Search

Crystalline sponge method represents a rather new trend in structural analysis. This method is to use networked porous metal complexes as “crystalline sponges”, which does not require the crystallization of the sample. It has large and regular cavities which can absorb the target molecules like sponges and arrange them in an orderly manner, so that their structures can be determined with X-ray diffraction. In this review, we focus on recent trends in crystalline sponge method. Following an introduction in the field, a first main section covers the birth of crystalline sponge method and the improvement of crystal synthesis method. The further section covers structural confirmation, including the guest molecular structure determination and host-guest interactions. The next main section covers the expansion of crystalline sponge method, such as the applications in synthesis, other crystalline sponge and visual observation. The final section covers the limitations and prospects of the crystalline sponge method. [ABSTRACT FROM AUTHOR]

For solution-based small-molecule organic photovoltaic cells (SM BHJ), thermal annealing is often regarded as a very vital processing to yield high-efficiency devices. Here, the device with the photoactive p-DTS(FBTTh2)2:PC60BM blends has been studied by varying the annealing temperature. The highest power conversion efficiency (PCE), fill factor (FF), and short-circuit current ( Jsc) has been achieved after the device was annealed at the temperature of 80 °C. X-ray diffraction (XRD) displayed that the p-DTS(FBTTh2)2 tends to form big islands with well-defined crystalline structure (long coherence length) surrounded by small islands of the PC60BM after annealing, and reached the largest grain size of 27 nm after annealing at 80 °C. AFM images demonstrated the most sufficient phase separation within the photoactive blend layer after annealing at 80 °C, which provides good photogenerated excitons dissociation. Such improvements have proved beneficial to decrease the ohmic loss and recombination in carrier-transport process via measuring series resistance and shunt resistance as well as hole mobility. This work opens up a new way to understand the relationship between thermal annealing and molecular interaction from the viewpoint of lattice relaxation. [ABSTRACT FROM AUTHOR]

An unprecedented uniform distribution and dispersion of 6vol.% SiC nanoparticles (NPs) in Mg–Zn matrix is obtained through a novel solidification processing method that combines semisolid-state mechanical mixing and liquid-state ultrasonic processing. The resulting Mg-based metal matrix nanocomposites (MMNCs) exhibit the highest hardness and the greatest hardness enhancement among all crystalline Mg-based MMNCs reported so far. The results shed light on a potential pathway for the development of ultrahigh-performance metallic materials reinforced by NPs through solidification processing. [ABSTRACT FROM AUTHOR]

Poly(ethylene terephthalate) (PET) resin is one of the most widely used thermoplastics, especially in packaging. Because thermal and hydrolytic degradations, recycled PET (RPET) exhibits poor mechanical properties and lacks moldability. The effects of adding elastomeric modifiers, chain extenders (CE), and poly(butylene adipate- co-terephthalate), PBAT, as a toughener to RPET on its moldability and mechanical property were investigated. Melt blending of RPET with CE, thermoplastic elastomer (TPE), and/or PBAT was performed in a thermokinetic mixer (K-mixer). The blended materials were then injection molded to produce tensile specimens. Various techniques were used to study the mechanical properties, rheological properties, compatibility, and crystallization behavior of the RPET blends. By melt blending with proper additives, recycled PET regained its moldability, thereby enabling the recycling of RPET. Furthermore, the addition of CE greatly enhanced the mechanical properties of RPET. While the RPET and TPE blends also showed improved mechanical properties, the improvement was less significant and the blends were often immiscible due to the difference in polarities between RPET and TPE. Finally, it was found that the mechanical properties of RPET blends depended on the prior thermal history of the material and could be improved with an extra annealing step that increased the degree of crystallinity. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

Abstract: In order to grow large mono-domain YBa2Cu3O7− δ bulk in the tubular furnace, the effect of Y2BaCuO5 (Y211) content and initial temperature of the slow-cooling process on the growth of YBa2Cu3O7− δ (Y123) bulk has been investigated. Single grain Y123 bulk samples with 20mol% and 30mol% Y211 addition have higher original crystallization temperature than that with 40mol% Y211; however, the melt-textured growth rate of the single domain seems to be faster for the system with higher Y211 concentrations. In addition, it seems that the crystal growth of YBCO is extremely sensitive to the initial temperature of slow-cooling. The optimal initial temperature of slow-cooling process, which should be chosen according to the Y211 phase content, has been brought to the fore in the growth of large grain bulk. The above data is very useful for the fabrication of large grain (RE)–Ba–Cu–O bulk, and a group of YBCO single domain samples with diameter of 53mm have been successfully produced, all of which present excellent magnetic levitation performance in the axial direction. [Copyright &y& Elsevier]

A novel compound, [Co(phen)3][V10O26]·H2O, was hydrothermally synthesized and characterized by single-crystal X-ray diffraction. This compound crystallizes in the orthorhombic space group Ccca with a=13.447(3), b=29.936(6), c=23.252(5) A˚, V=9360(3) A˚3, Z=8 and R=0.0285. Data were collected on a Rigaku R-AXIS RAPID IP diffractometer at 293 K in the range of 1.36<θ<24.99°. The structure of the compound consists of vanadium oxide layers, which are built up from the infinite VO4 chains by corners and edges sharing. The [Co(phen)3]2+ complexes occupy the interlayer space and contact each other via π−π stacking interactions of the phen groups to form infinite one-dimensional chains. [Copyright &y& Elsevier]

A novel three-dimensional inorganic bimetallic compound Cu[Mo3O10]·H2O 1 has been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction. Compound 1 crystallizes in the orthorhombic system, space group Pnma, a=8.6085(17) A˚, b=7.5822(15) A˚, c=13.690(3) A˚, V=893.6(3) A˚3, Z=4, λ(MoKα) = 0.71073 A˚ (R(F)=0.0357 for 1101 reflections). The structure of compound 1 is based on [{Mo3O10}2−]∞ isopolyoxomolybdate chains bonded together with CuO4 tetrahedra into a three-dimensional inorganic open framework. Three types of Mo–Cu layers and one-dimensional tunnels are observed in the title compound. [Copyright &y& Elsevier]