The Usefulness of X-ray Diffraction and Thermal Analysis to Study Dietary Supplements Containing Iron

X-ray powder diffraction (XRPD) and thermal analysis (differential scanning calorimetry/derivative of thermogravimetry (DSC/DTG)) are solid-state techniques that can be successfully used to identify and quantify various chemical compounds in polycrystalline mixtures, such as dietary supplements or drugs. In this work, 31 dietary supplements available on the Polish market that contain iron compounds, namely iron gluconate, fumarate, bisglycinate, citrate and pyrophosphate, were evaluated. The aim of the work was to identify iron compounds declared by the manufacturer as food supplements and to try to verify compliance with the manufacturer’s claims. Studies performed by X-ray and thermal analysis confirmed that crystalline iron compounds (iron (II) gluconate, iron (II) fumarate), declared by the manufacturers, were present in the investigated dietary supplements. Iron (II) bisglycinate proved to be semi-crystalline. However, depending on the composition of the formulation, it was possible to identify this compound in the tested supplements. For amorphous iron compounds (iron (III) citrate and iron (III) pyrophosphate), the diffraction pattern does not have characteristic diffraction lines. Food supplements containing crystalline iron compounds have a melting point close to the melting point of pure iron compounds. The presence of excipients was found to affect the shapes and positions of the endothermic peaks significantly. Widening of endothermic peaks and changes in their position were observed, as well as exothermic peaks indicating crystallization of amorphous compounds. Weight loss was determined for all dietary supplements tested. Analysis of the DTG curves showed that the thermal decomposition of most food supplements takes place in several steps. The results obtained by a combination of both simple, relatively fast and reliable XRPD and DSC/DTG methods are helpful in determining phase composition, pharmaceutical abnormalities or by detecting the presence of the correct polymorphic form.

The Use of ZrO2 Waste for the Electrolytic Production of Composite Ni–P–ZrO2 Powder

Ni–P–ZrO2 composite powder was obtained from a galvanic nickel bath with ZrO2 powder. Production was conducted under galvanostatic conditions. The Ni–P–ZrO2 composite powder was characterized by the presence of ZrO2 particles covered with electrolytical nanocrystalline Ni–P coating. The chemical composition (XRF method), phase structure (XRD method) and morphology (SEM) of Ni–P–ZrO2 and the distribution of elements in the powder were all investigated. Based on the analyses, it was found that the obtained powder contained about 50 weight % Zr and 40 weight % Ni. Phase structure analysis showed that the basic crystalline component of the tested powder is a mixed oxide of zirconium and yttrium Zr0.92Y0.08O1.96. In addition, the sample contains very large amounts of amorphous compounds (Ni–P). The mechanism to produce the composite powder particles is explained on the basis of Ni2+ ions adsorption process on the metal oxide particles. Current flow through the cell forces the movement of particles in the bath. Oxide grains with adsorbed nickel ions were transported to the cathode surface. Ni2+ ions were discharged. The oxide particles were covered with a Ni–P layer and the heavy composite grains of Ni–P–ZrO2 flowed down to the bottom of the cell.

A Review on the Role of Amorphous Aluminum Compounds in Catalysis: Avenues of Investigation and Potential Application in Petrochemistry and Oil Refining

Aluminum oxides and hydroxides are widely applied because of the great variety of their modifications. In particular, aluminum oxides and hydroxides are used in petrochemistry and oil refining. However, amorphous aluminum compounds have not been sufficiently studied due to the complexity of their synthesis and the problems encountered during their study. The study of amorphous aluminum compounds is hindered by the ambiguity of terminology. In this work, the structures of amorphous aluminum compounds prepared by different methods and the properties that determine their applications have been highlighted in detail. Amorphous aluminum compounds play both positive and negative roles in petrochemistry; however, in petroleum refining, amorphous compounds (without promoters and transition metal salts) demonstrate a promising catalytic performance in oil upgrading.

Extraction of Cellulose Polymeric Material from Populus tremula Fibers: Characterization and Application to the Adsorption of Methylene Blue and Crystal Violet

Cellulose is the most widely available biopolymer which is extensively used for several applications including textiles, composites, pharmaceutical, water treatment, etc. In this investigation, cellulose was chemically extracted from Populus tremula seed fibers. Samples were characterized using FT-IR, SEM, XRD, and TGA-DTA analyses. FT-IR spectrum of the extracted cellulose confirmed that hemicellulose and lignin were removed during alkali and bleaching treatments. SEM images showed the partially roughened surface of the fiber due to the removal of non-cellulosic elements and surface impurities during chemical modification. The crystallinity index values for untreated Populus tremula fibers and extracted cellulose were calculated to be 32.8% and 58.9%, respectively. The obvious increase in the crystallinity index for the extracted cellulose confirmed the removal of amorphous compounds present in raw populus. Alkali-treated populus fibers were more thermally stable than raw fibers. All changes observed after alkali and bleaching treatments evidenced the removal of amorphous contents and non-cellulosic components in raw populus fibers. Extracted cellulose exhibited excellent adsorption capacities of methylene blue (140.4 mg g−1) and crystal violet (154 mg g−1). The pseudo second order equation fitted well the kinetic data indicating a chemi-sorption process. The Freundlich model complied well with the experimental data suggesting that the adsorption of the studied dyes was multilayer.

Characterization of brown-black pigment isolated from soil bacteria, Beijerinckia fluminensis

Melanin is a ubiquitous pigment found in most organisms it is a dark-brown or black pigment formed by the oxidation of phenolic compounds. They are negatively charged amorphous compounds having quinone groups. In this study; melanin-producing microorganism was isolated from soil obtained from iron ore mine. The soil was enriched in modified Ashbys glucose broth for 15 days at 30°C further to which it was isolated on modified Ashbys agar at 30°C for seven days; the colonies showing pigmentation were selected for further study. Conditions were optimized for maximal production of melanin pigment. The effect of carbon nitrogen tyrosine and metal salts on pigment production was studied. Alkaline conditions were used to extract the pigment from cells, further characterized by UV-VIS spectroscopy for λ-max. FTIR was done to identify the native functional groups and XRD was performed to determine the melanins structure. TGA analysis was done to check its thermal stability. SEM was carried out to check the size and shape of the melanin pigment. The melanin pigment was also analyzed for UV protectant property which was studied by exposure of both melanized and non-melanized cells to UV light at 254nm. Key words: Beijerinckia fluminensis iron ore soil melanin and UV-protection.

REGULARITIES OF THE PROCESSES OF FORMATION OF THE STRUCTURE AND STRENGTH OF A CLINKER-FREE BINDER OF ALKALINE ACTIVATION

resource- and energy-consuming Portland cement is currently considered the most popular material in the construction industry, but its production can be attributed to the category of harmful industries in terms of the amount of emissions into the environment. Therefore, the development of a clinker-free technology for the production of binders based on mineral fine powders of aluminosilicate nature activated by an alkaline coater is a relevant and promising direction. In the work, the laws of the processes occurring during the structure formation of clinker-free binder systems of alkaline activation on alkaline cements using blast furnace granulated slags in a finely dispersed state are studied. Formulations are given and the properties of clinker-free binders of alkaline activation on mineral fine powders from rocks of sedimentary and magmatic origin are investigated. Electron probe studies and X-ray phase analysis revealed the presence of hydrated amorphous compounds close in composition to zeolites in cement stone. An analysis of the results allowed us to determine the optimal composition of clinker-free binder alkaline activation “silicified marl + volcanic tuff (70: 30%) + Na2Si03 + Na0H” with activity ranging from 42.0 - 54.5 MPa, depending on the conditions of hardening of the samples.

Adsorption and Desorption Study of Locally Available BOF Sludge to Remove Metal Ions from Aqueous Solutions

Coarse BOF sludge is a waste originating from steelmaking production. The major phaseof this waste is zinc ferrite. BOF sludge for this study was obtained from the metallurgical industryfrom a process of gas treatment in an oxygen converter. The sorption of cobalt, manganese and nickelions was investigated in the sample of the deposited sludge in a batch of experiments. The sorptionprocess was evaluated using three types of isotherm models. The sludge sample was alkaline andconsisted primarily of X-ray amorphous compounds and crystalline Fe oxides. The adsorptionprocess showed that a high removal efficiency was achieved at a lower initial concentration of metalions. Moreover, the equilibrium of the sorption process was achieved after 72 hours. Subsequently,the desorption of these adsorbed ions was investigated. The results of this study indicate that theapplication of metallurgical waste as a sorbent is highly effective for the treatment of wastewater.

Raman Microspectroscopic Imaging of Binder Remnants in Historical Mortars Reveals Processing Conditions

Binder remnants in historical mortars represent a record of the connection between the raw materials that enter the kiln, the process parameters, and the end product of the calcination. Raman microspectroscopy combines high structural sensitivity with micrometre to sub-micrometre spatial resolution and compatibility with conventional thin-sectional samples in an almost unique fashion, making it an interesting complementary extension of the existing methodological arsenal for mortar analysis. Raman spectra are vibrational fingerprints of crystalline and amorphous compounds, and contain marker bands that are specific for minerals and their polymorphic forms. Relative intensities of bands that are related to the same crystalline species change according to crystal orientations, and band shifts can be caused by the incorporation of foreign ions into crystal lattices, as well as stoichiometric changes within solid solution series. Finally, variations in crystallinity affect band widths. These effects are demonstrated based on the analysis of three historical mortar samples: micrometric distribution maps of phases and polymorphs, crystal orientations, and compositional variations of solid solution series of unreacted clinker grains in the Portland cement mortars of two 19th century castings, and the crystallinities of thermal anhydrite clusters in a high-fired medieval gypsum mortar as a measure for the applied burning temperature were successfully acquired.

Effect of Si Content on the Corrosion Behavior of 420 MPa Weathering Steel

: The effect of Si content (0.12%, 0.34%, and 0.48%) on the corrosion behavior of weathering steel in a simulated marine environment was investigated in a dry/wet alternating cycle corrosion experiment. Corrosion weight gain, X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), and electrochemical methods were used to measure the regularity and nature of the rust. The results show that the corrosion process could be divided into an initial stage where the corrosion rate increased and a later stage where the corrosion rate decreased before remaining stable. The corrosion rate was the lowest for a Si content in the weathering steel of 0.48%. The corrosion products of all three steel groups contains α-FeOOH, β-FeOOH, γ-FeOOH, Fe3O4, and large amounts of amorphous compounds. Furthermore, Si benefits the transformation of β-FeOOH and γ-FeOOH to stable phases. The addition of the Si alloying element is beneficial to the formation of dense and compact rust layers that enhance the electrochemical resistance of weathering steel and silicon oxide influences the self-corrosion potential of the corrosion products.

A Comparative First-Principles Study of Lithium, Sodium and Magnesium Insertion Energetics in Brookite Titanium Dioxide

ABSTRACTBrookite titanium dioxide is investigated from first principles as possible insertion-type cathode material for Li, Na and Mg. Recently structural similarity of this phase and amorphous titanium dioxide was reported. Low-concentration insertion energies and the corresponding voltages, however, suggest poor electrochemical performance of brookite in comparison to e.g. layered titania phases such as B-TiO2. We argue that this behavior could be explained by local electronic structure leading to higher voltages in amorphous compounds, since the lattice strains induced by intercalation in brookite are not sufficient to explain the poor binding energies with the investigated metals.