Evaluation and comparison of layered titanate nanosheets using TOF‐SIMS and g‐ogram analysis

Abstract

The evaluation of nanostructure is important to develop the highly controlled nanomaterials. In this study, two kinds of layered titanate nanosheets, which were produced by using hexylamine and laurylamine, respectively, as surfactants were investigated by Gentle Secondary Ion Mass Spectrometry Gentle-SIMS (G-SIMS) and g-ogram, which is the latest Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS) data analysis method for detecting more intact ions and obtaining the information on original chemical structures of samples precisely from complicated TOF-SIMS spectra. As a result, molecular related ions of the surfactants were detected from each sample, and the structural information of samples was obtained. From both samples, surfactant molecular ions connected with hydrocarbon were detected as more intact ions rather than molecular ions of themselves. It was suggested that hydrophobic domains of their lamellar mesostructure are formed robustly by more than two surfactant molecules connected with each other linearly. After all, important information on the chemical structure of the layered titanate nanosheets, which would be difficult to be found by using typical structural analysis methods such as X-ray diffraction and transmission electron microscopy, were obtained using G-SIMS and g-ogram. Therefore, it was shown that g-ogram and G-SIMS are helpful to evaluate the nanostructured materials. And it was also shown that g-ogram is applicable to organic-inorganic materials which contain long hydrocarbon structures.

Metal Oxide Nanosheets Synthesized by Bottom-up Approach: Applications to Catalyst and Separation Membranes

“…The positive charged DDA molecules act as cations if the pH is adjusted to 10.0-11.0. Previous studies using Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS) analysis, Gentle Secondary Ion Mass Spectrometry Gentle-SIMS (G-SIMS), and g-ogram methods also showed that the DDA molecule in only Ti DDA TEOA sample was not easily fragmented, implying the formation of robust hydrophobic domains with lamellar mesostructure 25), 26) . Thus, the proposed formation mechanism of layered titanate nanosheets is shown in Fig.…”