Fourier Transform Infrared Spectrophotometer Research Articles

Ensuring Photocatalyst Properties on Cellulosic Fabric by Using Citric Acid Modified with TiO2 Degussa P25 Nanoparticles

Citric acid, which is a type of polycarboxylic acid, is environmentally friendly, and non-harmful and it can be used as a cross-linker. Titanium dioxide (TiO2) nanoparticle is a catalyst that provides many properties for textile products with its large surface area. Present study, a mixture was prepared with different concentrations of citric acid and commercial TiO2 Degussa P25 nanopowder suspensions. Two different curing temperatures (120°C and 140°C) were applied to the cotton fabrics in the pad-dry-cure method. The adhesion of the chemicals to the fiber surface was confirmed by scanning electron microscopy (SEM) and Fourier transform infrared spectrophotometer (FT/IR) analysis. The yellowing effect caused by citric acid on cotton fabrics was eliminated with white TiO2 nanoparticles. Methylene blue was used for staining the samples. Color analyses were performed with a spectrophotometer to determine photocatalytic properties of the samples. It was determined that the samples treated with a mixture of 30 g/L citric acid and TiO2 suspensions were the most discolored samples after exposure to solar light. The photocatalyst properties of the samples were further improved by removing the aggregation of TiO2 NPs on the fiber surface with the washing procedure.

Synthesis of silica-encapsulated myristic acid phase-change-assisted nanocapsules for thermal management applications

Myristic acid-based silica (MA/SiO2) nano-encapsulated phase change materials (NePCMs) were synthesized by the sol–gel process. Five different samples of the MA/SiO2 nanocapsules were prepared by varying the mass of the myristic acid. The nanocapsules were characterized by Fourier transform infrared spectrophotometer (FTIR), X-Ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM), energy dispersive X-ray (EDX), and dynamic light scattering (DLS). These characterization techniques confirmed the successful encapsulation of the myristic acid inside the silica shell. The maximum latent heat was found to be 114.46 J/g for the sample which was prepared with 25 g myristic acid and 20 ml tetraethyl orthosilicate precursor material. The highest encapsulation ratio of approximately 62% was obtained in the same sample and the mean size of the nanocapsules was 597 nm. The thermal stability of these nanocapsules was assessed using the thermogravimetric analyzer (TGA) and differential scanning calorimetry (DSC) results exhibited that the thermophysical properties remained consistent after 50 heating/cooling thermal cycles indicating excellent durability of the NePCMs.

A comparative study of gelatin-based nanofiber and sponge wound dressings

Gelatin is a collagen-derived biopolymer with high biocompatibility, commonly used in the production of wound dressing materials. Gelatin-based wound dressings, obtained through different processing methods, come with their own advantages and disadvantages depending on their physical structure. In this study, the effects of gelatin wound dressing materials with two different morphologies on wound healing are investigated in detail. The study investigated that the preparation of gelatin-based wound dressing materials using two different methods, followed by their chemical characterization and examination of their effects on biocompatibility and wound healing. To comprehend the impact of nanofiber structure and porous sponge structure on the wound healing process, the chemical structure of the prepared wound dressings was analyzed using Fourier Transform Infrared Spectrophotometer (FTIR). The morphological structure was visualized through Scanning Electron Microscope (SEM), the thermal properties were determined using Thermogravimetric Analyzer (TGA) and Differential Scanning Calorimeter (DSC). Additionally, the in vivo wound healing effects of gelatin-based wound dressings with different structures were evaluated through macroscopic observation and histological analysis in a dorsal region wound-healing rat model, monitored for 21 days. It was observed that wound healing materials with desired nanofiber and porous sponge structures were successfully obtained based on the SEM analysis. The gelatin nanofiber dressing showed a randomly oriented, bead-free, and smooth morphology with an average fiber diameter of approximately 1250 ± 0.35 nm, while the crosslinked gelatin sponge dressing had pore sizes ranging from 20 to 160 μm, and interconnected pore structures. The chemical structure remained unaltered according to FTIR graphs and these results were further supported by DSC and TGA graphs. Results from in vitro biocompatibility studies indicated that the wound dressing materials were biologically compatible, non-toxic, and did not cause irritation or sensitivity to the skin. Regarding in vivo analysis, it was determined that gelatin dressing materials were functional in the wound healing process, without the use of any auxiliary materials.

Preparation and properties of montmorillonite incorporated natural rubber/ethylene propylene diene monomer rubber blends

This article aims to evaluate and compare two types of organic surface-modified-nanoclay of octadecylamine-modified-bentonite-nanoclay (ODA-BNC) and aminopropyltrimethoxysilane-octadecylamine-modified-nanomontmorillonite (APS-ODA-MMT). Each type of nanoclay is combined with silica as a bi-filler for natural rubber (NR)/ethylene propylene diene monomer rubber (EPDM) in a 50/50 blend ratio for possible vulcanized rubber nanocomposite application. The total filler content is 50 phr while nanoclay filler content ranges from 0 to 20 phr, keeping the other ingredients ratio fixed. The prepared composites are characterized by the Fourier transform infrared spectrophotometer (FTIR) and their mechanical and thermal properties are thoroughly investigated. The data reveal that the fillers added to the rubber can improve its surface properties according to their type and amount as confirmed by the Atomic force microscope (AFM), and Scanning electron microscope (SEM) investigation. The surface of rubber containing APS-ODA-MMT displayed higher height (251) and roughness surface (94.11), than those (69.8) and (45.62) respectively, containing ODA-BNC. Moreover, the acid resistance of the prepared composites is verified and indicated that increasing the nanoclay ratio (20%) enhances the acid resistance by reducing the surface distortion while keeping the surface morphology. The mechanical properties and Thermogravimetric Analysis (TGA) measurements showed that the rubber containing ODA-BNC has higher values of stress (2.2), elongation (975), and thermal stability (470, 505, 520°C) than those (1.75), (650), and (440, 460, 470°C) respectively, containing the APS-ODA-MMT. Moreover, the durability investigation of the vulcanized rubber via the AFM found the modified composites can be used in harsh environments as a covering layer in petrochemical networks or chemical factories.

Preparation of Poly (N-Isopropylacrylamide) -Poly (2-Ethyl-2-Oxazoline) and Their Self-Assembly Properties with Dicarboxylic Acid

This study reports the synthesis of copolymers that contain thermally responsive polymers, namely poly(N-isopropylacrylamide) (PNIPAM) and poly(2-ethyl-2-oxazoline) (PEOX), as well as biodegradable side groups that are water-soluble and capable of hydrogen bonding. The assay aims to produce heat-responsive PNIPAM and PEOX polymers with di-carboxylic acid (DCA) controlled structuring of the resulting pH-sensitive nano-structured polymers. These will be used as a template in the synthesis of inorganic materials. The study demonstrated the impact of pH, salt concentration, and temperature on the polymer/DCA. This fragment describes the functional groups of the thermosensitive polymers PNIPAM and PEOX. These polymers have carboxylic acid functional groups at both ends, are water soluble, and are capable of hydrogen bonding. The structure of these polymers can be recognized with small molecules of DCA in an aqueous solution at different pH, salt concentrations, and temperatures with H-bonds. Additionally, these polymers can be used as templates to synthesize hollow silica polymers. The synthesized monomers and polymers were structurally characterized using Fourier transform infrared spectrophotometer (FT-IR). The resulting structured polymers were identified by scanning electron microscopy and atomic force microscopy (SEM, AFM). UV-VIS spectrophotometer and Differential Scanning Calorimetry (DSC) were used to determine the Lower Critical Solution temperature of the polymers.

The Potential of Weissella confusa K2 Isolated from Longan (Dimocarpus longan) Fruit as High Exopolysaccharide-Producing Strain

Isolation of Lactic Acid Bacteria (LAB) from various sources has previously been carried out to obtain strains that produce high of exopolysaccharide (EPS). Isolate K2, which was LAB isolated from longan (Dimocarpus longan) fruit, can produce EPS. This study aimed to identify isolate K2, and evaluated the effect of supplementation carbon sources (glucose, fructose, sucrose, and lactose) and pH of media (4, 5, 6, 7, and 8) on EPS production. Isolate K2 was identified as Weissella confusa molecularly based on 16S rDNA, the type of carbon source, and the pH of media had significant effects (P<0.05) on EPS production. W. confusa K2 produced EPS that was highest on media with the supplementation of sucrose as a carbon source and produced the lowest EPS on lactose. The amount of EPS produced by W. confusa K2 under alkaline was higher than under acidic, the highest EPS of 47.703 g/L at pH 8 and the lowest EPS at pH 4 of 1.858 g/L. The physical properties showed EPS has good solubility in water with the solubility and Water Holding Capacity (WHC) at 40.533% and 354% respectively. Based on Surface morphology of EPS with Scanning Electron Microscope (SEM) analysis, the surface structure of EPS was a porous polymer matrix. Fourier Transform Infrared Spectrophotometer (FTIR) results of EPS showed the presence of absorption bands as characteristic of carbohydrates, such as the presence of O-H, C-H, C=O, C=C, C-O-C groups, and glycosidic bonds.

Banana fibre-chitosan-guar gum composite as an alternative wound healing material

Bio-composites, which can be obtained from the renewable natural resources, are fascinating material for use as sustainable biomaterials with essential properties like biodegradable, bio-compatibility as well cyto-compatibility etc. These properties are useful for bio-medical including wound healing applications. In this study, fibre obtained banana pseudo stem of banana plant, which is otherwise wasted, was used as a material along with chitosan and guar gum to fabricate a banana fibre-biopolymer composite patch. The physiochemical properties of the patches were examined using Fourier Transformed Infra-red spectrophotometer (FT-IR), tensile tester, Scanning Electron Microscope (SEM), contact angle tester, swelling and degradation studies. We further demonstrated that a herbal drug, Nirgundi could be loaded to the patch showed controlled its release at different pHs. The patch had good antibacterial property and supported proliferation of mouse fibroblast cells. The study thus indicates that banana fibre-chitosan-guar gum composite can be developed into an alternative wound healing material.

Crude oil sorption capacity of modified and unmodified biowaste

Contamination of water by crude oil is ubiquitous particularly in developing countries. The governments of affected countries raise a lot of concern because of the associated economic and environmental impacts which are not in tandem with the United Nations Sustainable Development Goals (SDGs), 6, 8, 11, 13 & 14. Remediation of crude oil-impacted water and soil become imperative. However, the exercise is expensive; hence the search for cheaper and local alternatives. In this study, unsegregated wood sawdust was collected from the various wood saw-dust dump sites within the main Timber shade in the vicinity of Udu Bridge, Udu LGA of Delta State, Nigeria. One half of the sample was chemically modified by acetylation using acetic anhydride while the other half wasn’t. They were characterized using Fourier Transformed Infra-Red Spectrophotometer (FTIR) and Scanning Electron Microscope coupled with Electron Dispersive X-ray (SEM/EDX) analyzer before employing them in the removal of the crude oil from the simulated crude oil spill- water media. The obtained results indicated that the modified sorbent (wood sawdust) sorbed more crude oil than the unmodified sorbent (wood sawdust). Experimental process control factors limited to time, sorbent dosage, particle size, was investigated using the modified sawdust. The modified sorbent gave maximum oil absorption capacity of 5.228 gg-1 for sorption time, 4.759 gg-1 for sorbent dosage and 5.838 gg-1 for particle size analyses. The study contributes to the knowledge of sorption studies using unsegregated wood sawdust for remediation of crude oil-contaminated media.

Euclea natalensis Suppresses Postprandial Hyperglycemia in Rats via the Inhibition of α-Glucosidase: In vitro, in vivo, and Molecular Docking Studies

Background:: Postprandial hyperglycemia is a key factor in type 2 diabetes, and its management is critical in alleviating the deleterious consequences of diabetes and its associated micro and macrovascular complications. Objective:: The current study aims to determine the effect of Euclea natalensis leaf extracts on α- glucosidase inhibition in vitro and postprandial hyperglycemia in vivo in rats. Methods:: Sequentially extracted leaf extracts of Euclea natalensis were evaluated for their inhibitory effects on α-glucosidase in vitro and the suppression of postprandial hyperglycemia in normoglycemic rats. The extracts were fingerprinted using a Fourier-transform infrared spectrophotometer (FTIR), and the bioactive compounds were evaluated by molecular docking for their interaction with α-glucosidase. Results:: FTIR fingerprinting of the extracts showed that they contain functional groups of important bioactive phytochemicals. The extracts inhibited α-glucosidase in vitro, with the methanol extract (1 mg/mL) showing the highest inhibitory effect of 93.52 ± 1.50% compared to 69.62% ± 1.45 of the standard drug acarbose (0.05 mg/mL). The extracts also reduced postprandial hyperglycemia in rats in a sucrose tolerance test, where the hexane and methanol extracts performed similarly to Acarbose. Molecular docking studies showed that 20(29)-lupene-3β- isoferulate 3 is the most potent α-glucosidase inhibitor with the lowest binding energy of -10.79 kcal/mol, 2 hydrogen bonds with residues ASP1526 and ASP1157, and numerous Van der Waal interactions with amino acids in the binding pocket of α-glucosidase. Conclusion:: Euclea natalensis leaf extracts were found to suppress postprandial hyperglycemia by inhibiting α-glucosidase activity; thus, it has a promising potential for use as an antidiabetic agent.

Green Synthesis, Characterization and Antibacterial Activity of Copper Nanoparticles from the Roots Extract of Piliostigma Reticulata Fabaceae

Nanotechnology is a fast-growing area in science which is an interdisciplinary field of both science and technology. In this study, the Roots extracts of Piliostigma reticulata were used for the green synthesis of Copper (Cu) nanoparticles (NPs) from copper Sulphate solution. Green synthesized metallic nanoparticles were characterized by UV– visible spectrophotometer, X-ray diffraction (XRD), Fourier Transform Infra-Red spectrophotometer (FTIR) and Scanning Electron Microscope (SEM). Using the Debye Scherrer formula, the average crystalline size of CuNPs was calculated as 51.0nm respectively. The UV–Vis spectroscopy results showed Surface Plasmon Resonance peaks at 500nm respectively. Fourier transform infrared spectroscopy was measured to identify the possible functional group of the biomolecules in the extract that act as reducing and capping agents of the nanoparticles. SEM analysis describes surface morphology of the synthesized nanoparticles which were roughly spherical in shape. The synthesized Nanoparticles showed antibacterial activity against pathogenic bacteria (Escherichia coli and Staphylococcus aureus) and the highest antibacterial activity was found in Cu-NPS compared plant root extract.

Green synthesis of selenium nanoparticles and its electrochemical properties

Green synthesis of selenium nanoparticles (SeNPs) is produced by mixing Curcuma longa leaves extract and sodium hydrogen selenite (NaHSeO3) solution. Curcuma longa leaves extract act as reducing, stabilizing and capping agent. Selenium nanoparticles formation was assisted by using microwave-assisted method. This work focusing on determining the electrochemical properties of the selenium nanoparticles (SeNPs) through characterization and application. Formation of SeNPs confirmed using UV-Vis spectrophotometer, morphological and size of the SeNPs through Field Emission Scanning Electron Microscopy (FESEM) presence of functional groups using Fourier-Transform Infrared Spectrophotometer (FTIR), amorphic nature of the SeNPs through X-Ray Diffraction (XRD) where spherical and average size of 251nm were observed. For its electrochemical properties, the 20µL SeNPs was used for modification in electrocatalytic of bare glassy carbon electrode (GCE). The electrooxidation by SeNPs/GCE of nitrite was examined via cyclic voltammetry where increase of oxidation current can be observed approximately at 0.8V.

Investigation of Antibacterial and Antifungal Efficacy of Zinc and Silver Nanoparticles Synthesized from Nasturtium officinale

Nanoparticles are nano-sized materials that can be widely used in fields such as medicine, pharmacology, and industry. The use of natural and easily available materials in nanoparticle synthesis is preferred because it is economical. Plants are extremely suitable for the synthesis of nanoparticles due to their natural and easy availability and the large number of components they contain with different properties. For this purpose, silver nanoparticles and zinc nanoparticles (AgNPs and ZnNPs), two different nanoparticles were synthesized from an edible plant, watercress (Nasturtium officinale). SEM (Scanning electron microscopy), SEM-EDX (Scanning electron microscopy-Energy dispersive X-ray), UV-VIS spectroscopy, XRD (X-ray crystallography), and FTIR (Fourier Transform Infrared Spectrophotometer) analyses of these nanoparticles were performed. In addition, the antimicrobial effects of these synthesized nanoparticles were determined by the disk diffusion method. As a result, nanoparticles obtained from Nasturtium officinale were effective on gram-negative bacteria (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa), gram-positive bacteria (Staphylococcus aureus, Streptococcus pyogenes), and fungi (Candida albicans). In particular, AgNPs with broad-spectrum antimicrobial activity were obtained from the watercress. While ZnNPs showed inhibition effects of 49% on K. pneumoniae, 51% on S. aureus, and 62% on C. albicans, AgNPs showed inhibition effects of 93% on P. aeruginosa, 87% on S. aureus, 81% on E. coli, 80% on C. albicans, 72% on K. pneumoniae, and 56% on S. pyogenes. Thus, it has been shown that Nasturtium officinale can be used effectively in the production of new biotechnological products, especially with antimicrobial properties.

Green Synthesis and Characterization of Silver Nanoparticles (AgNPs) and L-cysteine-capped AgNPs with Foeniculum vulgare seed extract for Colorimetric Hg2+ Detection

In this study, silver nanoparticles (AgNPs) and L-cysteine-capped AgNPs were synthesized separately using Foeniculum vulgare seed extract as the reducing agent and L-cysteine as the capping agent, which were characterized by ultraviolet–visible spectrophotometer (UV–vis), Fourier Transform Infrared spectrophotometer (FT-IR), X-ray diffractometer (XRD), and transmission electron microscopy (TEM). The utilization of the synthesized nanomaterials as colorimetric sensors for the detection of Hg2+ ions was also investigated. In this context, it was determined that L-cysteine-capped AgNPs exhibited better performance in the colorimetric Hg2+ detection in regards to sensitivity, selectivity, and applicability in real samples. It was observed that the colorimetric detection method was based on the disappearance of the brown color of the nanomaterial-contained colloidal solution and thus the decrease in the LSPR peak intensity. The method of the colorimetric Hg2+ detection with L-cysteine-capped AgNPs showed the good regression coefficient with the minimum detection limit of 0.36 μM in the linear Hg2+ concentration range of 1.0-10 μM, which indicated the competitive results compared to the latest reported colorimetric sensors in the literature. According to the obtained results, it has been concluded that the studied method enables to detection of Hg2+ ions colorimetrically via L-cysteine-capped AgNPs in a sensitive, selective, applicable in real samples, cheap, and easy way.

Deuterium Enrichment by PEM Water Electrolysis Using Water Circulation

Artemis Project, an international space exploration project proposed by the United States and involving Japan, plans a long-term manned lunar exploration in the late 2020s. That project considers the capture of He3, a resource for fusion that does not exist on Earth. On the other hand, He3 is produced by the half-life of tritium (T). Now new hydrogen isotope separation is required for recovering T exhausted from nuclear reactors.The water electrolysis is well known to enrich protium (H) in gas phase and, deuterium (D) and T in the electrolyte [1]. The modern electrolysis is performed by solid polymer membrane water electrolysis (PEMWE). However, there are few reported cases for the isotope separation by PEMWE. In this study for pursing high D separation, the optimization of the electrolysis system was investigated.The initial D concentrations in the electrolyte were 10, 30, and 50 at% IrO2 was used as the anode catalyst and Pt/C as the cathode one. The electrolysis was galvanostatically conducted. Hydrogen gas was analyzed by a quadrupole mass spectrometer (Q-Mass) to determine the ratio of H2, HD, and D2. The electrolyte was analyzed by Fourier transform infrared spectrophotometer (FT-IR) to determine the ratio of H2O, HDO, and D2O.Figure. 1 shows the schematic illustration of gas and water flow chart in experimental setup. Electrolyte was sent to the cell by the electric pump constantly. When the experiment was carried out, evolved gas and drained water was analyzed. The water out from the cell was returned into the electrolyte tank and electrolyzed repeatedly. The gas was introduced to Q-Mass. By using this circulation system, D was concentrated in the electrolyte efficiently . In this experiment, its concentration reached about 95at.%. To quantitatively evaluate the D enrichment by PEMWE, the separation factor α was calculated from the ratio of D concentrations in the electrolyte to the gas. The value of α was approximately 4.0. However, the valueslightly decreased above 90 at.% D. More detailed results will also be presented in our Poster, #176411. Figure 1

Deuterium Enrichment by PEM Water Electrolysis with Electrolyte Circulation

Nuclear fusion is attracting attention as a new energy supply method. Nuclear fusion requires high purity deuterium (D) as fuel, but it is difficult to separate and enrich the isotopes because they have very similar chemical properties. In polymer electrolyte membrane water electrolysis (PEMWE), protium (H) is easily generated as hydrogen gas at the cathode electrode, while D can be concentrated in the electrolyte [1]. In this study for pursing high D enrichment process, the electrolyte circulation was employed and the relationship between the consumption ratio and D concentration was investigated.The initial D concentrations in the electrolyte were 10, 30, and 50 at%. The electrolyte was supplied to the cathode. IrO2 was used as the anode catalyst and Pt/C as the cathode one. Experiments were conducted at atmospheric pressure and room temperature. The electrolysis was conducted at constant current. Hydrogen gas produced by electrolysis was analyzed by a quadrupole mass spectrometer (Q-Mass) to determine the ratio of H2, HD, and D2. The drain from the cathode was returned to the electrolyte reservoir. The electrolyte was analyzed by Fourier transform infrared spectrophotometer (FT-IR) to determine the ratio of H2O, HDO, and D2O.The D concentrations, CD , in the solution relative to the consumption ratio of the electrolyte, R, were shown in Fig. 1. The experimental results showed that CD increased exponentially with R, confirming D enrichment in the electrolyte. Figure 2 shows the variation of the separation factor, α, in the gases as a function of R. α is the [H]/[D] ratio in the evolved gas divided by the [H]/[D] ratio in the liquid. H was concentrated in the gas. While about 90% of the electrolyte was consumed, α remained constant value (α ≈ 4), but as the electrolyte was further consumed, α dropped to about 3.

High resolution, in situ, multispectral, spectroscopic mapping imaging system applied in heritage science

In the current work a setup for the acquisition of high resolution multispectral, spectroscopic mapping infrared images is presented. The idea is based on the Fourier Transform Infrared (FTIR) reflectoscopy since the object is illuminated using the source and the interferometer of an FTIR spectrophotometer and the reflected signal intensity from the object is measured using a high resolution response of a Focal Plane Array (FPA) of InSb sensor. The optical parts like optical fibers, mirrors, beamsplitters, FPA and the FPA lens are selected properly to allow the measurement at a wide frequency range depending on the spectral range of the source interferometer from wavelength 1.3 μm to 26 μm and the spectral range of the FPA which in this case is from wavelength 1.3 μm to 5.5 μm and beyond but with significant attenuation. Moreover, the FPA is triggered through the laser signal that measures the position of the moving mirror of the interferometer and by adjusting appropriately the speed of the scanner mirror and the FPA integration time, the array of interferogramms of a significant region of interest (ROI) can be acquired instantly. This is one of the main contributions of the present work since multispectral images in a non-micrometer level and from an area of a few centimeters by centimeters are acquired by extracting the interferogram, through each sensor of the FPA, in the illuminated ROI and in a time interval less than 1 sec. This is providing to the user the fast acquisition mapping images in a wavelength resolution of the order of less than manometer (based on the spectrophotometers resolution) in a broadband area as stated before. This kind of mapping, multispectral cube images with sub nanometer spectral interval among them, up to now, are acquired by scanning point by point, in an array format, in a ROI of 2 cm by 10 cm, lasting approximately 8.8 hours with 16 averaging per signal. By using this technology in the field of heritage science, the scientists can simultaneously observe, in the case of painted artworks like the ones presented in this manuscript, the overpaintings, pentimenti, defects in the underlayers based on the cube imaging, produced data set, as well as materials identification based on the spectra that are acquired per pixel simultaneously to the cube imaging data set. Using the iTomography system and applying mosaic scanning, the acquisition time of spectroscopic mapping cube images from the hole object, like the icon presented in this work, with dimensions 60 cm × 70 cm, is of the order of 8-10 minutes.

Isolation, Characterisation and Corrosion Inhibition Evaluation of 1, 3, 5-Trimethoxymethylbenzenefrom Seeds Extract of Cola nitida on Mild Steel Surface in Hyhrochloric Acid Solution

Corrosion inhibition of Mild steel in 1 M hydrochloric acid solution by 1, 3, 5-trimethoxymethylbenzene (TMMB) isolated from seeds extract of Cola nitida was studied using weight loss, potentiodynamic polarization and electrochemical impedance spectroscopic methods. TMMB was isolated from seeds of C. nitida by 72 hours maceration of the chopped seeds with dichloromethane. Filtered and concentrated extract was subjected to a combination of vacuum liquid, column and thin layer chromatographic techniques. The isolated compound was characterized using Fourier Transform Infra-Red (FT-IR) spectrophotometer, proton nuclear magnetic resonance (+H-NMR), C13 – NMR and DEPT-135 NMR spectrophotmeters. The results showed that the inhibition efficiency recorded by the weight loss method increased with the increase in TMMB concentration, but decreased with increasing temperature. The inhibition efficiencies recorded by the potentiodynamic polarization and electrochemical impedance spectroscopic methods also increased with increase in the concentration of TMMB. The calculated thermodynamic parameters showed that the corrosion inhibition process was endothermic and spontaneous in nature. Potentiodynamic polarization measurements confirmed that TMMB worked as a mixed – type inhibitor considering the value of Ecorrbeing less than 85 mV. Impedance measurement revealed that the charge transfer resistance offered by TMMB to the migration of aggressive ions on the surface of mild steel in acidic solution was enough to impede corrosion. The best line of fit to the adsorption of TMMB onto mild steel surface was found in Temkin isotherm. Formation of protective dense film on the steel surface in the presence of TMMB compared to the blank was revealed by scanning electron microscopy. The molecular structure of TMMB was optimized using Gausian 09 with density functional theory [DFT/B3LYP/6-31G (d,p)]. Physical adsorption has been proposed for the adsorption of TMMB onto mild steel surface.

Preparation and characterization of MgO-Al2O3-SiO2 glass-ceramics with different MgO/Al2O3 ratio and La2O3 addition

MgO-Al2O3-SiO2 (MAS) glass-ceramics were prepared by traditional melting and sintering method, and the effects of MgO/Al2O3 ratios and La2O3 contents on the microstructure and physicochemical properties of MAS glass-ceramics were studied. Herein, differential scanning calorimetry (DSC), X-ray diffraction (XRD), fourier-transform infrared spectrophotometer (FTIR), Field-emission scanning electron microscopy (FESEM), density, corrosion resistance, dielectric properties and thermal expansion coefficient (CTE) were carried out to evaluate the properties of both parent glass and glass-ceramics samples. The results show that adjusting the MgO/Al2O3 ratio from 0.69 to 0.47 can increase the characteristic temperatures of transition temperature (Tg) and crystallization peak temperature (Tp) in MAS parent glass. The reduction of MgO/Al2O3 ratio could promotes the precipitation of α-cordierite phase (Mg2Al4Si5O18), and the grain size of α-cordierite phase were increased from 200 to 500 nm. When the MgO/Al2O3 ratio was 0.63, the MA-2 sample has the highest flexural strength of 127.46 MPa. Furthermore, we also investigated the influence of La2O3 addition on the structure and properties of MAS glass-ceramics by employed MA-2 sample as a reference. The results show both the Tg (742–748 °C) and Tp (936–943 °C) of parent glass exhibit a slightly increasing with the La2O3 content was increased from 0.0 to 2.0 wt%. The La2O3 addition show a negligible influence on the crystal phase and morphology of MAS glass-ceramics. With increasing of the La2O3 content, the MAS glass-ceramics samples have a larger density (2.58–2.76 g/cm3) and a better chemical stability, and the CTE (6.12–8.17 × 10−6/°C), εr (5.04–6.17), and the flexural strength (127.46–150.15 MPa) also show an increased change trends. The prepared MAS glass-ceramics can be packaged with high expansion coefficient chips (such as GaAs) and is expected to become a potential candidate of dielectric materials for electronic devices, especially for high frequency applications in integrated circuits.

Glutaraldehyde Crosslinked Alginate-Chitosan Nanoparticles as Paracetamol Adsorbent

Paracetamol contained in wastewater can cause adverse effects on animal ecosystems, such as fish living in waters and cause harmful effects on humans. Adsorption techniques are used to remove these pharmaceutical compounds. Alginate-chitosan nanoparticles are non-toxic and effectively used as adsorbents to remove pharmaceutical compounds in wastewater. Research on glutaraldehyde crosslinked alginate-chitosan nanoparticles as paracetamol adsorbent has been carried out. This research used the ionic gelation method. Nanoparticles were characterized using transmission electron microscopy (TEM), scanning electron microscope (SEM-EDX) and Fourier transform infra-red spectrophotometer (FTIR). Furthermore, the nanoparticles were used for paracetamol adsorption. The results showed that the form nanoparticles are coarse solid powder and brownish yellow. The TEM image shows an average nanoparticle size of 8.22 nm. Glutaraldehyde crosslinked alginate-chitosan nanoparticles adsorbed paracetamol with adsorption kinetics followed a pseudo-second-order or Ho-McKay model, the adsorption rate constant of 0.0324 g mg−1 min−1. The isotherm study of paracetamol adsorption by glutaraldehyde cross-linked alginate-chitosan nanoparticles followed the isotherm Dubinin-Radushkevich isotherm model with a free energy value of 707.1068 kJ mol−1, and this value indicates the adsorption process by chemically or chemisorption.

Investigation of the usability of activated carbon as a filling material in nitrile butadiene rubber/natural rubber components and modeling by regression analysis

Activated carbon is a versatile material with a wide range of applications due to its porous structure and large surface area. In this study, activated carbon was manufactured from cellulose using zinc chloride and phosphoric acid activation agents, and it was characterized using Brunauer-Emmett-Teller (BET), Field-Emission Scanning Electron Microscopes (FE-SEM), Energy Distribution Spectroscopy (EDS), mapping, and Fourier Transform Infrared Spectrophotometer (FTIR). Two different types of activated carbon utilized as a filler in Nitrile Butadiene Rubber (NBR)/Natural Rubber (NR) blends at different proportions (%0, %5, %10, %15 and 20%), and compared its properties to those of carbon black. The results showed that the addition of activated carbon improved the mechanical properties of the rubber blends, including hardness, tensile strength, and unit elongation. Furthermore, the experimental data obtained were used to examine the effects of carbon black, activated carbon salt, and activated carbon acid values on density, hardness, tensile strength, and percentage elongation variables using Multiple Linear Regressions (MLR). These models provided successful results in predicting the data with fewer experiments. The results have the potential to contribute to the promotion of the use of environmentally friendly materials in future research and to be an important step towards a sustainable industry.