Showing papers on "Fourier transform infrared spectroscopy published in 2023"

Adsorption mechanism of shell powders on heavy metal ions Pb2+/Cd2+ and the purification efficiency for contaminated soils

Abstract: The adsorption capacity of oyster shell powders (SPs) and the adsorption mechanism of heavy metal ions (HMs; i.e., cadmium ions Cd2+ and lead ions Pb2+) on SPs are discussed by means of adsorption kinetics tests, adsorption-desorption tests, scanning electron microscopy and Fourier transform infrared spectroscopy. The influences of seepage velocity, heavy metal types, and SP addition amount/concentration on the adsorption effect of SPs in the treatment of HMs in laterite as well as quartz sand were analyzed. Studies have shown that i) the adsorption of HMs on SPs can be divided into three stages, i.e., the surface adsorption stage, the internal pore diffusion stage, and the equilibrium stage; ii) with the increase in seepage velocity, the effluent concentration of HMs will slightly increase, and the residual amounts at each section of the column generally decrease rapidly with the increase in migration distance; iii) the increase in the concentration of SP solution provides more adsorption points for the adsorption of HMs, and finally, the amount of HMs desorbed from quartz sand is reduced, which also reduces the concentration of HMs in the effluent. Overall, SPs possess high purification efficiency for the HMs of contaminated soils.

Design Hybrid Porous Organic/Inorganic Polymers Containing Polyhedral Oligomeric Silsesquioxane/Pyrene/Anthracene Moieties as a High-Performance Electrode for Supercapacitor

Abstract: We synthesized two hybrid organic–inorganic porous polymers (HPP) through the Heck reaction of 9,10 dibromoanthracene (A-Br2) or 1,3,6,8-tetrabromopyrene (P-Br4)/A-Br2 as co-monomers with octavinylsilsesquioxane (OVS), in order to afford OVS-A HPP and OVS-P-A HPP, respectively. The chemical structures of these two hybrid porous polymers were validated through FTIR and solid-state 13C and 29Si NMR spectroscopy. The thermal stability and porosity of these materials were measured by TGA and N2 adsorption/desorption analyses, demonstrating that OVS-A HPP has higher thermal stability (Td10: 579 °C) and surface area (433 m2 g−1) than OVS-P-A HPP (Td10: 377 °C and 98 m2 g−1) due to its higher cross-linking density. Furthermore, the electrochemical analysis showed that OVS-P-A HPP has a higher specific capacitance (177 F g −1 at 0.5 A F g−1) when compared to OVS-A HPP (120 F g −1 at 0.5 A F g−1). The electron-rich phenyl rings and Faradaic reaction between the π-conjugated network and anthracene moiety may be attributed to their excellent electrochemical performance of OVS-P-A HPP.

Orange G degradation by heterogeneous peroxymonosulfate activation based on magnetic MnFe2O4/α-MnO2 hybrid.

Abstract: Wastewater containing an azo dye Orange G (OG) causes massive environmental pollution, thus it is critical to develop a highly effective, environmental-friendly, and reusable catalyst in peroxymonosulfate (PMS) activation for OG degradation. In this work, we successfully applied a magnetic MnFe2O4/α-MnO2 hybrid fabricated by a simple hydrothermal method for OG removal in water. The characteristics of the hybrid were investigated by X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, Brunauer-Emmett-Teller method, vibrating sample magnetometry, electron paramagnetic resonance, thermogravimetric analysis, and X-ray photoelectron spectroscopy. The effects of operational parameters (i.e., catalytic system, catalytic dose, solution pH, and temperature) were investigated. The results exhibited that 96.8% of OG degradation was obtained with MnFe2O4/α-MnO2(1:9)/PMS system in 30 min regardless of solution pH changes. Furthermore, the possible reaction mechanism of the coupling system was proposed, and the degradation intermediates of OG were identified by mass spectroscopy. The radical quenching experiments and EPR tests demonstrated that SO4•̶, O2•̶, and 1O2 were the primary reactive oxygen species responsible for the OG degradation. The hybrid also displayed unusual stability with less than 30% loss in the OG removal after four sequential cycles. Overall, magnetic MnFe2O4/α-MnO2 hybrid could be used as a high potential activator of PMS to remove orange G and maybe other dyes from wastewater.

Properties and Characterization Techniques of Graphene Modified Asphalt Binders

Abstract: Graphene is a carbon-based nanomaterial used in various industries to improve the performance of hundreds of materials. For instance, graphene-like materials have been employed as asphalt binder modifying agents in pavement engineering. In the literature, it has been reported that (in comparison to an unmodified binder) the Graphene Modified Asphalt Binders (GMABs) exhibit an enhanced performance grade, a lower thermal susceptibility, a higher fatigue life, and a decreased accumulation of permanent deformations. Nonetheless, although GMABs stand out significantly from traditional alternatives, there is still no consensus on their behavior regarding chemical, rheological, microstructural, morphological, thermogravimetric, and surface topography properties. Therefore, this research conducted a literature review on the properties and advanced characterization techniques of GMABs. Thus, the laboratory protocols covered by this manuscript are atomic force microscopy, differential scanning calorimetry, dynamic shear rheometer, elemental analysis, Fourier transform infrared spectroscopy, Raman spectroscopy, scanning electron microscopy, thermogravimetric analysis, X-ray diffraction, and X-ray photoelectron spectroscopy. Consequently, the main contribution of this investigation to the state-of-the-art is the identification of the prominent trends and gaps in the current state of knowledge.

A novel method of domestication combined with ARTP to improve the reduction ability of Bacillus velezensis to Cr(VI)

Abstract: In this study, the Cr(VI)-resistant bacterium LYB-23 was isolated from waste chromium residues in Sichuan and identified as Bacillus velezensis. The chromium tolerance of LYB-23 was improved by domestication (continuously increasing the chromium concentration in the medium from 60 to 200 mg/L). Subsequently, we screened a mutant strain, B. velezensis SA-23, using atmospheric pressure room temperature plasma (ARTP) mutagenesis for 90 s based on the domesticated strain. The minimum inhibitory concentration of B. velezensis on chromium increased from 80 mg/L for the original strain to 200 mg/L for the domesticated strain and to 400 mg/L for the mutant strain. The Cr(VI) reduction experiment results show that SA-23 can completely reduce 100 mg/L Cr(VI) within 24 h, and the reduction rate of 200 mg/L Cr(VI) reached 78.45% within 72 h. Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) analysis showed that ARTP mutagenesis did not change the type of functional groups on the surface of bacteria after reductive adsorption of Cr(VI) and the crystalline state of Cr(III); however, mutagenesis changed the biological morphology of bacteria and greatly enhanced the role of phosphate groups in the process of adsorption and reduction of Cr(VI). This experiment for the first time used the combined domestication and ARTP mutagenesis to effectively improve the tolerance of bacteria to Cr(VI) and their reduction adsorption efficiency, which proved to be an efficient method for the breeding of environmental remediation engineering bacteria and for promoting the application of microbial remediation.

One-step synthesized biogenic nanoparticles using Linum usitatissimum: Application of sun-light photocatalytic, biological activity and electrochemical H2O2 sensor

Abstract: This study aimed to synthesize Ag NPs as a green catalyst for photocatalytic activity and to examine their biological activities. It was determined that they have high activity in catalytic and biological activities. The green synthesis which is an environmentally friendly and inexpensive method was used to synthesize Ag-NPs using Linum usitatissimum as a reducing agent. Transmission electron microscopy (TEM), infrared to Fourier transform infrared (FTIR) spectroscopy, UV-Visible (UV–Vis) spectroscopy, and X-ray diffraction (XRD) were used to characterize the Ag NPs. In UV–Vis examination, Ag-NPs had intense peaks in the 435 nm region. The antibacterial activity of Ag NPs was investigated, and Ag NPs showed a high lethal effect against S. aureus, E. coli, B. subtilis, and MRSA. In addition, Ag NPs were tested for anticancer activity against the HT-29 colon cancer cell line, MDA-MB-231 breast cancer cell line, healthy cell line L929-Murine Fibroblast cell Lines, and MIA PaCa-2 human pancreatic cancer cell line at various concentrations (1–160 μg/mL) and showed a high anticancerogenic properties against MDA-MB-231 cells. Ag NPs showed the ability of DNA cleavage activity. Also, the antioxidant activity of Ag NPs against DPPH was found to be 80% approximately. Furthermore, the photocatalytic activity of Ag NPs against methylene blue (MB) was determined to be 67.13% at the 180th min. In addition, it was observed that biogenic Ag NPs have high electrocatalytic activity for hydrogen peroxide (H2O2) detection. In the sensor based on Ag NPs, linearity from 1 μM to 5 μM was observed with a detection limit (LOD) of 1.323 μM for H2O2. According to these results, we conclude that the biogenic Ag NPs synthesized using Linum usitatissimum extract can be developed as an efficient biological agent as an antibacterial and anticancer also can be used as a photocatalyst for industrial wastewater treatment to prevent wastewater pollution.

Removal of chloride ion from drinking water using Ag NPs-Modified bentonite: Characterization and optimization of effective parameters by response surface methodology-central composite design.

Abstract: The presence of chloride ion as an environmental pollutant is having a devastating and irreversible effect on aquatic and terrestrial ecosystems. To ensure safe and clean drinking water, it is vital to remove this substance using non-toxic and eco-friendly methods. This study presents a novel and highly efficient Ag NPs-modified bentonite adsorbent for removing chloride ion, a common environmental pollutant, from drinking water using a facile approach. The surface chemical properties and morphology of the pristine Na-bentonite and Ag NPs-Modified bentonite were characterized by field emission scanning electron microscopy (FESEM) and X-ray spectroscopy (EDX), X-Ray diffraction (XRD), Fourier transform infrared (FTIR), and zeta potential (ζ). To achieve maximum chloride ion removal, the effects of experimental parameters, including adsorbent dosage (1-9 g/L), chloride ion concentration (100-900 mg/L), and reaction time (5-25 h), were examined using the Response Surface Methodology (RSM). The chloride ion removal of 90% was obtained at optimum conditions (adsorbent dosage: 7 g/L, chloride ion concentration: 500 mg/L, and reaction time: 20 h). The adsorption isotherm and kinetics results indicated that the Langmuir isotherm model and pseudo-second-order kinetics were found suitable to chloride ion removal. Additionally, the regeneration and reusability of the Ag NPs-modified bentonite were further studied. In the regeneration and reusability study, the Ag NPs-modified bentonite has shown consistently ≥90% and ≥87% chloride ion removal even up to 2 repeated cycles, separately. Thus, the findings in this study provided convincing evidence for using Ag-NPs modified bentonite as a high-efficiency and promising adsorbent to remove chloride ion from drinking water.

Synthesis and characterization of linear/nonlinear optical properties of graphene oxide and reduced graphene oxide-based zinc oxide nanocomposite

Abstract: In this paper, we aimed to investigate the linear and nonlinear optical properties of GO-ZnO and RGO-ZnO nanocomposites in comparison with pure GO and reduced graphene oxide (RGO). For this purpose, GO, RGO, GO-ZnO, and RGO-ZnO were synthesized and characterized by Fourier transform infrared (FT-IR), Ultraviolet-Visible (UV-Vis) absorption, X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDX). XRD and EDX analysis indicated the reduction of GO as well as the successful synthesis of GO-ZnO and RGO-ZnO nanocomposites. The FT-IR spectroscopy showed that absorption bands were at 3340 cm-1, 1630 cm-1, 1730 cm-1 and 480 cm-1 related to OH, C=C, C=O, and Zn-O stretching vibrations, respectively. The direct band gaps of GO, RGO, GO-ZnO and RGO-ZnO from UV-Vis spectra were at 3.36, 3.18, 3.63 and 3.25 eV, sequentially. Moreover, the third-order nonlinear optical properties were investigated using a z-scan technique with Nd: YAG laser (532 nm, 70 mW). It can be seen that the nonlinear absorption coefficient value [Formula: see text] increased from 5.3 × 10-4 (GO) to 8.4 × 10-3 cm/W (RGO-ZnO). In addition, nonlinear refractive index (n2) of the GO, RGO, GO-ZnO, and RGO-ZnO was obtained as 10.9 × 10-10, 14.3 × 10-10, 22.9 × 10-10, and 31.9 × 10-10 cm2/W respectively.

Influence of Surface Chemistry of Fiber and Lignocellulosic Materials on Adhesion Properties with Polybutylene Succinate at Nanoscale

Abstract: The production of bio-based composites with enhanced characteristics constitutes a strategic action to minimize the use of fossil fuel resources. The mechanical performances of these materials are related to the specific properties of their components, as well as to the quality of the interface between the matrix and the fibers. In a previous research study, it was shown that the polarity of the matrix played a key role in the mechanisms of fiber breakage during processing, as well as on the final properties of the composite. However, some key questions remained unanswered, and new investigations were necessary to improve the knowledge of the interactions between a lignocellulosic material and a polar matrix. In this work, for the first time, atomic force microscopy based on force spectroscopy measurements was carried out using functionalized tips to characterize the intermolecular interactions at the single molecule level, taking place between poly(butylene succinate) and four different plant fibers. The efficiency of the tip functionalization was checked out by scanning electron microscopy and energy-dispersive X-ray spectroscopy, whereas the fibers chemistry was characterized by Fourier-transform infrared spectroscopy. Larger interactions at the nanoscale level were found between the matrix and hypolignified fibers compared to lignified ones, as in control experiments on single lignocellulosic polymer films. These results could significantly aid in the design of the most appropriate composite composition depending on its final use.

Preparation and characterization of activated carbon from agricultural wastes and their ability to remove chlorpyrifos from water

Abstract: Chlorpyrifos is an organophosphate insecticide linked to neurological dysfunctions, endocrine disturbance, cardiovascular illness, genotoxicity, histopathological abnormalities, immunotoxicity, and oxidative stress. Therefore, the aim of this study was to prepare activated carbon from agricultural waste to adsorb and remove chlorpyrifos from aqueous solutions, as well as to study the physicochemical characteristics of the prepared activated carbon.Activated carbon was prepared from agricultural waste (banana peels, orange peels, pomegranate peels and date stones). The activated carbon prepared showed an exterior surface that was irregular and full of cavities with Brunauer-Emmett-Teller(BET) surface areas of 94.26, 111.75, 183.89, and 289.86 m2/g for activated carbon prepared from orange peels, date stone, pomegranate peels, and banana peels respectively. The Scanning Electron Microscope (SEM) image revealed that the activated carbon's exterior surface was irregular and full of various shapes and sizes of cavities.The Energy Dispersive X-Ray (EDX) indicated the existence of carbon, oxygen, silicon and potassium in banana peels-derived activated carbon, whereas carbon, oxygen, silicon and potassium, in addition to aluminium, were detected in the pomegranate peels-derived activated carbon. The Fourier-Transform Infrared Spectroscopy (FTIR) analysis of prepared activated carbon revealed several functional groups, including carboxylic acid, carbon dioxide, and aromatic compounds. Results also showed that the activated carbon significantly removed chlorpyrifos from water, recording 97.6%, 90.6%, 71.48%, and 52.00 % for activated carbon prepared from pomegranate peels, banana peels, date stones and orange peels, respectively. The study concluded that agricultural waste-derived activated carbon could be employed as an alternative pesticide adsorbent.

Synthesis and characterization of activated carbon supported bimetallic Pd based nanoparticles and their sensor and antibacterial investigation.

Abstract: Activated carbon (AC) supported palladium cobalt bimetallic nanoparticles ([email protected] NPs) were obtained by green synthesis method using Cinnamomum verum (C. Verum) extract. The obtained NPs were characterized by Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Crystallography (XRD), Transmission Electron Microscope (TEM) and Ultraviolet Visible (UV-VIS) spectroscopy, and the functional groups and morphology of the nanoparticle were elucidated. The resulting particle size was found to be 2.467 nm. NPs were evaluated using Cyclic Voltammetry (CV), Scan Rate (SR), and Differential Pulse Voltammetry (DPV) techniques for potential dopamine sensors application. According to the obtained DPV results, Limit of Detection (LOD) and Limit of Quantitation (LOQ) values are found to be 5.68 pM and 17.21 pM, respectively. It was also observed that AC supported PdCo nanoparticles obtained from C. verum extract sensed dopamine quite well. Besides, to examine the antibacterial properties of NPs, antibacterial analyzes were performed with Escherichia coli (E. Coli) and Staphylococcus aureus (S. Aureus). It was observed that it showed good antibacterial properties against gram positive (S. aureus) and gram negative (E. coli) bacteria. The study gave important results in terms of the synthesis of bimetallic NPs using the green synthesis method and their usability in different areas. With this study, it was observed that a good antibacterial dopamine sensor were obtained with the successful biogenic synthesis of AC supported PdCo bimetallic NPs.

Imparting cotton textiles glow-in-the-dark property along with other functional properties: photochromism, flame-retardant, water-repellency, and antimicrobial activity

Abstract: Abstract Screen-printing and spray-coating methods were used to produce photoluminescent, water-repellent, and antimicrobial films on textile fibers. The cotton fabrics were firstly finished with a flame-resistant agent. There are a number of functional agents that have been applied during the textile finishing process, including strontium aluminate pigment as antibacterial and photoluminescent agent, flame-retardant organophosphate, and water-repellent silicone rubber. The current research investigated the surface morphologies and chemical compositions of the screen-printed and spray-coated fabric cottons using scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray (EDX), wavelength dispersive X-ray fluorescence (WDXRF), and Fourier-transform infrared spectroscopy (FT-IR). According to morphological analysis, the phosphor nanoparticles had sizes ranging from 2 to 12 nm. After excitation at 399 nm, the generated colorless photoluminescent layer deposited onto cotton surface showed an emission profile at 516 nm. The luminescence spectra and CIE Lab characteristics confirmed that the phosphor-coated textiles displayed a white color in visible spectrum and green emission in the presence of UV light. It has been shown by analysis that the tested colors are very stable over time. The measurements of static water contact and sliding angles were also explored. The self-extinguishing activity of the coated fabrics retained their flame-retardant properties over 24 laundry cycles. Antimicrobial activity, hydrophobicity, and luminous properties were improved without affecting the intrinsic physical and mechanical features of the treated textiles. Details on the CIE Lab colorimetric measurements were discussed. The stiffness and air permeability were examined to explore the flexibility and breathability of the treated textile fibers. Excellent reversibility and photostability were seen in the phosphor-coated materials.