Ethane-1,2-diaminium dipicrate dihydrate

The title compound, C2H10N2 2+·2C6H2N3O7 −·2H2O, crystallizes with a complete picrate anion and half an ethyl­enediammonium dication on a mirror plane, and two half-water mol­ecules (both on a mirror plane) in the asymmetric unit. The N atoms from separate half ethyl­enediammonium dications are in near proximity to a phenolate O atom and two o-NO2 groups from the picrate anion, which, along with the water mol­ecule form N—H⋯O, O—H⋯O and weak intermolecular C—H⋯O hydrogen bonds that create cyclic patterns with graph-set descriptors R 2 4(8), R 4 4(12), and R 4 4(16). The crystal packing is strongly influenced by these inter­molecular inter­actions between symmetry-related water mol­ecules, the half ethyl­enediammonium dication and the picrate anion, forming a three-dimensional supermolecular structure

Ethane-1,2-diaminium dipicrate dihydrate

The title compound, C2H10N2 2+·2C6H2N3O7 −·2H2O, crystallizes with a complete picrate anion and half an ethyl­enediammonium dication on a mirror plane, and two half-water mol­ecules (both on a mirror plane) in the asymmetric unit. The N atoms from separate half ethyl­enediammonium dications are in near proximity to a phenolate O atom and two o-NO2 groups from the picrate anion, which, along with the water mol­ecule form N—H⋯O, O—H⋯O and weak intermolecular C—H⋯O hydrogen bonds that create cyclic patterns with graph-set descriptors R 2 4(8), R 4 4(12), and R 4 4(16). The crystal packing is strongly influenced by these inter­molecular inter­actions between symmetry-related water mol­ecules, the half ethyl­enediammonium dication and the picrate anion, forming a three-dimensional supermolecular structure

In Vitro Corrosion Behaviour of Ti–6Al–4V and 316L Stainless Steel Alloys for Biomedical Implant Applications

Pulsed laser deposition technique is one of the methods to coat the hydroxyapatite on 316L stainless steel and Ti–6Al–4V implants, which is used in orthopaedics and dentistry applications. In this study, hydroxyapatite (HAP) ceramics in the form of calcium phosphate were deposited on Ti–6Al–4V and 316L stainless steel by the pulsed laser deposition method. The coated thin film was characterised by X-ray diffraction (XRD), scanning electron microscopy with energy-dispersive spectroscopy (EDS) and atomic microscopy. The corrosion studies were carried out on coated and uncoated samples using potentiodynamic polarisation studies in simulated body fluid (Hanks’ solution). The bioactivity of the Hap-coated samples on Ti–6Al–4V and 316L stainless steel was evaluated by immersing them in simulated body fluid for 9 days. XRD and EDS analyses confirmed the presence of HAP. The corrosion studies showed that the treated samples have better corrosion resistance compared to Ti–6Al–4V and 316L stainless-steel substrates. The formation of apatite on treated samples revealed the bioactivity of the HAP-coated substrates. HAP-coated Ti–6Al–4V provides higher corrosion protection than the HAP-coated 316L stainless-steel substrates

Carrier separation and charge transport characteristics of reduced graphene oxide supported visible-light active photocatalysts.

Extending the absorption to the visible region by tuning the optical band-gap of semiconductors and preventing charge carrier recombination are important parameters to achieve a higher efficiency in the field of photocatalysis. The inclusion of reduced graphene oxide (rGO) support in photocatalysts is one of the key strategies to address the above-mentioned issues. In this study, rGO supported AgI–mesoTiO2 photocatalysts were synthesized using a sonochemical approach. The physical effects of ultrasound not only improved the crystallinity of AgI–mesoTiO2 but also increased the surface area and loading of the AgI–mesoTiO2 nanocomposite on rGO sheets. The low intense oxygen functionalities (C–O–C and COOH groups) peak observed in the high resolution C1s spectrum of a hybrid AgI–mesoTiO2–rGO photocatalyst clearly confirmed the successful reduction of graphene oxide (GO) to rGO. The interfacial charge transfer between the rGO and the p–n junction of heterostructured photocatalysts has decreased the band-gap of the photocatalyst from 2.80 to 2.65 eV. Importantly, the integration of rGO into AgI–mesoTiO2 composites serves as a carrier separation centre and provides further insight into the electron transfer pathways of heterostructured nanocomposites. The individual effects of photo-generated electrons and holes over rGO on the photocatalytic degradation efficiency of rhodamine (RhB) and methyl orange (MO) using AgI–mesoTiO2–rGO photocatalysts were also studied. Our experimental results revealed that photo-generated superoxide (O2−˙) radicals are the main reactive species for the degradation of MO, whereas photo-generated holes (h+) are responsible for the degradation of RhB. As a result, 60% enhancement in MO degradation was observed in the presence of rGO in comparison to that of the pure AgI–mesoTiO2 photocatalyst. This is due to the good electron acceptor and the ultrafast electron transfer properties of rGO that can effectively reduce the molecular oxygen to produce a large amount of reactive O2−˙ radicals. However, in the case of RhB degradation, h+ is the main reactive species which showed a slightly increased photocatalytic activity (12%) in the presence of rGO support where the role of rGO is almost negligible. This study suggests the effective roles of rGO for the degradation of organics, i.e., the rate of photocatalytic degradation also depends on the nature of compound rather than rGO support

Electrochemical Behavior of Biomedical Titanium Alloys Coated with Diamond Carbon in Hanks’ Solution

Biomedical implants in the knee and hip are frequent failures because of corrosion and stress on the joints. To solve this important problem, metal implants can be coated with diamond carbon, and this coating plays a critical role in providing an increased resistance to implants toward corrosion. In this study, we have employed diamond carbon coating over Ti-6Al-4V and Ti-13Nb-13Zr alloys using hot filament chemical vapor deposition method which is well-established coating process that significantly improves the resistance toward corrosion, wears and hardness. The diamond carbon-coated Ti-13Nb-13Zr alloy showed an increased microhardness in the range of 850 HV. Electrochemical impedance spectroscopy and polarization studies in SBF solution (simulated body fluid solution) were carried out to understand the in vitro behavior of uncoated as well as coated titanium alloys. The experimental results showed that the corrosion resistance of Ti-13Nb-13Zr alloy is relatively higher when compared with diamond carbon-coated Ti-6Al-4V alloys due to the presence of β phase in the Ti-13Nb-13Zr alloy. Electrochemical impedance results showed that the diamond carbon-coated alloys behave as an ideal capacitor in the body fluid solution. Moreover, the stability in mechanical properties during the corrosion process was maintained for diamond carbon-coated titanium alloys

Oxonium picrate

The title compound, H3O+·C6H2N3O7 −, consists of one picrate anion and one oxonium cation. The oxonium cation is located on a crystallographic twofold axis and both its H atoms are disordered, each over two symmetry-equivalent positions with occupancy ratios of 0.75. The picrate anions are also located on twofold axes bis­ecting the phenolate and p-nitro groups. π–π inter­actions between the rings of the picrates [centroid-to-centroid distances of 3.324 (2) Å] connect the anions to form stacks along the a-axis direction. The stacks are further joined together by the protonated water mol­ecules through hydrogen bonds to form two-dimensional sheets extending parallel to the ab plane. The sheets are stacked on top of each other along the c-axis direction and connected through C—H⋯O inter­actions between the CH groups of the benzene rings and the picrate nitro groups, with C⋯O distances of 3.450 (2) Å

2-Ethyl-6-methyl­anilinium 4-methyl­benzene­sulfonate

The title compound, C9H14N+·C7H7SO3 −, contains a 2-ethyl-6-methyl­anilinium cation and a 4-methyl­benzene­sulfonic anion. The cations are anchored between the anions through N—H⋯O hydrogen bonds. Electrostatic and van der Waals inter­actions, as well as hydrogen bonds, maintain the structural cohesion

Bis(N,N-dimethyl­formamide-κO)bis­(2,4,6-trinitro­phenolato-κ2 O 1,O 2)copper(II)

The mol­ecule of the title complex, [Cu(C6H2N3O7)2(C3H7NO)2], is disposed about a crystallographic centre of symmetry. The CuII cation is six-coordinated by two phenolate O atoms and two ortho-nitro O atoms of two picrate units and by two carbonyl O atoms from two coordinated dimethyl­formamide mol­ecules, forming a distorted octa­hedral geometry

Growth and structural, spectral, optical characterization of pure, ammonium dihydrogen phosphate (ADP) and tartaric acid doped triglycine sulphate (TGS) single crystals

Abstract: Ferroelectric crystals are interesting class of materials. They are similar to ferromagnetic materials in that, they exhibit hysteresis loops, spontaneous polarization and coercive field. Ferroelectric crystals have a number of practical applications and one of those is a pyroelectric infrared (PIR) detection. PIR devices can detect a person moving into or through a detection zone with high reliability. The slightest positive or negative thermal radiation change in contrast to a background, focused by the appropriate optics, triggers the sensor element. There is no interference between neighbouring units due to the passive nature of the detection principle. At the heart of every PIR detector is the pyroelectric crystal. The detectors use materials, such as triglycine sulfate (TGS) or lithium tantalite.In the present work, ADP and tartaric acid were employed as dopants. The grown crystals were subjected to different characterization studies inorder to study the properties of the TGS crystal. The results are discussed in this paper