The surface electronic states of 15 kinds of real metals have been investigated by temperature programmed photoelectron emission (TPPE) and XPS. The characteristics of the TPPE method are the amount of emitted photoelectrons (PE total count) and the photoelectric threshold value measured at different temperatures in the temperature-increase and subsequent temperature-decrease process. The metal surfaces were pretreated using ultrasonic cleaning in acetone (T1) and exposure to argon plasma (T2). The characteristics depended strongly on the metals and the pretreatments. The PE total count and threshold value for T1 and T2 were compared: for the PE total count the metals with the order T1>T2 were Pt, Cu, Ag, Au, Ta, Nb, and Co, those with almost the same level (T1≈T2) were Al, Pb, W, Ti, and Mo, and those with the order T1<T2 were Ni, Fe, and Sn; for the threshold value the metal with the order T1>T2 was Sn, those with almost the same level (T1≈T2) were Al, Pb, Au, Ni, Ta, W, Mo, Nb, Co, and Fe, those with the order T1<T2 were Pt, Cu, Ag, and Ti. The relationship between the PE total count and the threshold value obtained for both T1 and T2 pretreatments was investigated. The metals whose PE total count tended to decrease with increasing threshold value were Pt, Cu, Ag, Au, Ni, Zn, and Sn. The metals whose threshold values varied little in spite of the variation of the PE total count were Al, Pb, Ta, Pd, W, Ti, Mo, Nb, Co, and Fe. The TPPE method was demonstrated to be able to analyze very sensitively the dependence of the electronic state of real metal surfaces on the pretreatments.
The electrophoretic deposition of the artificial graphite particle, KS-25, on Cu foil has been examined in an acetonitrile bath containing additives such as triethylamine (TEA), tetramethylguanidine (TMG), and pyridine (Py). The charge-discharge capability of carbon anode for the Li-ion secondary battery prepared by the electrophoretic deposition method was estimated. Graphite particles were deposited electrophoretically on the anode substrate. The amount of graphite particle on Cu foil increased with an increasing deposition voltage, deposition time, and TEA concentration and was controllable in the range from 0 to 10mg·cm-2. The carbon anode provided relatively flat charge and discharge potentials (0 to 0.3V vs. Li/Li+) and high current capability (310mAh·g-1). Compared with the carbon anode composed of artificial graphite particles having a smaller grain size (KS-6), improvement in charge-discharge efficiency of the carbon anode with KS-25 particles was able to be observed in several of the early cycles. Moreover, the relationship between the ζ-potential and additive concentration, as well as the relationship between the amount of graphite particles deposited on Cu substrate and pKa of additives, and the results of the XPS measurement of graphite particle surface suggested that the charging of the graphite particle surface was caused by the deprotonation of carboxyl and alcohol groups by additives such as TEA, TMG, and Py.
Oligomer formation reactions during the preliminary treatment of a solution system consisting of ATMS-EtOH-H2 O were investigated using alkyltrimethoxysilane (ATMS) agents. Also, the preparation of hydrophobic TiO2 powders with ATMS agents was examined. The main findings of this study were as follows: (1) The amount of monomer of ATMS decreased during hydrolysis and condensation polymerization and the consumption rate at the initial stage up to 20% slowed in accordance with a decrease in the carbon number of the alkyl group of ATMS. However, the consumption rate exhibited a minimum value at a carbon number of 4-6 when the reaction proceeded further. (2) The average molecular weight of the oligomer determined from GPC elution curve increased with the duration of preliminary treatment. Condensation polymerization rates increased in the order n-DTMS, i-BTMS, n-PTMS, n-BTMS, and n-HTMS. (3) M value, which is a parameter of hydrophobic degree, increased with the increase in carbon number of the alkyl group of n-ATMS, ranging from 75% to 55%, while that of i-BTMS was 45%. (4) M values of TiO2 powders treated with each optimal amount of n-PTMS, n-BTMS, and i-BTMS increased with the duration of preliminary treatment, however, the time required to reach maximum M values took longer in the order i-BTMS, n-BTMS, and n-PTMS. By contrast, maximum M values were obtained with n-HTMS and n-DTMS without preliminary treatment of ATMS-EtOH-H2O solution, providing a hydrophobic property to TiO2 powders by mixing TiO2 and solution containing silane coupling agent, followed by heat treatment. (5) Average polymerization degrees promised maximum M values for TiO2 using n-PTMS, n-BTMS, n-HTMS, i-BTMS, and n-DTMS were 3.0, 2.1, 1.7, 1.4 and 1.0, respectively.
A novel electroless Ni Plating bath using Ti (III) ions as reluctant was proposed. In an industrial application of this plating bath, stability of the plating bath and plating rate are particularly important. Effects of plating bath components on Ni deposition rate onto Urethane foam or copper sheet were investigated, elucidating that Ni (II) ions, nitrilotriacetic acid and ammonium hydroxide concentration were important factors to control Ni deposition rate. Purity of Ni film reduced with Ti (III) ions was very high exceeding 99.9%.
Effect of ultrasonic irradiation on silver immersion plating onto nickel plate was investigated. Plating rate increased in order of plating under still, mechanical stirring and ultrasonic irradiation conditions. It was confirmed from pinhole tests and SENT observations that nickel was completely covered with Ag only under ultrasonic irradiation, and Ag grains became fine with the irradiation.