Poly(ethylene terephthalate) (PET) fiber knit-fabrics were irradiated by glow-discharge plasma (GDP) at one-atmosphere, then subsequently grafted with a hydrophilic acrylic acid (AA). Degradation of GDP-treated surface was determined by weight loss ratio. This degradation is proportional to time of exposure. The wicking-time method was used for roughly estimating hydrophilic durability of grafted surfaces versus the time of exposure and times of washing. On the grafted surface, characterized by X-ray photoelectron spectroscopy (XPS), carbon contents C1s decreased while oxygen contents O1s considerably increased. This results in an amount of oxygen polar functional groups like carboxylic (O−C*=O) and carbonyl (C*=O) groups introduced into the grafted surface. Grafted surface morphology observed by scanning electron microscopy (SEM) displays some large area of corn-structure compared to relative smooth morphology of the control fabric. It also suggested that hydrophilic improvement was closely related to oxygen containing functional groups incorporated onto the grafted fiber surface and the surface roughness.
Gallium primary ion TOF-SIMS fragment patterns from some nitrates and sulfates can be qualitatively inferred. Considering the chemical parameters: valence and electron negativity (electron affinity) of cations and anions in fragments, the regularity of fragment pattern appearance behavior from some nitrates and sulfates could be inferred, but the effect of surface contaminants like water should be taken into consideration as in the case of halides and oxides.
Recently in-situ XAFS analysis of the catalysts under reaction conditions has widely been performed together with synchrotron radiation light sources of the 2nd−3rd generation. In some cases this method requires time-resolving analytical techniques such as DXAFS and QXAFS. In addition, design of the in-situ cell is crucial for obtaining spectra which properly reflect the structures of the catalysts under reaction conditions. Two kinds of in-situ cells designed for experiments under high-pressure conditions are presented. Four of recent works are reviewed: Observation of Mo suboxide species during reduction of MoO3, Cu+ species formed in Cu-ZSM-5 during reduction process, structural change of Cu metal particles on Cu/ZnO under various reaction conditions, and Rh species during CO2 hydrogenation. Intermediate species appearing in the course of chemical reactions have very short lives, therefore continuous observation of surface species by in-situ method is indispensable for detection of such species. Moreover, the in-situ method is the only way to obtain the structure of catalysts under the reaction conditions.
A novel instrumentation has been made by coupling scanning tunneling microscopy (STM) with optical spectroscopic techniques that allow measurements of electronic band structures and, localized electronic states of isolated centers with an extremely high spatialresolution. The great analytical power of the STM-nanospectroscopy was demonstrated by presenting results of experiments on a nano-scale spatial variation of bandgap energy in a low-temperature grown (LT-) GaAs epi-film and photoabsorption spectra of isolated defects forming a localized energy level in the band gap.
The existence of magnetic domain has been known for a long time, and its importance is further growing because of rapid storage density increase of recording media. Magnetic domain observations made it possible to derive the microscopic magnetic parameters such as the magnetic anisotropy and the domain wall energy connected with exchange interaction in addition to the size of magnetic domain. Among the various methods for observing the magnetic domain, scanning probe microscopes are powerful tools owing to the user-friendliness and the flexibility to sample specimen and measurement environment. These instruments enable us to evaluate three dimensional magnetic domain structure and to explore novel magnetic materials in a high throughput way. Here, we show the results obtained from the measurements of ferromagnetic semiconductors, Mn doped GaAs and Co doped TiO2 thin films, and a colossal magnetoresistive material, La1−xSrxMnO3 composition-spread film.
Extremely asymmetric X-ray diffraction is a noble method to evaluate strain fields near crystal surfaces or interfaces. This method is sensitive to crystal structure near surface region because a glancing angle of X-ray is set near a critical angle of total reflection. A minute strain fields (≥ 0.1%) at surface brings a variation of intensity and width of rocking curves. Therefore we can evaluate strain near surfaces by analyzing curve-shape or integrated intensity of the curves. We show two examples of experimental strain evaluation. One is Si reconstructed surfaces. We quantitatively evaluated intrinsic strain fields near Si reconstructed surfaces, i.e., Si(111)-(7×7), Si(111)-(√3×√3)-Al, and Si(111)-(√3×√3)-Ag surfaces. From the fitting of the experimental rocking curves with calculated curves, we found that all reconstructed surfaces bring a contraction of the (111) spacing due to surface lattice relaxation, and such strain extends to some ten nm under the surfaces. Another example is silicide surface. We evaluated a strain evolution near hydrogen-terminated Si(111) surface due to nickel deposition. We found that a compressive strain gradually introduces into the substrate accompany with a growth of “Ni diffusion layer” near the hydrogen-terminated surface.
Decay processes of multi-layered islands on Au(100) surfaces, as well as nano-holes on Au(100) and Ag(100) surfaces in sulfuric acid aqueous solution under potential control have been investigated by in-situ electrochemical atomic force microscopy (EC-AFM). The influences of surface excess charge and of the high electric field at metal/electrolyte interface on the decay processes have been discussed. The decay rate of the first layer of the multi-layered islands is constant independently of the time elapse, suggesting that the detachment of the atoms from the step edges is a limiting process for the decay. The decay rate of the second or the third layer after the complete collapse of the upper layer is almost the same as that of the first layer. The rate is much greater than that before the complete collapse of the upper layer. The decay rate of the nano-islands and -holes on Au(100) has a minimum near the zero charge potential, and increases as the potential varies from the minimum.