Chemical Vapor Deposition and Thermal Oxidation of Cuprous Phosphide Nanofilm

Inorganic semiconductors usually show n-type characterization; the development of p-type inorganic semiconductor material will provide more opportunities for novel devices. In this paper, we investigated the chemical vapor deposition (CVD) of p-type cuprous phosphide (Cu3P) nanofilm and studied its thermal oxidation behavior. Cu3P film was characterized by optical microscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), laser Raman spectroscopy (Raman), and fluorescence spectroscopy (PL). We found that the thickness of film ranged from 4 to 10 nm, and the film is unstable at temperatures higher than room temperature in air. We provide a way to prepare inorganic phosphide nanofilms. In addition, the possible thermal oxidation should be taken into consideration for practical application.

Synergistic Flame-Retardant Effect of Aluminum Diethyl Phosphinate in PP/IFR System and the Flame-Retardant Mechanism

Synergistic flame-retardant effect of aluminum diethyl phosphinate (AlPi) in intumescent flame retardant polypropylene (PP/IFR) system and the flame-retardant mechanism were investigated. The flame retardancy of PP/IFR/AlPi (the mass ratio of IFR to AlPi is 2 : 1) was the best, which was proved by the results of the limiting oxygen index (LOI) test, UL-94 test, and cone calorimeter test ( CCT) test. Here, the LOI value of the sample was as high as 34% and passed the V–0 rating in UL–94 test. The peak heat release rate (PHRR) decreased by 92.57%, the total heat release (THR) reduced by 90.52%. Thermogravimetric (TGA) data showed that the introduction of AlPi improved thermal stability and changed the thermal degradation behavior of PP/IFR composites. Interestingly, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDXS) and laser Raman spectroscopy (LRS) proved that PP/IFR/AlPi had formed more residual carbon, but the flame retardancy was worse than PP/IFR/AlPi. This is because when the mass ratio of IFR to AlPi is 2 : 1, the synergy between IFR and AlPi was significant, gas-phase flame retardant and condensed-phase flame retardant reached a balance and obtained the best flame retardant effect.

The structural spectra of high dilutions and their unconventional application

Until few years, the so-called implausible science, homeopathy, was on the verge of being rejected on conventional physicochemical grounds. The mere selection of ultrahigh dilutions (UHD) (homeopathic potencies) for experimentation by mainstream scientists seemed impossible, but the curiosity to explore the science behind homeopathy kept igniting intellectual alma mater who subjected homeopathy to laboratories and test tubes, to know beyond its clinical application. Still, there exist a huge gap and a challenge to convince a conventional scientist to go beyond his domains and look for something which is apparently invisible (beyond Avogadro). But gradually we are overcoming this dogma and exploring the finer aspects and applications of UHDs. Much research has been undertaken, at least, to protect the identity of UHDs, and we are now verge of proving the plausibility of homeopathy from every aspect. This issue of International Journal of High Dilution Research features two interesting articles on nature of UHDs and their unconventional application. The first article by NC Sukul et al aimed to decipher the nature of the water structure of UHDs of two commonly used homeopathic drugs Natrum muriaticum and Sulphur by Laser Raman Spectroscopy. This work is in the series undertaken by the group, who earlier experimented using Nuclear Magnetic Resonance; Electronic, Vibrational and Raman spectroscopy to shown differences in UHDs of various drugs. The present experiment could differentiate the intensities (potencies) of Nat-m and Sulph when compared to their controls, on the basis of hydrogen bond strength and free OH groups. The second article by Nandy et al proposes a new dimension to the application of UHD. In an interesting manner, the author used UHDs of Ferrum metallicum and Zincum oxidatum to improve the electrical properties of the electroactive Poly (vinylidene fluoride-hexafluoropropylene) (PVDF-HFP). The PVDF-HFP composite films were synthesized in their usual way, but an incorporation of Ferrum and Zinc-o could make the film as homeo-PVDF-composite. This enhancement of the electrical properties and are possibly due to the presence of nanoparticle, as hypothesized by the group. The nature and application of UHDs are promising but challenging areas, which can only be validated through extensive research and validation. The realm of UHDs is expanding, and the day is not far when plausibility of homeopathy would be proved from every aspect, but at the same time we should also keep the momentum of research at pace in clinical research too!

Raman spectroscopy reveals variation in free OH groups and hydrogen bond strength in ultrahigh dilutions

Objective: To decipher the nature of water structure in two ultrahigh diluted (UHD) homeopathic drugs by Laser Raman Spectroscopy. Method: Two homeopathic drugs Calcarea carbonica (Calc.) and Sepia officinalis (Sep.) in 8cH, 202cH, and 1002cH and their diluent medium 90% ethanol in 8cH and 202cH were used in the present study. Laser Raman spectra of all the samples were obtained in the wave number region of 2400 – 4200 cm-1. The intensity ratio at vibration frequencies between 3200 and 3420 (R1) and that between 3620 and 3420 (R2) were calculated for each UHD of the samples. Results: The spectra show a marked difference in intensities in the stretching vibrations of CH and OH groups of all the samples. R1 values for three UHDs of Calc. and Sep. show negative and positive relationships, respectively. In the case of R2 values, the relationship in three UHDs is 81002 for Calc., and 8> 202 < 1002 for Sep. In the case of control (ethanol UHDs) both R1 and R2 show a negative relationship. Conclusion: R1 denotes a relative number of OH groups with strong and weak hydrogen bonds. R2 indicates the relative number of OH groups with broken and weak H-bonds. Therefore, the UHDs of the two drugs and the control are different from each other with respect to hydrogen bond strength of OH groups and the number of free OH groups or non-hydrogen bonded water molecules.

Raman spectroscopy shows difference in drugs at ultra high dilution prepared with stepwise mechanical agitation

Objective The present study aims at deciphering the nature of the water structure in two drugs at ultra high dilution (HD) by Laser Raman Spectroscopy. Method Two drugs like Sulphur and Natrum mur and their three high dilutions 30cH, 200cH and 1000cH were selected for the study. The 30cH means dilution 1060 with mechanical agitation in 30 steps.Raman spectra of the drugs and their medium (90%ethanol)were obtained in the wave number region of 2600-3800 cm-1. The intensity ratio at vibration frequencies between 3220 and 3420 (R1) and that between 3620 and 3420 (R2) were calculated for each HD as well as the control. Results Raman spectra show differences in intensities in different HD’s and their control in the stretching vibrations of CH and OH groups. The three HD’s of each drug show inverse relationship with respect to the R1 values. However, for R2 the relationship of HD’s for each drug is positive. Conclusion R1 provides information about the relative number of OH groups with strong and weak hydrogen bonds. R2 suggests the relative number of OH groups with broken and weak hydrogen bonds. Judged from R1 values the lower is the rank of HD, the stronger is the H-bond of the OH groups. In the light of R2 values the higher is the HD rank the more abundant is the free OH groups. So, hydrogen bond strength and free OH groups together make an effective HD rank relating to Sulphur and Natrum mur.

Raman spectroscopy reveals distinctive features of drugs at ultra high dilution

Background             Drugs at ultra high dilution (UHD) have been used in homeopathy for a couple of centuries. The central theme in homeopathic Materia Medica is that each drug has its own distinctive features which need to be matched with the symptoms of a patient for eliciting therapeutic response. However, UHD’s very often (above 12 cH) cross the Avogadro number, and are, therefore, devoid of original drug molecules. How do they maintain their individual identity ? This study aims to address this pertinent question.  Objective :             The medium of UHD’s is ethanol water. It is thought that water structures in a UHD carry the identity of the drug and its rank of dilution. The objective is to decipher the exact nature of water structure in UHD’s of different drugs by laser Raman spectroscopy.  Method :             Six homeopathic drugs and their control ethanol, all in 90% ethanol v/v, were used in the study. For Sulphur and Natrum mur, potencies used were 30 cH, 200 cH and 1000 cH, and for Calcarea carb and Sepia the potencies were 8 cH, 202 cH and 1002 cH. In addition to the four drugs we also used X-ray and Magnetis poli ambo which did not originate from any substance by exposure of ethanol water to X radiation and strong magnetic field.For this we could use their mother tinctures as well as ultrahigh dilutions(potencies) like 8cH, 14cH and 32cH. The potencies used for ethanol control were 8 cH, 14cH, 32cH and 20 cH. Raman spectra of all the potencies of 6 drugs, ethanol control and pure water were taken in the wave number region of 2400-4200 cm-1. All the samples were reduced to 25% ethanol by adding appropriate volume of water to each of them before taking the spectra. The mother tinctures MT of X-ray and Magnetis were studied. The intensity ratio of vibration frequencies between 3200 cm-1 and 3420 cm-1 (R1) and that between 3620 cm-1 and 3420 cm-1 (R2) were calculated for each UHD of the samples.  Results : All the UHD’s of the drugs and the control tested show difference in intensities in the stretching vibrations of CH and OH groups. The three UHD’s from low to high ranks of both Natrum mur and Sulphur show negative relationship with respect to R1 values, and positive one concerning  R2 values. R1 values for 3 UHD’s of Calcarea carb and Sepia show negative and positive relationships, respectively. In case of R2 values the relationship in 3 UHD’s is 81002 for Calcarea carb, and 8>202

Reduction of NOx by H2 on WOx-Promoted Pt/Al2O3/SiO2 Catalysts Under O2-Rich Conditions

This work addresses the reduction of NOx by H2 under O2-rich conditions using Al2O3/SiO2-supported Pt catalysts with different loads of WOx promotor. The samples were thoroughly characterised by N2 physisorption, temperature-programmed desorption of CO, scanning electron microscopy, X-ray diffraction, laser raman spectroscopy, X-ray photoelectron spectroscopy and diffuse reflectance infrared fourier transform spectroscopy with probe molecule CO. The catalytic studies of the samples without WOx showed pronounced NOx conversion below 200 °C, whereas highest efficiency was related to small Pt particles. The introduction of WOx provided increasing deNOx activity as well as N2 selectivity. This promoting effect was referred to an additional reaction path at the Pt-WOx/Al2O3/SiO2 interface, whereas an electronic activation of Pt by strong metal support interaction was excluded. Graphic Abstract

Temporal–Spatial Separation of Cu from Mo in the Jiama Porphyry Copper–Polymetallic Deposit, Southern Tibet, China

Jiama is a super-large porphyry copper–polymetallic deposit located in the Gangdese metallogenic belt of southern Tibet. The deposit consists of a combination of a polymetallic skarn, Cu–Mo mineralization at the contact between the Jiama Porphyry and hornfels, and distal Au mineralization in fault. The current metal reserves are 7.4 Mt Cu, 0.6 Mt Mo, 1.8 Mt Pb–Zn, 6.65 Moz Au, and 360.32 Moz Ag, with a skarn to porphyry–hornfels host-rock ratio of ~3:1. Based on detailed field and laboratory investigations, this paper indicates that: (i) the skarn and porphyry–hornfels orebodies are almost entirely preserved; (ii) the emplacement age of the Cu-bearing plutonic rocks is earlier than the plutons containing elevated Mo assays; (iii) the permeability of the wall rocks gradually decreases in an upward direction; (iv) the fluid temperature during the precipitation of Cu was higher than that of the Mo mineralization; (v) the lithospheric pressure during the precipitation of Cu and Mo was the same; (vi) the laser Raman spectroscopy shows that the fluid carrying the Cu was rich in magnetite, hematite, and anhydrite, and the fluid carrying Mo was rich in pyrite, CO2, and CH4; and (vii) the SR–XRF mapping shows that the concentration of Cu in the mineralizing fluid was high and that of Mo was low when Cu was deposited. Conversely, the concentration of Cu was relatively low and the concentration of Mo was relatively high during deposition of the Mo. This study also shows that the temporal and spatial separation of Cu and Mo in the porphyry copper–polymetallic deposit at Jiama was associated with the emplacement of the Jiama Porphyry. Transportation of mineralized fluid was controlled by the permeability of the wall rocks, and deposition of the metals related to changes along a redox front and pressure releases during hydrothermal brecciation at the roof of the Jiama Porphyry.

Synthesis and characterization of Fe(III)-Fe(II)-Mg-Al smectite solid solutions and implications for planetary science

This study demonstrates the synergies and limits of multiple measurement types for the detection of smectite chemistry and oxidation state on planetary surfaces to infer past geochemical conditions. Smectite clay minerals are common products of water-rock interactions throughout the solar system, and their detection and characterization provides important clues about geochemical conditions and past environments if sufficient information about their composition can be discerned. Here, we synthesize and report on the spectroscopic properties of a suite of smectite samples that span the intermediate compositional range between Fe(II), Fe(III), Mg, and Al end-member species using bulk chemical analyses, X-ray diffraction, Vis/IR reflectance spectroscopy, UV and green-laser Raman spectroscopy, and Mössbauer spectroscopy. Our data show that smectite composition and the oxidation state of octahedral Fe can be reliably identified in the near infrared on the basis of combination and fundamental metal-OH stretching modes between 2.1–2.9 μm, which vary systematically with chemistry. Smectites dominated by Mg or Fe(III) have spectrally distinct fundamental and combination stretches, whereas Al-rich and Fe(II)-rich smectites have similar fundamental minima near 2.76 μm, but have distinct combination M-OH features between 2.24 and 2.36 μm. We show that with expanded spectral libraries that include intermediate composition smectites and both Fe(III) and Fe(II) oxidation states, more refined characterization of smectites from MIR data is now possible, as the position of the 450 cm–1 absorption shifts systematically with octahedral Fe content, although detailed analysis is best accomplished in concert with other characterization methods. Our data also provide the first Raman spectral libraries of smectite clays as a function of chemistry, and we demonstrate that Raman spectroscopy at multiple excitation wavelengths can qualitatively distinguish smectite clays of different structures and can enhance interpretation by other types of analyses. Our sample set demonstrates how X-ray diffraction can distinguish between dioctahedral and trioctahedral smectites using either the (02,11) or (06,33) peaks, but auxiliary information about chemistry and oxidation state aids in specific identifications. Finally, the temperature-dependent isomer shift and quadrupole splitting in Mössbauer data are insensitive to changes in Fe content but reliability differentiates Fe within the smectite mineral structure.