Detection of chemical warfare agent Nitrogen Mustard-1 based on conducting polymer phthalocyanine nanorod modified electrode

A simple method is reported for the detection of chemical warfare agent Nitrogen Mustard-1 (NM-1) by using a modified electrode which was prepared by electrochemically immobilizing copper phthalocyanine (CuPc) into polypyrrole (pPy) in presence of a cationic surfactant cetyltrimethylammonium bromide (CTAB) during the polymerization of pyrrole in an aqueous solution. The surface of the modified and bare electrodes are characterized by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) techniques in order to know the surface morphology and elemental composition of the modified electrodes, respectively. SEM images indicated the presence of nanorods on pPy/CuPc/CTAB sample and EDS study confirmed the nanorods as CuPc. Moreover, EDS study confirmed that the nanorods are only on the pPy matrix and not inside the pPy. FTIR results confirmed the presence of CuPc in pPy film. AC impedance spectroscopy analysis of the modified electrode with NM-1 exhibited more electron transfer resistance. The prepared modified electrode showed good electrochemical activity with NM-1 when compared to the unmodified gold electrode.     

Electrochemical properties of nano-cobalt powder prepared by chemical reduction with and without cetyltrimethylammonium bromide and carbon-coated at 500 °C for secondary lithium Batteries

X-ray diffraction patterns show that Co-based powders prepared by chemical reduction with and without Cetyltrimethylammonium bromide (CTAB, C₁₉H₄₂BrN) and carbon-coated at 500°C are not crystallized and amorphous-like as they are just after the chemical reduction. The Co-based powder prepared by chemical reduction with CTAB has carbon-coated layers with thicknesses of 15–20 nm. Comparing the 20% carbon-added powders, the powder prepared by chemical reduction with CTAB and carbon-coated at 500 °C has a larger first discharge capacity (about 1,230 mAh g^?1) than the powder prepared by chemical reduction without CTAB and carbon-coated at 500 °C (about 902 mAh g^?1). The reason is believed to be that the carbon layer obstructs the expansion of the Co phase and the formation of the solid electrolyte interface on the surface of the Co. Comparing the powders that are carbon-coated with CTAB added, the 20% carbon-added powder has a larger first discharge capacity (about 1,230 mAh g^?1) than the 10% carbon-added powder (about 1,130 mAh g^?1).     

表面活性剂辅助制备钛阳极的电化学性能

用阳离子表面活性剂(CTAB)作为阳极氧化物涂层生长模板剂,用热分解法制备出30% RuO₂-70% TiO₂/Ti涂层电极。用计时电位、循环伏安方法分析CTAB用量对涂层电催化性能的影响。结果表明：CTAB 在降低析氯电位,提高电极电催化活性上具有显著的效果。表面活性剂CTAB所起的作用主要可以归结为两个方面,一方面用表面活性剂为模板剂使制备的阳极涂层具有高比表面积和多孔性结构,增大涂层的真实表面积;另一方面,CTAB辅助所制备的电极涂层具有高密度的缺陷结构,使涂层的催化活性位密度增大。     

表面活性剂对镀Ti金刚石-Ni复合电沉积行为的影响

研究了阴离子表面活性剂十二烷基硫酸钠(SDS,sodium dodecyl sulfate)和阳离子表面活性剂十六烷基三甲基溴化铵(CTAB,cetyl trimethyl ammonium bromide)对镀Ti金刚石-Ni复合电沉积的影响,并结合循环伏安、交流阻抗等电化学方法研究了镀Ti金刚石-Ni镀液中Ni电沉积过程。结果表明:与未镀覆金刚石相比,镀Ti金刚石与Ni层浸润性得到提高。浓度为0.05 g/L的SDS对Ni电结晶过程有抑制作用,而浓度为0.05 g/L的CTAB能促进Ni~(2+)离子转移并加快Ni的电沉积过程。SDS和CTAB都能促进电沉积过程中氢气的析出并细化Ni镀层,同时减少镀层针孔和凹痕。     

微生物吸附-化学还原法合成金钯纳米线机理研究

采用微生物吸附-化学还原法,以大肠杆菌(ECCs)为模板、十六烷基三甲基溴化铵(CTAB)为保护剂、抗坏血酸(AA)为还原剂制备金钯纳米线(Au-Pd NWs),考察不同金钯摩尔比对合成金钯纳米材料的影响,并通过SEM、TEM、XRD等技术进行了表征,研究其形成机理。结果表明,吸附还原作用使ECCs在短时间内还原生成了少量Pd(0)和Au(0),大量的钯离子和金离子聚集在ECCs表面周围;还原剂AA的加入使ECCs表面成为优先成核位点,菌体表面基团与晶核相互作用阻止其迁移;在CTAB的作用下,菌体表面的纳米颗粒逐渐形成链状纳米中间结构,中间结构通过Ostwald熟化作用进一步形成Au-Pd纳米线。通过ECCs和CTAB协同作用,有利于一维纳米结构的生长。     

微生物吸附-化学还原法制备金钯合金纳米线

采用微生物吸附-化学还原法,失效金、钯催化剂为原料,以大肠杆菌为模板、十六烷基三甲基溴化铵(CTAB)为保护剂、抗坏血酸为还原剂制备金钯合金纳米线(Au-Pd NWs),用SEM、TEM、XPS、XRD等技术对金钯合金纳米线进行了表征。结果表明,在大肠杆菌菌粉量为0.5 g/L、CTAB量为5.0 mmol/L、抗坏血酸浓度为1.0 mmol/L反应条件下,当金钯摩尔比控制在3:1~1:3之间,均有较大量纳米线生成,金钯摩尔比为1:1时形貌最佳;CTAB浓度对金钯合金纳米线直径影响较大。表征结果显示,金钯纳米线的晶面间距为0.232 nm,是一种具有面心立方(fcc)、多晶结构的双金属合金纳米线。     

PREPARATION OF MULTI-WALLED CARBON NANOTUBES USING NiO CATALYST SYNTHESIZED BY HYDROTHERMAL METHOD

The Ni(OH)2/SiO2 binary colloid was prepared using Ni(NO3)2.6H2O and (C2H5O)4SiO4 as starting materials and was used to form NiO/SiO2. composite powder by hydrothermal method and desiccant method in open air respectively. Multi-walled carbon nanotubes (MWCNTs) were synthesized respectively by chemical vapor deposition using the NiO/SiO2 catalyst prepared by different methods. The phase and morphology of the catalysts and the morphology, output yield and purity of MWCNTs were compared by XRD, TEM and SEM. The results show that the catalyst powder prepared by hydrothermal method, compared with that by desiccant method, is smaller, better dispersion and has stronger catalytic activity. Pure MWCNTs with smaller tube diameter and narrow range could be obtained at a high yield using that NiO/SiO2 powder prepared by hydrothermal method as catalyst.     

碘化多壁碳纳米管制备含有Ag/MWCNTs复合材料的银-环氧树脂浆料

提出一种将多壁碳纳米管碘化后制备银/多壁碳纳米管（Ag/MWCNTs）复合材料的方法。通过球磨对碘化多壁碳纳米管进行了功能化,并通过透射电子显微镜（TEM）、X射线衍射（XRD）、傅里叶变换红外光谱（FT-IR）、拉曼光谱和热重分析（TG）对其进行了表征。结果表明,经碘化处理后,银纳米粒子（Ag-NPs）能更好地粘附在碳纳米管表面,改善了银纳米粒子与碳纳米管之间的连接。羟基（-OH）基团的伸缩振动明显增强,激活了碳纳米管的表面,增加了碳纳米管表面Ag⁺形核的数量。在260 ℃以下,Ag/MWCNTs复合材料的质量损失小于MWCNTs的质量损失。最后,制备了银-环氧树脂浆料,发现使用Ag/MWCNTs复合物制备的浆料具有最低的电阻率和最高的热导率。     

Flexural destructive process of unidirectional carbon/carbon composites reinforced with in situ grown carbon nanofibers

Unidirectional carbon/carbon (C/C) composites modified with in situ grown carbon nanofibers (CNFs) were prepared by catalysis chemical vapor deposition. The effect of in situ grown CNFs on the flexural properties of the C/C composites was investigated by detailed analyses of destructive process. The results show that there is a sharp increase in the flexural load-displacement curve in the axial direction of the CNF-C/C composites, followed by a serrated yielding phenomenon similar to the plastic materials. The failure mode of the C/C composites modified with in situ grown CNFs is changed from the pull-out of single fiber to the breaking of fiber bundles. The existence of interfacial layer composed by middle-textured pyrocarbon, CNFs and high-textured pyrocarbon can block the crack propagation and change the propagation direction of the main crack, which leads to the higher flexural strength and modulus of C/C composites.     

Novel zinc‐rich epoxy paint coatings with hydrated alumina and carbon nanotubes supported polypyrrole for corrosion protection of low carbon steel: Part I: Inhibitor particles and their dispersions

In part 1 of this work, preparation, structure, spectroscopic, and electrochemical characteristics of the polypyrrole (PPy) deposited alumina/multi‐walled carbon nanotubes (MWCNTs) inhibitor particles (PDAMIPs) are presented. TEM observations evidenced uniform deposition of thin PPy film on the functionalized nanotubes, whereas co‐deposition of PPy and polystyrene sulfonic acid (PSS) lead to thick polymer coverage on hydrated alumina. Modification with polymer complexes resulted in moderately dispersed PDAMIPs, which is due to the various degrees of aggregation and coalescence. FTIR revealed compact and dense PPy structure on the functionalized MWCNTs while it was not the case on alumina and the PSS modified nanotubes. Closer interaction of PPy with the MWCNTs resulted in enhanced charge mobility, whereas greater electroactivity and reversibility of PPy were noted to samples containing functionalized nanotubes and low amount of PSS. Rheological study verified moderate micron‐scale dispersity and the modification caused various degrees of aggregations of the PDAMIPs. These were recognized to be valid in the suspensions at a solid phase concentration with component contents similar to the corrosion tested hybrid coatings. Rheological percolation of the nanotubes (with anisotropic factor of ～100) was confirmed at volume fractions of 3.30 × 10^?3 and 6.0 × 10^?4 which were under the dilute/semi‐dilute boundary type theoretical and experimental thresholds. This is related to the extensive interconnection of the nanotube‐supported filaments. Thus, overlapping of the nanotubes should contribute to the electrical percolation thereby galvanic corrosion prevention function of the zinc‐rich hybrid coatings, which is discussed in the 2nd part.     

Enhanced electrochemical performances of multi-walled carbon nanotubes modified Li3V2(PO4)3/C cathode material for lithium-ion batteries

The multi-walled carbon nanotubes (MWCNTs) modified Li₃V₂(PO₄)₃/C composite is synthesized by polyvinyl alcohol (PVA) based carbon-thermal reduction method using MWCNTs as a highly conductive agent. PVA mainly supplies a reductive atmosphere to reduce V⁵⁺ and provides a network of carbon to inhibit the aggregation of Li₃V₂(PO₄)₃ particles. The amorphous carbon coating and MWCNTs co-modified composite shows excellent high-rate lithium intercalation/deintercalation property and cycling performance between 3.0 and 4.3 V. The discharge capacities of 131.7 and 122.9 mAh g⁻¹ are obtained at rates of 1 C and 10 C, respectively, for the Li₃V₂(PO₄)₃/(C + MWCNTs). These improvements are attributed to the valid conducting networks of C + MWCNTs and the reduced Li₃V₂(PO₄)₃ particle size by the network carbon from the pyrolysis of PVA.     

Synthesis and characterization of mesoporous Mn-MCM-41 materials

MCM-41 has been synthesized at two different pH using cetyl-trimethylammonium bromide (CTAB) surfactant as template and adding the silica precursor to aqueous solutions containing CTAB. The obtained solids were calcined at 600 °C for 4 h. Mn-MCM-41 powders with different Mn/Si molar ratios were prepared using the incipient wetness method, followed by calcination at 550 °C for 5 h. At the end of the impregnation process the powders colour changed from white to brown whose intensity depends on manganese quantity. The materials characterization was performed by X-ray diffraction, N₂ adsorption, ²⁹Si Cross Polarization-Magic Angle Spinning NMR, and X-ray Photoelectron Spectroscopy. The effects of the manganese quantity and of the structural characteristic of the MCM-41 support were studied. The catalytic activity of the prepared systems was evaluated in a complete n-hexane oxidation.     

Fabrication of various electroless Ni-P alloy/multiwalled carbon nanotube composite films on an acrylonitrile butadiene styrene resin

Ni-P alloy/multiwalled carbon nanotube (MWCNT) composite films were fabricated on acrylonitrile butadiene styrene (ABS) resin by electroless plating and their microstructures, adhesion strengths, and friction properties were investigated. Various types of MWCNTs were used. In addition, various electroless plating baths were prepared to form Ni-P alloy matrices with various phosphorus contents. To enhance the adhesion strength, the ABS resin substrate was subjected to roughening treatment. The microstructures of the composite films were examined by scanning electron microscopy and X-ray diffraction. Their adhesion strengths were measured by tensile tests. The friction properties of the composite films were investigated using the ball-on-plate method. Ni-P alloy/MWCNT composite films containing various types of MWCNTs and with Ni-P alloy matrices having various phosphorus contents were fabricated on the ABS resin substrates by electroless deposition. The adhesion strength between the Ni-P alloy/MWCNT composite films and the ABS resin substrate was more than 1300 N cm^− 2. The Ni-P alloy/MWCNT composite films had considerably lower friction coefficients than the Ni-P alloy films. The friction coefficients of the composite films were significantly affected by the type of MWCNTs used.     

PET表面SiO2-AgCl复合薄膜制备及其性能研究

以正硅酸乙酯和AgNO3为主要原料,采用溶胶-凝胶分步水解法,引入有机γ-氯丙基三乙氧基硅烷(CPTES)和表面活性剂十六烷基三甲基溴化铵(CTAB)或聚乙烯吡咯烷酮(PVP),在PET基体上制备了抗菌SiO2-AgCl复合薄膜.通过对薄膜进行表面接触角测量、摩擦磨损性能检测、折叠实验及耐水性和抗菌实验,研究了不同分散剂对所制备复合薄膜的表面形貌、膜基结合力、耐水性、耐摩擦磨损性、防雾化及抗菌性能的影响.结果表明:以CTAB或PVP为分散剂的复合薄膜均获得了均匀的表面形貌和较好的抗菌性能,但前者具有更好的膜基结合力、耐水性、耐摩擦磨损性和防雾化性能.     

表面活性剂对电沉积TiO2/Ni复合镀层的影响

研究了表面活性剂对纳米TiO2在镀液中的分散行为和沉积行为的影响,结果表明十六烷基三甲基溴化铵(CTAB)对纳米TiO2颗粒的分散效果显著,镀液40min内不发生明显分层。相比其他表面活性剂,由于纳米颗粒在涂层中均匀分散,CTAB分散的镀层显微硬度最好,且热稳定性好,孔隙率显著降低。运用SEM、EDAX和XRD研究了镀层的表面形貌和成分。CTAB分散的纳米TiO2-Ni基镀层表面平整致密、晶粒均匀,镍基晶粒长大伴随着纳米TiO2被夹持嵌埋过程,TiO2多分布于镍基间隙。分析认为纳米粉末TiO2与Ni符合迁移、吸附、嵌埋的力学共沉积过程。     

Simultaneous immobilization of cobalt tetrasulfonated phthalocyanine during electropolymerization of pyrrole in presence of surfactants: a study of film morphology and its conductivity

An attempt was made to electrochemically immobilize tetrasulfonated phthalocyanine (CoTsPc) into polypyrrole in presence of three types of surfactants (cationic, anionic, and neutral) during the polymerization of pyrrole in an aqueous solution with different potential regions. The surface characteristics of anodically/cathodically prepared electrodes with cetyltrimethylammonium bromide (CTAB), sodium dodecyl sulfate (SDS), and Triton X-100 were investigated using the scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) measurements. The SEM and XPS measurements revealed the position and orientation of CoTsPc and surfactant, respectively, in the prepared films. The film conductivity was deduced from AC impedance and its conductivity values were found to be very low when compared to the literature results. The decrease of film conductivity in presence of the surfactant and CoTsPc could be associated with the fewer amounts of counter ions in the film and also the absence of conjugation for electron hopping within the film.     

Comparative study of one-dimensional NiCo alloy nanostructures assembled by in situ and ex situ applied magnetic fields

For the study of magnetic field-assisted assembly behavior, one-dimensional (1D) NiCo alloy nanostructures were solvothermally obtained at 180 °C under an in situ magnetic field (the magnetic field as applied during the chemical reduction) and ex situ field (after the chemical reduction was finished). Microscopic morphology and magnetic properties differences were investigated using scanning electronic microscope (SEM) and vibrating sample magnetometer (VSM) for these products. Magnetic measurement results show that 1D ordered microstructures under in situ magnetic field possess higher saturation magnetization M_s, remnant magnetization M_r, coercivity H_c and reduced magnetization M_r/M_s than 1D ordered microstructures under ex situ field, and the four magnetic parameters of the two ordered microstructures are much higher than those randomly distributed alloy particles prepared in the absence of external magnetic field.     

Improvement in Cr Nanoparticle Content in Ni-Cr Film by Co-deposition with Combined Surfactant HPB and CTAB

The effects of single surfactant hexadecylpyridinium bromide(HPB) and cetyltrimethylammonium bromide(CTAB) and the combination of HPB and CTAB on the Cr nanoparticle content in the Ni-Cr film prepared by codeposition were investigated. Single HPB/CTAB addition inhibited the oxidation and amorphous transformation of the Cr nanoparticles in the plating bath and effectively stabilized the Cr nanoparticles content at approximately 10 mass% as a function of time. Moreover, the combination of HPB and CTAB formed a cylindrical micelle structure on the Cr nanoparticle surface, which prompted the formation of a layer of NiCr_2O_4. As a result, the Cr nanoparticle content increased sharply to 20 mass%.     

复合模板合成介孔二氧化钛分子筛及其脱模

以工业TiOSO4液为钛源,通过CTAB和P-123超分子复合模板诱导钛热水解自组装合成介孔分子筛前驱体,研究臭氧氧化、萃取、煅烧及综合脱模等对介孔TiO2结构的影响。采用化学分析、XRD、FT-IR、TG、SEM和BET等测试技术对样品进行表征。结果表明：水热处理的前驱体为锐钛相介孔TiO2;经臭氧氧化、分步萃取及多步煅烧脱模的综合脱模路线所得产物TiO2含量高达92.1%（质量分数）,比表面积为133 m2/g,平均孔径为4.65 nm。     

Enhanced fracture toughness in carbon-nanotube-reinforced amorphous silicon nitride nanocomposite coatings

Multiwalled-carbon-nanotube (MWCNT)-reinforced silicon nitride coatings were grown to evaluate the toughness contribution of nanotubes in a ceramic coating. An MWCNT array was first grown using catalytic chemical vapor deposition of acetylene on a silicon substrate. This aligned MWCNT preform was then infiltrated with an amorphous silicon nitride matrix by low-pressure chemical vapor deposition of dichlorosilane (DCS) and ammonia (NH₃). The fracture toughness of this material was determined by generating cracks using nanoindentation and then employing finite-element analysis to estimate the bridging toughness contribution of the MWCNTs. The MWCNT bridging toughness of the composites is determined to be ～5.6 MPa m^1/2, which is seven times higher than that of the matrix. The interfacial frictional stress is also estimated and ranges from 7 to 20 MPa.