Fourier Transform Infrared Absorption Research Articles

Structural role of chromium sulfate in modified borate glasses and glass ceramics

Different glasses in the system xCr2(SO4)3-(60−x)B2O3–15CaO-15Na2O-10P2O5 where x ranging between 0 and 35 mol% has been prepared via ordinary melt quenching method. Fourier transform infrared (FTIR) spectroscopic measurements, X-ray diffraction (XRD) pattern, and scanning electron microscopy (SEM) are the main tools adopted for retrace structural changes correlated with increasing Cr2(SO4)3 content. XRD spectra of glasses of Cr2(SO4)3 ≤ 2 mol% have revealed that the amorphous structure is dominant within such region of composition. However, glasses containing higher Cr2(SO4)3 contents (x = 5–35 mol%) are characterized by the formation of specific polycrystalline phases within the glass network. Data based on FTIR absorption support the presence of BO3, BO4, SO4, and CrO4 functional groups which were randomly distributed within the main borate network. Besides, the density and molar volume of the studied samples were estimated and correlated with additional physical parameters. Based on the measured density, the concentration of Cr2(SO4)3, field strength (F), and inter-nuclear distance (ri) are calculated. It was concluded that the increase in Cr and S content leads to a decrease in inter-nuclear distance which agree with an increase in field strength and Vicker's micro-hardness number of the investigated glasses.

Corrosion protection of zinc by a silane conversion coating modified with graphene oxide

Graphene possesses an adverse side effect that can aggravate metal corrosion, which impedes its applications in metal protection. This work aims to demonstrate a strategy to effectively inhibit the corrosion activity of graphene and, thus, apply graphene protection to a metal. A γ‐(2,3‐glycidoxypropyl)propyltrimethoxysilane/reduced graphene oxide (GPTMS/rGO) composite coating was prepared on a Zn surface by immersion in a GPTMS‐modified graphene oxide (GO) solution. The formation mechanism of the coating was investigated by means of scanning electron microscopy (SEM), Raman spectroscopy, Fourier transform infrared absorption (FTIR) spectroscopy, and X‐ray photoelectron spectroscopy (XPS). Afterward, the corrosion resistance of the coating was studied by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP). The results show that a dense layer of the GPTMS/rGO coating covers the Zn surface during the immersion process with the GO reduction reaction. The thickness of the GPTMS/rGO composite coating is approximately 20 μm, which is much thicker than that of a GPTMS coating. Furthermore, the formed coating shows good corrosion resistance with an icorr value of 0.029 μA/cm2, and the protection efficiency of the coating reaches 99.94%. After a 12‐day immersion in a 0.6‐M NaCl solution, the coating maintains its high corrosion resistance.

FTIR spectral band shifts explained by OM–cation interactions

AbstractBackground: The organic matter (OM) in soils interacts with polyvalent cations such as Ca2+ through hydroxyl (OH), carboxylic acid, ester, keto, aldehyde (summarized as C=O), and carboxylate (COO−) functional groups. Such interactions affect the bonding strength of the double bond between the C and the O atom in the functional groups, which is assumed to shift the wavenumber (WN) region of O–H (hydroxyl), C=O, COO−, and OMcat (i.e., C=O interacting with cations plus O–H groups) absorption band maxima in the Fourier transform infrared (FTIR) spectra. Such band shifts limit the evaluation of spectral information on OM in soil samples.Aims: The objective of this study was to analyze the extent of band shifts and the changes in absorption band intensities for relations with cation concentrations, and to estimate effects of band shifts on OM properties such as potential wettability of OM evaluated from FTIR absorption band ratios.Methods: Polygalacturonic acid (PGA) solutions were mixed with a CaCl2 solution at different relations. The freeze‐dried mixtures were analyzed with FTIR spectroscopy in the mid‐infrared spectral range by using KBr‐technique. The FTIR spectra were interpreted with respect to O–H, C=O, COO−, and OMcat bands, the latter reflecting the formation of PGA‐Ca2+ complexes.Results: The FTIR spectra of the PGA–Ca mixtures compared to that of pure PGA indicate band shift effects by CaCl2 addition on both, intensity and WN value of the OMcat, C=O and COO− absorption band maxima. The COO−/C–O–C ratio increased with Ca2+ concentration while the C–H/C–O–C ratio decreased. Furthermore, the C=O and COO− absorption band maxima were shifted towards lower WN values, while the OMcat absorption band was shifted towards higher WN values. The shift of OMcat band maxima was two times higher than that of the C=O band maximum and increased with Ca2+ concentration.Conclusion: Spectral band shifts depend on polyvalent cation concentration and limit automated interpretations of FTIR spectra without prior soil‐specific spectral corrections.

Analysis of spatial orientation distribution of highly oriented polyimide film using micro ATR-FTIR spectroscopic imaging method

Molecular orientation of aromatic polyimides (PIs) and their precursor of poly(amic ester)s (PAE) in the biaxially oriented films were analyzed by polarized microscopic attenuated-total-reflection Fourier-transform infrared absorption spectroscopy (micro pATR-FTIR) imaging. The films were prepared by shearing a lyotropic liquid crystal (LC) solution of the PAE on a glass substrate and subsequent drying under a N2 flow, and the long axis of polymer chains were distributed around the shear direction. In the film, streak-shaped defects were observed along the shear direction with optical microscopy. Such structural heterogeneities on the micrometer (μm) scale are expected to be visualized in spatial distribution map of molecular orientation order acquired with micro pATR-FTIR imaging. In this study, uniaxial orientation order parameter, S, and a mean square cosine value, ⟨cos2ψ⟩, were used to quantify the degree of orientation of the PI main chain and that of aromatic imide plane, respectively. It was revealed that the films are apparently homogeneous in the spatial distribution map of the S, while the films exhibited obvious heterogeneity in that of ⟨cos2ψ⟩, in which “face-on” and “edge-on” orientation domains coexist. The results indicate that orientation direction of the rigid PI chains is fixed in the averaged orientation direction of the oriented PAE matrix during thermal imidization, while the aromatic imide ring can be rotated around the main chain. Furthermore, cracks in the PI film were successfully visualized by ATR-FTIR imaging, and the orientation distribution inside the cracks was investigated. Through this structural study, we validated the quantitative capability of the micro pATR-FTIR imaging method thorough the analyses of highly oriented PI films and demonstrated its ability to investigate μm-scale heterogeneity on the basis of molecular orientation analyses.

Evaluation of biosurfactant production potential of Lysinibacillus fusiformis MK559526 isolated from automobile-mechanic-workshop soil.

Biosurfactants are amphipathic biological compounds with surface active potential and are produced by many microorganisms.Biosurfactant production by Lysinibacillus fusiformis MK559526 isolated from automobile-mechanic-shop soil was investigated with a view to assessing itspotential for production and potential for optimization. Effects of carbon and nitrogen sources, pH, temperature and incubationperiods on biosurfactant production were evaluated with a view to optimizing the processes. Fourier Transform Infra-Red absorption peaks and Gaschromatography mass spectrometry were used to determine the functional groups of the chemical make-up and the chemical profile of the biosurfactantrespectively. Lysinibacillus fusiformis surfactant had emulsification index of 65.15 ± 0.35 %, oil displacement of 2.7 ± 0.26 mm, zone ofhaemolysis of 7.3 ± 0.16 mm and a positive drop collapse test. Optimized culture conditions for biosurfactant production: temperature, 35 ºC; pH, 7.0;starch solution, 40 g/L and urea, 1.5 g/L showed a reduction in surface tension to 28.46 ± 1.11 mN/m and increased emulsification index to 93.80 ± 0.41 %.Maximum biosurfactant production of 2.92 ± 0.04 g/L was obtained after 72 h. The biosurfactant contained peptides and fatty acids. The predominant fattyacid was 9-Octadecenoic acid (80.80%). The above results showing high emulsification potential and remarkable reduction in the surfacetension are good biosurfactant attributes. Consequently, Lysinibacillus fusiformis MK559526 is a good candidate for biosurfactant production.

CdO Nanoparticles: A Highly Effective Catalyst in Cyclocondensation Reaction of 3,4-Methylenedioxyphenol, Aromatic Aldehydes, and Active Methylene Compounds under Ultrasonic Irradiation

In the last decades, metal oxide nanoparticles (NPs) have been used as inexpensive efficient heterogeneous catalysts in different chemical reactions, due to their favorable properties such as high available surface area, small loading of catalyst, convenient catalyst recycling, and degradation of environmental pollutants. An efficient synthesis of xanthenones and [1]benzopyrano[d]pyrimidinediones are achieved by cyclocondensation reaction of 3,4-methylenedioxyphenol, aromatic aldehydes, and active methylene compound including dimedone or 1,3-dimethylbarbituric acid using CdO NPs as a robust catalyst under ultrasonic irradiation in water at room temperature. The described catalyst was prepared successfully by a simple precipitation method and characterized by the Fourier transformed infrared absorption (FT-IR) spectroscopy, X-Ray diffraction (XRD) analytical technique, and scanning electron microscopy (SEM). All synthesized compounds were well characterized by IR, 1H and 13C NMR spectroscopy, and also by elemental analyses. The remarkable advantages of this protocol are high yields of products, short reaction times, use of simple and readily available starting materials, experimental simplicity, and applying the sonochemical method as an efficient method and innocuous tool for the synthesis of heterocycles.

UV-enhanced nano-nickel ferrite-activated peroxymonosulfate for the degradation of chlortetracycline hydrochloride in aqueous solution.

In this study, nano-nickel ferrite (NiFe2O4) was successfully prepared by hydrothermal synthesis and applied to the oxidative removal of chlortetracycline hydrochloride (CTH) in the presence of ultraviolet radiation (UV) and peroxymonosulfate (PMS). Several characterization methods were used to reveal the morphology and surface properties of nano-NiFe2O4, including X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared absorption (FTIR) spectroscopy. The removal efficiency of CTH, the factors affecting the reaction process and the reaction mechanism of PMS activated by UV combined with nano-NiFe2O4 (UV + nano-NiFe2O4/PMS) in aqueous solution were systematically studied. The results showed that the UV + nano-NiFe2O4/PMS system led to a higher removal efficiency of CTH than other parallel systems. The results also showed that the CTH removal efficiency was enhanced under optimal conditions ([nano-NiFe2O4] = 1 g L−1, [PMS] = 1 g L−1, [UV wavelength] = 254 nm and [pH] = 11) and that a removal efficiency of 96.98% could be achieved after 60 min. In addition, the influence of the PMS concentration, CTH concentration, dosage of added nano-NiFe2O4 and pH on the PMS activation efficiency and CTH oxidative degradation effect was studied. Inorganic anions such as Cl−, HCO3−, CO32− and NO3− increased the removal efficiency of CTH by 21.29%, 27.17%, 25.32% and 5.96% respectively, while H2PO4− inhibited CTH removal, and the removal efficiency of CTH decreased 6.08% after 60 min. Free radical identification tests detected SO4−˙, OH˙ and 1O2 and showed that these species participated in the degradation reaction of CTH. The results of LC-MS and TOC analysis showed that CTH was degraded in the UV + nano-NiFe2O4/PMS system through hydroxylation, demethylation, deamination, and dehydration reaction and finally mineralized into CO2. These findings confirmed that nano-NiFe2O4 is a green and efficient heterogeneous catalyst for activation of PMS and demonstrates potential applicability in the treatment of antibiotic wastewater.

Fourier transform infrared absorption (FTIR) on dry stratum corneum, corneocyte-lipid interfaces: experimental and vibrational spectroscopy calculations

Many questions concerning the biophysical and physiological properties of skin are still open. Skin aging, permeability, dermal absorption, hydration, and drug transdermal delivery, are few examples of processes with unveiled underlying mechanisms. In this work, it is presented a comparison between Fourier transform infrared absorption (FTIR) of dry stratum corneum and stratum corneum under lipase action supported by first-principles density functional vibrational calculations. The molecular structure of stratum corneum was modeled by an archetype of its hygroscopic proteic portion inside the corneocytes, the natural moisturizing factor, coupled to glycerol molecules which represent the lipid fraction of stratum corneum. Vibrational spectra were calculated and compared to experimental data obtained on the animal model of stratum corneum. The experimental results indicated prominent spectral differences between dry and lipase-treated stratum corneum. Principal components analysis and hyerarchical clustering indicated that 1200, 1650, and 1695 cm−1 bands are the most influential on the discrimination. It is noticed that bands in the fingerprint region (800–1800 cm−1) were correctly assigned. Moreover, the calculations revealed the existence of two coupled vibration between the hydroxyl group of lipid and methylene (1120 and 1160 cm−1), which are of special interest since they probe the lipid-amino acid coupling. The model was also able to predict the shear modulus of dry stratum corneum in excellent agreement with the reported values from the literature. Other physical/chemical properties could be calculated exploring the chemical accuracy and molecular resolution of this model. Research in dermatology, cosmetology, and biomedical engineering in the specific topics of drug delivery and/or mechanical properties of skin are examples of fields that would potentially take advantage of this approach.

Crystal Structure and Non-Hydrostatic Stress-Induced Phase Transition of Urotropine Under High Pressure.

High-pressure behavior of hexamethylenetetramine (urotropine) was studied in situ using angle-dispersive single-crystal synchrotron X-ray diffraction (XRD) and Fourier-transform infrared absorption (FTIR) spectroscopy. Experiments were conducted in various pressure-transmitting media to study the effect of deviatoric stress on phase transformations. Up to 4 GPa significant damping of molecular librations and atomic thermal motion was observed. A first-order phase transition to a tetragonal structure was observed with an onset at approximately 12.5 GPa and characterized by sluggish kinetics and considerable hysteresis upon decompression. However, it occurs only in non-hydrostatic conditions, induced by deviatoric or uniaxial stress in the sample. This behavior finds analogies in similar cubic crystals built of highly symmetric cage-like molecules and may be considered a common feature of such systems. DFT computations were performed to model urotropine equation of state and pressure dependence of vibrational modes. The first successful Hirshfeld atom refinements carried out for high-pressure diffraction data are reported. The refinements yielded more realistic C-H bond lengths than the independent atom model even though the high-pressure diffraction data are incomplete.

Molecular characteristics and antioxidant activity of laminarin extracted from the seaweed species Laminaria hyperborea, using hydrothermal-assisted extraction and a multi-step purification procedure

The objective of this study was to determine the effect of hydrothermal-assisted extraction (HAE) and a multi-step purification process on the molecular characteristics and antioxidant activity of extracts of laminarin from the brown seaweed Laminaria hyperborea. The HAE with optimised extraction conditions (time - 30 min; temperature - 99.3 °C; sample to solvent ratio - 1:21.3 (w/v)) resulted in 368 mg/g laminarin in the Crude Extract. Purification using solvents, molecular weight cut-off filter (MWCO; 10 kDa) and solid-phase extraction (SPE) improved the concentration to 542.6 mg/g, 906.6 mg/g and 862.5 mg/g on dry weight extract basis, respectively (p < 0.05). The crude HAE extract had greater antioxidant activity, as determined by 1,1-diphenyl-2-picryl-hydrazyl radical scavenging and ferric reducing antioxidant power assays, than the purified fractions (p > 0.05). The identification of a chromatographic peak at 17.66 min (retention time) and FT-IR (Fourier transform infrared) absorption bands at 1420 cm−1 (carboxyl groups), 2950 cm−1 (C-H stretch) and at 2410 cm−1 (transmitting angle peak) was similar between the purified samples and a laminarin standard that was used as a control, confirming the presence of laminarin. The quadruple time of flight mass spectrometry (Q-ToF-MS) confirmed the molecular weight of purified laminarin was in the range of 5.7 kDa–6.2 kDa. HAE under optimised conditions was an effective method to recover biologically active laminarin from L. hyperborea. A multi-step purification, involving solvents and MWCO filters in a sequence could improve the purity of laminarin, however, purification reduced the antioxidant activity compared to the crude HAE extract.

Spectroscopic investigation of long-term outdoor-exposed crystalline silicon photovoltaic modules

Degradations of an encapsulant of a random copolymer of ethylene and vinyl acetate (EVA), in long-term outdoor-exposed (OE) crystalline silicon (c-Si) photovoltaic (PV) modules were investigated by Raman and Fourier transform-infrared (FT-IR) spectroscopy measurements. Two predominant chemical and photochemical degradations, discoloration (yellow-browning) and formation of acetic acid (AcOH), were observed in EVA encapsulants in c-Si PV modules exposed outdoors for approximately 27 years in Japan (Kirishima module). The yellow-browning of the encapsulants was suggested to be due to reaction of additives, such as UV absorbers that were incorporated in the encapsulants, because no marked degradation of EVA itself was observed in the FT-IR absorption spectrum. Contrastingly, the absorption intensity of C = O of the colorless EVA in the Kirishima module decreased to 70 %, which was similar to that for the encapsulant in a damp-heat-tested (DHT) module at 85 °C with 85 % relative humidity for 4000 h (68 %), suggesting that AcOH was formed from EVA. The degradation mechanisms of the EVA encapsulants in long-term OE and DHT c-Si PV modules were explored by spectroscopy and other analyses.

Natural Pigment –Poly Vinyl Alcohol Nano composites Thin Films for Solar Cell

Solar cells thin films were prepared using polyvinyl alcohol (PVA) as a thin film, with extract of natural pigment from local flower. A concentration of 0.1g/ml of polyvinyl alcohol solution in water was prepared for four samples, with various concentrations of plant pigment (0, 15, 25 and 50) % added to each of the four solutions separately for preparing (PVA with low concentrated dye , PVA with medium concentrated dye and PVA with high concentrated dye ) thin films respectively . Ultraviolet absorption regions were obtained by computerized UV-Visible (CECIL 2700). Optical properties including (absorbance, reflectance, absorption coefficient, energy gap and dielectric constant) via UV- Vis were tested, too. Fourier transform infrared (FTIR) spectrophotometer was employed to test the samples. Thermal analysis of thin films, including melting point (Tm), onset degree, endset degree, and crystallinity% were tested by differential scanning calorimeter (DSC). Three dimensional morphologies of thin films were inspected by atomic force microscopy (ATM). Contact angle also was tested as an index to hydrophilicity. Results proved that the ultraviolet and FTIR absorption increase after adding the natural pigment to PVA thin film, as well as it increases with increasing concentration of natural pigment. DSC analysis revealed an increase of PVA melting point when adding 15% concentration and it decreases with a 50% concentration of pigment. AFM results show an increase in surface roughness, hence the surface bearing index of PVA thin films is inversely proportional to pigment concentration. Contact angle decreases from 46.5° for pure PVA thin film to 44. 8°, 42. 6° and 35.2° after adding (15, 25, and 50)% concentration of natural dye respectively. Optical properties were enhanced by adding the natural dye, hence energy gap decreased from 3 eV for pure PVA to 2.3 eV for the PVA with a high concentrate dye. Dielectric constant increased with increasing concentration of dye, which leads to high polarization of solar cell.

Ethanol-Drop Grinding Approach: Cadmium Oxide Nanoparticles Catalyzed the Synthesis of [1,3]Dioxolo[g][1]benzopyran-6-carboxylic Acids and Pyrido[d]pyrimidine-7-carboxylic Acids

In the last decades, it has extensively been verified that nanostructured transition metal oxides emerge as inexpensive, available and extremely efficient heterogeneous catalysts in chemical transformations. The high electrical conductivity, high carrier concentration, and improved reactivity in cadmium oxide nanoparticles (CdO NPs) make it as a potential candidate for applications in the fields of nanocatalysis. [1]Benzopyran and pyridopyrimidine derivatives compose major classes of heterocyclic compounds, which have a wide spectrum of biological activities. In the present work, we report a facile and highly effective synthesis of 8- aryl-8H-[1,3]dioxolo[4,5-g][1]benzopyran-6-carboxylic acids and 1,3-dimethyl-2,4-dioxo-5- phenyl-1,2,3,4,5,8-hexahydropyrido[2,3-d]pyrimidine-7-carboxylic acids via CdO NPs catalyzed cyclo condensation reaction of 4-substituted phenylmethylidenepyruvic acids with 3,4- methylenedioxyphenol or 6-amino-1,3-dimethyluracil, which was accomplished under ethanoldrop grinding at room temperature. The described catalyst was prepared successfully by a simple precipitation method and characterized by the Fourier transformed infrared absorption (FT-IR) spectroscopy, X-Ray diffraction (XRD) analytical technique, and scanning electron microscopy (SEM). A number of [1,3]dioxolo[g][1]benzopyran-6-carboxylic acids and pyrido[d]pyrimidine- 7-carboxylic acids were effectively synthesized in high yields (96-98%) within short reaction times (10-15 min). All synthesized compounds were well-characterized by IR, 1H and 13C NMR spectroscopy, and also by elemental analyses. In summary, we have developed a very simple and impressive procedure for the synthesis of 8-aryl-8H-[1,3]dioxolo[4,5-g][1]benzopyran-6-carboxylic acids and 1,3-dimethyl- 2,4-dioxo-5-phenyl-1,2,3,4,5,8-hexahydropyrido[2,3-d]pyrimidine-7-carboxylic acids as biologically interesting structures in the presence of CdO NPs as an efficient recyclable heterogeneous catalyst. The remarkable advantages for the offered protocol compared with traditional methods are short reaction time, good yields of the products, and the ease of operation with simple work-up procedure.

Evaluation of the In Vivo Biocompatibility of Amorphous Calcium Phosphate-Containing Metals.

Among the biomaterials based on calcium phosphate, hydroxyapatite has been widely used due to its biocompatibility and osteoconduction. The substitution of the phosphate group by the carbonate group associated with the absence of heat treatment and low synthesis temperature leads to the formation of carbonated hydroxyapatite (CHA). The association of CHA with other metals (strontium, zinc, magnesium, iron, and manganese) produces amorphous calcium phosphate-containing metals (ACPMetals), which can optimize their properties and mimic biological apatite. This study aimed to evaluate the biocompatibility and biodegradation of ACPMetals in mice subcutaneous tissue. The materials were physicochemically characterized with Fourier Transform InfraRed (FTIR), X-Ray Diffraction (XRD), and Atomic Absorption Spectrometry (AAS). Balb-C mice (n = 45) were randomly divided into three groups: carbonated hydroxyapatite, CHA (n = 15), ACPMetals (n = 15), and without implantation of material (SHAM, n = 15). The groups were subdivided into three experimental periods (1, 3, and 9 weeks). The samples were processed histologically for descriptive and semiquantitative evaluation of the biological effect of biomaterials according to ISO 10993-6:2016. The ACPMetals group was partially biodegradable; however, it presented a severe irritating reaction after 1 and 3 weeks and moderately irritating after nine weeks. Future studies with other concentrations and other metals should be carried out to mimic biological apatite.

Rapid intraoperative diagnosis of gynecological cancer by ATR-FTIR spectroscopy of fresh tissue biopsy.

A rapid and reliable intraoperative diagnostic technique to support clinical decisions was developed using Fourier-transform infrared (FTIR) spectroscopy. Twenty-six fresh tissue samples were collected intraoperatively from patients undergoing gynecological surgeries. Frozen section (FS) histopathology aimed to discriminate between malignant and benign tumors was performed, and attenuated total reflection (ATR) FTIR spectra were collected from these samples. Digital dehydration and principal component analysis and linear discriminant analysis (PCA-LDA) models were developed to classify samples into malignant and benign groups. Two validation schemes were employed: k-fold and "leave one out." FTIR absorption spectrum of a fresh tissue sample was obtained in less than 5 minutes. The fingerprint spectral region of malignant tumors was consistently different from that of benign tumors. The PCA-LDA discrimination model correctly classified the samples into malignant and benign groups with accuracies of 96% and 93% for the k-fold and "leave one out" validation schemes, respectively. We showed that a simple tissue preparation followed by ATR-FTIR spectroscopy provides accurate means for very rapid tumor classification into malignant and benign gynecological tumors. With further development, the proposed method has high potential to be used as an adjunct to the intraoperative FS histopathology technique.

Organo-mineral associations in a Spodosol from northern Brazil

The associations between organic and mineral matter in the horizons of an Amazonian humiluvic Spodosol profile were studied by investigating the composition of the constituent organic compounds, the surface wettability and the relationships among the chemical, structural, and microstructural properties using Fourier Transform Infrared (FTIR) spectroscopy and contact angle (CA) analysis. With increasing the profile depth, the CH FTIR absorption decreased accompanied by a relative increase in CO FTIR absorption. A number of significant correlations were found between the experimental variables measured. In particular, the positive correlation between soil organic carbon (SOC) (1.43 to 31.13 g kg−1) and intensity of aromatic structural CC peak at 1620 cm−1 downward the soil profile suggested the existence of higher amounts of more stable organic compounds with depth. The negative correlation between the intensity of aliphatic structures peaks from 3000 to 2800 cm−1 and the clay minerals content indicated an increasing soil wettability with depth. The relative affinity of organic matter to mineral surfaces changed as a function of the mineral type distribution along the soil profile. As well, the chemical composition of organic matter and the type of phase fractions influenced whole soil wettability based on the SOC/clay relation to CA.

Multivariate analysis for FTIR in understanding treatment of used cooking oil using activated carbon prepared from olive stone.

In this study, activated carbons prepared from the green and black olive stone (green OSAC and black OSAC) were used as adsorbents to investigate their removal efficiencies for oxidation products and polar compounds from used sunflower and corn cooking oils. The degree of oxidation level and polar compounds were evaluated using Fourier transform infrared (FTIR) with the principal component analysis and ultra-performance liquid chromatography. Two FTIR absorption peaks were used for the oil evaluation, namely 3007–3009 cm-1, which is related to C-H symmetric stretching vibration of the cis double bonds, and ~1743 cm-1, which is related to = CH and ester carbonyl stretching vibration of the functional groups of the triglycerides, C = O. The principal component analysis results showed significant variations in the oxidation level of the sunflower and the corn oils occurred after consecutive heating and French fries frying for 10 days. The oxidation products that are adsorbed on the surface of the OSAC forms π-complexes with the C = C parts of the OSAC system. It can be concluded that the prepared adsorbents can be promising, efficient, economically effective, and environmentally friendly alternative adsorbents for oil treatment applications.

Nanoceramics and novel functionalized silicate-based magnetic nanocomposites as substitutional disinfectants for water and wastewater purification.

Herein, we successfully synthesized nano-porous Co2O3/Cu2O3: Al2O3: SiO2 ((0, 5, 7, 9) Co-CAS) using the acidic sol-gel approach and calcined at 800°C for 4h. The crystallization behavior and spectroscopic properties were investigated using X-ray diffraction, field emission-scanning electron microscopy, and Fourier-transform infrared absorption spectra analysis. The antibiotic properties of the nano-porous CAS, 5Co-CAS, and 9Co-CAS magnetic nanocomposites was studied against some potentially pathogenic bacteria in water and wastewater samples. The bacteria tested included Escherichia coli, Salmonella enterica, Pseudomonas aeruginosa, Listeria monocytogenes, Staphylococcus aureus, Enterococcus faecalis, and Bacillus subtilis. Incorporating Co2O3 resulted in the identification of three peaks at 2θ = 10.2°, 13.4°, and 15°. The introduction of cobalt nanoparticles created a ferromagnetic behavior in the CAS nanoceramic, with the magnetic moment and saturation values increasing with increased Co2O3 doping. 9Co-CAS was most potent against all the tested pathogens with minimum inhibitory concentrations of 25mg/L within 40min for E. coli and P. aeruginosa and 50mg/L within 10min for S. enterica; the lowest antibacterial activity was observed with the unmodified CAS. The findings revealed that the manufactured nanocomposite materials were potent disinfectants with a promising application for water and wastewater treatment.

An innovation in obtaining the aggregation N of the synthesized diamond under HPHT conditions

Diamond crystals were synthesized with CH4N2S additive in FeNiCo–C system at pressure of 6.0 GPa and temperature ranging from 1285 to 1300 °C conditions, employing the temperature gradient growth (TGG) method. All of the obtained crystals displayed the sharp Raman spectra at 1331 cm−1. The photoluminescence (PL) spectra of the synthetic diamonds showed that there was no signal resulting from the nitrogen vacancy (NV) related color centers. However, the Ni-related PL feature, in particularly, the 793.6 nm (NE8 center) with vibronic structure was noticed. Furthermore, Fourier transform infrared (FTIR) measurements indicated that hydrogen (H) impurity was incorporated into the obtained crystals and the characteristic absorptions located at 1405 cm−1, 2800 cm−1 and 2920 cm−1, respectively. Most interestingly, the synthesized diamond crystals did not contain the single substitutional N atoms (C-center), but only the aggregation N impurity occupied diamond lattices and the corresponding FTIR absorption peak located at 1095 cm−1. Hence, this work also provided a new way of thinking for the preparation of diamond, which contained only the aggregation N defects.

African black velvet tamarind (Dialium guineense) as a green adsorbent for groundwater remediation

Process shells of black velvet tamarind fruits was investigated as an adsorbent for the potential removal of the pollutant heavy metal ions of Fe, Cr, Pb, Mn and Zn in well water samples collected from six different locations in Enugu Metropolis, Eastern Nigeria. Fourier Transform Infra-Red Spectroscopy absorption bands characteristic of stretching, scissoring and bending vibrations of - O-H groups of alcohols (R-OH) and phenols (Ph-OH), Sp3 (–C-H) of an oxygen bonded carbon atom, –C-O-C- bond and Sp2 (---C==C—H) carbons in a ring structure were seen between 3400 to 3200 cm-1, 1438 to 1371 cm-1, 2922/2851 cm-1 and 1155/1028 cm-1 as well as the 1509 cm-1 in the infra-red region of the electromagnetic spectrum in the infra-red absorption spectrum of processed black velvet tamarind fruit shells. Metal ion analysis was carried out by Flame Atomic Absorption Spectroscopy. The results showed that the adsorbent removed 40.50 to 63.30, 33.33 to 52.63, 26.23 to 48.05 and 15.00 to 37.84% respectively of Fe, Zn, Cr and Mn in the well water samples but was ineffective in removing Pb. This demonstrates the usefulness of black velvet tamarind fruit shells in decontaminating heavy metal burdened water and suggests that the technique has potential to reclaim polluted water of such nature, ameliorate the problems of insufficient potable water and waste disposal as well as protect the environment from heavy metal pollution.