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Copper slag (CS) granules received from a Japanese smelter were melted using an alumina crucible under Ar gas flow in an electric furnace. The melt was removed from the furnace and cooled slowly with various holding times in air and then water-quenched. The increase of cooling time in air promoted the partial crystallization of CS samples: the separation of Fe-rich and Si-rich phases, the precipitation of fayalite and magnetite phases and the formation of Al2O3- and SiO2-rich non-crystalline aluminosilicate phase. The CS melt was subdivided into smaller ones through a hand-made yttria-doped stabilized zirconia polycrystal sieve and repelled by a rotational graphite plate. After cooling crystallized CS granules were successfully fabricated. The crystallized CS granules including fayalite and magnetite phases satisfied a lower limit for the elution amounts of As and Pb fixed as ≤150 mg/kg in 1 mol/L HCl aqueous solution as specified in the guideline of JIS 0058-2:2005 as a test method for acid-extractable contents of chemicals.

In general, glasses have a random structure, but they can take on unique structures due to bond selectivity. In this paper, we introduce the bond selectivity of oxygen- and fluorine-containing glasses and the formation of glass structures derived from the bond selectivity of each anion. We present the relationship between BaMgBO3F crystals and BaF2-MgO-B2O3 glasses. The crystal is composed of oxide and fluoride layers. The corresponding glass is suggested to have a bicontinuous structure from structural analysis and simulation. The glass has a favorable structure for luminescence and shows higher luminescence efficiency than the corresponding crystal. Such a structure is also favorable for nucleation; the BaF2-ZnO-B2O3 glass precipitated fluoride crystals with a very small particle size distribution at 5 nm upon heat treatment. Various structural analyses suggest that the fluoride sites in the fluoride-rich domain of this glass structure are similar to the crystals. This paper suggests that various functionalities can be developed by utilizing the mixing heterogeneity derived from the selective binding of fluoride and oxide. [ABSTRACT FROM AUTHOR]

In recent years, crystal growth processes have attracted great interest because of the importance in semiconductor devices as well as organic devices. In the present articles, experimental innovations to observe crystal growth processes using various microscopic methods are reviewed. Correspondingly, novel approaches in the theoretical investigation of crystal growth processes are also reviewed. Step dynamics including macrostep formation and step bunching, pattern formation, high-quality crystallization, chemical vapor deposition (CVD) process, and various crystal growth environments not only in vacuum but also in liquid and in space are focused. [ABSTRACT FROM AUTHOR]

An aqueous solution of 2,3-cis gallate type catechin (-)-epigallocatechin-3-O-gallate (EGCg) and caffeine afforded a precipitate of Creaming-down Phenomenon, which crystallized slowly for about three months to give a colorless block crystal. By X-ray crystallographic analysis, the crystal was determined to be a 2 : 2 complex of EGCg and caffeine, in which caffeine molecules were captured in a hydrophobic space formed with three aromatic A, B, and B' rings of EGCg. It was considered that the solubility of the 2 : 2 complex in water rapidly decreased and the 2 : 2 complex precipitated from aqueous solution. The hydrophobic spaces of EGCg captured a variety of heterocyclic compounds, and the molecular capture abilities of heterocyclic compounds using EGCg from the aqueous solutions were evaluated. Since the C ring of EGCg has two chiral carbon atoms, C 2 and C 3 , the hydrophobic space of EGCg was a chiral space. EGCg captured diketopiperazine cyclo(Pro-Xxx) (Xxx=Phe, Tyr) and pharmaceuticals with a xanthine skeleton, proxyphylline and diprophylline, in the hydrophobic space, and recognized their chirality.

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It was found in the early 1990s that bulk metallic glasses (BMGs) are formed by use of high stability of supercooled liquid to crystallization which can be achieved only for multicomponent alloys with the three-component rule. Since then, much effort has been devoted to clarify the formation ability, atomic configuration, microstructure, thermal stability and various fundamental properties of BMGs. More recently, further high-order multicomponent nonequilibrium bulk alloys, which have been called as high entropy (HE) type alloys, have attracted special interest and the HE alloys have also been extended to crystalline bulk supersaturated solid solution alloys as well as BMGs. This paper aims to present the structure, thermal stability and mechanical properties of HE BMGs, Pseudo-HE BMGs and HE amorphous alloys, in addition to ordinary BMGs, and to investigate the features and prospects of their new high-order multicomponent glassy and amorphous alloys. [ABSTRACT FROM AUTHOR]

We investigated the stereocomplex crystallization process of poly(L-lactic acid)/poly(D-lactic acid) blend from the glassy state and the molten state with polarized optical microscopy, DSC, synchrotron radiation X-ray scattering and FT-IR measurements. In the case of crystallization from the glassy state, we observed homo crystals, that is the pure crystal form of poly(L-lactic acid) or poly(D-lactic acid), and stereocomplex crystals below the melting point of homo crystals. The lamellar structure of homo crystals grows during heating, and above the melting point of homo crystals two long spacing periods, 63 and 20 nm, respectively, were observed. The sub-micron scale crystals grew further and the aggregate of sub-micron scale crystals developed a rough surface. On the other hand, during cooling from the molten state, the long spacing period was 40 nm. On the micron scale, we could observe crystals with a size of several ten pm with a smooth surface. [ABSTRACT FROM AUTHOR]

Protein crystals form in supersaturated solutions via a nucleation and growth mechanism. The amyloid fibrils of denatured proteins also form via a nucleation and growth mechanism. This similarity suggests that, although protein crystals and amyloid fibrils are distinct in their morphologies, both processes can be controlled in a similar manner. We show that ultrasonication is one of the most effective methods of agitation for accelerating spontaneous fibrillation. We also show that ultrasonication is also useful for forming crystals of proteins. We address the underlying mechanism of the ultrasonication-dependent breakdown of supersaturation, leading to the formation of amyloid fibrils or protein crystals. [ABSTRACT FROM AUTHOR]

Poly(lactic acid) (PLA) is an environmentally-friendly biodegradable polymer. It is often used in packages, in automobiles, and for electronics. We can even expected that PLA replaces petroleum-based plastics. PLA crystallization can be controlled by cooling and heating, organic solvents, and vacuum ultraviolet irradiation. This paper focuses on controlling the crystalline structure by thermal-, solvent-, and photo-induced crystallization. The effect of the crystalline structures on PLA membranes on gas transport properties was systematically investigated. Interestingly, unlike common crystalline polymer membranes, the permeability through a crystalline PLA membrane was larger than that through an amorphous PLA membrane. PLA is an interesting polymer, whose gas permeability is not significantly affected by its isomer ratio and crystallinity in the L:D-donor ratio range of 98.7:1.3-50:50 and in the crystallinity range of 0-25%. [ABSTRACT FROM AUTHOR]

The deterioration mechanism of polyethylene with increased temperature resistance (PERT) used for hot water supply plumbing was investigated. The deterioration in 120°C air was analyzed by using FT-IR. The following results were found (1) Degradation begins from the place where orientation relaxes gently and the amount of antioxidants decreases. The degradation by oxidation starts from surface. It advances along the surface, but does not advance that much into the bulk. (2) The progress of surface deterioration can be evaluated by the ratio acid to aldehyde peak of the carbonyl group. (3) It is necessary to evaluate not only the amount of carbonyl groups, at around 1600 cm-1 but also its type (acid or aldehyde). The above result correlate with the results of tensile-strength tests and thermal measurements. The deterioration process of PERT can be analyzed more clearly by the FT-IR imaging method and visualization in two dimensions. [ABSTRACT FROM AUTHOR]

A novel in situ pulse NMR measurement system during uniaxial drawing was developed by incorporating drawing and stress-detecting devices into a ¹H pulse NMR. The temperature was controlled by heated air or an infrared guided heating system from the direction normal to the uniaxial direction. This in situ pulse NMR system was used to investigate the melt drawing of ultra-high molecular weight polyethylene with different molecular weight distributions. Analysis of the results indicates that the disentanglement during melt drawing depends on the molecular weight distribution. Melt drawing of ultra-high molecular weight polypropylene was also analyzed. Disentanglement and oriented crystallization depends on the drawing temperature. From these results, it is shown that the developed in situ pulse NMR system is useful to analyze the dynamic structure of polymers during uniaxial drawing. [ABSTRACT FROM AUTHOR]

A simultaneous measurement system of wide-angle X-ray diffraction (WAXD), small-angle X-ray scattering (SAXS) and Raman or transmission- type infrared spectroscopy was developed by us. Its purposes is to clarify the static and dynamic structural changes of polymer materials subjected to the various external condition changes. Some examples described here include the study of the stretch-induced reorientation phenomenon of a-axially-oriented polyethylene, the study of structural change in photo-induced solid-state polymerization reaction of muconic acid ester monomer crystal, the study of the two-stage high-temperature phase transitions of aliphatic nylons, the study of stress-induced crystalline phase transition of an oriented poly(tetramethylene terephthalate) sample and its relation to the higher-order structural change, and the study of structural regularization process of poly(L-lactic acid) in the isothermal crystallization of the meso phase. These case studies in the clarification of hierarchical structural changes of polymer materials have proven that the simultaneous measurement systems can be useful to examine the structural changes in polymer systems. [ABSTRACT FROM AUTHOR]

This paper discusses the fabrication method of Poly(vinylidene fluoride) (1) crystal having excellent dielectric properties. We tried to control crystal structure of PVDF in the blend films of PVDF and Poly(methyt methacrylate) (PMMA) prepared by solvent casting. PVDF/PMMA = 60/ 40wt.% blend was dissolved in DMF solvent at 120°C. After casting, the PVDF/PMMA blend films were baked at 150°C (B). Each film was quenched (Q) from melting state and then was annealed at 120°C (QA). As a result, we demonstrated that PVDF (I) crystal grows preferentially under the existence of PMMA. That the crystallization speed of the quenched and annealed PVDF/PMMA blend films (QA) with the blend ratio of PVDF/ PMMA = 60/40wt.% is comparatively slow and forms the PVDF (I) crystal. [ABSTRACT FROM AUTHOR]

Crystallization behaviors of polymer blends are reviewed. The crystallization of polymers is delayed in polymer blends by exclusion of non-crystalline components from the crystal growth front and crystals grow nonlinearly with crystallization time. Various crystalline morphologies are obtained by controlling the degree of exclusion in polymer/polymer, polymer/oligomer and polymer/carbon dioxide systems. On the other hand, the crystallization rate of polypropylene and poly(l-butene) was found to be drastically accelerated by blending the polyolefln with cyclodextrin inclusion complexes. In the blends with a two-phase region below the melting temperature, characteristic crystallization behavior occurs by competitive progress of phase separation and crystallization. Crystallization of polycarbonate was induced by the up-hill diffusion of the liquid-liquid phase separation via spinodal decomposition and connected spherulites were developed, for instance. [ABSTRACT FROM AUTHOR]

The phase transition from the crystalline-amorphous alternative lamellar structure (CA-LAM) to Gyroid (Gyr) in polybutadiene-block-poly(ε-caprolactone) was investigated using small angle X-ray scattering. It was found that the phase transition from CA-LAM to Gyr occurred via metastable structure. When the composition of crystalline component was close to the Gyr/hexagonally packed cylinder phase boundary in a phase diagram, the hexagonal structure was first observed as a intermediate structure. On the other hand, when the composition was close to the Gyr/lamellar phase boundary, the layer structure was first formed as an intermediate structure. These results indicate that the regularity of this intermediate structure was dependent on the composition of the crystalline component. [ABSTRACT FROM AUTHOR]

Nano-structured spherical particles of polyamide-6 (N6) are generated by rapid mixing of a cresol solution of N6 with an aqueous solution of methanol. Their structures and morphologies are studied vs. relative compositions of N6 and solvent molecules. Very slow crystallization at compositions near the boundary of crystal-solution phase separation brings about precipitates of axialite-like or fiber-like morphology. On the contrary, rapid crystallization far from the phase boundary, thereby with much larger supersaturation, is found to generate spherical particles with peculiar nano-scale structures. Light scattering and small angle X-ray scattering from the particles show that the structure of the particle is similar to the usual spherulites in bulk N6, but with a smaller long period and a more ordered stacking of the constituent lamellae. [ABSTRACT FROM AUTHOR]

Convectional, sedimentation and drying dissipative patterns during the course of dryness of solutions and suspensions including polymer solution are reviewed. The whole processes of convection were analyzed in the seven steps: irregular circulation accompanied with the upward heat transportation, global convectional flow from the central area toward outside edge at the surface layers of liquid, cooperative formation of distorted Benard cells, reversal of the global flow of convection, growing of the spoke lines from the outside edge toward central area at the liquid surface layers, cluster and further bundle formation of the spoke lines, and the convectional flow by the pinning effect. The sedimentary colloidal particles were suspended above the substrate by the electric double layers and moved by the balancing of the external force fields including convectional flow and sedimentation. Principal macroscopic drying patterns are broad rings and spoke lines. Microscopic patterns such as star, needle, street road, string and cross-like are formed. The stratified structures form from micro to macro scales. Information on the size, shape, conformation, flexibility and/or solute concentration of polymers and particles is transferred cooperatively toward drying patterns, and further accompanied with the amplification and selection processes during the course of dryness. [ABSTRACT FROM AUTHOR]

The evolution processes of regular structure in isothermal crystallization phenomena of crystalline polymers have been investigated from the viewpoints of molecular level, crystal lattice, and higher-order structure on the basis of time-dependent infrared spectral data and synchrotron small- (SAXS) and wide-angle X-ray scattering (WAXD) data. The polymers treated here were isotactic polypropylene (iPP), nylon 10/10 and polyoxymethylene (POM). In the case of iPP, the formation and growing processes of regular helical segments in the molten state are described by utilizing the concept of critical sequential length for infrared bands. Combination of these spectroscopic data with the SAXS and WAXD data clarifies the formation process of domains consisting of regular helical segments, the increment of correlation of neighboring domains, and the development of stacked lamellar structure, during which the remarkable growth of crystal lattices consisting of regular helices occurs in parallel. In the case of nylon 10/10, weak hydrogen bonds are formed between amide groups even in the molten state. Once the isothermal crystallization starts to occur, these more-or-less correlated domains built up by the hydrogen bonds are formed followed by the formation of crystal lattices consisting of relatively regular methylene segments. Such growth is quite different from the case of iPP crystallization. The study of POM is based on the observation of infrared bands intrinsic to the folded chain crystals (FCC) and extended chain crystals (ECC). From the time-resolved measurements of these infrared bands as well as the SAXS and WAXD in the isothermal crystallization process of POM, we clarified that the lamellar structure of FCC morphology is formed at first. Then some new lamellae are formed in between these original lamellae, resulting in the formation of ECC parts in which the regular helices pass through the several neighboring lamellae as taut tie chains. [ABSTRACT FROM AUTHOR]

Polymer crystallization from the melt occurs via two main mechanisms: primary nucleation and crystal growth. The crystal growth mechanism on polymer crystallization has been widely investigated. However, the primary nucleation mechanism has not been discussed in detail yet. In this study, the nucleation rate (I) and saturation nucleus number (Ns) of the α and β forms of isotactic polypropylene (iPP) were measured in a wide range of crystallization temperature (Tc). Calcium pimelate was used as a β-nucleation agent. The nucleation behavior of the α and β forms of iPP were discussed. The crystallization temperature dependence for α and β forms showed bell-shaped curves with the maximum nucleation rates (Imax) at about Tc = 50 and 78 °C, respectively. The nucleation of the β form is dependent not only on the nucleation agent but also on nucleation temperature. [ABSTRACT FROM AUTHOR]

The strain-induced crystallization of natural rubber (NR), dispersed in styrene-butadiene rubber (SBR), was investigated by measuring the tear energy (G) of crosslinked NR/SBR blends. The NR, SBR and NR/SBR blends were crosslinked with various amounts of dicumyl peroxide. The G values of NR, SBR and NR/SBR blends, measured over wide-ranges of temperature and tear rate, were superposed into a master curve with a Williams-Landel-Ferry shift factor. The master curve of G for the NR/SBR blend abruptly increased at temperatures where NR crystals formed on straining, whereas that of SBR was shown a single master curve. Since the master curve of G for NR/SBR blend corresponded to a master curve that was calculated from the G of NR and SBR, the G of NR/SBR blend was associated with the dimensional features of the NR dispersoid and the crosslink density. These results clearly demonstrate that the strain-induced crystallization of NR in blends plays an important role in the mechanical properties of blends. [ABSTRACT FROM AUTHOR]

Crystal thicknesses lc of isotactic polybutene-1 (it-PB1) have been investigated for crystallization in the melt over a wide range of crystallization temperature T from 40 to 90°C by small angle X-ray scattering experiments and density measurements. Single crystal morphology was also observed by transmission electron microscopy and optical microscopy. The lc value demonstrates two linear dependences on inverse supercooling; a transition from one dependence to the other has been observed around T= 60-70°C. One of the two dependences obeys the nucleation theory in the high supercooling range, and the other obeys the theory in the low supercooling range. Chain folding free energy q determined from the low supercooling range is larger than that determined from the high supercooling range. We discuss possible mechanisms for the transition, taking account of the entropy of chain folding directions. We propose that the difference in the q values could be due to the change in directional entropy of chain folding caused by kinetic roughening. [ABSTRACT FROM AUTHOR]

We performed polarized optical microscope (POM), depolarized light scattering (DPLS) and small-angle X-ray scattering measurements on the structure formation process or the crystallization process of isotactic polystyrene (iPS) under shear flow below and above the nominal melting temperature Tm. It was found that a micron scale anisotropic oriented structure termed here as "string-like object" was formed even above the nominal melting temperature that is stable for more than 24 h, but melted at around 270°C far above the nominal melting temperature. The string-like object acts as a nucleation agent for the folded chain lamella crystal (or the kebab). We also examined the shear rate dependence of the structure formation to find a critical shear rate and a critical strain for the formation of the string-like object, suggesting the orientation and relaxation of the chains plays an important role in the formation of the structure. [ABSTRACT FROM AUTHOR]

Lateral surface and end surface free energies of melt-crystallized isotactic polybutene-1 (it-PB1) trigonal and tetragonal crystals have been determined by small angle X-ray scattering (SAXS) and in-situ observation of the crystal growth kinetics. Lateral surface free energy σ of the trigonal phase is about 7 times as large as the value σHoff calculated according to Hoffman's model of surface free energy, while that of the tetragonal phase is roughly in agreement with the σHoff value. The discrepancy between the values of σ and σHoff for the trigonal phase can be attributed to the loss of the conformational entropy of the ethyl side chains of it-PB1. [ABSTRACT FROM AUTHOR]

The oriented film of polyoxymethylene has not been prepared on an industrial scale although it shows excellent mechanical performance as an engineering plastic. A 2-step orientation method was applied to the polymer in order to develop it for an industrial use. Prior to drawing, the POM sheet was rolled based on the results of fundamental studies using press and simultaneous biaxial drawings. The physical structure was stabilized by the rolling treatment due to the smaller lamella, although the mechanical characteristics depended on the direction of the film. The temperature control was important in the process where the drawing ratio was more than 8 times and the temperature was 170°C. The drawing of 10 times or more was impossible for the excess orientation. The tensile modulus of the film obtained by the large-scale test was smaller than that of the basic test film because of the lack of uniformity and the relation between the crystallization rate and the drawing time. This study showed that an oriented polyoxymethylene film could be produced in an industrial scale by controlling the crystal structure. [ABSTRACT FROM AUTHOR]

The crystallization of active pharmaceutical ingredients (APIs) in matrix-type transdermal patches has implications for the rate of drug absorption through the skin and patch adhesion strength. Therefore, the presence or absence and the degree of API crystallinity must be controlled to guarantee the quality of patches. In this study, the utility of laboratory-level X-ray diffractometers for the detection and analysis of crystalline APIs in transdermal patches was investigated using medical patches of tulobuterol and isosorbide dinitrate. Several matrix-type patches employ a controlled drug delivery system containing intentionally crystallized API. Both benchtop and high-resolution laboratory X-ray diffractometers can detect several characteristic peaks of the APIs in these patches even if the patches are wrapped in an outer bag, although a benchtop model provides peak heights one-seventh to one-fifth that of a high-resolution instrument. An isosorbide dinitrate patch containing an unintentionally crystallized spot was wrapped in an outer bag, followed by measurements using both X-ray diffractometers. For both instruments, several isosorbide dinitrate-derived peaks were detected only at the crystallized spot, although the signal-to-noise ratio was poorer for the benchtop model. These results show that a high-resolution X-ray diffractometer is advantageous for high-detection sensitivity and offers a high degree of freedom of the measurement position on the sample. It was concluded that a laboratory-level high-resolution X-ray diffractometer can be used to examine the crystalline state of APIs in patches inside an unopened outer bag.

Three forms of pseudo-crystalline polymorph of thiamine chloride hydrochloride are dependent on hydration states. We investigated how the measurement environment affects the transition of the pseudo-crystalline polymorph, and aimed to establish a reliable method of identifying the forms clearly by IR spectrophotometry. We prepared three pseudo-crystalline forms and compared their IR spectra. In the IR spectra obtained by the potassium chloride (KCl) disk method, Form II was identified based on its characteristic absorption, but Forms I and III could not be distinguished clearly. Form I transformed to Form III after mixing with undried KCl powder, and Form III transformed to Form I by simply being left in the laboratory environment. These results suggested that the reversible transformation between Forms I and III occurred depending on the hydration status during the process of measurement, as measured by the shift in the absorption wavenumber of the primary alcohol stretching vibration. In addition, Forms I and III could not be distinguished clearly by the X-ray powder diffraction and their crystalline forms were similar plate crystals. However, in the IR spectra by the attenuated total reflection (ATR) method, the three forms could be identified based on each characteristic absorption. In summary, the ATR method does not require pretreatment for sample analysis, can be performed quickly, and is thus suitable to identify crystalline polymorph forms such as pseudo-crystalline polymorphs of thiamine chloride hydrochloride, which transform easily depending on the hydration status in a measurement environment.

The coamorphous formation between naringenin (NRG) and hesperetin (HPT) was investigated with the aim of enhancing their solubility and membrane permeability. In addition, application to emulsion of coamorphous was investigated. The melt-quenched particles (MQPs) of NRG and HPT were prepared in a range of molar ratios of NRG/HPT (3/1 to 1/3). All MQPs showed the amorphous state and single glass transition temperature. MQPs of NRG/HPT (1/1) could kept the amorphous state under storage. On the other hand, other MQPs recrystallized from the compound with a higher molar ratio. These results indicated that NRG and HPT formed the coamorphous at a molar ratio of 1 to 1. The coamorphous formation enhanced the apparent solubilities of NRG and HPT in aqueous media. Furthermore, MQPs of NRG/HPT (1/1) increased a permeated amount of NRG and HPT via the synthetic membrane in Franz Cell. When the solubility of NRG and HPT in oil components were investigated, the MQPs of NRG/HPT (1/1) enhanced the solubility of both compounds. This study highlighted the importance of coamorphous formation as a formulation to enhance solubility in oil components and aqueous media, and membrane permeability of both NRG and HPT.

Relationship between water molecules and parent and hydroxypropylated cyclodextrins (denoted as CD and HP-CD) was assessed in this paper. The trends in ad-desorption isotherms of CD for water molecule were quite different compared to those of HP-CD. Ad-desorption isotherms of CD showed the hysteresis under our experimental conditions. The molar ratio of hydration (R-value) using α-CD, β-CD, γ-CD, HP-α-CD, HP-β-CD, and HP-γ-CD was 7.1, 11.4, 13.5, 12.5, 14.0, and 16.7, respectively. These results indicated that the adsorption capability of water molecule of HP-CD was greater than that of CD. Additionally, the changes in characteristics of CD and HP-CD at different water activity conditions were demonstrated. X-ray diffraction patterns were significantly different between CD and HP-CD. The crystal structure of HP-α-CD, HP-β-CD, and HP-γ-CD showed amorphous at different water activity conditions. Finally, sorption entropy and heat of sorption of water molecules were calculated in this experiment. In summary, these results provide useful information for understanding the relationship between water molecules and parent and hydroxypropylated cyclodextrins.