Fourier Transform Infrared Spectra Research Articles

Nanomodified bamboo (Phyllostachys aurea) biomass: its adsorbent features in the removal of dyes from water under high salinity conditions.

The effluent generated by textile industries is among the most polluting to the environment. Dyes such as methylene blue (MB) and indigo blue (IB) are used in cotton dyeing. This work proposes to evaluate the potential of in natura (BIN) and nanomodified (BNP) bamboo (Phyllostachys aurea) biomass as biosorbents for the removal of MB and IB dyes in an aqueous medium under high salinity conditions. These materials were characterized by Fourier transform infrared (FTIR) and X-ray (XRD) spectroscopies and scanning electron microscopy (SEM) to investigate their morphology and interaction with the dyes and the nanoparticles. The FTIR spectra revealed the existence of hydroxyl and carbonyl groups, ethers, phenols, and aromatic compounds, indicating the presence of a lignocellulosic structure. XRD and SEM analyses confirmed the effectiveness of the nanocomposite synthesis process. The dyes were quantified by ultraviolet-visible spectroscopy (UV/Vis). The material's pH at the point of zero charge (pHPZC) was 5.52 (BIN) and 4.84 (BNP), and the best IB and MB sorption pH were 3.0 and 9.0 for BNP, respectively, employing 30min of contact time. The material sorption capacity (Qexp) was assessed using batch procedures, in which 100-1000mg/L dye concentrations were tested with a 0.5g/L adsorbent dose. The dye's Qexp for BIN and BNP was 25.41 ± 0.58 and 23.42 ± 0.07mg/g (MB) and 84.26 ± 1.1 and 130.81 ± 0.20mg/g (IB), respectively. The kinetic model that best fit BNP experimental data was the pseudo-2nd-order with r2 = 0.99868 (MB) and r2 = 0.99873 (IB), and Freundlich, D-R, and Temkin isotherms best fit the dye sorption data. The bamboo nanomodification facilitates the biosorbent removal from the medium after sorption, enabling large-scale studies and industrial applications-the investigated materials provided promising adsorption features for removing contaminant dyes in saline water.

The effect of plasma activated water on antimicrobial activity of silver nanoparticles biosynthesized by cyanobacterium Alborzia kermanshahica

BackgroundSilver nanoparticles are extensively researched for their antimicrobial properties. Cold atmospheric plasma, containing reactive oxygen and nitrogen species, is increasingly used for disinfecting microbes, wound healing, and cancer treatment. Therefore, this study examined the effect of water activated by dielectric barrier discharge (DBD) plasma and gliding arc discharge plasma on the antimicrobial activity of silver nanoparticles from Alborzia kermanshahica.MethodsSilver nanoparticles were synthesized using the boiling method, as well as biomass from Alborzia kermanshahica extract grown in water activated by DBD and GA plasma. The physicochemical properties of the synthesized nanoparticles were evaluated using UV-vis spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, dynamic light scattering (DLS), zeta potential analysis, transmission electron microscopy (TEM), and gas chromatography-mass spectrometry (GC-MS) analysis. Additionally, the disk diffusion method was used to assess the antimicrobial efficacy of the manufactured nanoparticles against both Gram-positive and Gram-negative bacteria.ResultsThe spectroscopy results verified the presence of silver nanoparticles, indicating their biosynthesis. The highest amount of absorption (1.049) belonged to the nanoparticles synthesized by boiling under GA plasma conditions. Comparing the FTIR spectra of the plasma-treated samples with DBD and GA revealed that the DBD-treated samples had more intense peaks, indicating that the DBD method proved to be more effective in enhancing the functional groups on the silver nanoparticles. The DLS results revealed that the boiling method synthesized silver nanoparticles under DBD plasma treatment had a smaller particle size (149.89 nm) with a PDI of 0.251 compared to the GA method, and the DBD method produced nanoparticles with a higher zeta potential (27.7 mV) than the GA method, indicating greater stability of the biosynthesized nanoparticles. Moreover, the highest antimicrobial properties against E. coli (14.333 ± 0.47 mm) were found in the DBD-treated nanoparticles. TEM tests confirmed that spherical nanoparticles attacked the E. coli bacterial membrane, causing cell membrane destruction and cell death. The GC-MS results showed that compounds like 2-methylfuran, 3-methylbutanal, 2-methylbutanal, 3-hydroxy-2-butanone, benzaldehyde, 2-phenylethanol, and 3-octen-2-ol were much higher in the samples that were treated with DBD compared to the samples that were treated with GA plasma.ConclusionThe research indicated that DBD plasma was more efficient than GA plasma in boosting the antimicrobial characteristics of nanoparticles. These results might be a cornerstone for future advancements in utilizing cold plasma to create nanoparticles with enhanced antimicrobial properties.

Green synthesis of graphene oxide and magnetite nanoparticles and their arsenic removal efficiency from arsenic contaminated soil

Graphene-based nanomaterials have been proved to be robust sorbents for efficient removal of environmental contaminants including arsenic (As). Biobased graphene oxide (bGO-P) derived from sugarcane bagasse via pyrolysis, GO-C via chemical exfoliation, and magnetite nanoparticles (FeNPs) via green approach using Azadirachta indica leaf extract were synthesized and characterized by Ultraviolet-Visible Spectrophotometer (UV-vis.), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), mean particle size and Scanning electron microscopy (SEM) along with Energy dispersive spectroscopy (EDX) analysis. Compared to cellulose and hemicellulose, the lignin fraction was less in the precursor material. The GOC, bGO-P and FeNPs displayed maximum absorption at 230, 236, and 374 nm, respectively. FTIR spectrum showed different functional groups (C-OH, C-O-C, COOH and O-H) modifying the surfaces of synthesized materials. Graphene based nanomaterials showed clustered dense flakes of GO-C and thin transparent flakes of bGO-P. Elemental composition by EDX analysis of GO-C (71.26% C and 27.36% O), bGO-P (74.54% C and 24.61% O) and FeNPs (55.61% Fe, 4.1% C and 35.72% O) confirmed the presence of carbon, oxygen, and iron in synthesized nanomaterials. Sorption study was conducted with soil amended with different doses of synthesized nanomaterials (10, 50 and 250 mg) and exposed to 100, 300 and 500 ppm of As. Arsenic concentrations were estimated by colorimetry and atomic absorption spectroscopy (AAS). GO-C, bGO-P, and FeNPs showed substantial As removal efficiency i.e., 81 to 99.3%, 65 to 98.8% and 73.1–89.9%, respectively. Green synthesis of bGO-P and magnetite nanoparticles removed substantial amounts of As compared to GO-C and can be effectively deployed for As removal or immobilization. Higher and medium sorbent doses (250 and 50 mg) exhibited greater As removal and data was best fitted for Freundlich isotherm evidencing favorable sorption. Nevertheless, at low sorbent doses, data was best fitted for both models. Newly synthesized nanomaterials emerged as promising materials for As removal strategy for soil nano-remediation and can be effectively deployed in As contaminated soils.

The radiative efficiency and global warming potential of HCFC-132b.

Hydro-chloro-fluoro-carbons (HCFCs) are potent greenhouse gases which strongly absorb the infrared (IR) radiation within the 8 - 12 μm atmospheric windows. Despite international policies schedule their phasing out by 2020 for developed countries and 2030 globally, HCFC-132b (CH2ClCClF2) has been recently detected with significant atmospheric concentration. In this scenario, detailed climate metrics are of paramount importance for understanding the capacity of anthropogenic pollutants to contribute to global warming. In this work, the radiative efficiency (RE) of HCFC-132b is experimentally measured for the first time and used to determine its global warming potential (GWP) over 20-, 100- and 500-year time horizon. Vibrational- and rotational-spectroscopic properties of this molecule are first characterized by exploiting a synergism between Fourier-transform IR (FTIR) spectroscopy experiments and quantum chemical calculations. Equilibrium geometry, rotational parameters and vibrational properties predicted theoretically beyond the double-harmonic approximation, are employed to assist the vibrational assignment of the experimental trace. Finally, FTIR spectra measured over a range of pressures are used to determine HCFC-132b absorption cross section spectrum from 150 to 3000 cm-1, from which istantaneous and effective REs are derived and, in turn, used for GWP evaluation.

Production and characterization of efficient bioflocculant in high-turbidity drinking water treatment: identification of flocculation-related genes

Bioflocculants are eco-friendly water treatment agents produced by bioflocculant-producing strains that are valuable in drinking water turbidity removal. The major challenges in the application of bioflocculants include low flocculation efficiency, high production costs, and unclear flocculation-related genes. In this study, Pseudomonas sp. ZC-41 a highly efficient bioflocculant-producing strain, was isolated from activated sludge to produce polysaccharide-based bioflocculant MBF-ZC with 94.12% flocculation efficiency under more economical culture conditions, which can solve the problem of low flocculation efficiency. Fourier transform infrared spectra (FTIR) and X-ray photoelectron spectroscopy (XPS) confirmed MBF-ZC contained hydroxyl, carboxyl, and amine groups, crucial for flocculation via adsorption bridging effects as the main flocculation mechanism. The 2393 differentially expressed genes (DEGs) in the transcriptome of strain ZC-41 were classified into five co-expression modules, and the turquoise module was associated with flocculation efficiency and bioflocculant yield. Nineteen flocculation-related genes were identified by combining functional pathways related to sugars. In addition, response surface methodology was optimized to achieve the efficiency of 93.57% for turbidity removal from high-turbidity water by bioflocculant. The results not only provide a solid theoretical foundation to solve the challenges of bioflocculants, but also enrich strategies for high-turbidity drinking water treatment.

Design of Bionanomaterial of Chitosan Carbohydrate Polymer Composited with Broccoli Extract and Zinc Oxide Nanoparticles: Anticancer Activity in Human Osteosarcoma.

In the current research, a chitosan/broccoli extract/ZnO nanoparticle (CH/BE/ZnO) bionanocomposite was created. The physicochemical properties of CH/BE/ZnO bionanocomposite were investigated using a variety of methods, including field emission scanning electron microscopy (FESEM), elemental analysis (CHN-O), X-ray diffraction (XRD), Fourier transform infrared spectrum (FTIR), Brunauer-Emmett-Teller (BET), and transmission electron microscopy (TEM). The CH/BE/ZnO bionanocomposite's biological activity was assessed by examining its cytotoxicity capabilities against a bone cancer cell line (MG63). The total pore volume and specific surface area of CH/BE/ZnO are 0.134 cm3/g and 16.99 m2/g, respectively. The IC50 results for CH/BE/ZnO bionanocomposite in bone cancer investigations using the MTT test against the MG63 cell line was 115μg/mL. The results indicate that the CH/BE/ZnO bionanocomposite is an effective chemotherapeutic agent against human osteosarcoma. The CH/BE/ZnO bionanocomposite showed high performance and structure, which means innovating nanomaterial agents for biological applications in the future.

Antibacterial, antioxidant, and anti-giardia properties of the essential oil, hydroalcoholic extract, and green synthesis of the silver nanoparticles of Salvia mirzayanii plant

In this study, an environmentally-friendly, simple, and low-cost approach was developed for the production of silver nanoparticles (Ag NPs) accelerated by Salvia mirzayanii plant. The identification process involved ultraviolet-visible (UV-Vis) spectrophotometry, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), and scanning electron microscopy (SEM). The UV–Vis spectrum exhibited a peak at 450 nm which is a characteristic surface plasmon resonance of Ag NPs. The XRD and EDS analyses confirmed the crystalline nature and the presence of silver element, while the SEM analysis displayed the production of almost spherical nanoparticles. The FTIR spectrum exhibited that the Ag NPs were functionalized with biomolecules found in the extract, which are involved in the production and stabilization of the NPs. The antibacterial activity of the essential oil, the hydroalcoholic extract and Ag NPs was examined against antibiotic-resistant bacteria, Staphylococcus aureus (S. aureus), and Escherichia coli (E. coli). The anti-Giardia activity was tested on Giardia lamblia cysts at different time intervals. The results exhibited that the MIC values for essential oil, hydroalcoholic extract and Ag NPs against S. aureus were 1.65 µL/mL, 75 mg/mL, and 0.125 mg/mL respectively. The MBC was attained 6.25 µL/mL, 300 mg/mL, and 0.25 mg/mL, for essential oil, hydroalcoholic extract and Ag NPs, respectively. The MIC values for essential oil, hydroalcoholic extract and NPs against E. coli were 3.12 µL/mL, 150 mg/mL, and 0.06 mg/mL, respectively. The MBC was determined to be 50 µL/mL, 300 mg/mL, and 0.25 mg/mL for essential oil, hydroalcoholic extract and Ag NPs, respectively. In addition, the antioxidant activity was determined using the ferric reducing antioxidant power (FRAP) test. The results indicated that the essential oil of this plant exhibited the highest antibacterial and anti-giardial properties, whereas its extract demonstrated the strongest antioxidant properties.

Synthesis and characterization of zinc oxide nanoparticles from aqueous extract of elephant grass (Pennisetum purpureum)

Objective: To synthesise and characterise Pennisetum purpureum zinc oxide nanoparticles from aqueous extracts of elephant grass (Pennisetum purpureum). Methodology: Zinc oxide nanoparticles were synthesised with aqueous extract of elephant grass (Pennisetum purpureum) and zinc acetate dihydrate. It was characterized by using various dispersion methods such as UV-visible spectrophotometry, Transmission Electron Microscopy (TEM), Fourier Transform Infrared (FTIR) Spectroscopy and X-ray diffraction (XRD) to determine the morphology, crystallographic structure, chemical composition, physical properties and crystalline size of the nanoparticles. Results: The results showed that Zinc oxide nanoparticles were synthesized and characterized using various dispersion methods. UV–Vis spectra showed typical absorption peaks around 370nm (Pennisetum purpureum). FTIR revealed the presence of biomolecules and functional groups (C-O, O-H, CH, C≡C, C=C, N-O) that performs various functions like stabilizers, capping and coating agents in nanoparticle synthesis. XRD revealed the crystallographic structure, chemical composition, physical properties and crystalline size of the nanoparticles. The average crystalline size of zinc oxide nanoparticles was calculated using Debye–Scherer equation and the average size was 23.37nm. Conclusion: In this study, simple and green method for the synthesis of zinc oxide nanoparticles using aqueous extract of elephant grass (Pennisetum purpureum) and characterization using various dispersion methods was described. The formation of zinc oxide nanoparticle was confirmed by UV-Visible spectroscopy. The FTIR spectrum showed that the phytochemicals found in the plant extract was incorporated into the zinc oxide nanoparticle as capping and stabilizing agents. XRD results revealed the average size of 23.37nm (Pennisetum purpureum ZnO) and Transmission Electron microscopy (TEM) confirmed the morphology to be spherical.

Synthetic and natural antibacterial carbon adsorbents for clinical nuclear waste management

Patients undergoing high-dose radioiodine ablation (RAI) therapy in Nuclear Medicine Department need to be isolated in a special designed ward for a few days. Large amount of clinical radioactive wastewater from patient body is produced during high-activity RAI therapy. The radioactive wastewater needs to store in a delay tank until the radioactivity decayed below acceptable limit before being discharged and indirectly limit the patient admission and treatment. This study is to propose an alternative antibacterial adsorbent for I-131 extraction from clinical radioactive wastewater at the nuclear medicine department using graphene oxide silver (GOAg) and bamboo activated carbon (BAC). The synthesised adsorbents and their sediments (filtered sample) were analysed using field emission scanning electron microscopy (FESEM) for morphological analysis and analysed using X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) and X-ray diffraction (XRD). XPS spectra for C 1s adsorbents show intensity peaks at 284.45 eV (C=C) and 285.3 eV (C–C) for GOAg and its sediments, and 284.35 eV (C–C), 287.00 eV (C=O), and 290.07 eV (π–π∗ transitions) for BAC and its sediments. FTIR spectra reveal various functional groups of adsorbents: C=C (1637.50772 cm−1), C=O (1340.48041 cm−1), and C–O–C (1031.88060 cm−1) for GOAg and its sediments, and C=C (1635.57897 cm−1), C–C (1257.54421 cm−1), and C–O (1188.10925 cm−1) for BAC and its sediments. XRD patterns exhibit peaks at 2θ = 27.82°, 29.39°, 32.24°, and 46.22°, which can be attributed to the (002) diffraction plane, (220) crystallographic plane, (111) plane of Ag2O, and (200) crystallographic plane, respectively, for GOAg and its sediments. Meanwhile, the peaks at 2θ = 26.56° and 42.41°, which correspond to (002) and (100) planes, respectively, for BAC and its sediments. The d-spacing and the crystallinity index of each adsorbent were also determined. The estimation of the remaining β− particles during the adsorption of I-131 was carried out using PHITS. The finding of this study is beneficial for alternative radionuclide extractions technique from clinical radioactive wastewater in nuclear medicine.

Effect of pH-shifting and ultrasound on soy/potato protein structure and gelation

The substitution of meat proteins with plant-based proteins from various sources is often motivated by nutritional considerations. However, the inherent limited solubility of plant proteins, which results in suboptimal techno-functional properties, remains a persistent challenge in food formulation. The purpose of this study was to investigate the impact of pH-shifting (P), high-intensity ultrasound (U), and ultrasound-assisted pH-shifting on the structure and solubility of soy protein isolate (SPI), potato protein isolate (PPI), and the soy/potato protein complex (SPI/PPI complex). Additionally, a detailed examination of the gel properties of SPI, PPI, and the SPI/PPI complex was conducted to assess the changes that occurred before and after modification. The results of particle size, zeta potential, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), free sulfhydryl (R-SH), surface hydrophobicity (H0), Fourier transform infrared spectrum (FTIR) and fluorescence intensity showed that P and U treatment promoted the unfolding of proteins structures and decreased particle size, and augmented protein-water interactions, leading to enhanced solubility. The pH-shift and ultrasound (PU) treatment further amplified these structural alterations in proteins. Consequently, the gelling characteristics of the modified proteins were substantially improved, with notable increases in hardness, elasticity, and water-holding capacity (WHC). The findings facilitate developing more targeted plant protein-based gel products that specific techno-functional attributes, concurrently allowing for modifications to their nutritional profiles.

Facile two step approach of Chitosan/Nickel/ZrO2 bio-nanocomposite and investigation of their antimicrobial activities against Escherichiacoli

Chitosan nanoparticles (CH NPs), ZrO2, Ni/ZrO2. CH/ZrO2 and CH/Ni/ZrO2 complex have been synthesized then its antibacterial mechanisms of nanomaterials against Escherichia coli (E. coli) was evaluated by agar well diffusion and systematically analyzed by measuring the diameter of the inhibition zone. X-ray diffraction (XRD) patterns and Fourier transform infrared (FTIR) spectra and Energy dispersive X-ray (EDX) results demonstrated the formation of CH/Ni/ZrO2 matrix. Also, the crystalline sizes were found to be 15, 13, 10 and 8 nm for ZrO2, Ni/ZrO2, CH/ZrO2 and CH/Ni/ZrO2 respectively. The FTIR spectrum revealed bands ranging from 400 to 800 cm−1, indicating the presence of metal–oxygen bonds. Additionally, bands at 1620, 1523, and 1300 cm−1 suggested the presence of amide groups, confirming the presence of CH in the produced CH/Ni/ZrO2 nanocomposite. In SEM analysis, the irregular spherical nanoparticles are observed in case ZrO2 and CH/ZrO2 samples, while spherical with an oval-shaped structure are observed in case of Ni/ZrO2 and CH/Ni/ZrO2 sample. Mean diameter of inhibition zone were observed to be 13 ± 2.51, 12 ± 2.08, 16 ± 1.3 mm,17 ± 2.3 mm and 18 ± 0.8 nm for CH, ZrO2, Ni/ZrO2, CH/ZrO2 and CH/Ni/ZrO2 respectively. The eco-friendly and cost-effective synthesis of Chitosan assisted Ni/ZrO2 NPs can be utilized as an effective antibacterial agent.

Effect of Dy3+ ions on physical, structural and thermal properties of ZnNaPbB glasses

In this report, inspired by the excellent spectroscopic characteristics of dysprosium (Dy3+) ions doped borate glasses, a series with the composition (70-x)B2O3-10ZnO-10PbO-10Na2CO3-xDy2O3 (here ‘x’ have the values as 0.1, 0.5, 1.0, 1.5 and 2.0 in mol % ) was made using the melt quenching process and named as ZnNaPbBDy0.1 to ZnNaPbBDy2.0. Here we study the physical, structural and thermal properties of Dy3+ ions doped Zinc Sodium Lead Borate (ZnNaPbB) glasses through different characterization techniques like Fourier transform infrared (FT-IR), Raman spectroscopy, Differential scanning calorimetry (DSC) and decay spectroscopy. Several physical parameters were evaluated to assess the effect of Dy3+ inclusion. FT-IR and Raman spectra confirm the presence of BO3 and BO4 structural units. The data recorded by DSC spectra have been used to predict the glass transition temperature (Tg). The nature of decay spectra was estimated which diverges from exponential to non-exponential at higher concentrations. The decay spectral data is used to calculate the experimental lifetimes for all the glass samples. The Inoakutti Hirayama (I-H) model and Dexter’s plot are used to confirm the type of interaction between the donor and acceptor Dy3+- Dy3+ ions is dipole–dipole in nature that is responsible for the emission intensity quenching with concentration. All the above results might be advantageous for variety of applications in photonic devices.

Microfluidics assisted green synthesis of copper oxide nanoparticles from the aqueous leaf extract of Ipomoea quamoclit L. with its antimicrobial and antioxidant activity

IntroductionGreen nanosynthesis of medicinal plants are useful for the development of antibiotic agents. In this work, we have explored the antimicrobial and antioxidant activity of green synthesised copper oxide (CuO) nanoparticles (NPs) from tropical medicinal plant Ipomoea quamoclit L. MethodsWith the aid of microfluidic technology, a low-cost, polydimethylsiloxane (PDMS) lab-on-chip micromixer for green nanosynthesis of CuO nanoparticle using Ipomoea quamoclit is presented. The UV–Vis characteristics, Fourier Transform Infra-red (FTIR) spectrum, antimicrobial and antioxidant response using DPPH and hydrogen peroxide (H2O2) were reported. The antimicrobial efficacy of the synthesised CuO-NPs is tested against two-gram positive bacteria Staphylococcus aureus, Micrococcus luteus, two gram negative bacteria, Enterobacter cloacae, Klebsiella pneumoniae and two fungi species Candida albicans, Aspergillus niger. ResultsUV–Vis spectrum for the synthesised CuO-NPs showed the absorbance at 670 nm, scanning electron microscope (SEM) image analysis and dynamic light scattering (DLS) analysis confirmed the presence of spherical shaped nanoparticle sized between 65 and 94.5 nm. The presence of bioactive functional groups of N-H, C-H and C=0 stretching was identified using Fourier Transform Infrared spectroscopy (FTIR). The maximum mean zone of inhibition obtained was 10.45±0.25 mm for fungi A. niger. The antioxidant activity using DPPH scavenging assay and hydrogen peroxide scavenging assay showed the IC50 value 33.94 μg/ml and 42.54 μg/ml respectively. ConclusionsThe obtained results reveal the potential of CuO-NPs synthesised from I. quamoclit L. as a remarkable medicinal entity for wound healing, respiratory infection, fungal infection and urinary tract infection along with the improved antimicrobial and antioxidant activity.

TMAB modified NiFe2O4 nanoparticles for the Effective removal of Eriochrome Black-T azo dye

The Eriochrome Black-T (EBT) azo dye was removed from aqueous solution using TMAB (tetramethyl ammonium bromide) stabilised NiFe2O4 (TMAB@NFO) nanoparticles, which have been synthesized through polymeric precursor method. X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectra (FTIR) were used to analyse the TMAB@NFO nanoparticles. Adsorption studies were conducted under a variety of conditions, including pH, adsorbent dosage, and contact time, intraparticle diffusion, pseudo-first- and pseudo-second-order kinetic models were used to analyse the kinetic data. According to the systematic study of adsorption isotherms and kinetics models, TMAB@NFO nanoparticles will adsorb EBT dye utilising the Freundlich model and pseudo-second-order kinetics. The intraparticle diffusion model revealed a linear relationship (R2 - 0.98, 0.97, and 0.94 for TMAB@NiFe2O4 and bare NiFe2O4-NPs), demonstrating how surface modification influences the overall EBT adsorption process and the pore diffusion rate. Additionally, the manufactured nano adsorbents of NiFe2O4 were effectively regenerated and reused after the treatments up to four times following the elimination of 89% of EBT dye by TMAB@NiFe2O4-NPs. The results have demonstrated the enormous potential of TMAB @NiFe2O4-NPs to eliminate EBT in a practical way. KEY WORDS: Tetramethyl ammonium bromide, NiFe2O4, EBT, Surface capping, Adsorption, Kinetics Bull. Chem. Soc. Ethiop. 2024, 38(6), 1569-1581. DOI: https://dx.doi.org/10.4314/bcse.v38i6.6

Optimizing the polar phase transformation in PVDF-HFP/BaTiO3-activated carbon composite films with the mixture design of experiments

ABSTRACT A salient bottleneck to driving the wider use of polyvinylidene fluoride (PVDF) and its copolymers in smart applications is the requirement for a high-voltage poling process required to activate their β -phase crystal structure before the realisation of the piezoelectricity response. In pursuit of enhancing the β-phase content of PVDF-based films, various approaches have been employed in recent years. Yet, a perfect solution to the challenge remains elusive. Here, we report a preliminary investigation into the production of unpoled poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) films reinforced with barium titanate (BaTiO3) and activated carbon (AC) to improve the piezoelectric property. Employing the mixture design of experiments (MDOE) method, various formulations of the composite’s constituents weight fractions were determined. Afterwards, series of composite films were produced via a toxic-free solution casting method and characterised by Fourier Transform Infrared Spectrum (FTIR) to determine the β-phase content. A non-linear polynomial regression model was established from the experimental FTIR data, and the adequacy of the model was confirmed using ANOVA. Subsequently, an MDOE-enabled optimisation was undertaken, generating a formulation of the composite to obtain the highest β-phase content to be 15 wt.% BaTiO3 and 0.74 wt.% AC. This combination produces a theoretically predicted β-phase content of 72.7 %. A further experimental test employing the optimal formulation produced a β-phase content of 71.90 %, achieved with neither mechanical stretching, thermal annealing, nor electrical poling.

Chemometric classification of Vietnamese green tea (Camellia sinensis) varieties and origins using elemental profiling and FTIR spectroscopy

SummaryThe objective of this study was to employ multi‐elemental analysis and chemometric multivariate data analysis for identifying the geographical origin of Camellia sinensis cultivated in Vietnam's northeastern region. Ninety‐two tea leaf samples encompassing four distinct varieties were sourced from Bac Can and Thai Nguyen provinces. These samples underwent analysis through Fourier transform infrared (FTIR) spectroscopy and chemometrics, while elemental quantification was achieved via inductively coupled plasma mass spectrometry (ICP‐MS), utilising mixed standards for 26 elements. The FTIR spectra exhibited characteristic peaks, denoting the functional groups of the potential compounds present. ICP/MS analysis identified the presence of 14 elements in the tea samples, revealing significant variations in content across the four varieties. principal component analysis (PCA) of the FTIR data illustrated that the initial two principal components accounted for 91.26% of the total variance, effectively segregating the four green tea varieties into distinct clusters. Conversely, PCA of the ICP‐MS spectra also distinguished the four varieties, albeit Trung Du and Hybrid F1 exhibited a proximate distribution. This closeness may be incidental and not indicative of correlation, considering the limited variable set. Our findings ascertain that ICP/MS and FTIR, augmented by chemometric software, serve as efficacious tools for ascertaining the geographical origins of tea.

Detection of Verticillium infection in cotton leaves using ATR-FTIR spectroscopy coupled with machine learning algorithms

Verticillium wilt (VW) is a soil-borne vascular disease that affects upland cotton and is caused by Verticillium dahliae Kleb. A rapid and user-friendly early diagnostic technique is essential for the preventing and controlling VW disease. In this study, Fourier transform infrared (FTIR) spectroscopy with attenuated total reflectance (ATR) technology was used to detect VW infection in cotton leaves. About 1800 FTIR spectra were obtained from 348 cotton leaves. The cotton leaves were collected from three categories: VW group, infected group and control group (non-infected). The vibrational peak of chitins at 1558 cm−1 was identified through mean and differential analysis of FTIR spectra as a criterion to differentiate the VW or infected group from the control group. Classification models were constructed using various machine learning algorithms. The support vector machines (SVM) model exhibited the highest predictive accuracy (>96 %) in each group and a total accuracy (>97 %) for the three groups. These results provide a new approach for detecting Verticillium infection in cotton leaves and shows a promising potential for the future applications of the method in plant science.

Elucidating the bacterial inactivation mechanism by argon cold atmospheric pressure plasma jet through spectroscopic and imaging techniques.

This study aims to assess the potential bacterial inactivation pathway triggered by argon (Ar) cold atmospheric pressure plasma jet (CAPJ) discharge using spectroscopic and imaging techniques. Electrical and reactive species of the Ar CAPJ discharge was characterized. The chemical composition and morphology of bacteria pre- and post-CAPJ exposure were assessed using Fourier transform infrared (FTIR), Raman micro-spectroscopy, and transmission electron microscopy (TEM). A greater than 6 log reduction of E. coli and S. aureus was achieved within 60 and 120 s of CAPJ exposure, respectively. Extremely low D- values (< 20 s) were recorded for both the isolates. The alterations in the FTIR spectra and Raman micro-spectra signals of post-CAPJ exposed bacteria revealed the degree of destruction at the molecular level, such as lipid peroxidation, protein oxidation, bond breakages, etc. Further, TEM images of exposed bacteria indicated the incurred damages on cell morphology by CAPJ reactive species. Also, the inactivation process varied for both isolates, as evidenced by the correlation between the inactivation curve and FTIR spectra. It was observed that the identified gas-phase reactive species, such as Ar I, O I, OH•, NO+, OH+, NO2-, NO3-, etc. played a significant role in bacterial inactivation. This study clearly demonstrated the effect of CAPJ exposure on bacterial cell morphology and molecular composition, illuminating potential bacterial inactivation mechanisms.

Colour tunability of Dy3+ & Sm3+ activated yttrium aluminium gallium nanocrystals for display applications

A set of powder samples of Y3AlGa4O12 doped with Dy3+ and Sm3+ with different concentration of Sm3+ ion were prepared via sol-gel synthesis. X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive (EDS), Fourier transform infrared (FTIR) and photoluminescence spectral studies were carried out. All the diffraction peaks matched the cubic lattice Y3AlGa4O12, as given by the XRD. The SEM images revealed aggregated spherical particles ranging from 50 to 130 nm. The EDS analysis confirmed the presence of the initial chemicals in the synthesized samples. FTIR spectrum was used to examine the vibrational modes in the sample. Under a 366 nm excitation wavelength, the emission spectrum showed the peaks at 492 nm (blue), 580 nm (yellow), 673 nm (red), and 760 nm (near-infrared) corresponding to the characteristic transitions 4F9/2 → 6H15/2,13/2,11/2,9/2 of the Dy3+ ion, respectively. In comparison, the peaks at 568 nm, 614 nm, 664 nm, and 711 nm corresponded to the characteristic transitions 4G5/2 → 6H5/2,7/2,9/2,11/2 of the Sm3+ ion. Under near ultraviolet light excitation, the superposition of these blue, yellow and red colours produced excellent white light emission. The intensities of these transitions varied with the concentration of Sm3+ ion and the excitation wavelength. The emission spectrum of Dy3+ overlapped with the excitation spectrum of Sm3+, indicated possible energy transfer from Dy3+ to Sm3+. According to Inokuti-Hirayama's theory of energy transfer, the mechanism of energy transfer was understood to be quadrupole-quadrupole interaction. The CIE chromaticity co-ordinates and correlated colour temperature values showed that these samples were suitable for light-emitting diode applications.

Effect of the Ratio of Soluble and Insoluble Dietary Fiber from Rice Bran with Extrusion Cooking Treatment on Pasting, Thermal, and Structural Properties of Rice Starch Gel

AbstractThis study aims to investigate the effect of different ratios of soluble and insoluble dietary fiber (0/100, 25/75, 40/60, 55/45, 70/30, 85/15, 100/0) in rice bran treated with or without extrusion cooking on the physicochemical and structural properties of rice starch. As the ratio of soluble dietary fiber (SDF) increases, the PV (peak viscosity), FV (final viscosity), SB (setback value), and BD (breakdown value) of starch are significantly decreased, indicating that a higher SDF ratio can delay the short‐term retrogradation of starch. Compared with the unextruded rice bran SDF/IDF starch gel, the content of weak bond water and free water in the extruded rice bran SDF/IDF starch gel is higher while the content of strong bond water in the starch gel is lower at the same SDF/IDF ratio. Meanwhile, for the results X‐ray diffraction (XRD) and fourier transform infrared spectrum (FTIR), the rice starch with the extruded rice bran SDF/IDF ratio of 25:75 shows the lowest relative crystallinity of 3.48% and the lowest peak to height ratio of FTIR (1047 cm−1/1022 cm−1) of 1.0746, suggesting that the inhibition effect on rice starch retrogradation is better. This may be beneficial for the utilization of different ratios of SDF/IDF from extruded rice bran and physicochemical properties improvement of rice starch gel.