[5‐(p‐alkoxy)phenyl‐10, 15, 20‐tri‐phenyl] porphyrin and their rare earth complex liquid crystalline

Three series of porphyrin liquid crystalline compounds, [5‐(p‐alkoxy)phenyl‐10, 15, 20‐tri‐phenyl] porphyrin and their rare earth complexes (Tb (III), Dy (III), Er (III), Yb (III)), with a hexagonal columnar discotic columnar(Col_h) phase have been synthesized. These compounds were characterized by elemental analysis, molar conductances, UV‐visible spectra, infrared spectra, luminescence spectra, and cyclic voltammetry. These compounds exhibit more than one mesophases, which transition points of temperature change from ?33.6 to 16.0 °C, and transition points of temperature for isotropic liquid also increase from 4.9 to 38.2 °C, with increasing chain length. Their surface photovoltage (SPV) response have also been investigated by the means of surface photovoltage spectroscopy (SPS) and field‐induced surface photovoltage spectroscopy (EFISPS). It was found that their SPV bands are analogous with the UV‐visible absorption spectra and derived from the same transition. Copyright © 2007 John Wiley & Sons, Ltd.     

Fabrication and electrochemistry study of multi-thiol coronary molecule monolayers

Single-component monolayer of novel multi-thiol coronary molecule and two-component mixed monolayer composed of coronary molecule and n-alkanethiol on gold substrates are described. The assembly of monolayers is characterized by ellipsometry, infrared spectroscopy and X-ray photoelectron spectroscope. The electrochemical properties of the single- and two-component monolayers are evaluated by cyclic voltammetry and electrochemical impedance spectroscopy experiments. Coronary molecule with multi-thiol groups has the ability to form stable monolayer via the interaction of mercapto groups and Au surface. Electrochemical impedance measurements indicate that 89.9% of the gold surface is blocked by the coronary molecule, which is attributed to the special spatial structure of the coronary molecule. The uncovered site on gold surface in coronary molecule monolayer could be occupied by the second suitable molecule. The mixed monolayer prepared by stepwise assembly of coronary molecule and n-alkanethiol has complete compact packing and few defects.     

Repeatedly using the decomposition product of struvite by ultrasound stripping to remove ammonia nitrogen from landfill leachate

In this study, the decomposition of struvite by ultrasound stripping and the recycle use of the decomposition product for the treatment of landfill leachate were investigated. The results indicated that when the decomposition of struvite by ultrasound stripping was performed at 55 °C for 40 min, the ammonium in the struvite could be almost completely eliminated from the solution system. The characterization analysis showed that magnesium phosphate and the dissolved phosphate ions were the main active derivatives. Approximately 90% of the total ammonia nitrogen (TAN) in landfill leachate can be removed by reusing the decomposition product at pH 9 for 60 min. Repeated use of the struvite decomposition product revealed that the TAN removal efficiency decreased with an increase in the number of recycles. However, in the process of multiple recycling, about 90% of TAN removal could be maintained by supplementing a certain amount of the preformed struvite to the solution for every recycle. An economic analysis demonstrated that 79.3% of the treatment cost could be saved by the proposed process compared to the non-recycling process.     

Ultrasonically assisted synthesis of barium stannate incorporated graphitic carbon nitride nanocomposite and its analytical performance in electrochemical sensing of 4-nitrophenol

We describe the ultrasonic assisted preparation of barium stannate-graphitic carbon nitride nanocomposite (BSO-gCN) by a simple method and its application in electrochemical detection of 4-nitrophenol via electro-oxidation. A bath type ultrasonic cleaner with ultrasonic power and ultrasonic frequency of 100 W and 50 Hz, respectively, was used for the synthesis of BSO-gCN nanocomposite material. The prepared BSO-gCN nanocomposite was characterized by employing several spectroscopic and microscopic techniques such as X-ray diffraction, X-ray photoelectron spectroscopy, fourier transform infra-red, field emission scanning electron microscopy, and high resolution transmission electron microscopy, to unravel the structural and electronic features of the prepared nanocomposite. The BSO-gCN was drop-casted on a pre-treated glassy carbon electrode (GCE), and their sensor electrode was utilized for electrochemical sensing of 4-nitrophenol (4-NP). The BSO-gCN modified GCE exhibited better electrochemical sensing behavior than the bare GCE and other investigated electrodes. The electroanalytical parameters such as charge transfer coefficient (α = 0.5), the rate constant for electron transfer (k_s = 1.16 s⁻¹) and number of electron transferred were calculated. Linear sweep voltammetry (LSV) exhibited increase in peak current linearly with 4-NP concentration in the range between 1.6 and 50 μM. The lowest detection limit (LoD) was calculated to be 1 μM and sensitivity of 0.81 μA μM⁻¹ cm⁻²_. A 100-fold excess of various ions, such as Ca²⁺, Na⁺, K⁺, Cl⁻, I⁻, CO₃²⁻, NO₃, NH₄⁺ and SO₄²⁻ did not able to interfere with the determination of 4-NP and high sensitivity for detecting 4-NP in real samples was achieved. This newly developed BSO-gCN could be a potential candidate for electrochemical sensor applications.     

壳聚糖/乙炔黑修饰电极上萘酚异构体的电化学行为及同时测定

制备了壳聚糖/乙炔黑复合修饰电极(CS-AB/GCE),采用SEM和交流阻抗法对其进行表征。并利用循环伏安法(CV)研究了萘酚异构体(α-N和β-N)在该修饰电极上的电化学行为,对实验条件进行了优化。结果表明,在p H 7.0的PBS缓冲液中,α-N和β-N在该修饰电极上均出现一不可逆氧化峰,且在20~200m V/s范围内,其峰电流与扫速呈线性关系,表明电极过程是受吸附控制的不可逆过程。计算了电极过程的部分动力学参数,优化了差分脉冲伏安法(DPV)的实验参数,并对α-N和β-N进行同时测定,发现二者的微分氧化峰电流值与其浓度在2.5×10-6~1.0×10-4mol/L范围内呈良好的线性关系(rα-N=0.996;rβ-N=0.998)。α-N和β-N的检出限(S/N=3)分别为3.4×10-7mol/L和2.4×10-7mol/L。采用该法对实际水样进行检测,得到α-N和β-N的加标回收率分别为96.7%~105.1%和98.8%~103.9%。     

两种二茂铁甲基二氧大环多胺的电化学性质

利用循环伏安法对我们新设计合成的两种二茂铁甲基二氧大环多胺化合物——１－二茂铁甲基－１,４,８,１１－四氮杂环十三烷－５,７－二酮（简称ＦｃＣＨ２Ｌ１）和１－二茂铁甲基－１,４,７,１１,１４－五氮杂环十六烷－３,１５－二酮（简称ＦｃＣＨ２Ｌ２）——的电化学性质进行了研究,包括酸碱度的影响以及它们对Ｚｎ２＋,Ｃａ２＋,Ｃｄ２＋,Ｃｕ２＋,Ｎｉ２＋,Ｃｏ２＋等金属离子的电化学响应情况．在乙醇和水的混合溶剂体系中化合物ＦｃＣＨ２Ｌ１对Ｎｉ２＋具有选择性络合,而化合物ＦｃＣＨ２Ｌ２对高氧化态的Ｎｉ３＋有稳定作用     

不同退火条件对多孔阳极氧化铝热释光的影响

本文采用两步阳极氧化法在0.5mol/L的草酸溶液中制备了多孔且排列有序的多孔阳极氧化铝（PAA）薄膜,并对薄膜进行不同条件的退火后处理,通过对PAA薄膜的热释光（TL）特性表征和机理分析,研究了基底及后处理中退火时间、退火温度及退火气氛等条件对其热释光特性的影响．结果表明,相同辐照剂量下,去除铝基底的双通PAA薄膜,接触辐射面积大,吸收辐射能量多,表现出更强的热释光响应;相同退火环境中,经γ辐照后的PAA薄膜的TL特性随退火处理的时间延长而增强;退火时间均控制为4h时,薄膜的TL强度随退火温度的升高也明显增强,在空气中经600℃退火的PAA薄膜显示出最大的TL强度;并且PAA薄膜在空气中退火后的TL发光强度明显高于在真空中退火后的强度．     

多孔阳极氧化铝薄膜光学常数的确定

根据多孔阳极氧化铝(AAO)薄膜的实验透射谱(200—2500nm)，采用极值包络线算法确定其光学常数，并由此较精确地计算出AAO薄膜样品在该波段的光学常数.结果表明，多孔氧化铝薄膜表现出直接带隙(能隙约4．5eV)半导体的光学特性，且其光学常数与制样中的重要工艺参数阳极氧化电压有显著的相关性，即随阳极氧化电压的增加，AAO薄膜的厚度、折射率和光学能隙变大，消光系数减小．同时，计算得到的薄膜厚度与实测值相吻合，则说明计算结果和实验值是自洽的. 关键词： 薄膜光学 光学常数 多孔阳极氧化铝 阳极氧化电压     

吸附溶出伏安法测定毗喳酮的研究

本文报道了用吸附溶出伏安法测定毗喳酮.以悬汞电极为工作电极，在Na}B,O,-NaOH介质(pH=10)中，毗喳酮产生一尖锐的吸附还原峰,E，二一1. 29V (vs. SCE )，峰电流与毗喳酮浓度在2. 0 X 10-'-8. 0 X 10-smol " L-’范围内呈良好的线性关系.检测限为2. 0 X 10-0mol " L-'(富集90s).本文对毗喳酮在悬汞电极上的电化学行为进行了探讨，对测定毗喳酮的最佳条件进行了详细的选择，利用本法测定了片剂中毗喳酮含量，结果满意.     

离子液体中电沉积制备钴纳米线阵列

Porous anodic alumina (PAA) was used as a template to prepare Co nanowires array from 1-ethyl-3-methylimidazolium chloride ionic liquid by direct current method. The surface morphology of porous anodic alumina template was observed by field emission-scanning tunneling microscopy (FE-SEM) before and after the electrodeposition of Co nanowires. The electrodeposition of Co nanowires was characterized by transmission electron microscopy (TEM) and X-ray powder diffraction (XRD). TEM results indicate that the Co nanowire surface is coarse and porous when aqueous solution was used as electrolyte， and the Co nanowire deposited from the ionic liquid is uniform and smooth. XRD results show that the electrodeposition of Co is a mixture of crystal and microcrystal phase.