1.Analytical Characterization of Erythritol Tetranitrate, an Improvised Explosive.
Matyáš R1, Lyčka A2,3, Jirásko R4, Jakový Z1, Maixner J5, Mišková L6, Künzel M1. J Forensic Sci. 2016 May;61(3):759-64. doi: 10.1111/1556-4029.13078. Epub 2016 Apr 4.
Erythritol tetranitrate (ETN), an ester of nitric acid and erythritol, is a solid crystalline explosive with high explosive performance. Although it has never been used in any industrial or military application, it has become one of the most prepared and misused improvise explosives. In this study, several analytical techniques were explored to facilitate analysis in forensic laboratories. FTIR and Raman spectrometry measurements expand existing data and bring more detailed assignment of bands through the parallel study of erythritol [(15) N4 ] tetranitrate. In the case of powder diffraction, recently published data were verified, and (1) H, (13) C, and (15) N NMR spectra are discussed in detail. The technique of electrospray ionization tandem mass spectrometry was successfully used for the analysis of ETN. Described methods allow fast, versatile, and reliable detection or analysis of samples containing erythritol tetranitrate in forensic laboratories.
2.Thermoresponsive physical hydrogels of poly(lactic acid)/poly(ethylene glycol) stereoblock copolymers tuned by stereostructure and hydrophobic block sequence.
Mao H1, Shan G1, Bao Y1, Wu ZL2, Pan P1. Soft Matter. 2016 Apr 28. [Epub ahead of print]
CBABC-type poly(lactic acid) (PLA)/poly(ethylene glycol) (PEG) pentablock copolymers composed of a central PEG block (A) and enantiomeric poly(l-lactic acid) (PLLA, B), poly(d-lactic acid) (PDLA, C) blocks were synthesized. Such pentablock copolymers form physical hydrogels at high concentrations in an aqueous solution, which stem from the aggregation and physical bridging of copolymer micelles. These gels are thermoresponsive and turn into sols upon heating. Physical gelation, gel-to-sol transition, crystalline state, microstructure, rheological behavior, biodegradation, and drug release behavior of PLA/PEG pentablock copolymers and their gels were investigated; they were also compared with PLA-PEG-PLA triblock copolymers containing the isotactic PLLA or atactic poly(d,l-lactide) (PDLLA) endblocks and PLLA-PEG-PLLA/PDLA-PEG-PDLA enantiomeric mixtures. PLA hydrophobic domains in pentablock copolymer gels changed from a homocrystalline to stereocomplexed structure as the PLLA/PDLA block length ratio approached 1/1.
3.A three-step method for the deposition of large cuboids of organic - inorganic perovskite and application in solar cells.
Shahbazi S1, Malekshahi Byranvand M2, Tajabadi F3, Afshar S4, Taghavinia N5. Chemphyschem. 2016 Apr 28. doi: 10.1002/cphc.201600229. [Epub ahead of print]
In this research, we report a three-step method for the deposition of CH3NH3PbI3 perovskite films with a high crystalline structure and large cuboids overlayer morphology. The method includes PbI2 deposition which follows by dipping into C4H9NH3I (BAI) solution and (BA)2PbI4 perovskite formation. In the final step, the low thermodynamically stable (BA)2PbI4 phase converts to the more stable CH3NH3PbI3 perovskite by dipping into CH3NH3I(MAI) solution. The final product was characterized by XRD, SEM, UV-Vis and PL analysis methods. The experimental results indicated that the prepared perovskite has cuboids with the high crystallinity and large size (up to 1 µm) as confirmed by XRD and SEM data. Photovoltaic investigation showed that the three step method results in higher solar cell efficiency (15% enhancement in efficiency) with a better reproducibility compared to the conventional two-step deposition method.
4.Ti-Ag-Pd alloy with good mechanical properties and high potential for biological applications.
Zadorozhnyy VY1,2, Shi X3, Gorshenkov MV1, Kozak DS4, Wada T2, Louzguine-Luzgin DV5, Inoue A1,6,7,8, Kato H2. Sci Rep. 2016 Apr 28;6:25142. doi: 10.1038/srep25142.
Ti-based alloys containing Ag were produced by tilt-casting method and their properties were studied. Even in its as-cast state, Ti94Ag3Pd3 showed relatively high tensile properties, good electrochemical behavior, and good biocompatibility. The relatively good mechanical properties of the as-cast α-Ti-type Ti94Ag3Pd3 alloy (tensile strength up to 850 MPa and elongation of ~10%) can be explained by its severely deformed, fine crystalline structure. The high biocompatibility of Ti94Ag3Pd3 can be explained by the Ag-Pd interaction, which inhibits the release of Ag ions from the surface. Ag, in combination with Pd has no toxic effects and demonstrates useful antimicrobial properties. The Ti94Ag3Pd3 alloy shows a good potential to be applied as a biomedical implant alloy.