辊流变仪中,黏弹性高分子介观液滴经反复拉伸和松弛形成了有细丝相连的两个黏弹液珠,研究了黏弹液珠的聚并过程,依形状叫做BSB(bead-string-bead,液珠-细丝-液珠)聚并.BSB现象与常见的通过滴间液膜破裂实现的液滴聚并过程大不相同.根据界面上的Laplace力、液珠移动时的黏性阻力和细丝中黏弹应力之间的平衡,推导出一个力学模型来描述BSB现象,理论分析与实验结果相符较好.细丝直径的变化和稳定性由过程参数和物料参数共同决定,尤其是液滴的黏弹性有较大影响.这一效应对多相高分子与复杂流体加工过程的基础理解富有启发.