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The discovery of lead-free hybrid double perovskites\ud provides a viable approach in the search for stable and environmentally\ud benign photovoltaic materials as alternatives to lead-containing systems\ud such as MAPbX3 (X = Cl, Br, or I). Following our recent reports of\ud (MA)2KBiCl6 and (MA)2TlBiBr6, we have now synthesized a hybrid\ud double perovskite, (MA)2AgBiBr6, that has a low band gap of 2.02 eV\ud and is relatively stable and nontoxic. Its electronic structure and\ud mechanical and optical properties are investigated with a combination\ud of experimental studies and density functional theory calculations

The elastic properties and thermal expansion behavior of lead-free halide double perovskite, Cs2AgBiBr6, were studied first with the aid of first principles calculations, which were followed by experimental characterization. The calculated full elastic constants enable the complete mapping of Young's and shear moduli, and Poisson's ratios of Cs2AgBiBr6 along all crystallographic orientations. Results show that significant anisotropy in them despite the fact that Cs2AgBiBr6 possesses cubic symmetry. Detailed structural analysis and a spring model were utilized to rationalize the observed anisotropy. Further, the theoretical results were validated by recourse to nanoindentation and high-pressure synchrotron powder X-ray diffraction experiments. The superior mechanical behavior of Cs2AgBiBr6 over the hybrid bromide analogues, MAPbBr(3) (MA = CH3NH3+), were attributed to the higher framework stiffness of the former, which is a result of the presence of relatively stronger Ag-Br and Bi-Br bonds in it. Variable temperature single crystal X-ray diffraction reveal linear and volumetric thermal expansion coefficients to be about 20% lower than those of MAPbBr(3), again suggesting its higher framework rigidity. The superior stiffness, thermal expansion behavior, moisture stability, and nontoxicity of Cs2AgBiBr6 make it a strong candidate for potential applications in optoelectronics and photovoltaics. (C) 2017 Elsevier B.V. All rights reserved.

Hybrid organic–inorganic materials that adopt perovskite-like architectures show intriguing order–disorder phase transitions and exciting electronic properties. We extend the classical concept of ionic tolerance factors to this important class of materials and predict the existence of several hitherto undiscovered hybrid perovskite phases.

Poly(3,4-ethylenedioxythiophene) (PEDOT) is formed inside a metal–organic framework (MOF). MOF removal leads to sub-millimetre structures of the nanostructured conducting polymer., Reactions inside the pores of metal–organic frameworks (MOFs) offer potential for controlling polymer structures with regularity to sub-nanometre scales. We report a wet-chemistry route to poly-3,4-ethylenedioxythiophene (PEDOT)–MOF composites. After a two-step removal of the MOF template we obtain unique and stable macroscale structures of this conductive polymer with some nanoscale regularity.

Density functional theory screening of the hybrid double perovskites (MA)2BIBiX6 (BI=K,Cu,Ag,Tl; X=Cl,Br,I) shows that systems with band gaps similar to those of the MAPbX3 lead compounds can be expected for BI=Cu,Ag,Tl. Motivated by these findings, (MA)2TlBiBr6, isoelectronic with MAPbBr3, was synthesised and found to have a band gap of ~2.0eV.

We report how mechanical and dynamical properties in formate-based perovskites can be manipulated by the preparation of an A-site solid-solution., We report how mechanical and dynamical properties in formate-based perovskites can be manipulated by the preparation of an A-site solid-solution. In the series [NH3NH2]1–x[NH3OH]xZn(HCOO)3 with xmax = 0.48, the substitution of [NH3NH2]+ by [NH3OH]+ is accompanied by a series of complex changes in crystal chemistry which are analysed using PXRD, SCXRD, 1H solid state NMR, DSC and nanoindentation. NMR shows increased motion of [NH3NH2]+ in [NH3NH2]0.52[NH3OH]0.48Zn(HCOO)3, which results in a shift of the ferroelectric-to-paraelectric phase transition temperature from Tc = 352 K (x = 0) to Tc = 324 K (x = 0.48). Additionally, the loss of hydrogen bonds directly influences the mechanical response of the framework; the elastic moduli and hardnesses decrease by around 25% from E110 = 24.6 GPa and H110 = 1.25 GPa for x = 0, to E110 = 19.0 GPa and H110 = 0.97 GPa for x = 0.48. Our results give an in-depth insight into the crystal chemistry of ABX3 formate perovskites and highlight the important role of hydrogen bonding and dynamics.

Anti-beta (2)-glycoprotein I (anti-β2-GP1) is one of the important pathogenesis factors responsible for thrombosis formation in patients with antiphospholipid syndrome (APS). Administration of intravenous immunoglobulin (IVIg) is a common method used to inhibit the abnormal antibody levels and decrease the mortality of APS in emergency situations. We hypothesize that the Fc fragment of IgG is the molecular structure responsible for these effects. The present study investigates the beneficial effects of both recombinant and natural human Fc fragments of heterogeneous IgG against human anti-β2-GP1 antibodies in mouse models with APS. Results showed that both recombinant and natural human Fc fragments moderately but significantly decreased the levels of serum anti-β2-GP1 antibodies and had anti-coagulation effects in human β2-GP1-immunized mice. Furthermore, both recombinant and natural human Fc fragments inhibited thrombosis formation and decreased mortality in mouse models infused intravenously with human anti-β2GP1 antibodies from patients with APS. Findings suggest that the Fc fragment might be one of the active structural units of heterogeneous IgG. Thus, recombinant human Fc fragment administration may be a useful treatment for individuals with APS.

The life cycle of seaweed Laminaria japonica involves a generation alternation between diploid sporophyte and haploid gametophte. The expression of foreign genes in sporophte has been proved. In this research, the recombinant expression in gametophyte was investigated by particle bombardment with the rt-PA gene encoding the recombinant human tissue-type plasminogen activator (Reteplase), which is a thrombolytic agent for acute myocardial infarction (AMI). Transgenic gametophytes were selected by their resistance to herbicide phosphiothricin (PPT), and proliferated in an established bubble column photo-bioreactor. According to the results from quantitative ELISA, Southern blotting, and fibrin agarose plate assay (FAPA) for bioactivity, it was showed that the rt-PA gene had been integrated into the genome of gametophytes of L. japonica, and the expression product showed the expected bioactivity, implying the proper post-transcript modification in haploid gametophyte.

Polymorphism in formate-based dense metal-organic frameworks with the general formula ABX3 is predicted by quantum chemical calculations and confirmed experimentally. In particular [NH3NH2]Zn(HCOO)3 crystallizes in two different polymorphs, a perovskite-like framework and a chiral structure with hexagonal channels. A detailed thermodynamic analysis reveals that both structures are very close in free energy and that entropy driven effects are responsible for stabilizing the channel structure.

Organic-inorganic halide perovskites, especially methylammonium lead halide, have recently led to remarkable advances in photovoltaic devices. However, due to environmental and stability concerns around the use of lead, research into lead-free perovskite structures has been attracting increasing attention. In this study, a layered perovskite-like architecture, (NH4)3Bi2I9, is prepared from solution and the structure solved by single crystal X-ray diffraction. The band gap, which is estimated to be 2.04 eV using UV-visible spectroscopy, is lower than that of CH3NH3PbBr3. The energy-minimized structure obtained from first principles calculations is in excellent agreement with the X-ray results and establishes the locations of the hydrogen atoms. The calculations also point to a significant lone pair effect on the bismuth ion. Single crystal and powder conductivity measurements are performed to examine the potential application of (NH4)3Bi2I9 as an alternative to the lead containing perovskites.

In order to comprehensive understand and control volatile organic compounds (VOCs) release from particleboards, this paper takes Larix gmelini particleboard as example and analysis VOCs from raw materials. In the first, VOCs of Larix gmelini particles were detected. Secondly urea-formaldehyde resin (UF) adhesive and Larix gmelini particleboard were analyzed using the method of Thermal desorption -GC/MS to qualitative VOCs emissions. At last, source of VOCs was found theoretically through comparison the differences of raw materials. The result of experiments revealed that VOCs from particleboards include alkane, terpenes, aromatic hydrocarbon, alcohol, aldehyde, and ester and so on. The highest group of Larix gmelini particles was α -pinene (33.4%), followed by β-phellandrene (13.0%), hexanal (11.3%). 46 kinds of compounds were identified in UF adhesive. The main VOCs in UF adhesive are toluene, styrene, furfural and benzaldehyde, pentadecane etc. Mix of UF adhesive and wood shavings were identified 54 matters. The highest group was hexanal (67.02%) followed by 2-pentyl-furan(7.97%), α -pinene(5.10%). 63 kinds of compounds were analyzed and identified in particleboards. The highest group was hexanal (8.59%) followed by naphthalene (7.92%), 1-butoxy-2-propyl alcohol(6.60%), 2- butoxy - alcohol(6.47%), Nonanal (5.66%). Toluene and benzaldehyde derived from UF adhesive furfural and benzaldehyde maybe have a chemical reaction after pressing. We can judge hexanal, α -pinene, 1-methylnaphthalene and nonanal from Larix gmelini particles.

The static head space solid-phase micro-extraction (HS-SPME) technique was applied to extract the volatile organic compounds of Larix gmelini particles,and the extracting condition was optimized, that is, 40 minute extracting time at 80℃, then 30 minute absorption, 4 minute desorption. The volatile organic compounds (VOCs) of Larix gmelini particles were analyzed by head space solid-phase micro-extraction gas chromatography-mass spectroscopy (HS-SPME-GC-MS) under the optimal testing condition. The results show that 9 kinds of compounds were analyzed and identified with HS-SPME-GC-MS. And the main component was alpha-pinene (0.334 of mass fraction), then beta-phellandrene (0.130 of mass fraction),hexanal (0.113 of mass fraction), 3-carene (0.094 of mass fraction), and 2, 6-bis (1, 1-dimethylethyl)-4-(1-methylpropyl)-phenol (0.031 of mass fraction). The further study of VOCs emission of Larix gmelini panels can be supported by the optimized condition and raw materials' component analysis.