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Three-dimensional structural analyses of huge spherulites of poly(oxyethylene) (PEG) using X-ray computerized tomography (CT) in blends of PEG and amorphous poly(d,l-lactic acid) are reported for the first time. Slit-shaped cracks that were straight or curved were clearly observed using X-ray CT. Furthermore, they appeared to form a set of spokes, presenting a signature of a huge spherulite. Several aspects that are representative of an axialite structure are presented, and they are in good agreement with the intuitively proposed structural model for axialite long ago, although the size scale is much larger in our study.

Both AB diblock and ABA triblock copolymers consisting of poly(L-lactide) (PLLA: A) and poly(ethylene glycol) (PEG: B) were deposited on a silicon surface on which poly(D-lactide) (PDLA) had been preimmobilized. The deposit of the diblock copolymer (PLLA-PEG) formed band structures similar to those observed when the same copolymer was directly deposited on the silicon surface. In contrast, the deposit of the triblock copolymer (PLLA-PEG-PLLA) formed many particulates scattering over the surface. When the PLLA-PEG deposit was subjected to water-soaking, the original band morphology was completely replaced by the particulate morphology that was identical to that of the PLLA-PEG-PLLA deposit. Their FT-IR analyses revealed that both copolymers had been bound through the stereocomplex (sc) formation between the preimmobilized PDLA chains and the PLLA blocks of the copolymers. Grazing-incidence small-angle X-ray scattering (GISAXS) also supported these surface morphologies. It was therefore evident that hydrophilic PEG chains can be immobilized on the PDLA-preimmobilized surface by the sc formation.

Direct determination of the discrete distribution for crystalline lamellar thickness has been performed for poly( d , l -lactic acid)/poly(oxyethylene) (PDLLA/PEG) blends by conducting small-angle X-ray scattering (SAXS) measurements using synchrotron radiation. The PDLLA used was an random (racemic) copolymer of bio-based poly( l -lactic acid) (PLLA) and poly( d -lactic acid) (PDLA) with the lactide monomer ratio of l : d = 50:50. It is known that PLA is miscible with PEG in the amorphous state. In the current paper, we report comprehensive results on structural analyses of PDLLA/PEG blends in the course of heating and cooling process using SAXS to elucidate the change in the thickness distribution of the lamellae. As a consequence, it was found that the distribution of the lamellar thickness moves toward the larger value (in other words, lamellar thickening) as temperature approaches the melting point. Typically, the thickness distribution was dispersed in the range of 10–20 nm at room temperature and it changed toward 40 nm in the vicinity of the melting temperature. To the best of our knowledge, this is the first report of direct determination of the discrete distribution for the crystalline lamellar thickness and their in-situ changes in the course of the lamellar thickening process. As a result, the lamellar thickening was found to occur at much lower temperature for the blend samples with 10% and 20% of PDLLA contents as compared to the PEG 100% sample. This phenomenon can be ascribed to the melting point depression owing to the miscibility between PEG and PDLLA. Thereby, thinner lamellae were melted and thicker ones appeared at much lower temperature for the blends than for the PEG 100% sample. As for the average repeating distance (long period) of the lamellar stacks, an abrupt increase similar to the critical divergence was observed (from 25 nm to 50 nm) in the heating process. Not only for the melting behavior but also in the course of recrystallization, change in the lamellar-thickness distribution was uncovered, which shows strong hysteresis depending on what temperature the sample was cooled down from.

Intriguing images of dislocation structures were observed by the transmission electron microscopy (TEM) technique for hexagonally packed cylindrical microdomains in a block copolymer (polystyrene-block-polyethylenebutylene-block-polystyrene triblock copolymer) film. The polystyrene (PS) cylinders were embedded in the polyethylenebutylene (PEB) matrix and oriented perpendicular to the surface of the thin section for the TEM observations. In order to understand such strange dislocation structures, we applied an image processing technique using two-dimensional Fourier transform (FT) and inverse Fourier transform (IFT) methods. It was found that these intriguing images were not ascribed to real dislocation structures but were fake ones due to the moiré effect caused by the overlapping of hexagons with a slightly mismatched orientation. Furthermore, grain boundaries in the ultrathin section can be identified by image processing using FT and IFT methods.

Higher-order crystalline structures in blends of poly(lactide)/poly(oxyethylene) (PLA/PEG) were investigated using small-angle X-ray scattering (SAXS). For this purpose, the fact that two polymers are both crystalline makes situation much complicated. To simplify, we used non-crystalline PLA: poly( d , l -lactide) (DLPLA), which is a racemic copolymer comprising d - and l -lactide moieties. Higher-order peaks arising from the ordered lamellar stacking of PEG (i.e. the lattice peaks) were observed in the various blend samples, as well as in the PEG 100% sample, all of which were cast from their solutions in dichloromethane. Surprisingly, we found that the structure is more or less regular in the blend of DLPLA/PEG at compositions of 5–20 wt% of DLPLA than that in the PEG 100% sample. We further examined changes in such regular structures with temperature and found very peculiar SAXS profiles just 1 °C below melting temperature, which can be ascribed to a lamellar particle scattering. To our best knowledge, such a well-defined particle scattering has neither been reported for polymer blends, nor for the crystalline lamellar structure. Moreover, crossover from the lattice scattering to the particle scattering was observed in the temperature range from room temperature to 64 °C for the PEG 100% sample and blend samples with 5–20 wt% of DLPLA.

The effects of thermal gradient on dynamical behavior of nanoparticles dispersed in polymer matrix were studied by X-ray photon correlation spectroscopy. Anisotropic motions of nanoparticles were observed when the sample was kept in a cell using a capillary tube covered with copper block. As the same experiment using another cell without such thermal gradient clearly demonstrated that even the small thermal gradient around the probe windows caused the anisotropic dynamical behavior.

The new experimental system has been launched by coupling with the measurement techniques, which are grazing incidence small/wide-angle X-ray Scattering (GISWAXS) and grazing incidence X-ray diffraction (GIXD), as well as X-ray reflectivity (XR), at the BL03XU of SPring-8. Using this integrated system, we can achieve to measure the hierarchical structure of the same sample.

The performance of a fast pixel array detector with a grid mask resolution enhancer has been demonstrated for X-ray photon correlation spectroscopy experiments., The performance of a fast pixel array detector with a grid mask resolution enhancer has been demonstrated for X-ray photon correlation spectroscopy (XPCS) measurements to investigate fast dynamics on a microscopic scale. A detecting system, in which each pixel of a single-photon-counting pixel array detector, PILATUS, is covered by grid mask apertures, was constructed for XPCS measurements of silica nanoparticles in polymer melts. The experimental results are confirmed to be consistent by comparison with other independent experiments. By applying this method, XPCS measurements can be carried out by customizing the hole size of the grid mask to suit the experimental conditions, such as beam size, detector size and sample-to-detector distance.

We explored the isothermal crystallization process of poly(3-hydroxybutyrate) by means of simultaneous measurements of time-resolved wide-angle X-ray diffraction (tr-WAXD) and small-angle X-ray sca...

A new beamline called the frontier soft-material beamline at BL03XU for soft materials was recently installed at SPring-8, using an in-vacuum undulator. The photon flux can reach 1013 photons sec−1 and the energy resolution is about 10−4 at an energy of 12.4 keV. The present paper introduces details on the instrumental and some of the first scattering data measured at BL03XU, revealing its cutting-edge design and high performance.

Block copolymers forming glassy spheres in the matrix of rubbery chains can exhibit elastomeric properties. It is well known that the spherical microdomains are arranged in the body-center cubic (bcc) lattice. However, recently, we have found packing in the face-centered cubic (fcc) lattice, which is easily transformed into the bcc lattice upon uniaxial stretching. In the same time, the packing regularity of the spheres in the bcc lattice was found to be enhanced for samples completely recovered from the stretched state. This reminds us that a cycle of stretching-and-releasing plays an important role from analogy of densification of the packing in granules upon shaking. In the current paper, we quantify the enhancement of packing regularity of spherical microdomains in the bcc lattice upon uniaxial stretching of the same elastomeric triblock copolymer as used in our previous work by conducting small-angle X-ray scattering (SAXS) measurements using high brilliant synchrotron radiation. Isotropically circular rings of the lattice peaks observed for the unstretched sample turned into deformed ellipsoidal rings upon the uniaxial stretching, with sharpening of the peaks in the direction parallel to the stretching direction and almost disappearing of the peaks in the perpendicular direction. By quantitatively analyzing the SAXS results, it was found that the packing regularity of the spherical microdomains was enhanced in the parallel direction while it was spoiled in the perpendicular direction under the stretched state. The enhanced regularity of packing was unchanged even if the stretching load was completely removed.

Oriented films of cellulose prepared from algal cellulose were hydrothermally treated to convert them into highly crystalline cellulose Iβ. The lateral thermal expansion behavior of the prepared cellulose Iβ films was investigated using X-ray diffraction at temperatures from 20 to 300 °C. Cellulose Iβ was transformed into the high-temperature phase when the temperature was above 230 °C, allowing the lateral thermal expansion coefficient of cellulose Iβ and its high-temperature phase to be measured. For cellulose Iβ, the thermal expansion coefficients (TECs) of the a - and b -axes were α a = 9.8 × 10 −5 °C −1 and α b = 1.2 × 10 −5 °C −1 , respectively. This anisotropic thermal expansion behavior in the lateral direction is ascribed to the crystal structure and to the hydrogen-bonding system of cellulose Iβ. For the high-temperature phase, the anisotropy was more conspicuous, and the TECs of the a - and b -axes were α a = 19.8 × 10 −5 °C −1 and α b = −1.6 × 10 −5 °C −1 , respectively. Synchrotron X-ray fiber diffraction diagrams of the high-temperature phase were also recorded at 250 °C. The cellulose high-temperature phase is composed of a two-chain monoclinic unit cell, a = 0.819 nm, b = 0.818 nm, c (fiber repeat) = 1.037 nm, and γ = 96.4°, with space group = P 2 1 . The volume of this cell is 4.6% larger than that of cellulose Iβ at 30 °C.

We succeeded in elongational crystallization of isotactic polypropylene (iPP) by compressing the supercooled melt. When the elongational strain rate () surpassed a critical value (*=2×102 s−1), crystallization behavior and structure discontinuously changed. The induction time decreased by 10−6 times (Figure), the crystal size decreased by 10−3 times and morphology changed from spherulites to ‘nano-oriented crystals (NOCs)’. It is concluded that large induced the ‘oriented melt’ and NOCs. The NOCs showed high crystallinity and ultra-high performances, such as high tensile stress (210 MPa).

The formation of symmetrical and asymmetrical (miktoarm) star-like nanogels by the cross-linking reaction of complementarily reactive diblock copolymers via a radical crossover reaction of alkoxyam...

The effect of surface molecular motion on the wetting behavior of water on the thin film surfaces of poly(fluoroalkyl methacrylate)s with various fluoroalkyl (Rf) groups [PFMA-Cy; y: fluoromethylene number in Rf groups, y = 1, 2, 4, 6, and 8] was characterized. The receding contact angle of PFMA-Cy with short Rf groups (y = 1, 2, 4, and 6) was larger than that of poly(fluoroalkyl acrylate) with short Rf groups [PFA-Cy, y ≤ 6]. This stable hydrophobicity observed for PFMA-Cy is due to the restriction of thermal molecular motion by the α-methyl group. Wide-angle X-ray diffraction (WAXD) and grazing incidence WAXD measurements revealed that the Rf groups [PFMA-Cy, y ≤ 6] were not crystallized. PFMA-C8 showed high advancing and receding contact angles due to the crystallization of fluoroalkyl groups at the surface region. The hydrophobicity of PFMA-C8 was improved after annealing due to the ordering of fluoroalkyl groups.

Simultaneous measurements of WAXD, SAXS, and Raman spectra have been performed during the water-induced phase transitions of poly(ethylenimine) (PEI). As is well-known, PEI transforms among four ki...

Covalently networked polymer gels were developed with two notable functionalities: de-cross-linking by dynamic covalent exchange based on a radical crossover reaction and insertion of a monomer into the cross-linkers. The network polymer gels were synthesized by free-radical copolymerization of styrene and a bifunctional monomer with an alkoxyamine linker that has two capabilities to exchange with other alkoxyamine derivatives in the radical process and to polymerize styrene in a controlled manner. Three types of network polymers with different cross-linking densities were obtained by changing the ratio of the bifunctional monomer to styrene. The de-cross-linking reaction was carried out by heating the network polymers with excessive alkoxyamine compound in anisole, and it was made clear that the de-cross-linking behavior strongly depended on the cross-linking densities. The insertion of styrene into the alkoxyamine units at the cross-linking points was also performed by heating the network polymers swoll...

The melt isothermal crystallization behavior has been investigated for a series of blend samples of deuterated (D) and hydrogenated (H) species of isotactic polypropylene by means of time-resolved Fourier transform infrared (FTIR) spectral measurement and simultaneous small-angle X-ray scattering (SAXS)/wide-angle X-ray diffraction (WAXD) measurements using synchrotron radiation source in SPring-8. The SAXS data collected were analyzed in the three different time regions. The Guinier plot in the early stage of crystallization gave the average size of isolated domains formed in the melt. In the middle stage, the correlation between these domains was analyzed using the Debye−Bueche equation. In the later stage of crystallization, the correlation function was calculated to estimate the degree of crystallinity and the long period of the stacked lamellae. The IR data analysis clarified the formation process of regular helical chains in the isothermal crystallization phenomenon. The combination of FTIR, WAXD, a...

Kinetics of cross-linking copolymerization of acrylate- and methacrylate-monomers in a liquid crystal blue phase to prepare the polymer-stabilized blue phase were investigated based on dynamic mechanical analysis. Although the polymerization rate of methacrylate-monomers is generally much lower than that of acrylate-ones, we found that a methacrylate cross-linker enhanced the cross-linking copolymerization and an acrylate one suppressed it when acrylate- and methacrylate-monomers were copolymerized with cross-linking. The order of copolymerization rate of monofunctional monomer/difunctional one was monoacrylate (mA)/dimethacrylate (dMA), mA/diacrylate (dA), monomethacrylate (mMA)/dMA, and mMA/dA. The synchrotron small-angle X-ray scattering measurements were carried out to evaluate the aggregated structure of polymer networks in the polymer-stabilized blue phase and found the regular polymer structure corresponding to the disclination lattice of the blue phase, indicating that the polymers were segregated preferentially in the disclination cores. The degree of the regularity of polymer networks was opposite order of copolymerization rate. We obtained a good correlation among the polymerization kinetics, the mechanical elastic constant and the polymer aggregation structure in the polymer-stabilized blue phases, leading to a novel strategy to control the structure and the performance of the polymer-stabilized blue phases.

The phase transition behaviors of low-molecular-weight polyethylene-poly(ethylene oxide) (PE-b-PEO) diblock copolymers with the monomeric units of PE/PEO = 17/40 and 39/86 have been successfully investigated through the temperature-dependent measurements of wide-angle X-ray diffraction (WAXD), small-angle X-ray scattering (SAXS), infrared and Raman spectra, as well as thermal analysis. These diblock copolymers had been believed to show only order-to-disorder transition of lamellar morphology in a wide temperature region, but it has been found here for the first time that this copolymer clearly exhibits the three stages of transitions among lamella, gyroid, cylinder, and spherical phases in the heating and cooling processes. The WAXD and IR/Raman spectral measurements allowed us to relate these morphological changes to the microscopic changes in the aggregation states of PEO and PE segments. In the low-temperature region the PEO segments form the monoclinic crystal of (7/2) helical chain conformation and the PE segments of planar-zigzag form take the orthorhombic crystalline phase. These crystalline lamellae of PEO and PE segments are alternately stacked with the long period of 165 Angstroms. In a higher temperature region, where the PEO crystalline parts are on the way of melting but the PE parts are still in the orthorhombic phase, the gyroid morphology is detected in the SAXS data. By heating further, the gyroid morphology changes to the hexagonally packed cylindrical morphology, where the orthorhombic phase of PE segments is gradually disordered because of thermally activated molecular motion and finally transforms to the pseudohexagonal or rotator phase. Once the PE segments are perfectly melted, the higher-order structure changes from the cylinder to the spherical morphology. These morphological transitions might relate to the thermally activated motions of two short chain segments of the diblock copolymer, although the details of the transition mechanism are unclear at the present stage.

Surface properties of polymeric materials were controlled by fabrication of nano-structure and submicronorder structure of poly(fluoroalkyl acrylate) using the chemical and physical surface modification techniques. The relationship between the ordered structure of fluoroalkyl (R f) groups and water repellency mechanism was precisely investigated by grazing-incidence X-ray diffraction, water contact angle measurements and X-ray photoelectron spectroscopy. It was revealed that poly{2-(perfluorooctyl)ethyl acrylate} (PFA-C8) was crystallized and formed ordered structure to result in high water repellency. Surface nano-texturing onto PFA-C8 film surface was carried out using an anodic aluminum oxide (AAO) membrane as a mold. The nano-texture of AAO mold with a pore diameter of 200 nm was transformed onto the PFA-C8 film surface to fabricate nano-structure, which revealed high water and oil repellency. On the other hand, various types of monomers were grafted on the solid surface through surface-initiated atom...

Microphase-separated structures in poly(styrene-block-isoprene) (SI) block copolymer thin films were investigated by transmission electron microtomography (TEMT). The SI block copolymer showed cylindrical microdomains in the bulk state. Several block copolymer thin films with different thicknesses were prepared by spin-coating and were extensively annealed before the TEMT experiments. Intriguingly, although the cylindrical morphology orienting parallel to the substrate was observed in most of the cases, spherical microdomains were found at certain film thicknesses. The thickness dependence was investigated using a computer simulation based on the self-consistent-field theory, producing a morphological phase diagram based on minimizing free energy. We find that the distortion of the hexagonal lattice of the cylindrical microdomains caused the morphological transition to the spherical microdomains.

Recently, the carbon dioxide (CO2) process with sphere forming block copolymer (bcp) templates successfully introduced nanometer cells into polymeric materials. CO2 selectively swells CO2-philic domains of fluorinated blocks and introduces nanometer voids in the CO2-philic domains. We extended the same methodology to bcp templates with nonspherical domains. Depending on the initial morphologies controlled by selectivity of casting solvents, vertically or horizontally aligned polymer nanosheets spontaneously appeared after the CO2 process and were confirmed by scanning electron microscopy and grazing incident small-angle X-ray scattering. Selective swelling of minority domains with CO2 induces transition to lamellar morphology during the process and results in stacking sheet structure after depressurization of CO2.

Surface-initiated atom transfer radical polymerization of 2-(perfluorooctyl)ethyl acrylate on a flat silicon wafer was carried out to give poly{2-(perfluorooctyl)ethyl acrylate} (PFA-C8) brush thin film with three different thicknesses of 4, 11, and 43 nm, respectively. The water contact angle of the PFA-C8 brush surface was 120°. The molecular aggregation state of the perfluoroalkyl (Rf) group of PFA-C8 brush was analyzed by X-ray reflectivity (XR), wide-angle X-ray diffraction, and grazing incidence X-ray diffraction (GIXD) measurements. XR analysis revealed that Rf groups at the air/brush interface formed a densely packed structure, while a relatively low-density region was generated at the brush/substrate interface. The peaks of in-plane GIXD for brush films with thicknesses of 11 and 43 nm were observed at qxy=12.5 nm−1, which indicated that Rf groups at the outermost surface oriented perpendicular to the surface of silicon substrate. In an out-of-plane diffraction profile of the 43 nm-thick PFA-C8 brush film, peaks corresponding to a periodic length of the bilayer lamellae were observed. Therefore, Rf groups of the thicker brush film were crystallized and formed ordered bilayer lamellar structure at the outermost surface. In contrast, no diffraction pattern was observed from the PFA-C8 at a thickness of 4 nm by WAXD and GIXD. These results indicate that an amorphous layer was formed at the interface of the brush/substrate. The Rf groups at the anchoring region of the brush could not form a sufficiently ordered structure due to immobilization of brush chain ends on the substrate. It was suggested that the Rf groups in a PFA-C8 brush thin film at the outermost surface aggregated in a different manner from those in the anchoring region.

Anomalous small-angle X-ray scattering (ASAXS) profiles of Zr80Pt20ribbons have been measured at the ZrKabsorption edge. By annealing the melt-spun ribbons at 800 K, well defined SAXS patterns from nanoquasicrystals were observed, although the compositions of the quasicrystals (QC) and the amorphous matrix have previously been reported to be the same. The SAXS intensities were found to show a small anomalous effect at the ZrKedge. Contrast analysis suggested that the origin of the small-angle scattering is a small compositional fluctuation coupled with a small density difference, which enhances SAXS intensity but reduces the anomalous effect. A constant ASAXS intensity ratio for QC microstructure suggests that the ratio of the composition difference to the density difference between QC and the amorphous matrix is almost constant for the ZrPt ribbons examined here.

Phase development during melt-drawing of ultra-high molecular weight polyethylene (UHMW-PE) was analyzed by in situ small-angle X-ray scattering measurements using synchrotron radiation at the SPring-8. Films with different entanglement characteristics were prepared by solution blending of higher and lower MW samples with a viscosity average MW of 1.07 × 10 7 (higher) and 1.73 × 10 6 (lower), followed by compression molding at 180 °C. Independent of blend ratio, the strong streak attributed to extended-chain crystals (ECCs) appeared on the equator at the beginning point of the plateau stress region in the stress profile, which was one of the characteristic features of melt-drawing. A series of detailed analyses of these streaks suggested that two components with different dimensions were formed during melt-drawing: one was a precursory ECC, and the other was a mature ECC. These two ECC components grew synchronously at the beginning point of the plateau stress region for both films, independent of the entanglement characteristics of the film. However, the time of this synchronized growth was longer for the film with the lower MW component than for the film containing only the higher MW component. The resultant morphologies of the melt-drawn samples observed by transmission electron microscopy also reflected these characteristics. These results demonstrate that molecular entanglement characteristics dominate the unique crystallization mechanism that forms ECCs with different dimensions during melt-drawing of UHMW-PE.

A new system of rapidly-scanning DSC/WAXD/SAXS simultaneous measurements has been successfully developed at the BL40B2 in SPring-8, Japan. The combination of the ultra-bright and highly-directional X-ray beams with the highly-sensitive two-dimensional (2D) detectors such as an imaging plate (IP), a CCD detector and a flat panel (FP) detector has made it possible to perform the rapidly-scanning time-resolved measurements of WAXD and SAXS for the polymeric materials subjected to the various kinds of external field like temperature, tensile force, magnetic field, hydrostatic pressure, and so on. The experimental data about the phase transitions of vinylidene fluoride-trifluoroethylene copolymer with VDF 82 mol % content and poly(vinylidene fluoride) form I have been presented as actual examples, where the phase transitions of the polar crystal consisting of planar-zigzag chains to the gauche-type high-temperature phase have been confirmed definitely and the remarkable change in lamellar stacking structure could be detected in the temperature region immediately below the melting point.

The time-resolved small-angle X-ray scattering technique was used to investigate the structural change during uniaxial stretching of dynamically asymmetric polymer blends irradiated by an electron beam. The concentration fluctuations were enhanced by stretching and became large in particular along the direction of deformation. In the early stages of the stretch-induced enhancement of concentration fluctuations, the growth rate of their q-Fourier mode was found to have a maximum at a certain value of q [= (4π/λ)sin(θ/2), where θ and λ are the scattering angle and the wavelength of the X-rays, respectively]. A dominant mode in the enhancement of concentration fluctuations exists in the initial stage, like the early stage of spinodal decomposition for fluid mixtures. The viscoelastic effects of the growth rate were taken into consideration, so that for blends irradiated by an electron beam, elastic effects are found to significantly suppress the growth rate of concentration fluctuations at small wavenumbers.

Degree of supercooling (ΔT) dependence of nano-nucleation was studied by means of small angle X-ray scattering (SAXS) and a new nucleation theory was proposed. We obtained the ΔT dependence of size distribution f(N,t) directly, where N is number of particle and t is time, which concluded that the “induction period” of crystallization is not controlled by so called “spinodal decomposition” but by nucleation one. It clarified that the critical nano-nucleation mainly controls not only the steady nano-nucleation but also macro-crystallization experimentally as the zero-th approximation by using the newly obtained ΔT dependence of f(N,t) and nucleation rate (I) of macroscopic crystal obtained by means of optical microscope (OM). Time evolution of total free energy of nucleation of a huge closed system δG(t) was obtained experimentally for the first time, which clearly confirmed that nano-nucleation is the process where δG(t) passes through an activation barrier and reaches the most stable state by completion of melt-solid (crystal) phase transition due to well known “Ostwald ripening”. We proposed a new nucleation theory by introducing a “mass distribution function Q(N,t) ∝ Nf(N,t)”. We proposed a new basic equation of the mass conservation law, ∂ Q ( N , t ) / ∂ t = − ∂ j ( N , t ) / ∂ N , where j(N,t) is net flow. This solved the serious problem in classical nucleation theory (CNT), where so called “fundamental kinetic equation” does not satisfy the mass conservation law. The coupling of our “real image” and correct theory will enable us to realize the ultimate structure and physical properties of materials, which should be a very interesting “fruit”.

When we mixed two transparent aqueous solutions of tetrasodium N,N-bis(carboxylatomethyl) glutamate (GLDA) and sodium oleate (OleNa), a white gel phase was formed when the total solute concentratio...

Nucleation mechanism of polymers was studied by means of small angle X-ray scattering (SAXS) by improving our two previous studies. The first one showed first direct SAXS observation of nucleation of polyethylene (PE). The second one reported how “size distribution f(N,t)” of nuclei of nano-meter size (nano-nuclei) evolves with time (t), where N is number of “repeating unit” in a nucleus. Unfortunately the f(N,t) was obtained by incorrect analysis of SAXS intensity (IX), i.e., too simple one-dimensional (1D) nucleus was assumed to analyze the IX. In this paper, we determined simultaneously correct f(N,t) and “two-dimensional (2D) shape” of nano-nucleus. From this it is clarified that nano-nucleus shows significant fluctuation in size and shape and repeats frequent generation and disappearance, which corresponds to the conclusion that the end surface free energy of the nano-nucleus (σe(nano)) is 1/5 times as large as that of macroscopic crystal (σe(macro)). f(N,t) decreased with increase of N. f(N,t) increased and saturated with increase of t.

ポリアルキルシロキサン超薄膜の二次元凝集構造と分子運動特性について，面内微小角入射 X 線回折(in-plane GIXD)測定を中心に詳細な検討を行った．長鎖アルキル基を有するポリアルキルシロキサン超薄膜の分子凝集状態は，超薄膜の調製法に強く依存した．長鎖アルキル基の融点以上の温度で気相からの化学吸着(CVA 法)によりシリコン基板上に固定化されたポリアルキルシロキサン超薄膜は非晶を形成した．これは，アルキル基の融点以上の温度においてアルコキシシリル基が基板表面で重合・固定化したため，長鎖アルキル鎖の結晶化が妨げられたことに起因する．一方，溶液からの化学吸着，および水面キャスト法により調製した超薄膜の長鎖アルキル基は結晶性を示した．これは，これらの調製法では，温和な条件下において長鎖アルキル基が結晶化を伴いながら，アルコキシシリル基の重合とシリコン基板への固定化が進行したためであると考えられた．

The spin-crossover properties of lipophilic, supramolecular Fe(II) complexes bridged by 4-(3-dodecyloxy)propyl-1,2,4-triazole [Fe(II)(1)3Cl2] were investigated in chloroform and cast films. A purple low-spin (LS) complex in a powdery form was transformed into pale yellow high-spin (HS) polymers by dissolution in chloroform. The formation of lipophilic molecular wires in chloroform was observed with transmission electron microscopy. The casting of chloroform solutions onto solid supports produced purple, transparent films (LS state). The cast films exhibited sluggish spin-crossover (LS ⇋ HS) behavior without thermal hysteresis. On the other hand, the cocasting of equimolar dodecanol or tetradecanol with Fe(II)(1)3Cl2 produced composite films in which alcohol molecules were bound to the complex by ionic hydrogen bonding (ROH···Cl−) and van der Waals interactions. At room temperature, the cast films exhibited regular lamellar structures before and after alcohol doping; this was confirmed by wide-angle X-ray diffraction measurements. Interestingly, the Fe(II)(1)3Cl2/CnOH (n = 12 or 14) ternary films showed a reversible abrupt spin crossover accompanied by thermal hysteresis. The observed bistability was related to dynamic structural transformations between lamellar and hexagonal structures. This study provides a novel supramolecular approach to designing spin-crossover polymer films with controlled thermal bistability. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5192–5202, 2006

Biodegradable segmented poly(urethanerea)s (SPUU's) were synthesized by a standard two-step prepolymer method using lysine-based diisocyanete and polycaprolactone diol (PCL) as a soft segment combined with 1, 4-butanediamine (BDA) as a hard segment. Thermal analysis by differential scanning calorimetry, wide angle X-ray diffraction (WAXD), and small angle X-ray scattering measurements revealed that the relative ratio of PCL and BDA segments in SPUU changed the crystallinity of PCL segment and the microphase separation structure consisted with soft and hard segments. Diffraction pattern in WAXD due to the crystal of PCL components disappeared in the case of SPUU containing 71% of PCL segment. Furthermore, the SPUU with 71% PCL segment showed good elastic properties because the crystallization of PCL component was completely inhibited by the strong aggregation of hard segments. BOD biodegradation test was performed by dipping SPUU into activated sludge for 30 days. Higher degradation rate was observed in the SPUU with higher enntent of PCT segment.

Crystal structure in thin films of melt-crystallized and annealed polyethylene (PE) was examined by grazing incidence X-ray diffraction measurements. Choosing appropriate incident angles of X-rays to the films, surface and bulk molecular aggregation states were successfully extracted. Consequently, it was found that chain packing structure in the surface region was different from that in the bulk one. Based on paracrystalline analysis for the (110) reflection and its higher-order ones of PE orthorhombic crystal, it was clarified that the ordering for the crystalline lattice was lower in the surface region. Also, apparent crystallinity in the surface was lower than the bulk one. These results indicate that disordered crystallites were preferentially formed in the surface region.