FTIR Spectroscopy Research Articles

Quantifying the Abundance of Alkane Moieties in Lignins with FTIR Spectroscopy and PLS Regression; Estimating Grafting Degree of Esterification

Quantifying the Abundance of Alkane Moieties in Lignins with FTIR Spectroscopy and PLS Regression; Estimating Grafting Degree of Esterification

Nanocrystallization tuning of structural, thermoelectric and electrical properties of SrTiO3-doped vanadate glasses

Glass-ceramic nanocrystals (GCNs) were obtained by annealing parent SrTiO3-V2O5 (SV) glasses prepared using the melt-quenching technique at the crystallization temperature, Tc. The amorphous nature and glassy behavior of the quenched glasses were confirmed by XRD, DSC and FTIR spectroscopy. In the heat-treated samples, the crystal size was found to range from 40 to 80 nm for all studied samples. It was observed that as the SrTiO3 content in the GCNs increased, density (d) steadily rose. The change of vanadium ions concentration(C) has the predominant role for changing Seebeck coefficient in both glass and GCNs samples. The nanocrystallization process at temperatures close to the onset of Tc, lasting for one hour, notably increased the electronic conductivity of the initial glasses. Consequently, the modification in nanostructure resulted in enhanced conductivity. In comparison to the original glasses, the final materials demonstrated significantly improved electrical conductivity. The accumulation of V4+-V5+ pairs at the formed interlayer zones between nanocrystallites and the glassy phase is accountable for electron hopping in the current system, which is markedly higher than in the glassy matrix. The formed nanocrystallites play a crucial role in augmenting the conductivity of such nanomaterials. The maximum obtained value of the power factor (PF) is 0.9 × 10−4 mW/mk2 for the glass sample (x = 20) reflecting a very low thermoelectric power conversion efficiency while in GCNs, the PF values were well-enhanced to 0.6 mW/m.K2 at x = 20.

Thermophysical Investigation of Multiform NiO Nanowalls@carbon Foam/1-Octadecanol Composite Phase Change Materials for Thermal Management

Multiform NiO nanowalls with a high specific surface area were constructed in situ on carbon foam (CF) to construct NiO@CF/OD composite phase change materials (CPCMs). The synthesis mechanism, microstructures, thermal management capability, and photothermal conversion of NiO@CF/OD CPCMs were systematically studied. Additionally, the collaborative enhancement effects of CF and multiform NiO nanowalls on the thermal properties of OD PCMs were also investigated. NiO@CF not only maintains the porous 3D network structure of CF, but also effectively prevents the aggregation of NiO nanosheets. The chemical structures of NiO@CF/OD CPCMs were analyzed using XRD and FTIR spectroscopy. When combined with CF and NiO nanosheets, OD has high compatibility with NiO@CF. The thermal conductivity of NiO@CF/OD-L CPCMs was 1.12 W/m·K, which is 366.7% higher than that of OD. The improvement in thermal conductivity of CPCMs was theoretically analyzed according to the Debye model. NiO@CF/OD-L CPCMs have a photothermal conversion efficiency up to 77.6%. This article provided a theoretical basis for the optimal design and performance prediction of thermal storage materials and systems.

Mutation/metal deficiency in the "electrostatic loop" enhanced aggregation process in apo/holo SOD1 variants: implications for ALS diseases

Despite the many mechanisms it has created to prevent unfolding and aggregation of proteins, many diseases are caused by abnormal folding of proteins, which are called misfolding diseases. During this process, proteins undergo structural changes and become stable, insoluble beta-sheet aggregates called amyloid fibrils. Mutations/disruptions in metal ion homeostasis in the ALS-associated metalloenzyme superoxide dismutase (SOD1) reduce conformational stability, consistent with the protein aggregation hypothesis for neurodegenerative diseases. However, the exact mechanism of involvement is not well understood. Hence, to understand the role of mutation/ metal deficiency in SOD1 misfolding and aggregation, we investigated the effects of apo/holo SOD1 variants on structural properties using biophysical/experimental techniques. The MD results support the idea that the mutation/metal deficiency can lead to a change in conformation. The increased content of β-sheet structures in apo/holo SOD1 variants can be attributed to the aggregation tendency, which was confirmed by FTIR spectroscopy and dictionary of secondary structure in proteins (DSSP) results. Thermodynamic studies of GdnHCl showed that metal deficiency/mutation/intramolecular S–S reduction together are required to initiate misfolding/aggregation of SOD1. The results showed that apo/holo SOD1 variants under destabilizing conditions induced amyloid aggregates at physiological pH, which were detected by ThT/ANS fluorescence, as well as further confirmation of amyloid/amorphous species by TEM. This study confirms that mutations in the electrostatic loop of SOD1 lead to structural abnormalities, including changes in hydrophobicity, reduced disulfide bonds, and an increased propensity for protein denaturation. This process facilitates the formation of amyloid/amorphous aggregates ALS-associated.

Chemical Identification of Purified Molecule (3-Ethyl-6,7-dihydroxy-2- phenyl-chromen-4-one) Prepared from Alpinia officinarum with Anti- Cryptococcus neoformans Potential

Background: Plants contain a large number of molecules with various potentials, including antifungal impact. Cryptococcus neoformans (C. neoformans) is a yeast that causes Cryptococcosis infection in both immunocompromised and normal individuals worldwide. Objective: This study aimed to investigate the inhibitory impact of plant extracts on C. neofor-mans and perform purification of the most bioactive product for further chemical identifica-tion. Methods: The anti-C. neoformans potential of fourteen plants extracted by using various sol-vents, including water, methanol, and benzene, was tested. The most promising compound with anti-C. neoformans was purified. The minimal inhibitory level of the purified sub-frac-tion as compared to fluconazole as a standard drug was determined. The chemical identifica-tion of the purified product was carried out using FTIR, 1HNMR, elemental analysis, and Mass spectroscopy. Results: Alpinia officinarum (A. officinarum) methanolic extract has the highest antifungal impact on C. neoformans and showed an inhibition zone of 3.2±0.2 cm. The methanolic ex-tract was separated into 14 fractions, where the fifth fraction showed the highest activity. It was further separated into four sub-fractions that were tested to characterize the most promis-ing molecule with anti-C. neoformans impact, which was further chemically identified as 3-Ethyl-6,7-dihydroxy-2-phenyl-chromen-4-one. The purified product led to significant altera-tions in the ultra-structure of C. neoformans relative to the standard drug.

Clay Minerals and Long-Term Fertilization Effects on Soil Organic Carbon Stocks, Soil Carbon Pools, and Soil Enzymes in an Inceptisol of Coimbatore, Tamil Nadu

ABSTRACT Soil Organic Carbon (SOC) is an important indicator for soil health and quality. The present study was conducted in five-decade-old Long-Term Fertilizer Experiment involving the finger millet−maize cropping sequence in an Inceptisol to examine the effects of inorganic fertilizers and manures on soil organic carbon stock in relation to C sequestration. This study was based on 10 treatments: 50%NPK, 100%NPK, 150%NPK, 100%NPK + HW, 100%NPK + ZnSO4, 100%NP, 100%N, 100%NPK + FYM, 100%NPK (− S), and control. We assess the clay mineral interaction with soil organic carbon stock and soil enzyme activity. The semi-quantification and characterization of clay minerals were sourced from X-ray diffraction (XRD) analysis, and the SOC stock was calculated based on SOC concentration, Bulk density, and Depth. From the study, results revealed that clay minerals were studied by XRD and FTIR spectroscopy analysis. The results revealed that dominant clay minerals in the experimental soil were in the order of Montmorillonite, 2:1 interstratified minerals, Vermiculite, and Illite, and the buildup of SOC stock raised from 6.3 Mg C ha−1 to 12.9 Mg C ha−1 over five decades. The maximum SOC stock of 12.9 Mg ha−1 was recorded in 100% NPK + FYM while the control registered 7.5 Mg C ha−1. The study conclude that balanced fertilization of 100% NPK with FYM contributed toward the increase in SOC, SOC stock, and carbon sequestration for improving soil fertility status.

(Y3+/Sm3+)-doped and co-doped CoFe2O4 for heterogeneous advanced oxidation process: structural, magneto-optical, and photocatalytic investigations.

The photocatalytic properties of CoFe2O4 nanoparticles were activated by the doping and co-doping of a low level of Y3+ and Sm3+ cations. After optimizing the annealing temperature, 900°C was found to be the optimal temperature for the successful incorporation of Y3+ and Sm3+ into the spinel structure. The purity of our samples annealed at 900°C was confirmed using several characterization methods, including PXRD, SEM, XPS, VSM, FTIR, and Raman spectroscopy. Thus, we were able to increase the photocatalytic degradation of orange G dye from 9.9 to 64.63% for the Sm3+-doped sample, 76.42% for the Y3+-doped sample, and even 85.81% for the co-doped sample under 60min of UV-visible light irradiation. The beneficial effect of samarium and yttrium doping and co-doping is attributed to several factors: the first factor is doped and co-doped rare earth impurities induce distortion in the lattice, the larger the ionic radii of dopant element, the highest is the photocatalytic activity; second factor, upon doping and co-doping of rare earth impurities in the structure of CoFe2O4 leads to the creation of donor state level within the band gap, causing the Fermi energy to shift near the conduction band. Third factor, co-doping produced strong interactions, which accelerated photocarrier mobility and transport; lastly, longer electron-holes lifetime. We have provided a detailed study of the structural, vibrational, and optical properties to support our conclusions.

Yttrium iron garnet single-crystal particles - a simple and effective synthesis

Abstract Yttrium iron garnet (YIG) is a ferrimagnetic material which found applications in magnetics, electronics and optics. For those applications, a monocrystalline structure is often required. Although effective methods to grow large YIG single crystals exist, fabricating such structures in a powder form can be challenging. Here, we show a simple procedure to obtain large quantities of monocrystalline Y3Fe5O12 particles based on the precipitation synthesis. The average size of the single crystals was evaluated to be 149(6) nm. The morphology of the particles was analysed using SEM, TEM, DLS and nitrogen adsorption techniques. The material was tested for its structural properties with the use of XRD and electron diffraction methods. The chemical composition was investigated using FTIR, EDS and Raman spectroscopy. Finally, the thermal characteristics were analysed using TGA, while magnetic properties were tested with the use of the SQUID magnetometry. The obtained results are in good agreement with the theoretical values.

Oral squamous cell carcinoma identification by FTIR spectroscopy of oral biofluids.

This case study evaluated the efficacy of mid-infrared spectroscopy on the identification of oral squamous cell carcinoma, following the assessment of unstimulated whole saliva. The trial follows a matched case-control design. Saliva samples were characterized through mid-infrared spectroscopy, and chemometric tools were applied to distinguish between case and control participants, further identifying the spectral regions that played a pivotal role in the successful identification of oral squamous cell carcinoma. Mid-infrared spectroscopy was capable to discriminate between cancer patients and matched controls with 100% of correct predictions. Additionally, the spectral regions mostly contributing to the successful prediction were identified and found to be potentially associated with significant molecular changes crucial to the carcinogenic process. The application of mid-infrared spectroscopy in saliva analysis may be regarded as an innovative, noninvasive, low cost, and sensitive technique contributing to the identification of oral squamous cell carcionma.

Search for new materials based on chitosan for the protection of cultural heritage

Microorganisms are a significant cause of damage to cultural heritage, including paintings. Currently, the palette of antiseptics that are used in painting has narrowed considerably. This is due to the increased demands placed on such substances. It was shown that low molecular weight chitosan (LMWC) obtained from the king crab (Paralithodes camtschaticus) exhibits high activity against dominant fungi-destructors of paintings in the State Tretyakov Gallery. Nevertheless, the increasing market demand for chitosan has prompted the exploration of alternative sources. Insects, notably the bioconverter black soldier fly (Hermetia illucens), stand out as one of the most cultivated options. This study investigates the effectiveness of chitosan, isolated from H. illucens by a novel method developed by authors, in inhibiting fungi that damage tempera paintings. The activity of 33 and 39 kDa chitosans from H. illucens is comparable to the most active chitosans previously studied from P. camtschaticus. However, there are characteristic differences between these compounds, as shown by the results of FTIR spectroscopy, which may affect their consumer properties when used in paint materials. Our studies suggest that LMWC from H. illucens is a promising material that can expand the range of antiseptics used in painting.Graphical

Exopolysaccharides from the Green Microalga Strain Coelastrella sp. BGV—Isolation, Characterization, and Assessment of Anticancer Potential

Algal metabolites have been extensively studied as potential anticancer therapeutics. Among them, polysaccharides have attracted much attention because of their beneficial biological effects and safety. In the present research, the chemical characteristics, antitumor, and proapoptotic activities of extracellular polysaccharides (EPS) isolated from a new Bulgarian strain of the green microalga Coelastrella sp. BGV were investigated. A fast and convenient method of precipitation with cold ethanol was used to isolate EPS from the culture medium. The chemical characteristics of the isolated EPS were examined by colorimetric and spectrophotometric analyses, HPSEC-RID and HPLC-UV chromatography, and FT-IR spectroscopy. The results showed that the isolated EPS sample consists of three carbohydrate fractions with different molecular weights (11.5 × 104 Da, 30.7 × 104 Da, and 72.4 × 104 Da, respectively) and contains 7.14 (w/w%) protein. HPLC-UV analysis revealed the presence of galactose and fucose. The total uronic acid content in the sample was 4.5 (w/w%). The IR-FT spectrum of EPS revealed the presence of various functional groups typical of a polysaccharide (or proteoglycan) composed primarily of neutral sugars. The anticancer potential of the obtained EPS was assessed using cell lines with cancerous and non-cancerous origins as in vitro experimental models. The results of the performed MTT assay showed that EPS reduced the viability of the cervical and mammary carcinoma cell lines HeLa and MCF-7, while the control non-cancer cell lines BALB/3T3 and HaCaT were less affected. The HeLa cell line showed the highest sensitivity to the effects of EPS and was therefore used for further studies of its anticancer potential. The ability of EPS to inhibit cancer cell migration was demonstrated by wound-healing (scratch) assay. The cell cycle FACS analysis indicated that the EPS treatment induced significant increases in the sub G1 cell population and decreases of the percentages of cells in the G1, S, and G2-M phases, compared to the control. The fluorescent microscopy studies performed using three different staining methods in combination with Annexin V-FITC flow cytometric analysis clearly demonstrate the ability of EPS to induce cancer cell death via the apoptosis pathway. Moreover, an altered pattern and intensity of the immunocytochemical staining for the apoptosis- and proliferation-related proteins p53, bcl2, and Ki67 was detected in EPS-treated HeLa cancer cells as compared to the untreated controls. The obtained results characterize the new local strain of green microalgae Coelastrella sp. BGV as a producer of EPS with selective antitumor activity and provide an opportunity for further studies of its pharmacological and biotechnological potential.

Ag doped TiO2 anchored on metal free g-C3N4 for enhanced solar light activated photodegradation of a dye

Heterogeneous semiconductor photocatalysis has attracted researcher's attention in wastewater treatment owing to the improved surface area, optical properties, and charge transfer rate for boosted degradation of organic pollutants. Thus, the g-C3N4/Ag/TiO2 was prepared following a hydrothermal route for the degradation of azo dye tartrazine (TA) used as a food colourant under solar light. Before application, the composite and pristine materials were interrogated for physicochemical and structural properties using SEM, TEM, EDS, XPS, XRD, UV–vis DRS, PL, BET, Raman, and FTIR spectroscopy. The PL and electrochemical analysis revealed that the CNAT composite had a high charge transfer rate that was coupled with low charge carrier complexation. The degradation efficiency of 91 % was realized in 180 min and the rate of pseudo-first-order kinetics of 0.01143 min−1 was obtained. The CNAT catalyst also displayed high removal efficiency towards a cocktail of naproxen (NPX) and TA. The improved removal efficiencies stem from increased visible usage, reduced charge carrier compounding, and formation of Z-scheme heterojunction with high redox capabilities. The total organic carbon removal reached 95 % while CNAT showed high convincing stability even after four cycles. Given the above results, the hydrothermally prepared composite catalyst can be extended to other organic pollutants such as pharmaceuticals, pesticides, and reduction of inorganics.

Microencapsulation of the Biocide Benzisothiazolinone (BIT) by Inclusion in Methyl-β-cyclodextrin and Screening of Its Antibacterial and Ecotoxicity Properties

The excessive use of biocides has considerable environmental and economic impacts; this is why new technologies have been sought to decrease the concentration levels applied in an effort to reduce the use of these substances. Microencapsulation using cyclodextrins has been widely used in the food and pharmaceutical industries as a way of reducing the concentrations of the active substance necessary to achieve a biological effect and/or eliminate its irritating or toxicological effects. In this study, the inclusion complexation behavior and binding ability of benzothiazolinone (BIT) with different β-cyclodextrins (β-CD, HP-β-CD, and Me-β-CD) was investigated. The intermolecular interactions were examined through UV and FTIR spectroscopy, DSC, 1D 1H NMR, and 2D ROESY. The highest stability constant was observed for the BIT/Me-β-CD inclusion complex (299.5 ± 2.9 M−1). Antibacterial activity was investigated against Staphylococcus aureus and Escherichia coli, and the results revealed that the BIT/Me-β-CD inclusion complex displays a higher antibacterial activity than BIT. The acute toxicity of the biocide and inclusion complex was also examined using the photobacterium Aliivibrio fischeri. Although BIT exhibited higher toxicity than the inclusion complex, further investigation is needed due to the quorum quenching effect of β-CDs. The data found suggest that BIT microencapsulation can increase its aqueous solubility and can be used as an effective tool to improve its chemical, biological, and ecotoxicological properties.

Investigation of the crystal structure, spectral properties, and interactions of N-(R-nitrophenylsulfonamido)benzoic acids with human serum albumin

This study introduced the synthesis of two novel compounds in the N-(R-nitrophenylsulfonamido)benzoic acids (NO2-SBA), designated as HL6 and HL8. Detailed structural information for HL6 and HL8 was acquired through the employment of various characterization techniques such as single-crystal and powder X-ray diffraction, FT-IR spectroscopy, 1H and 13C NMR spectroscopy, and elemental analysis. X-ray diffraction and Hirshfield surface analysis provides a comparative analysis of hydrogen bonding in HL6·H2O and HL8, revealing significant differences in their interaction patterns and resulting crystal structures. Although both molecules possess the same number of hydrogen bond donors and acceptors, the nature of these interactions and their orientations lead to distinct packing arrangements. In HL6·H₂O, the presence of water molecules introduces additional hydrogen bonding possibilities, which are absent in HL8, significantly affecting the overall structure. Additionally, interactions of all nine compounds in the NO2-SBA series [categorized as o-ABA: HL1–HL3, m-ABA: HL4–HL6, and p-ABA: HL7–HL9] with human serum albumin (HSA) were investigated to understand how structural characteristics influence binding mechanisms and affinity. Fluorescence spectroscopy was employed to further examine these interactions, providing a better understanding of their pharmacological properties. The compounds exhibited moderate affinity to HSA, with the o-ABA series displaying a binding constant (Kb) ten times stronger than the other series, underscoring the significant role of the N,R groups in binding interactions.

Surface-controlled oxygen vacancy-rich Bi/BiVO4 Schottky junction for highly selective and active photocatalytic nitrogen fixation

The modulation of active site density and localized electron concentration represents a crucial step in enhancing nitrogen activation, thereby significantly augmenting the efficiency of photocatalytic nitrogen fixation. In this paper, Bi/BiVO4 Schottky junctions enriched with oxygen vacancies (Bi/Vo-BVO) were fabricated by in situ reduction. Compared to BiVO4, Bi/Vo-BVO composites exhibited 8.4-fold enhancement in ammonia synthesis yield, reaching a maximum rate of 167.74 μmol·g−1·h−1. In situ FTIR spectroscopy and isotopic labeling experiments definitively demonstrated that the nitrogen constituent of NH4+ is derived from N2. N2-TPD and DFT calculation collectively suggest that the surface of Bi/Vo-BVO, enriched with ligand-unsaturated V4+ species, furnishes a substantial array of chemisorption sites for N2 molecules, attributed to the abundance of oxygen vacancies. In situ XPS coupled with DFT corroborate that the photoexcited electrons within the BiVO4 valence band accumulate in the conduction band, thereby directly facilitating the activation of N2 adsorbed at the V4+ active sites; The built-in electric field established at the interface between Bi and BiVO4 substantially facilitates the enrichment of Bi-emitted thermal electrons within oxygen vacancies on BiVO4 surface. These electrons subsequently migrate towards and interact with the adsorbed N2 via the V4+ active sites. The synergistic photothermal electrons activation mechanism of N2 not only enhances the efficiency of light energy utilization but maximizes the catalytic efficacy of the photocatalyst through the full exploitation of its intrinsic catalytic potential.

Characterization and optimization of desulfurized construction gypsum modified with functionalized nanocellulose

This study focuses on the development and characterization of a novel composite material based on flue gas desulfurization (FGD) gypsum modified with functionalized nanocellulose. The incorporation of 0.1 wt% nanocellulose into the FGD gypsum matrix resulted in significant improvements in mechanical strength, water resistance, and thermal insulation properties. The flexural and compressive strength of the optimized composite increased by 32 % and 27 %, respectively, compared to the control sample. The water absorption decreased by 22 %, and the softening coefficient increased from 0.72 to 0.85, indicating enhanced water resistance. The thermal conductivity of the composite was reduced by 31 %, showcasing its potential as an energy-efficient building material. SEM analysis revealed a refined microstructure with improved interfacial bonding between the nanocellulose and gypsum matrix, while FTIR spectroscopy confirmed the presence of chemical interactions between the components. The moisture buffering capacity of the composite was also superior, with a 38 % higher moisture buffering value than the control sample. These findings highlight the potential of functionalized nanocellulose as a reinforcing agent in FGD gypsum-based composites, offering a promising solution for the development of high-performance, eco-friendly building materials.

Microplastics pollution in sediments of the Thames and Medway estuaries, UK: Organic matter associations and predominance of polyethylene

Microplastics at 10 sites along a 77 km transect of the river Thames estuary (UK) and 5 sites along 29 km of the Medway estuary were separated from sediment and analysed by ATR-FTIR spectroscopy. Microplastics were observed at all sites. Highest Thames concentrations were in urban London between Chelsea and West Thurrock (average 170.80 particles kg−1 ± 46.64, 3.36 mg kg−1 ± 1.79 by mass), mid-outer estuary sites were two to three times lower. Microplastics were slightly dominated by particles (54 %) over fibres (45 %), including polymer types ranked: polyethylene > PET > polypropylene > polyamide. Medway microplastics decreased seaward, with one urban-municipal site impacted by a combined-sewer-overflow containing a high proportion of fibres (Rochester, 484 particles kg−1, 7.39 mg kg−1 by mass). Microplastic abundance was correlated to organic carbon (TOC %) (R2 of 0.71 Thames and 0.96 Medway), but not sediment particle size. Sedimentary microplastics accumulation in the Thames was controlled by urbanisation-distance, and site hydrodynamics.

Facile and innovation synthesis of Zn-Mn-Co-LDH/polypyrrole and its application in investigating ethanol oxidation in an alkaline medium

Overvoltage and low current are observed for ethanol electrooxidation on the surface of many unmodified electrodes. Therefore, it is desirable to use a suitable catalyst for ethanol electrooxidation to increase the current. This research introduces a new sensor to catalyze ethanol oxidation in an alkaline environment. This new Zn-Mn-Co LDH/PolyPyrrole/GCE nanocomposite sensor exhibits high catalytic activity for ethanol electrooxidation. It changes the oxidation potential of ethanol to a less positive potential. To identify this proposed sensor, X-ray diffraction (XRD), Brauner Emmett-Teller (BET), X-ray photoelectron spectroscopy (XPS), FT-IR spectroscopy, field emission scanning electron microscopy (FESEM), thermal analysis (TGA), high-resolution transmission electron microscopy (HR-TEM) and cyclic voltammetry techniques were used. Ethanol electrooxidation was investigated by cyclic voltammetry technique. The effects of scan rate and ethanol concentration on the ethanol oxidation peak have been investigated. The proposed sensor showed long-term stability. This prepared nanocomposite can be used as an anode catalyst for ethanol fuel cells.

A novel organic-inorganic hybrid hollow polymer capsule with rich amino/imino groups for anionic contaminant removal in wastewater: Synthesis, performance and mechanism

Herein, we developed a new organic-inorganic hybrid polymer adsorbent, termed PECP, by one-step precipitation polycondensation between polyethyene polyamine and hexachlorocyclotriphosphazene. The morphology and microstructure of PECP were investigated by FTIR, SEM, TEM, XPS, XRD and N2 adsorption. Results show PECP owned a hollow capsule structure and lots of amino/imino groups. The adsorption capacity of PECP for anionic dye methyl orange (MO) was up to 1031.9 mg g-1. The adsorption process was very fast. After five cycles, the adsorption capacity of PECP for MO still remained at 89 % of the initial adsorption capacity. Meanwhile, PECP delivered a high adsorption capacity for other anionic contaminants like acid chrome blue K (1003.5 mg g-1), congo red (1152.2 mg g-1) and diclofenac sodium (914.2 mg g-1). In the binary systems contaminated with double dyes, the separation factors of MO for methylene blue, Rhodamine B and crystal violet were up to 450.8, 55.4 and 355.9, respectively. The experimental data unveiled that the MO removal by PECP was very consistent with the pseudo-second-order kinetic model and the Langmuir isotherm model. The removal process was spontaneous and endothermic. FTIR spectroscopy and XPS analysis confirmed the role of electrostatic force and hydrogen bond on the adsorption of MO on PECP.

Solvent extraction of titanium(IV) from orthophosphoric acid media using Aliquat-336/kerosene and stripping with nitric acid

Titanium extraction from acidic solutions was investigated using Aliquat-336, considering factors like acid type and concentration for leaching, diluent type for solvent extraction, equilibration time, extractant concentration, phase ratio, and temperature. Kerosene exhibited superior performance as an aliphatic diluent for Aliquat-336 compared to other utilized diluents. The extraction efficiency was inversely proportional to the dielectric constant of the diluents. The quantitative Ti(IV) extraction efficiency from phosphoric acid (6 M H3PO4) leach liquor of ilmenite and rutile achived 98 % at room temperature (298 K) in 10 min after mixing with 0.1 M Aliquat-336 dissolved in kerosene at a phase volume ratio of 1:1 (Aq:Org). The exothermic extraction process occurred spontaneously. The proposed extraction mechanism using Aliquat-336/kerosene involves ion-pair association of the extractant with a Ti(IV) complex, confirmed by FTIR spectroscopy. The Ti(IV) ions were effectively stripped using HNO3 (3 M) with an aqueous:organic phase volume ratio of 1:1 at 25 °C after a contact time of 10 min in each step. The Aliquat-336/kerosene efficiently tested for Ti(IV) recovery from acidic Abu-Ghalaga ilmenite and rutile leachate. The findings indicate that, the phosphate medium is highly efficient in extracting Ti(IV), even with low concentration of Aliquat-336 in kerosene, especially in comparison to the impurities such as Fe, Cr, and Al. The EDX, XRD, and wet chemical analyses of the final product after the hydrolysis of stripped Ti(IV) from samples originating from the Abu-Ghalaga area and rutile samples, confirmed the formation of high-purity TiO2 (predominantly anatase phase). The SEM results showed particles with a regularly spherical structure and uniform size.