- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Effect of Unsymmetrically Branched Alkyl Chains on the Electrochemical Band Gap and Thermal Stability of the PCDTBT
摘要： This work introduces a modified poly[N-9’-heptadecanyl-2,7-carbazole-alt-5,5-(4’,7’-di-2-thienyl-2’,1’,3’-benzothiadiazole)] (PCDTBT) with the unsymmetrically branched N-alkyl chain, which name as poly[N-9’-(2-hexyldecyl)-2,7-carbazole-alt-5,5-(4’,7’-di-2-thienyl-2’,1’,3’-benzothiadiazole)] (P1). The synthesis of P1 involves dimerization, cyclization, tosylation, N-alkylation, bromination, Stille’s and Suzuki’s coupling reactions. Suitable analysis techniques have used to study the chemical, physical, electrochemical, optical, and thermal properties of P1. The analysis results show that P1 possesses higher HOMO and LUMO energy levels than the previously reported PCDTBT, which have been narrowing the electrochemical band gap down to 1.58 eV. However, the P1 experiences 5% thermal degradation at 280 °C, which is relatively less favourable than the PCDTBT. Hence, the replacement of the symmetrically branched alkyl chains of PCDTBT with unsymmetrically branched alkyl chains results in both improvement and draw-back on the characteristics of the polymer.
关键词： bond energy,Alkylation,cyclic voltammetry,electrochemistry,polymerization
更新于2025-11-19 16:56:35
-
A Label-Free Fluorescent DNA Machine for Sensitive Cyclic Amplification Detection of ATP
摘要： In this study, a target recycled ampli?cation, background signal suppression, label-free ?uorescent, enzyme-free deoxyribonucleic acid (DNA) machine was developed for the detection of adenosine triphosphate (ATP) in human urine. ATP and DNA fuel strands (FS) were found to trigger the operation of the DNA machine and lead to the cyclic multiplexing of ATP and the release of single stranded (SS) DNA. Double-stranded DNA (dsDNA) was formed on graphene oxide (GO) from the combination of SS DNA and complementary strands (CS(cid:48)). These double strands then detached from the surface of the GO and in the process interacted with PicoGreen dye resulting in amplifying ?uorescence intensity. The results revealed that the detection range of the DNA machine is from 100 to 600 nM (R2 = 0.99108) with a limit of detection (LOD) of 127.9 pM. A DNA machine circuit and AND-NOT-AND-OR logic gates were successfully constructed, and the strategy was used to detect ATP in human urine. With the advantage of target recycling ampli?cation and GO suppressing background signal without ?uorescent label and enzyme, this developed strategy has great potential for sensitive detection of different proteins and small molecules.
关键词： cyclic ampli?cation,ATP detection,DNA machine,label-free ?uorescence,graphene oxide,logic gate
更新于2025-11-19 16:46:39
-
CePd‐Nanoparticles‐Incorporated Carbon Nanofibers as Efficient Counter Electrode for DSSCs
摘要： In this study, the cerium-palladium (CePd) incorporated carbon nanofibers (CNFs) were manufactured by low-cost and versatile electrospinning technique and successfully applied as a counter electrode to fabricate the dye-sensitized solar cells (DSSCs). The utilized physiochemical techniques, X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscope (FESEM), and transmission electron microscope (TEM) confirmed the formation of carbon nanofibers (CNFs) incorporated by Ce and Pd nanoparticles. CePd incorporated CNFs were preliminary presented good electrocatalytic activity towards the iodide redox couple, as investigated by cyclic voltammetry. The DSSC fabricated using CePd incorporated CNFs based counter electrode (CE) attained an applicable power conversion efficiency (PCE) of 4.52% along with open circuit voltage (VOC) of 0.739 V, a short-circuit current density (JSC) of 11.42 mA/cm2 and fill factor (FF) of 0.54. According to primary results, the CePd incorporated CNFs based CE is a promising, and cost-effective alternative CE for photoelectrochemical devices.
关键词： Alloys nanoparticles,Solar cells,Electrocatalyst,Cyclic voltammetry,Carbon nanofibers
更新于2025-09-23 15:23:52
-
A novel non-enzymatic zinc oxide thin film based electrochemical recyclable strip with device interface for quantitative detection of catechol in water
摘要： Catechol, one of the major effluents released by various chemical and metal processing industries, causes severe pollution of groundwater. Monitoring of catechol in water using cost-effective, handheld sensor is demanding for the safety of the environment. In this work, non-enzymatic zinc oxide thin film based electrochemical strip sensor is developed on conducting glass substrate for detection of catechol. The preparation of strip without employing standard Pt or Ag/AgCl electrodes and simply depositing ZnO through wet chemical process represents a cost-effective innovative technique. The ZnO thin film is characterized using field emission scanning electron microscope (FESEM), energy dispersive X-ray spectroscopy (EDS), atomic force microscopy (AFM) and grazing incidence X-ray diffractrometer (GIXRD). Catechol is electrochemically detected by means of cyclic voltammetry and amperometry. A prominent redox peak of the developed strip attributed to the detection of catechol is observed at -0.26 V in cyclic voltammetry. The strip is integrated with readout meter and an algorithm is built based on the experimentally observed linear variation of amperometric current with catechol concentration. The quantitative detection performance is demonstrated by testing 0.1-12 ppm catechol solutions.
关键词： Zinc oxide,Catechol,Electrochemical strip sensor,Amperometry,Cyclic voltammetry
更新于2025-09-23 15:23:52
-
Synthesis of N-CuMe2Pc nanorods/graphene oxide nanocomposite for symmetric supercapacitor electrode with excellent cyclic stability
摘要： Recent progress in the construction of non-peripheral octamethyl-substituted copper(II) phthalocyanine (N-CuMe2Pc) has opened up new strategies for energy storage applications. Since metal phthalocyanines can deliver excellent redox activities, we have prepared composite based on different ratios of N-CuMe2Pc and graphene oxide (GO) through a simple ultrasound process and evaluated their electrochemical performance for supercapacitor applications. As-prepared composites exhibit superior electrochemical activities as the results of the synergistic effect. A maximum specific capacitance of 291.6 F g?1 is achieved for the G10P2 electrode (Graphene oxide 10 mg and N-CuMe2Pc 2 mg) at 0.5 A g?1 which two times higher than their individual components. Further, the fabricated symmetric device shows that the excellent cyclic stability of about 100.1% over 5000 cycles. The experimental findings ensure the potential application of copper-phthalocyanine/GO composite as an electrode material for the next-generation supercapacitor applications.
关键词： Nanocomposite,Specific capacitance,Cyclic stability,Graphene oxide,Phthalocyanine
更新于2025-09-23 15:23:52
-
Synthesis and characterization of novel imine substituted phthalocyanine for sensing of l-cysteine
摘要： New mono-nuclear cobalt (II) tetra[4-(2-{(E)-[(4-bromophenyl)imino]methyl}phenoxy)] phthalocyanine (CoTBrImPc) complex has been synthesized for the first time in pure state. The synthesized dark blue coloured complex was characterized by elemental analysis, IR, UV-Vis, NMR, Mass, powder X-ray diffraction and thermogravimetric analysis (TGA) to understand the structural integrity, purity and crystalline property of the complex. The synthesized phthalocyanine complex was found to be electrochemically active and it was immobilized on the glassy carbon electrode by drop-casting method and used for the detection of L-cysteine. The CoTBrImPc modified electrode was found to be a good electrocatalyst for the catalytic oxidation of L-cysteine with shift in the overpotential towards less positive potential and an increase in the catalytic current compared to bare glassy carbon electrode (GCE). The linear response was observed for the voltametric detection of L-cysteine in the concentration range 10-100 nM with coefficient of regression R2= 0.9993 and LOD of 3 nM and sensitivity of 2.99 μA nM-1 cm-2. The amperometric sensor was also developed for the detection of L-cysteine which showed linear response in the concentration range same as that of cyclic voltammertry technique with a linear equation y = 0.7582x+16.9535 and correlation coefficient of R2= 0.9961. The LOD and LOQ values for amperometric detection were 4 nM and 12 nM, respectively with the sensitivity value of 10.81 μA nM cm-2.
关键词： TGA,L-cysteine,XRD,Amperometry.,Phthalocyanine,cyclic voltammetry
更新于2025-09-23 15:23:52
-
Electrodeposition of lead selenide films from ionic liquids based on choline chloride
摘要： The paper presents some experimental results regarding the electrodeposition of PbSe thin films at 70 oC from two choline chloride (ChCl) based ionic liquids containing PbCl2 and SeO2 as precursors in choline chloride-ethylene glycol (ILEG) and choline chloride-urea (IL) eutectic mixtures. In this article we will detail our investigation of cathodic processes involved during the electrodeposition of binary semiconductor compound, PbSe as well as of singular Pb and Se elements. The cathodic branches of the recorded cyclic voltammograms in the cases of ionic liquids containing both Pb2+ + Se4+ show successively the Se underpotential deposition, Se bulk deposition and Pb deposition followed by a formation of PbSe semiconductor compound. However, at the most negative potentials the Se content of final layers decreases by a partial electrochemical dissolution of Se which reduces to Se2- soluble species. PbSe thin films have been electrodeposited on copper or nickel substrates under potentiostatic control at 70 oC for 0.5-4 h. The adherent and uniform deposits were characterized by SEM-EDX and XRD techniques. SEM images have shown adherent and grey deposits with uniform morphology and cubic PbSe crystals. A stoichiometry of around Pb1.1Se was indicated by EDX elemental analysis. XRD confirmed the formation of PbSe compound, showing a nanocrystalline structure, with crystallites average sizes in the range of 10-35 nm.
关键词： DES ionic liquids,electrodeposition,selenide semiconductors,Lead selenide,cyclic voltammetry
更新于2025-09-23 15:23:52
-
Photophysical Properties of Phthalimide and Pyromellitic Diimide Tethered Imidazolium Nitrophenolate Salts
摘要： Structural aspects of the salt of 2-(3-(1H-imidazol-1-yl)propyl) isoindoline-1,3-dione (L1) with 2,4,6-trinitrophenol as well as the salts of N,N’-bis(3-imidazol-1-yl-propyl)-pyromelliticdiimide (L2) with 2,4-dinitrophenol (H24dnp) and 2,4,6-trinitrophenol (H246tnp) are reported along with the solid and solution studies on the photophysical properties of these salts. The fluorescence emission of the L1 and L2 are quenched by H24dnp and H246tnp both in solid and in solution. In solution the L1 has comparable binding constant with H24dnp and H246tnp but the relative ability to quench the fluorescence emission of L1 by H24dnp is less than the quenching abilities of the H246tnp. These two nitrophenols independently do not distinguish the L1 from L2 but the extent of quenching caused independently by the H24dnp or H246tnp on L1 or L2 make them easily distinguishable. Addition of water quenches the fluorescence emission of L1 and L2; but the addition of water to solution of the nitrophenolate salts result in the recovery of fluorescence emissions from the quenched states. The salts in solid state have short emission life-times. The PET effect prominently caused by mineral acids on L1 or L2 is not observed in the nitrophenolate salts. In solid state the O-π interactions contributed to stacking of the aromatic in the 2,4,6-trinitrophenolate salt of L2, hence it is non-fluorescent.
关键词： Binding of imidazole,Charge-assisted hydrogen bonds,Fluorescence,Cyclic imide,Nitrophenol derivatives
更新于2025-09-23 15:23:52
-
Electrochromic behavior of films and ?smart windows? prototypes based on π-conjugated and non–conjugated poly(pyridinium triflate)s
摘要： This study is focused on two electrochromic poly(pyridinium triflate)s. They are aromatic rigid-rod polymer PV1 and PV12 containing alkyl linkages. Electrochromic behavior of both polymers was comparatively investigated by employing a three-electrode cell and ?smart windows? prototypes. The electrochromic properties of polymer films were examined by electrochemical and spectroelectrochemical methods. Polymers with π-conjugate and non-conjugate structure demonstrate reversible redox process accompanied by a reversible color change both in three-electrode cell and electrochromic device (ECD). In general, introduction of the non-conjugated spacers to the PV12 backbone structure leads to deterioration in the optical contrast and switching time in comparison with π-conjugated PV1. The same effect was also detected for ECD. The reason behind this is thought to be a complication of electron transport in the system due to non-conjugated PV12 backbone structure.
关键词： Electrochromic polymers,Poly(pyridinium) salts,Conjugated polymer,Cyclic voltammetry,Electrochromism
更新于2025-09-23 15:22:29
-
[ASME ASME 2018 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems - San Francisco, California, USA (Monday 27 August 2018)] ASME 2018 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems - Microstructural Evolution in SAC305 and SAC-Bi Solders Subjected to Mechanical Cycling
摘要： Fatigue failure of solder joints is one of the most common methods by which electronic packages fail. Electronic assemblies usually must cope with a temperature varying environment. Due to the mismatches in coefficients of thermal expansion (CTEs) of the various assembly materials, the solder joints are subjected to cyclic thermal-mechanical loading during temperature cycling. The main focus of this work is to investigate the changes in microstructure that occur in SAC305 and SAC+Bi lead free solders subjected to mechanical cycling. In this paper, we report on results for the SAC+Bi solder commonly known as SAC_Q or CYCLOMAX. Uniaxial solder specimens were prepared in glass tubes, and the outside surfaces were polished. A nanoindenter was then used to mark fixed regions on the samples for subsequent microscopy evaluation. The samples were subjected to mechanical cycling, and the microstructures of the selected fixed regions were recorded after various durations of cycling using Scanning Electron Microscopy (SEM). Using the recorded images, it was observed that the cycling induced damage consisted primarily of small intergranular cracks forming along the subgrain boundaries within dendrites. These cracks continued to grow as the cycling continued, resulting in a weakening of the dendrite structure, and eventually to the formation of large transgranular cracks. The distribution and size of the intermetallic particles in the inter-dendritic regions were observed to remain essentially unchanged.
关键词： Bismuth,Microstructure,SAC Alloy,Hysteresis,Evolution,Lead Free Solder,Cyclic Stress-Strain Curve
更新于2025-09-23 15:22:29