Fourier Transform Infrared Spectroscopy Spectroscopy Research Articles

Contemporary Developments and Emerging Trends in the Application of Spectroscopy Techniques: A Particular Reference to Coconut (Cocos nucifera L.).

The number of food frauds in coconut-based products is increasing due to higher consumer demands for these products. Rising health consciousness, public awareness and increased concerns about food safety and quality have made authorities and various other certifying agencies focus more on the authentication of coconut products. As the conventional techniques for determining the quality attributes of coconut are destructive and time-consuming, non-destructive testing methods which are accurate, rapid, and easy to perform with no detrimental sampling methods are currently gaining importance. Spectroscopic methods such as nuclear magnetic resonance (NMR), infrared (IR)spectroscopy, mid-infrared (MIR)spectroscopy, near-infrared (NIR) spectroscopy, ultraviolet-visible (UV-VIS) spectroscopy, fluorescence spectroscopy, Fourier-transform infrared spectroscopy (FTIR), and Raman spectroscopy (RS) are gaining in importance for determining the oxidative stability of coconut oil, the adulteration of oils, and the detection of harmful additives, pathogens, and toxins in coconut products and are also employed in deducing the interactions in food constituents, and microbial contaminations. The objective of this review is to provide a comprehensive analysis on the various spectroscopic techniques along with different chemometric approaches for the successful authentication and quality determination of coconut products. The manuscript was prepared by analyzing and compiling the articles that were collected from various databases such as PubMed, Google Scholar, Scopus and ScienceDirect. The spectroscopic techniques in combination with chemometrics were shown to be successful in the authentication of coconut products. RS and NMR spectroscopy techniques proved their utility and accuracy in assessing the changes in coconut oil’s chemical and viscosity profile. FTIR spectroscopy was successfully utilized to analyze the oxidation levels and determine the authenticity of coconut oils. An FT-NIR-based analysis of various coconut samples confirmed the acceptable levels of accuracy in prediction. These non-destructive methods of spectroscopy offer a broad spectrum of applications in food processing industries to detect adulterants. Moreover, the combined chemometrics and spectroscopy detection method is a versatile and accurate measurement for adulterant identification.

Novel procaine-based gemini zwitterion incorporated PVDF membranes for efficient treatment of oily wastewater

Oily wastewater treatment has great significance due to environmental and industrial perspectives. Oily wastewater has emerged as one of the leading causes of water contamination. Owing to the lower efficiencies of the conventional methods, membrane technology is an emerging solution for separating the stabilized oil contaminants from water. In this work, a novel procaine-based zwitterionic geminal surfactant (PZGS) i.e., 3,3′-((((4,4′-(decanedioylbis(azanediyl)) bis(benzoyl))bis(oxy)) bis(ethane-2,1-diyl)) bis(diethylammoniumdiyl)) bis(propane-1-sulfonate) synthesized by utilizing procaine hydrochloride and 1,3-propane sultone precursors. The PZGS was well-characterized by 1H NMR, 13C NMR, and FTIR spectroscopy. The synthesized PZGS was utilized to fabricate procaine-based zwitterionic gemini surfactant incorporated PVDF membranes (PZGS-Mx-PVDF), and the membranes were thoroughly investigated by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), and contact angle goniometry. It is observed that the performance of these newly fabricated membranes (PZGS-Mx-PVDF) was significantly improved after incorporating PZGS into the PVDF membranes. The surface of membranes has become water-friendly as the water contact angle substantially changed from 84.1° to 58.1°. In controlled addition of PZGS, the PZGS-M2-PVDF membrane has shown a substantially improved flux of 4.5 times to pristine PVDF. The maximum oil rejection of > 99.3% was attained using the PZGS-M1-PVDF membrane. A high flux recovery ratio (FRR) of about 83% was observed with the PZGS-M2-PVDF membrane. The PZGS-Mx-PVDF membranes have shown a good flux recovery ratio after continuous use of oil-in-water emulsions. The excellent separation efficiency, high permeation flux, and good flux recovery ratio indicated that the introduced PZGS-Mx-PVDF membranes have a significant potential for oily wastewater treatment.

Physicochemical Properties of Mango Pulp and Mid-infrared Characterization

Aim of the present study was to predict physicochemical parameters that are ash content, water content and fat content and to predict the presence of different organic molecule in the mango pulp. The prediction for the presence of the organic molecules has been done with the Fourier Transform Infrared Spectroscopy (FTIR). The spectra of mango pulp were measured using FTIR ranging from wavenumber 400 cm-1 to 4000 cm-1. Physicochemical parameters has been analysed with hot air oven, muffle furnace and automated Soxhlet apparatus for moisture content, ash content and crude fat content respectively. This study showed that FTIR spectroscopy has efficiency to distinguish some organic molecules present in the mango pulp.

Effect of polymers and micro fibres on the thermo-chemical and rheological properties of polymer modified binders

ABSTRACT Polymer-modified bitumen provides superior thermo-chemical and rheological properties. This study focuses on the correlation between the thermo-chemical and rheological characteristics of bitumen modified with five different polymers in addition to neat bitumen. The polymers include an amine-wax-based additive, thermoplastic elastomers, a system of elastomers and microfibres, plastomers and a system of plastomers and microfibres. The chemical compositions were investigated using Fourier-transform infrared spectroscopy (FTIR), while the thermal behaviour was studied using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The modified bitumen’s rheological performance was analysed using frequency sweep, linear amplitude sweep (LAS), and multiple stress creep and recovery (MSCR) tests. Rheological properties showed that the combination of fibre and polymers improved the thermal susceptibility of the bitumen at all ranges of temperature compared to other blends that only included single polymers. FTIR spectroscopy suggests that the polymer modification resulted in successful blending and active cohesion between the polymer matrix and bitumen. TG/DTG analysis confirmed that the modified blends exhibited greater thermal stability than neat bitumen. Glass transition temperature (Tg) was obtained from DSC to predict the polymers’ low-temperature rheological properties whereas, degree of crystallinity and melting point showed the intermediate and high temperature properties of the binders.

Synthesis of Iron Nanoparticles Using Sargassum wightii Extract and Its Impact on Serum Biochemical Profile and Growth Response of Etroplus suratensis Juveniles.

The present study focuses on the green synthesis of iron nanoparticles using plant extracts as reducing, capping, and stabilizing agents. Aqueous seaweed extracts with the addition of iron solution were mixed using a magnetic stirrer which resulted in a color change indicating the formation of iron nanoparticles. The iron nanoparticles were successfully synthesized using Sargassum wightii extract. The synthesized iron nanoparticles were characterized by UV-Vis spectrophotometer, Fourier transform infrared spectroscopy (FTIR), and zeta potential techniques. The UV-Vis spectra showed a peak at 412 to 415nm. Zeta potential revealed that the synthesized iron nanoparticles were negative and positive charges. FTIR spectroscopy analysis showed the presence of chemical bond and amide group likely to be responsible for the green synthesis of iron nanoparticles. The effect of nano-iron as a dietary iron source on the growth and serum biochemical profile of Etroplus suratensis fingerlings was evaluated. Iron nanoparticles were fed to E. suratensis fingerlings for 60days with two levels 10mg (T1) and 20mg (T2) and a control group without iron nanoparticles. The highest WG% and SGR and lowest FCR were observed in the T2 group which is significantly different (p < 0.05) from other groups. The serum biochemical profile showed significantly increased activity on 20mg/kg of nano-iron-supplemented diet. The findings of the present study concluded that supplementation of nano-iron at the 20mg/kg level to the regular fish diet has a better impact not only on growth but also on the overall health of the fish.

Thermal aging of electrical cable insulation made of cross‐linked low density polyethylene for under‐hood application in automotive industry

AbstractThe thermal aging of two electrical cable insulations made of cross‐linked low density polyethylene (XLPE) only differing by their stabilization system was studied in air between 125 and 200°C. The chemical consumption of the two types of antioxidants (phenol and sulfide), the build‐up of oxidation products and the consequences of thermal oxidation on the mechanical properties were respectively determined by measurement of the oxidation induction time (OIT), Fourier transform infrared spectroscopy (FTIR) and uniaxial tensile testing. It was found that the chemical consumption of each antioxidant occurs in turn almost independently, starting with the sulfide antioxidant and involving small but well detectable antagonistic effects. As soon as the antioxidant concentration becomes very low, that is, practically undetectable by OIT measurements, the thermal oxidation of XLPE is detected by FTIR spectroscopy causing a catastrophic decrease in the fracture properties. It was shown that the complete consumption of antioxidants coincides with the end of the oxidation induction period and the onset of the sudden decrease in the elongation at break. Based on all these experimental results, a simplified kinetic model was developed to account as faithfully as possible for the consumption kinetics of antioxidants, evaluate their antagonistic effects and, using a relevant end‐of‐life criterion, predict the lifetime of the two XLPE insulations. It was found a satisfying agreement between theory and experiment.

Prediction of the Total Base Number (TBN) of Engine Oil by Means of FTIR Spectroscopy

The objective of this study is to develop a statistical model to accurately estimate the total base number (TBN) value of diesel engine oils on the basis of the Fourier transform infrared spectroscopy (FTIR) analysis. The research sample consisted of oils used in the course of 14,820 km. The samples were collected after each 1000 km and both FTIR and TBN measurements were performed. By applying the measured absorbance values, five statistical models aimed at predicting TBN values were elaborated with the use of the following information: aggregated values of measured absorbance in defined spectral ranges, extremes at wavenumbers, or the surface area of spectral bands related to the vibrations of specific molecular structures. The obtained models may be considered a continuation and an extension of previous studies of this type described in the literature on the subject. The results of the study and the analysis of the obtained data have led to the development of two models with high predictive capabilities (R2 &gt; 0.98, RMSE &lt; 0.5). Another model, which had the smallest number of variables in comparison to other models, had markedly lower R2 value (0.9496) and the highest RMSE (0.5596). Yet another model, where the dimensionality of the pre-processed full spectra was reduced to four aggregates through averaging, turned out to be slightly worse than the best one (R2 = 0.9728). The study contributes to a more in-depth understanding of the FTIR-based TBN prediction tools that may be readily available to all interested parties.

Moisture absorption and spectroscopic studies of epoxy clay nanocomposite

Epoxy resins are prone to serious moisture absorption inspite of their inherent advantages, which can be mitigated by the incorporation of montmorillonite nanoclay that provide tortuous path to flow of moisture. Moisture absorption studies of epoxy clay nanocomposites is carried out, to analyse the effect of nanoclay content, immersion media and immersion temperature. Nanocomposites prepared in 0.5, 1 and 1.5 wt% using magnetic stirring and ultrasonication and neat epoxy specimen were immersed in distilled water and artificial seawater maintained at 28 and 38 °C till saturation. Fick’s and Langmuir’s models were applied to calculate the kinetic parameters from the water absorption graphs. Atomic force microscopy (AFM), X-ray diffraction spectroscopy (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope with energy dispersive X-ray (SEM–EDX) characterizations were performed. Diffusivity is least for nanocomposite containing 0.5 wt% nanoclay at both temperatures in both medium. However, it is least when the medium is distilled water. As the temperature of immersion medium increases, the diffusivity also increases. Saturation moisture uptake increased with increase in nanoclay content, because of the residual hydrophilic nature of nanoclay. AFM and XRD analysis revealed better dispersion and exfoliated structure of nanoclay respectively at 0.5 wt% loading. FTIR spectroscopy was applied to identify the chemical bonds that helped in proposing the reaction mechanism of the nanocomposite synthesis. Spectra comparison of dry and wet specimens complimented the moisture absorption data by showing lower infrared transmittance in wet specimens. With Increase in nanoclay content, the transmittance decreased corresponding to increase in saturation moisture uptake for distilled water immersed specimens. SEM–EDX analysis distinguished between the cations entered from the artificial seawater and cations that were still present in the nanoclay.

Successive Ion Layer Adsorption and Reaction Method Developed ZnO Thin Films for NO2 Gas Sensing

The present investigation deals with the NO2 gas detection via nanostructured zinc oxide (ZnO) thin films harvested over a glass substrate via a simple and facile successive ion layer adsorption and reaction (SILAR) approach. ZnO nanostructured thin films are developed by different SILAR cycles (ZnO:15, ZnO:30, ZnO:45, ZnO:60). The physicochemical, optical, and morphological properties of prepared thin films are explored by various characterization techniques. The phase purity and grains size are confirmed by X‐ray diffraction (XRD) and Scherrer formula, which reveal the hexagonal phase structure with variant grain size (≈16–21 nm). The surface morphology of deposited films shows the well‐dispersion of ZnO nanoparticles, which is picturized by field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), attenuated total reflectance (ATR). UV–Vis and FTIR spectroscopy elaborates on the optical properties and functional groups of ZnO films, respectively. Further, the sensing ability of ZnO thin films is studied with different concentrations (50–250 ppm) of NO2 gas in the span of 50 ppm by recording the resistance transient. The ZnO:30 thin‐film displays an enhanced gas sensing response of 1.42 GΩ at 100 °C compared to other synthesized films and at different temperature ranges. The ZnO:30 film shows the highly selective response toward the NO2 gas compared to other interference gas species. Thus, the present study highly recommends the investigated method for the ZnO thin film formation to be employed toward NO2 gas sensing.

Comparative analysis by UV-vis and FT-IR spectroscopy of the chemical degradation of polyethylene used as greenhouse cover film

Greenhouse culture usually requires a controlled environment for optimum plant growth and production. However, regular plastic films used for their coverage create an uncontrolled microclimate, especially in areas with harsh climatic conditions. Three low-density polyethylene (LDPE) films, a commercial ordinary film, a three-layer film, and a monolayer film were used as a greenhouse covering materials to study its behavior in presence of a cultivar and harsh climatic conditions. They were exposed to natural weathering and UV radiations in the semi-arid environment of a city located in northern Algeria. This study aims to investigate and compare the lifespan and deterioration of the materials used for a 5-month period to improve future greenhouse cultivation. Fourier-transform infrared spectroscopy (FT-IR) and ultraviolet-visible spectrophotometry (UV-vis) were used to study the aging and degradation of these films. FTIR 1030/2848 bands ratio was used to determine the chemical oxidation rate of each film. Visible changes in the material structure were also recorded during the aging process. Materials underwent photo and thermo degradation, leading to chemical and mechanical changes. The monolayer film has suffered more mechanical degradation than the multilayer films, leading to its total crumbling in a short lifetime. The three-layer and ordinary films were more resistant and showed approximately the same behavior towards the rough climatic conditions. Furthermore, the UV-visible spectrum indicated a high loss of transparency of the polyethylene films during their use. The two studied multilayer films seem more adequate for greenhouse culture under the semi-arid regions.

Physicochemical and bio-metabolite characterizations of chitosan isolated from American cockroach (Periplaneta americana) and cricket (Acheta domesticus)

Background: Chitosan is gaining increased research interest due to its wide range of potential applications in the field of biotechnology, medicine and pharmacology, agriculture, textiles, cosmetics and wastewater treatments. This study was designed specifically to explore locally available chitosan from American cockroaches (Periplaneta americana) and cricket (Acheta domesticus) as an alternative source of chitosan for industrial application. Methods: Chitosan was extracted by alkaline deacetylation of chitin and were physicochemically characterized using Fourier Transformed Infrared Spectroscopy (FTIR), scanning electron microscope (SEM), degree of deacetylation (DD), solubility and Gas Chromatography-Mass Spectrometry. Results: The yielding proportion of Chitosan obtained from P. americana and A. domesticus were 99.7 and 90.6%. The cockroach and cricket chitosan have the same degree of deacetylation of 90.3 % and 88.5%respectively. The FTIR Spectroscopy of the chitosan from P. americana and A. domesticus revealed that the obtained chitosan was in alpha polymorphic form. This fact was confirmed by the scanning electron microscope (SEM) which shows the morphology of the chitosans from both insects. Chitosan from Cockroach and crickets compares favourably and were found to exhibit some similarities. It was established that P. americana chitosan was more soluble in dilute acetic acid with about 102.1% solubility, while A. domesticus chitosan had 93%. The GCMS analysis revealed the presence of a class of compounds like benzene derivative, alkene derivative, bicycle derivative, bicycle alcohol derivative, multiple cyclic compounds, saturated tricycle and derivatives of chloroalkane, fatty acid, saturated, and saturated alcohol. Conclusion: Based on all these qualities possessed by the chitosan of both insects, they can replace commercial chitin and chitosan in terms of utilization and applications. Therefore, both insects are promising alternative sources of chitin and chitosan.

Green synthesis of silver nanoparticles using fruits extracts of Syzygium cumini and their bioactivity

The biosynthesis of silver nanoparticles have received great attention in the field of nanotechnology because of its antimicrobial and biomedical applications. In the current research scenario, the green synthesis of metal nanoparticles is expected to be cost-effective and environmentally benign alternative. In this effort, the fruit extracts from the Syzygium cumini was used as the reducing agent to synthesize silver nanoparticles (AgNPs) and the antioxidant, antibacterial, and anti-inflammatory properties of the synthesized nanoparticles have been evaluated. The synthesized Ag nanoparticles were characterized by UV–Visible spectroscopy (UV), Fourier-transform infrared spectroscopy (FTIR), Powder X-ray Diffraction (XRD) and scanning electron microscope (SEM).The formation of silver nanoparticles was confirmed by optical performance i.e change in color using UV–Visible spectroscopy showing a characteristic peak of silver nanoparticles at 443 nm. The presence of OH and C=O of plant secondary metabolites of Syzygium cumini were confirmed by FTIR spectroscopy, liable for capping and reduction of metal nanoparticles surface. Powder XRD analysis was used to analyze the crystal structure. This medicinal plant extract mediating green biosynthesized silver nanoparticles exhibited good in vitro- antioxidant, antibacterial and anti-inflammatory activities. Therefore, results of the present study highlights the synthesis of cost-effective, eco-friendly drugs with less side effects, which showed that there is the urge of in vivo studies at a molecular level to develop silver nanoparticles through greener approach using the medicinal plant (Syzygium cumini) extract as antibacterial, antioxidant, and anti-inflammatory agent for the treatment of bacterial infection, inflammation and many free radical oriented diseases.

FT-IR Spectral Signature of Sensitive and Multidrug-Resistant Osteosarcoma Cell-Derived Extracellular Nanovesicles.

Osteosarcoma (OS) is the most common primary bone cancer in children and adolescents. Despite aggressive treatment regimens, the outcome is unsatisfactory, and multidrug resistance (MDR) is a pivotal process in OS treatment failure. OS-derived extracellular vesicles (EVs) promote drug resistance to chemotherapy and target therapy through different mechanisms. The aim of this study was to identify subpopulations of osteosarcoma-EVs by Fourier transform infrared spectroscopy (FT-IR) to define a specific spectral signature for sensitive and multidrug-resistant OS-derived EVs. EVs were isolated from sensitive and MDR OS cells as well as from mesenchymal stem cells by differential centrifugation and ultracentrifugation. EVs size, morphology and protein expression were characterized. FT-IR/ATR of EVs spectra were acquired in the region of 400–4000 cm−1 (resolution 4 cm−1, 128 scans). The FT-IR spectra obtained were consistently different in the EVs compared to cells from which they originate. A specific spectral signature, characterized by a shift and a new band (1601 cm−1), permitted to clearly distinguish EVs isolated by sensitive and multidrug-resistant OS cells. Our data suggest that FT-IR spectroscopy allows to characterize and define a specific spectral signature for sensitive and MDR OS-derived EVs.

5‐Ethylidene‐2‐norbornene Polymerization by α‐Diimine Nickel Catalyst: A Revealing Insight into the Pivotal Function of Binuclear and Mononuclear Catalyst Structure in Tailoring Polymer Architecture

AbstractThe present investigation is undertaken to provide a deeper understanding of the 5‐ethylidene‐2‐norbornene (ENB) homopolymerization. To this end, binuclear and mononuclear nickel α‐diimine catalysts, as well as modified methylaluminoxane (MMAO) as a cocatalyst, are selected and utilized. Al/Ni ratio of 1000 coupled with a temperature 25 °C and a polymerization time 12 h are chosen as the optimal statistics. It is shown that the highest obtained activity for binuclear and mononuclear catalysts are 511 and 478 kg polymer/mol, respectively. Thereafter, the characterization of the obtained poly 5‐ethylidene‐2‐norbornene (PENB) is performed by fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). Concerning the glass transition of cyclic polyolefin, DSC analysis reveals that catalyst structure is a determining factor (Tg binuclear: 176 °C and Tg mononuclear: 140 °C). As validated by dynamic mechanical thermal analysis (DMTA), it is realized that the alteration in the catalyst structure exerts a far‐reaching influence on the polymer architecture. Surprisingly unexpectedly, excluding addition polymerization, an in‐depth examination of polymer structure uncovers the potentially tenable participation of both cationic and ring‐opening polymerization, albeit, with a diversified degree of contribution. Lastly, PENB is functionalized with three functional groups, and then the successful grafting of polar functional groups into modified cyclic polyolefin backbone is confirmed by NMR and FTIR spectroscopy.

UV-cured electroactive polyurethane acrylate coatings with superhydrophobic surface structure of biomimetic peacock feather for anticorrosion application

In this work, UV-cured electroactive polyurethane acrylate (EPU) materials with the superhydrophobic surface structure of biomimetic peacock feather were firstly prepared and applied in anticorrosive coatings. Firstly, amine-capped aniline trimer (ACAT) and vinyl-capped aniline trimer (VCAT) were synthesised and characterised by 1H-nuclear magnetic resonance spectroscopy (NMR), Fourier transform infrared spectroscopy (FTIR) and mass spectroscopy. Polyurethane acrylate (PUA) was synthesised and characterised by 1H NMR and FTIR spectroscopy. EPU was then prepared through the UV curing of PUA with 0, 1, 3 and 5 wt% VCAT (named EPU0, EPU1, EPU3 and EPU5, respectively) and characterised via FTIR. The redox capabilities of the as-prepared EPU series were investigated by cyclic voltammetry studies. EPU with higher VCAT loading (EPU5) exhibited better corrosion protection performance than those with lower VCAT loadings (EPU0, EPU1 and EPU3) based on a series of electrochemical corrosion measurements because of the formation of a dense metal oxide layer as evidenced by Raman spectroscopy. Moreover, EPU5 with the surface structure of biomimetic peacock feather (denoted by BEPU5) was prepared by nanocasting technique with polydimethylsiloxane as the flexible transparent negative template. The surface morphology and wettability of BEPU5 was investigated by scanning electron microscopy and contact angle (CA) analysis. The CA of BEPU5 remarkably increased to 145° compared with that of EPU5 63°. This massive increase in CA indicates efficient superhydrophobic properties, which were induced by the biomimetic peacock feather and produced outstanding corrosion protection performance for short and long terms based on a series of electrochemical corrosion measurements. This study is the first of its type to produce a biomimetic feather with massive increase in superhydrophobic properties, which is expected to revolutionise biomimetic industrial coating technologies towards better corrosion protective coatings.

Soil organic matter qualification with FTIR spectroscopy under different soil types in Estonia

Soil organic matter (SOM) is a heterogeneous material consisting of different functional groups depending on soil texture and moisture regime. The lability of SOM (rapidity of turnover rate) is also an important indicator in soil quality evaluation. In this study, SOM lability (p-WEOC) was assessed based on the proportion of total soil organic carbon (SOC) represented by water-extractable organic carbon (WEOC) for a wide range of Estonian arable soils. We applied Fourier-transform infrared spectroscopy (FTIR) to examine the SOM relationships between qualitative (functional groups, SOM lability (p-WEOC), hydrophobicity (HI), degree of degradation (DDI), and water repellency (W)) and quantitative (total SOC and WEOC concentration) parameters depending on soil texture and moisture regime. Gleysols had the highest SOC and WEOC concentrations and p-WEOC was typically highest in automorphic sandy soils and lowest in sandy Gleysols. Overall, p-WEOC values for Gleysols were lower than those for automorphic soils. SOC and WEOC concentrations were positively correlated with all measured absorbance peaks and p-WEOC was negatively correlated with some peaks but positively correlated with DDI. HI and W were highest in Gleysols; however, sandy and automorphic soils had higher DDI. In general, automorphic soils had higher lability and the SOM was more degraded than wet soils. In summary, it is possible to assess and compare SOM composition in different soil types with FTIR spectroscopy, although eliminating inorganic material from soil will provide more accurate results.

Synthesis and catalytic study of CeO2 heterostructures with (Zn0.003-xCdx)S0.003 for the removal of crystal violet dye

In the present work different CeO2 heterostructures are synthesized with (Zn0.003-xCdx)S0.003 via co-precipitation method by varying the concentration of zinc (Zn) and cadmium (Cd). The synthesized heterostructures were characterized by X-ray diffraction (XRD), Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), UV–visible spectroscopy, Photoluminescence (PL) and Raman spectroscopy. XRD results confirmed the formation of NPs with average crystallite size of 3–5 nm. TEM micrographs depicted the formation of agglomerated non-symmetrical NPs. EDS spectra gives confirmation for the presence of all the elements in synthesized material. FTIR, PL and Raman spectroscopy confirmed the presence of ZnS and CdS in synthesized heterostructures with CeO2 NPs. The photocatalytic activity has been studied by the UV–visible spectrophotometer. The crystal violet (CV) dye was used to check the photocatalytic activity of the synthesized heterostructures. It has been observed that the heterostructures of CeO2 with (Cd0.0015Zn0.0015)S0.003 has shown enhanced catalytic activity and large rate constant than all other synthesized samples.

Rheological properties and dynamic thermal stability ofPVC/La L2/Ca‐Zncomposite stabilizer

AbstractLanthanum complex with curcumin (La L2)/Ca‐Zn composite stabilizer was prepared using La L2and Ca‐Zn stabilizer, in which Ca‐Zn stabilizer was obtained from calcium stearate and zinc stearate at their mass ratio of 5:1. The rheological properties and dynamic thermal stability of polyvinyl chloride (PVC) stabilized by La L2/Ca‐Zn composite stabilizers were estimated through a torque rheometer. The degraded fragments obtained from the torque experiments were measured by Fourier‐transform infrared spectroscopy (FTIR) and ultraviolet–visible (UV‐vis) spectroscopy. La L2had an effective synergistic effect with Ca‐Zn stabilizer. Compared with La L2, La L2/Ca‐Zn composite stabilizer could more significantly improve the rheological properties and dynamic thermal stability of PVC. An optimal synergistic effect could be observed when the mass ratio of La L2with Ca‐Zn stabilizer was about 8:2, in which the plasticizing torque and equilibrium torque of PVC was 33.3 N m and 22.5 N m, respectively, and its dynamic thermal stabilizing time was 25.1 min. The possible thermal stability mechanism of La L2/Ca‐Zn composite stabilizer for PVC was suggested based on the evaluation of FTIR spectroscopy and UV‐vis spectroscopy.

Defect- and H-Free Stoichiometric Silicon Carbide by Thermal CVD from the Single Source Precursor Trisilacyclohexane

Stoichiometric silicon carbide (SiC) thin films were grown using thermal chemical vapor deposition (TCVD) from the single source precursor 1,3,5-trisilacyclohexane (TSCH) on c-Si (100) substrates within an optimized substrate temperature window ranging from 650 to 850 °C. X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) analyses revealed that the as-deposited films consisted of a Si-C matrix with a Si:C ratio of ~1:1. FTIR and photoluminescence (PL) spectrometry studies showed that films deposited ≥ 750 °C were defect- and H-free within the detection limit of the techniques used, while ellipsometry measurements yielded an as-grown SiC average refractive index of ~2.7, consistent with the reference value for the 3C-SiC phase. The exceptional quality of the films appears sufficient to overcome limitations associated with structural defects ranging from failure in high voltage, high temperature electronics to 2-D film growth. TSCH, a liquid at room temperature with good structural stability during transport and handling as well as high vapor pressure (~10 torr at 25 °C), provides a viable single source precursor for the growth of stoichiometric SiC without the need for post-deposition thermal treatment.

Production of di-rhamnolipid with simultaneous distillery wastewater degradation and detoxification by newly isolated Pseudomonas aeruginosa SRRBL1

Distillery industries generate around 12–15 L aqueous waste per liter of alcohol production. Characteristics of distillery wastewater (DWW) dark brown color containing organic and inorganic pollutants with heavy metals (HMs) cause pernicious effects on the terrestrial and aquatic ecosystems. Unknowingly untreated DWW irrigation adversely affects the productivity of the crops due to the unavailability of minerals, reduction in seed germination and seedling growth. So, this study screened potential isolates that have plant growth promotion (PGP) and biosurfactant (BS) production properties. 5% inoculum of Pseudomonas aeruginosa SRRBL1 produced 2.9 g/L BS from minimal salt media (MSM) amended with 20% (v/v) DWW at 37 °C and 120 revolutions per minute (rpm) after 72 h incubation. Thin-layer chromatography (TLC), Fourier transform-infrared spectroscopy (FT-IR), proton nuclear magnetic resonance (1H NMR) and liquid chromatography-mass spectrometry (LC-MS) analysis indicated that extracted BS was di-rhamnolipid in nature. Simultaneously SRRBL1 reduced color, biochemical oxygen demand (BOD), chemical oxygen demand (COD), total solids (TS), heavy metals (HMs) such as iron (Fe), zinc (Zn), nickel (Ni), lead (Pb), cadmium (Cd) and chromium (Cr) were 61.76%, 53.53%, 61.32%, 56.61% 74.44%, 70.76%, 51.56%, 73.06% 58.96% and 27.49%, respectively from DWW. In addition, FT-IR and gas chromatography-mass spectrometry (GC-MS) identify functional groups and metabolites found in DWW. Major identified metabolites listed as endocrine disruptive chemicals (EDCs) such as octadecane; heneicosane; 1,2-Benzenedicarboxylic acid, butyl 8-methylnonyl ester; oxirane, tetradecyl-; 1,4-Dioxane-2,5-diol, 2TBDMS derivative; n-tetracosanol-1 octadecanoic acid and hexadecanoic acid in untreated DWW were diminished and some new metabolites produced after bacterial treatment. Furthermore, phytotoxicity assay on Triticum aestivum confirmed that treated wastewater enhanced seed germination up to 73%. Hence it indicated that SRRBL1 can be applied for di-rhamnolipid production from DWW with simultaneous pollutants reduction.