An environmentally friendly greening material was fabricated using water-soluble, biodegradable polyaspartic acid derived from biomass. Polyaspartic acid was cross-linked with 1,4-diaminobutane, where the best water absorption was achieved when the cross-linking agent/polymer ratio was 20%. Moreover, germination tests of soil employing the water-absorbing polymer showed promoted elongation growth and suppressed axial length dispersion in tested plants.

  For classical, discrete many-body systems in thermodynamically equilibrium state, expectation value of internal energy, structure, and free energy can be well characterized by a single specially-selected microscopic structure, which is recently revealed by our study. This finding relies on the fact that configurational density of states (CDOS) for typical classical system under constant composition before applying interatomic interaction can be well characterized by multidimensional gaussian distribution. Although gaussian distribution is an well-known and widely-used function in diverse fields, it is quantitatively unclear why the CDOS takes gaussian when system size gets large, even for projected CDOS onto a single chosen coordination. Here we demonstrate that for binary system at equicomposition, one-dimensional CDOS along coordination of pair correlation can be reasonably described by gaussian distribution under an appropriate condition, whose deviation from real CDOS mainly reflects the existence of triplet closed link consisting of the pair figure considered. The present result will make significant advances in analytic determination of the special microscopic states to characterized macroscopic physical property in equilibrium state.

To investigate the formation of a Mg-based long-period stacking ordered (LPSO) structure, we systematically studied the preference of the short-range order (SRO) in metastable disordered phases of Mg-RE-Zn (RE = Y, La, Er, Ho, Dy, Tb) and Mg-Gd-Al ternary alloy systems through first-principles calculations. Both the RE-Zn (RE = Y, Er, Ho, Dy, Tb) and Gd-Al pair cluster probabilities exhibited an increasing tendency. On the other hand, in a Mg-La-Zn system, which does not form an LPSO structure, the La-Zn pair cluster probability does not increase. This preference toward SRO in the disordered phases of Mg-based ternary alloys indicates that L1₂-type ordering in the LPSO structure as well as the possibility of LPSO formation should have a strong correlation with the SRO tendency of energetically competitive disordered phases.

Tin dioxide (SnO₂) films were epitaxially grown on m-plane sapphire and (001) plane titanium dioxide (TiO₂) substrates using mist chemical vapor deposition. The quality of SnO₂ film was evaluated by full width at half maximum (FWHM) of X-ray diffraction (XRD) ω-rocking curve. The lowest value of FWHM was 0.06° for the SnO₂ film on TiO₂ substrate, which was lower than the other reported values. Not only vertical lattice constant but also lateral one were measured by XRD reciprocal space mapping (RSM) and transmission electron microscopy (TEM). Then, the lattice constants of the SnO₂ film on TiO₂ substrate were the same as those of the bulk SnO₂. From the results of TEM and electron backscattering diffraction (EBSD) observations, the quality of the SnO₂ film was higher at upper portion of the SnO₂ film. These results indicated that high-quality single crystal SnO₂ film was formed on TiO₂ substrate.

Photochemical behaviors of native lignin derivatives such as sulfric lignin (SL), dioxane lignin (DL), alkaline lignin (AL), lignosulfonate (LS) and lignophenol (LP) were qualitatively investigated using UV spectroscopy and Fluorescence spectroscopy. All lignin derivatives were prepared directly from softwood (Hinoki cypress, Chamaecyparis obtusa) and hardwood (Birch, Betula maximowicziana) with different degrees of conjugation in structures produced through isolation processes. Though all lignin derivatives showed broad absorption peaks between 260-350 nm in UV spectra, it was difficult to estimate influences of conjugations because of broad peaks. On the other hands, fluorescence spectra demonstrated different peaks from 300 nm to 600 nm with several shoulder peaks due to different relaxation processes according to wood species and for different chemical structures of lignin. Moreover, the strongest fluorescence of SL in THF at 310 nm and 380 nm implied relatively parallel conformations of aromatic rings fixed in complicated 3-dimensional structures. LS and LP showed different peaks between wood species. On the other hands, relatively small fluorescence of other lignins also implied conjugations positioned randomly in lignin macromolecular chains. As a result, it was found that different peaks in emission spectra were reflected by not only different energy levels of conjugations around aromatic rings but conformation of aromatic conjugation groups.

To understand the adsorption of functional proteins onto metal oxides in living bodies at the atomic/molecular scale, we examined the adsorption behaviors of amino acids, the fundamental elements of proteins, onto atomically flat surfaces of metal oxides not in ultra-high vacuum but in aqueous solutions using atomic force microscopy (AFM) as a preliminary step in the study of the adhesion processes of living cells onto various biomaterials. Two types of atomically flat Al₂O₃(0001) surface were observed in aqueous solutions of glycine and L-alanine using the AFM in contact mode. The first type (single-step surface) consisted of atomically flat terraces separated periodically by almost parallel steps of unit cell height. By contrast, the step height in the second type (multi-step surface) was about 5–10 unit cells owing to step bunching. In glycine solution, specific adsorption onto the multi-step surface was observed in the terrace positions apart from step edges, whereas no adsorbates were found in the AFM images of the single-step surface. Conversely, uniform adsorbates were found on both single- and multi-step surfaces in L-alanine solution. The multi-step surface is expected to be used as a tool for controlling glycine adsorption owing to the specificity of adsorption.