温度对浸镀锡镀层的影响

在基于氯化胆碱-水溶液(ChCl-H2O)的浸镀锡溶液中,以铜片为基材,在不同温度下进行浸镀锡研究.分别利用X-荧光光谱仪、扫描电子显微镜、X-射线衍射仪、可焊性测试仪和电化学工作站,考察了浸镀锡速率、形貌、物相和性能受温度的影响程度.结果表明,随着温度的升高,浸镀锡的沉积速率不断加快,浸镀锡镀层的耐蚀性和可焊性均有提高;镀层表面在较低温度时光亮平整,但随温度上升,变得越来越粗糙;在70℃时,锡镀层的晶相组成由Sn和Cu6 Sn5两相共存转变Sn、Cu6Sms和Cu3 Sn三相共存.在ChCl-H2O体系中,铜基浸镀锡的反应活化能Ea为24.6 kJ·mol-1.     

Electrospinning of poly(vinylpyrrodine) template for formation of ZrO2 nanoclusters for enhancing properties of composite proton conducting membranes

Nanosized ZrO₂ clusters were prepared by electrospinning a poly(vinylpyrrodine) (PVP)/ZrO₂ mixture for calcination to remove PVP template and sizing. The morphological, chemical, structural, and thermal resistance changes during preparation stages were investigated using scanning electron microscope, energy-dispersive X-ray spectroscopy, transmission electron microscope, X-ray diffraction, and thermogravimetric analysis. The obtained ZrO₂ clusters were used for preparation of nanocomposite membranes by dispersion in 2,6-pyridine polybenzimidazole (2,6-Py-PBI) matrix at 5?wt% content followed by phosphoric acid (PA) doping. The ZrO₂ nanoclusters were found to be uniformly distributed in 2,6-Py-PBI/PA matrix leading to a remarkable increase in the PA doping level and proton conductivity of the obtained composite membrane.     

Zn2+作为化学镀镍溶液稳定剂的研究

为了保持化学镀镍液的稳定性,添加微量Zn2 作为化学镀Ni-P合金镀液的稳定剂,通过稳定性试验以及镀速和镀层形貌分析,评价了Zn2 的稳定作用,探讨了Zn2 的作用机理.研究表明,加入Zn2 可提高Ni-P合金化学镀液的稳定性,并使镀层形貌得到较大的改善.     

Convex-nanorods of α-Fe2O3/CQDs heterojunction photoanode synthesized by a facile hydrothermal method for highly efficient water oxidation

Morphology controlling and surface modification of semiconductors is the key for efficient photoelectrochemical (PEC) water splitting systems. This work provides a new strategy for achieving morphology control and heterojunction construction simultaneously by one-step hydrothermal method. The α-Fe₂O₃/CQDs heterojunction photoanode with convex-nanorods morphology is successfully prepared by hydrothermal method in CQDs (Carbon Quantum Dots) aqueous contained iron precursor followed by low temperature annealing treatment. Compared with bare hematite photoanode, the α-Fe₂O₃/CQDs photoanode has 8.5 time higher photocurrent density (at 1.23 V vs. RHE) of 0.35 mA cm^?2 and a negative shift of onset potential about 300 mV. The enhanced photoelectrochemical response is attributed to the convex-nanorods which benefit higher absorbance of light and the formed α-Fe₂O₃/CQDs heterojunction, which can efficiently enhance the electron-hole separation and reduce the surface charge recombination. The morphology and properties of the sample were characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fouriertrans form infrared spectroscopy (FTIR), UV–vis spectra, X-ray diffractometry (XRD), X-ray photoelectron spectra (XPS), and photoelectrical measurements.     

Electrospray Deposition of Photoresist: A Low Impact Method for the Fabrication of Multilayered Films

Electrospray deposition has been investigated as a substitute for photoresist spin coating. The morphology of Microposit S1813 photoresist films has been studied as a function of several spray conditions including resist concentration, substrate surface, and flow rate. Film morphology is controlled by three process parameters: the surface energy determines the equilibrium conditions of resist on the substrate; the viscosity and volume flux determine the relaxation time for the depositing resist solution after impact on the substrate. Electrosprayed photoresist films have been used for photolithographic patterning and it has been demonstrated that electrospray deposition is an effective method for deposition of photoresist on top of fragile, thin films, which can be used for multilayered thin film fabrication.

     

水溶液体系中304不锈钢上电沉积碳膜的研究

采用电沉积技术在较低的电压(10.0 V)下以氯乙酸、硫酸钠和氯化胆碱混合水溶液为电沉积液,在304不锈钢基体上电沉积碳膜。通过扫描电镜(SEM)和拉曼光谱分析碳膜的形貌和结构,通过接触角仪测试碳膜的疏水性能,通过多功能材料表面性能综合测试仪(CFT-Ⅰ)测试碳膜的摩擦学性能。研究结果表明,硫酸钠的加入能够促使碳膜在304不锈钢上的沉积,添加氯化胆碱能够有效提高304不锈钢表面碳膜的疏水性能,降低碳膜的摩擦系数。     

Soluble carbon nanotubes and their applications

Carbon nanotubes (CNTs) have been the forefront of nanoscience and nanotechnology due to their unique electrical and mechanical properties and specific functions. However, due to their poor solubility in solvents, the applications using the materials have been limited. Therefore, strategic approaches toward the solubilization of CNTs are important in wide fields including chemistry, physics, biochemistry, biology, pharmaceuticals, and medical sciences. In this article, we summarize: (i) the strategic approaches toward the solubilization of CNTs using chemical and physical modifications, (ii) nanocomposites of CNTs and biological molecules including DNA, (iii) formation of CNTs with topological structures, (iv) separation of metallic and semiconducting nanotubes, (v) the preparations of films and fibers of CNTs and hybrid materials of CNTs and organic and inorganic molecules.     

铝基氧化铝表面化学镀铜工艺研究

在铝基板表面的氧化铝上实施化学镀铜,获得剥离强度良好的化学镀铜层.利用扫描电子显微镜观察了化学镀铜层的剖面形貌;测定了硅烷化前后氧化铝表面的润湿性;分析了硅烷化时间和施镀时间对氧化铝表面铜厚度的影响.结果表明:在铝基板表面氧化铝上所制得的化学镀铜层与基体结合力良好,可以满足印制线路板的要求.     

Soluble carbon nanotubes and nanotube-polymer composites

For these two decade, tremendous amount of researches and developments dealing with carbon nanotubes (CNTs) have been carried out. Most of them are focusing on finding the unique and outstanding properties of CNTs and trying to utilizing them as the advanced materials. Whenever we start the research and the development of CNTs, the first difficulty is the dispersion of CNTs into the solvents since the CNTs form strong aggregation. Up to date, large efforts have been carried out for the preparation of CNT dispersion and the typical strategies are summarized. Such a dispersion technique allows us to use CNT as a material. Several applications of the CNT dispersion is also introduced.     

Phosphorylation of ovalbumin by dry-heating in the presence of pyrophosphate: Effect of carbohydrate chain on the phosphorylation level and heat stability

Ovalbumin (OVA) derived from egg white (N-OVA) and recombinant OVA (Re-OVA), which was essentially carbohydrate-free, expressed by Escherichia coli, were phosphorylated by dry-heating for 1 day in the presence of pyrophosphate (PP-N- and PP-Re-OVA). The phosphorus contents of N- and Re-OVA were 0.79% and 0.46%, respectively, after phosphorylation. The secondary structural change of both OVAs was small, and the midpoint temperature of both OVAs determined from the thermal unfolding curve was decreased by phosphorylation. In addition, the differential scanning calorimetry thermograms of both OVAs showed a lowering of denaturation temperature by phosphorylation. The stability of both OVA solutions after heating at pH 7.0 was improved, and the degree of stabilization was higher for PP-N-OVA than for PP-Re-OVA. This suggests that the phosphate groups introduced to the carbohydrate chain also play an important role in the heat stability of OVA.