Functional Group Analysis Research Articles

A Comparative Study of Coprecipitation and Solvothermal Techniques for Synthesizing Pure and Cu‐Doped SnO2 Nanoparticles

Tin oxide (SnO2), with its low resistivity properties and high transparency in the visible spectrum, makes it an attractive electron transfer layer (ETL) for use in perovskite solar cells. Here, we use two techniques, coprecipitation and solvothermal, to synthesize pure and 4% copper‐doped SnO2. The X‐ray diffraction patterns revealed that the films synthesized using both methods have a crystalline structure with a tetragonal arrangement. Furthermore, the lack of any secondary peaks indicated the absence of mixed tin oxide (Sn2O4) or copper oxide (CuO) components. Additionally, it demonstrated that adding a 4% Cu doping concentration reduced the crystal size in both methods. The optical results indicate adequate transmission in the central range of the visible spectrum. Calculations were performed to find the energy gap of pure SnO2 in both techniques to be 3.85 eV and 4.17 eV, respectively. When we doped SnO2 with 4% Cu, this band gap energy decreased to 3.75 eV and 3.9 eV. Furthermore, with 4% Cu doping, the particle size decreases, as demonstrated by FESEM. The EDX spectroscopy images revealed that the synthesized nanoparticles consisted of copper, oxygen, and tin. The analysis of functional groups using Fourier transform infrared (FTIR) spectra and the roughness analysis using AFM images showed a decrease in roughness from 46.1 nm to 12.3 nm in doped samples prepared by solvothermal synthesis, compared to those synthesized by the coprecipitation technique from 4.7 nm to 0.3 nm. We discovered that Cu plays an essential role in reducing nanocrystalline SnO2 particle sizes. In addition, the solvothermal technique is more impressive than coprecipitation in the synthesis of tin oxide nanostructure.

ZnO and lactic acid bacteria interaction in yogurt: sensory, surface morphology, and functional group analysis

ZnO and lactic acid bacteria interaction in yogurt: sensory, surface morphology, and functional group analysis

Oyster mushroom drying in tray dryer: Parameter optimization using response surface methodology, drying kinetics, and characterization

In this study, the drying of oyster mushrooms (P. ostreatus) in a tray dryer was optimized. The parameters used to optimize the drying process were drying temperature, airspeed, mass loading, and moisture content. Its drying kinetics were investigated at the optimum drying parameters. A quadratic equation was obtained to predict the moisture content of mushrooms at the given drying temperature, airspeed, and mass loading, and it was validated against experimental results. A minimum moisture content (9.99 wt%) was obtained at the optimum conditions of 60 °C, 3 m/s airspeed, and mass loading of 200 g using a tray dryer. Proximate analysis, shelf-life analysis, inorganic elemental analysis, and functional group analysis were done as a characterization method for mushrooms after drying at the optimum drying conditions. About 27.8 wt% protein and 50.2 wt% carbohydrates were found in proximate results. Besides, potassium and sodium were the dominant elements as estimated by spectrophotometry analysis. The induction period (IP) of dried mushrooms at room temperature is 3520:47 (hour: minute) from the oxidation stability analysis, and the water activity of dried mushrooms was found to be 0.36. The drying kinetics of oyster mushrooms were studied at various temperatures (50–75 °C), optimum airspeed (3 m/s), and mass loading (200 g). The best-fit model describing the mushrooms drying kinetics was found to be Midilli et al., with the lowest RMSE (0.008749), X2 (0.0014), and the highest R2(0.9993) values. The kinetic triplet activation energy, effective diffusivity, and diffusivity constant (Ea, Deff, D0) for oyster mushrooms drying were determined and found to lay in the general range for foodstuffs. The value of Deff results lies within the range of 10−8 to 10−12 m2/s, with Ea of 15.32 kJ/mol and D0 value 2.263 × 10−6 m2/s.

The Impact of Chitosan Incorporation on the Mechanical Characteristics of Biodegradable Packaging based on PLA/PCL Blend

The development of environmentally sustainable plastics has gained prominence due to their eco-friendliness and renewable nature. In this research, eco-friendly plastic was formulated by blending Polylactic Acid (PLA) and Polycaprolactone (PCL) with the incorporation of chitosan as a filler. The primary objective of this study is to scrutinize and delineate the influence of varying compositions of PLA/PCL/chitosan on the mechanical attributes of eco-friendly plastics. This was achieved through hot pressing methods at a temperature of 200°C for a duration of 1 hour. The composition ratios for PLA/PCL were set at 2/8 g, 3/7 g, 5/5 g, 7/3 g, and 8/2 g, while chitosan compositions ranged from 0.2 g to 0.6 g. Comprehensive assessment of the eco-friendly plastics involved biodegradability tests, tensile strength measurements, elongation evaluations, functional group analyses, and examination of plastic film morphology. Optimal performance, ascertained through characterization, was achieved with a composition of PLA/PCL/Chitosan at 8/2/0.6 g, yielding a 38.8% degradation rate, a tensile strength of 42.53 MPa with a composition of PLA/PCL/Chitosan at 8/2/0.4 g, and an elongation of 6.96% with a composition of PLA/PCL/Chitosan at 8/2/0.2 g. The functional groups identified included N-H, C-H, C=O, and C-O groups, indicating a blending process without the formation of new functional groups. Morphology testing revealed a smooth surface, although some undissolved chitosan particles were evident, likely due to non-uniform blending.

Synthesis of CuSe/PVP/GO and CuSe/MWCNTs for their applications as nonenzymatic electrochemical glucose biosensors.

Copper selenide (CuSe) is an inorganic binary compound which exhibits metallic behavior with zero band gap. CuSe has multiple applications in electrocatalysis, photothermal therapy, flexible electronic and solar cells. In the current study, copper selenide based nanocomposites CuSe/PVP/GO and CuSe/MWCNTs were synthesized by using the sol-gel method for application as a non-enzymatic glucose biosensor. Different characterization methods were employed, such as X-ray diffraction (XRD), photoluminescence (PL), Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible (UV-Vis) spectroscopy, and photoluminescence for determining various aspects of CuSe/PVP/GO and CuSe/MWCNTs nanocomposites including phase formation, functional group analysis, band gaps and morphology. Electrochemical impedance spectroscopy (EIS) showed that the resistances of modified electrode/bare electrode were 12.3 kΩ/17.3 kΩ and 6.3 kΩ/17.3 kΩ for CuSe/PVP/GO and CuSe/MWCNTs nanocomposites, respectively. Cyclic voltammetry showed that both CuSe/PVP/GO and CuSe/MWCNTs nanocomposites are promising biosensors for detection and monitoring of the glucose level in an analyte. The sensitivity and limit of detection are 2328 μA mM-1 cm-2/0.2 μM and 4157 μA mM-1 cm-2/0.3 μM for CuSe/PVP/GO and CuSe/MWCNTs, respectively. Chronoamperometry confirmed that our nanocomposite was the best sensor for glucose even in the presence of other interferents like ascorbic acid (AA), uric acid (UA) and dopamine (DA).

Unlocking the valorization potential of Rooibos tea waste-derived activated carbon in the adsorptive removal of remazol brilliant blue R dye

In this work, we report the use of spent rooibos tea leaves to fabricate activated carbon and use it to adsorptively remove the toxic Remazol Brilliant Blue R (RBBR) from the aqueous solution. The resulting activated carbon (SRTLAC) was characterized by Brunauer-Emmett-Teller N2 adsorption/desorption for surface area analysis, scanning electron microscopy, thermogravimetric analysis, Fourier transform infrared spectroscopy, Raman spectroscopy, and X-ray diffraction for morphological, functional group and crystallinity analyses. A Taguchi design approach was employed to determine the optimal conditions for the RBBR adsorption onto SRTLAC. Among the process variables studied, the sorbent dosage, initial concentration, and pH predominantly affected the removal capacity. The maximum removal of 246.5 mg/g was attained at the highest initial RBBR concentration of 120 mg/L, solution pH of 2, sorbent dosage of 20 mg, and agitation time of 110 min. The analysis of variance results showed that RBBR initial concentration contributed the most significant percentage (95.33 %) towards the removal uptake, highlighting its considerable impact. The adsorption data collected at various concentrations (20 – 120 mg/L) were modelled using three non-linear regression isotherms and kinetic models. The Langmuir isotherm model provided the optimal fit for adsorption, suggesting a monolayer and homogenous sorption system with a maximum capacity of 491.38 mg/g. Meanwhile, the pseudo-2nd order kinetic models accurately elucidated the sorption mechanism. The RBBR species interacted with the SRTLAC functional groups via hydrogen bonding, dipole-dipole interactions, and ion-dipole forces. Therefore, SRTLAC presents a powerful tool for ridding the environment of RBBR dye pollution.

Synthesis of polyaniline-coated composite anion exchange membranes based on polyacrylonitrile for the separation of tartaric acid via electrodialysis.

The increasing need to tackle major societal challenges such as environmental sustainability and resource scarcity has heightened global interest in green and efficient separation technologies. The separation of organic acids, particularly tartaric acid, holds significant industrial importance in the food and pharmaceutical sectors. Purifying tartaric acid is crucial due to its roles as a chiral catalyst, antioxidant, and stabilizer, which are vital for ensuring product quality and efficiency. In this study, we synthesized heterogeneous anion exchange membranes by casting a solution of polyacrylonitrile (PAN) homogeneously dispersed with micronized anion exchange resin [polystyrene-divinylbenzene-trimethyl ammonium chloride (PS-DVB-TAC)]. These membranes were further coated with polyaniline (PANI) through in situ polymerization at different time intervals such as 2, 12, and 24 h. Cation exchange membranes were also prepared by solution casting of PAN dispersed with micronized cation exchange resin, sulfonated poly-styrene-co-divinylbenzene, and SPS-DVB. These synthesized anion exchange membranes with and without a PANI coating were examined for their separation performance of tartaric acid, along with the cation exchange membranes in a four-compartment electrodialyser at a constant voltage. The newly fabricated membranes were characterized by different techniques, including attenuated total reflectance-Fourier transform infrared spectroscopy for functional group analysis, scanning electron microscopy for their surface morphology, and the four-probe method for electrical conductivity. In addition, ion exchange capacity and water uptake have been measured. The electrodialysis experiments showed that 14.82 wt% of tartrate ions moved into the product compartment through the uncoated anion exchange membrane within 30 min at a voltage of 30 V. Under the same conditions, membranes coated with PANI at 2, 12, and 24 h raised the separation efficiency to 21.19%, 34.13%, and 37.21%, respectively. Findings indicate that membranes coated with PANI for extended periods demonstrate superior separation efficiency for tartaric acid. Consequently, this energy-efficient method shows significant potential for application in the food and pharmaceutical industries for separating tartaric acid and other organic and amino acids. This research can advance practical and sustainable separation technologies, addressing critical societal issues like resource efficiency and environmental sustainability.

Investigation of the properties of high-strength fibers by methods of physico-chemical analysis

The carbon fiber (CF) of UMT 49-12K-ER grade, manufactured by Alabuga-Volokno LLC (Umatex JSC), was the subject of an extensive study. This investigation encompassed an analysis of its physico-chemical properties. The interplanar dimensions and chemical composition of the CF were determined using X-ray diffraction and atomic emission spectroscopy. Surface properties of the CF, including specific surface area and pore size distribution, were investigated through nitrogen adsorption. The BET specific surface area was measured at 0.29 m2/g. The volume of mesopores and their size distribution were calculated using the Barrett, Joyner, and Halenda method. Additionally, an analysis of surface functional groups was conducted through a back titration method. It was observed that there was no presence of carboxyl, phenolic, or carbonyl groups. The diffraction patterns were processed with a two-component profile description model. The results of atomic emission spectral analysis revealed that silicon compounds were the dominant impurities in the chemical composition of the CF. Further investigations determined that, in an inert environment, the epoxy coupling agent used to enhance the performance properties of this CF undergoes thermal decomposition at temperatures of 300–400 °C. The CF itself does not experience weight loss when heated up to 950 °C. It was also discovered that this CF ignites in the presence of oxygen at temperatures exceeding 550 °C, surpassing the thresholds noted in previous publications for carbon fibers without such specialized additives. The results of this research have suggested new methodologies for studying carbon fibers.

Gas Chromatography-Mass Spectrometry and Functional Group Analysis of Methanol Extract of Bidara Leaves (Ziziphus mauritiana)

Bidara leaves are a plant that is quite abundant in Medan and has many benefits in the health sector. The aim of this research is to predict the content of secondary metabolite compounds in bidara leaf extract, through qualitative tests by screening using specific reagents, functional group analysis with FT-IR and mass analysis with GC-MS. The screening results showed that the methanol extract of bidara leaves contained alkaloids, flavonoids, tannins, saponins and phenols. Functional group analysis shows that the wavelength area is 3300 cm-1, namely OH absorption, 2700 - 2900 cm-1 shows C-H absorption, 1600 - 1700 cm-1 shows C=O absorption, 1400 - 1450 cm-1 shows C-H absorption, 1365 - 1385 cm-1 shows CH3 bent absorption, and 1000 – 1100 cm-1 shows C-O absorption. The results of mass analysis using GC-MS showed four dominant peaks from the compound, namely Z-5-Methyl-6-heneicosen-11-one, 17-Pentatriacontene, Ethyl iso-allocholate and Pentacosane.

Multi-Modal Structure and Distribution Analysis of Functional Groups on Carbon Supports for Polymer-Electrolyte Fuel Cells

Although structures of the functional groups formed on the surface of the carbon supports and their distribution on/inside supports have crucial impacts on determining performance of the catalyst electrodes, understanding of the relationship between them remains unclear, because of limitation of experimental methods for quantitative analysis of them with high spatial resolution. It is well-known that functional groups of the catalyst supports affect chemical properties of the supports, such as, redox- and acid-base properties, hydrophobicity, and electronic interaction. Thus, they should have a great influence on various aspects those related to the performance of polymer electrolyte fuel cell (PEFC), such as the activity, mass transportability, and durability of the catalysts and catalyst layers, and manufacturing process of catalysts and catalyst layer. 1,2). Furthermore, recently, in addition to various conventional high-surface area carbon supports, such as, Vulcan and Ketjen black, accessible carbon supports with mesopores which can host Pt particles protects them from direct ionomer adsorption and allow proton and O2 to have reasonable access to Pt particles, have been attracting great attention for improving catalyst utilization, activity, mass transportability, and suppression of Pt dissolution 3-5). The relationship between structure variation of functional groups on various supports and electrode performances should be of interest. The major difficulty for analyzing the functional groups on carbon supports come from the structure complexity of carbon surface (as well as inner part of the carbon particles), inhomogeneous distribution of various functional groups produced in various chemical processes, and multi-component structure of catalyst electrodes with catalysts and ionomers. Against such background, in this study, we have developed a new experimental approach utilizing multi-modal analysis method with x-ray photoelectron spectroscopy (XPS), x-ray absorption spectroscopy (XAS), temperature-programmed-desorption mass spectroscopy (TPD-MS), vibrational spectroscopy, electron tomography (3D-TEM), and cryo transmission electron microscopy (cryo-TEM). By combining suitable experimental probes for each structural feature and each component in multi-component structures, and by analyzing in integrated manner, we are able to understand the complex structure of functional groups on and inside carbon supports. Here, we demonstrate an example of the analysis for Vulcan (VULCAN® XC72, Cabot Corporation) and Pt-supported Vulcan (TEC10V30E, Tanaka Kikinnzoku Kogyo K. K. ). Vulcan is a solid carbon support used for polymer electrolyte fuel cell catalysts. The sample was reduced for about 30 minutes in a 100% hydrogen atmosphere at room temperature. Hard x-ray photoelectron spectroscopy (HAXPES) using synchrotron radiation x-rays with x-ray energy of 8 keV (BL46XU at SPring-8) . Also soft X-ray XAS were performed on BL1N2 at Aichi SR . Figure 1 shows the C1s HAXPES spectrum and the C K-edge XANES spectrum acquired by total electron yield (TEY) method. HAXPES was normalized by the signal intensity of the C-C substrate components (sp2, sp3) of the support at 284.5 eV 6), whereas the C K-edge XANES is normalized by the signal intensity of the 2pz (π*) orbital extending perpendicular to the carbon hexagonal network plane of the C–C substrate component of the support at 285.2 eV 7, 8). The functional groups are clearly observed in both spectra and the signal intensity of the functional group of the Pt catalyst increased with respect to the support alone, indicating that the amount of functional group on the support increased due to the Pt loading process. By combining other experimental results and theoretical simulations, the relationship between structure properties and electrode performance can be discussed. Acknowledgement This work was conducted in FC-Platform project supported by the New Energy and Industrial Technology Development Organization (NEDO). References :1) E. Antolini, Applied Catalysis B: Environmental 88, 1 (2009)2) Y.-J. Wang, N. Zhao, B. Fang, H. Li, X. T. Bi, and H. Wang, Chem Rev 115, 3433 (2015)3)V. Yarlagadda, M. K. Carpenter, T. E. Moylan, R. S. Kukreja, R. Koestner, W. Gu, L. Thompson, and A. Kongkanand, ACS Energy Letters 3, 618 (2018)4)S. Ott, A. Orfanidi, H. Schmies, B. Anke, H. N. Nong, J. Hübner, U. Gernert, M. Gliech, M. Lerch and P. Strasser , Nature Mater., 19, 77 (2020)5)A. Kobayash, T. Fujii, C. Harada, E. Yasumoto, K. Takeda, K. Kakinuma, and M. Uchida, Acs Appl. Energy Mater. 4 2307 (2021)6) S. Kundu, Y. Wang, W. Xia, and M. Muhler, J. Phys. Chem. C, 112, 16869 (2008)7) Y. Murakami, Y. Ota, and T. Okada, Anal. Sci., 39, 67 (2023)8) C. L. Guillou, S. Bernard. F. de la Pena, and Y. L. Brech, Anal. Chem., 90, 8379 (2018) Figure 1

Analysis of Protein Profile and Functional Groups in Biofilms in the Hypersaline Environment

Halophilic microorganisms include extremophiles that can live and develop in a hypersaline environment. Biofilm, as microecology, consists of a collection of microorganisms attached to a surface, forming an Extracellular Polymeric Substance (EPS) matrix. This study aims to analyze the protein profile and functional groups of biofilms that grow in hypersaline environments. The method used in this study is the SDS PAGE test to diagnose protein profiling and FTIR to analyze biofilm functional groups. The samples used to grow the biofilm came from salt ponds with different NaCl levels, namely 2%, 25%, and 40%. The results showed that each NaCl treatment had different functional groups in the biofilm samples. In the 2% NaCl treatment, there were peaks with solid intensity at the wavenumber 1100 cm-1, indicating the carboxylic acid functional group. In the 25% NaCl treatment, peaks with solid intensity at wavenumber 2250 cm-1 indicate the isocyanate functional group. In the 40% NaCl treatment, there were peaks with solid intensity at wavenumber 860 cm-1, indicating the alkene functional group. The protein analysis for each treatment shows the presence of pyruvate kinase protein in the biofilm with 2% NaCl. The 25% NaCl biofilm sample contained avidin protein, and the 40% NaCl biofilm sample contained tyrosine protein.

Nanocomposites of Ni-Co-Mn MOFs and PANI functionalized CNTs-GNPs with excellent electrochemical performance for energy storage applications

Supercapacitors, pivotal for eco-friendly energy solutions, demand efficient Ni-Co-Mn MOF-based electrodes. These electrodes, combining carbon nanotubes (CNTs), graphene nanoplatelets (GNPs), and polyaniline (PANI), were created through a facile ultrasonication-assisted solvothermal method, fostering their utility in energy storage systems. Scanning electron microscopy (SEM) reveals a distinctive flower-like morphology that facilitates faradic reactions. X-ray diffraction (XRD) and Fourier-transform infrared (FT-IR) spectroscopy confirm composition and functional group analysis. Comparative studies demonstrate the superiority of the Ni-Co-Mn/PCG (PANI-CNT-GNP) nanocomposite in charge storage over pristine Ni-Co-Mn MOF. Notably, the Ni-Co-Mn/PCG-40 nanocomposite, with 40 mg of PCGs, exhibited outstanding electrochemical performance, boasting the highest specific capacity (1238C/g @ 2 Ag), minimal internal reversibility, and excellent stability. This enhanced performance is attributed to efficient interconnected pathways and the uniform flower-like structure that aids in both electron and ion transportation. The asymmetric supercapacitor assembled from Ni-Co-Mn/PCG-40 showcased exceptional metrics: 380C/g @ 0.7 Ag specific capacity, a maximum energy density of 90 Wh/kg, a maximum power density of 17,000 W/kg, and 100 % stability over 5000 cycles. This research suggests a promising, cost-effective, and environmentally friendly supercapacitor solution for energy storage applications, addressing both pollution mitigation and energy crisis concerns.

Conventional properties, rheological characteristics, and thermal performance of waste polyurethane modified asphalt with butyl rubber

To enhance the low-temperature performance of waste polyurethane (WPU) modified asphalt, a composite modifier incorporating butyl rubber (BR) was investigated. In this study, recycled waste polyurethane for industrial filling is selected, which is belonging to the Polyether polyols. Various concentrations of BR were introduced to WPU modified binder, with and without stabilizer. The blends underwent conventional asphalt performance tests, dynamic shear rheometer (DSR), and bending beam rheometer (BBR) tests. Thermal performance and morphology were analyzed using differential scanning calorimeter (DSC) and fluorescence microscopy (FM). Fourier transform infrared spectroscopy (FTIR) experiments revealed the mechanism of WPU/BR modified asphalt. Results indicated that adding 3% BR to 15% WPU increased ductility at 5 ℃ by over 5 times, elevating the performance grade from PG-22 to PG-28. BR addition lowered the glass transition temperature, enhancing stability at higher temperatures. Besides improving low-temperature performance, BR also enhanced high-temperature performance and deformation resistance. Functional group analysis suggested a chemical modification process. Considering overall performance and modification effects, the optimal composite modifier was found to be 15% WPU and 3% BR.

Pembuatan Karbon Aktif Dari Limbah Pelepah Kelapa Sawit (Elaies Guineesis Jacq.) Sebagai Media Peyerapan Ion Logam Fe Air Sumur Menggunakan Aktivator Asam Fosfat (H3PO4)

Oil palm (elaies) is a tropical plant that is widely found in Indonesia. The increasing production of this plant has an impact on the increasing amount of oil palm frond waste every year. During this time, the community only utilizes the fruit for the manufacture of CPO while the fronds are discarded and become waste. Palm frond waste contains constituent components in the form of cellulose and lignin so that it has the potential to be utilized as an adsorbent. The manufacture of activated carbon is carried out with the stages of carbonization and activation using H3PO4. The finished activated carbon was then tested for moisture content, ash content, and iodine absorption according to SNI 06-3730-1995, functional group analysis testing with Fourier Transform Infra Red FTIR and Fe metal ion absorption test in well water using an AAS spectrophotometer. From these tests, 7% moisture content, 4% ash content and 909.45 mg/gr iodine absorption were obtained. FT-IR testing obtained 11 fungal groups and Fe metal absorption using an AAS spectrophotometer obtained 77%, so it can be concluded that the activated carbon made is in accordance with SNI 06-3730-1995 specifications

Effect of carboxymethyl cellulose addition on the characteristic of chitosan-based bioplastic

Bioplastic is an alternative solution in solving the problem of the plastic waste accumulation. Chitosan is a marine product waste from the crustacean group that can be used as a raw material for bioplastic because of its good film-forming ability. However, the bioplastic from chitosan has the property of being easily broken, so another material is added, namely carboxymethyl cellulose (CMC), that increase the bond’s compactness. This study aims to determine the effect of the addition of CMC on the characteristics of bioplastic made from 2% chitosan and 0.5% glycerol with a volume ratio of 10:1 chitosan:CMC. The experimental design used was a completely randomized design (CRD) with the addition of CMC (0%, 0.25%, 0.5%, 0.75% and 1%). The characteristics of the bioplastic tested in this study included film thickness, density, water content, solubility, tensile strength, elongation, antibacterial activity, and functional group analysis. The addition of 0.5% CMC resulted the bioplastic with a film thickness of 0.072 mm, the density of 0.836 g/cm3, the water content of 16.99%, the solubility of 40.5%, the tensile strength of 12.83 MPa, the elongation of 41.76%, inhibition zone of the antibacterial activity of 2.83 mm and a new group is formed in film that was made.

Quantitative Analysis of Functional Groups in Different Metamorphic Grade Indian Coals using FTIR technique

To enhance the clean and economical feasible utilization of coal and reduce the coal or rock dynamic disaster, one should have an in-depth knowledge of coal macromolecular structures. In view of this, the chemical and physical structural properties of low to high-rank six Indian coals using Fourier transform infrared spectroscopy (FTIR) are presented. Four absorbance bands were identified in the subtracted spectrum for the functional group’s semiquantitative analysis in coal: hydroxyl, aliphatic, oxygen-containing, and aromatic structures associated with absorbance band at 3000–3600 cm-1, 2800–3000 cm-1, 1000–1800 cm-1, and 700–900 cm-1 respectively. Spectrum deconvolution technique was used to determine the FTIR structural parameters of coal samples. To investigate the structural transformation during coal metamorphism, correlations with Vitrinite reflectance (Ro) were formed. The present study will help to predict the conversion of organic groups to valuable liquids and gases from those samples. The macromolecular structure of coal could be useful to design the synthesis methods for carbon-based materials.

Reinforced water hyacinth based biodegradable cutlery: Green alternative to single-use plastics

Water hyacinth (WH) is an invading water plant that severely threatens biodiversity. The aim of this study was to utilize fibres from this underutilized plant to develop binderless biodegradable plates, in combination with different proportions (10%, 20% and 30%) of waste paper (WP), sugarcane leaf (SC), and banana stem fibre (BF), added as reinforcing agents. The properties of these products are compared with WH plates with starch as a binder (ST). The use of an epoxidized castor oil-based coating to enhance hydrophobicity was also studied. Analytical tests including functional group analysis, mechanical property, wettability, surface morphology, thermal stability and biodegradability studies were performed. It was observed that BF samples had the best mechanical properties, followed by SC, WP and ST, with BF-20 showing the maximum tensile strength (6.23 MPa) and elongation (10.09%). The thermogravimetric analysis showed the reinforced samples to be suitable for high-temperature applications, with SC-30 having a T5 value of 269.75 °C. The contact angles indicated that WH could be considered a suitable raw material for manufacturing biodegradable products with low wettability, and the addition of cellulose-rich reinforcing agents can further enhance its water resistance. SC-30 showed the highest hydrophobicity with a contact angle of 124.3°. Coating using an epoxidized castor oil-based solution can reduce the wettability of even super hydrophilic surfaces. All the samples showed good biodegradability, with most samples degrading completely within 20 days. Hence, water hyacinth reinforced with cellulose-rich reinforcing agents can be regarded as a superior raw material for manufacturing biodegradable cutlery.

Fabrication of LD-slag derived zeolite Y coated polysulfone (PSf) membrane for decontamination of groundwater

Faujesite type zeolite Y was prepared via ultrasonic energy facilitated hydrothermal technique using Linz-Donawitz (LD) process slag as a precursor material. The surface modification of the polysulfone membrane was conducted with the as-synthesized zeolite powder in the presence of N-methyl pyrrolidone (NMP) solvent. The synthetic zeolite nanoparticles (ZNPs) were sonicated by mixing them in NMP solvent before spreading over the membrane surface. The ZNPs layered flat sheet membrane was fabricated via dry-cast technique followed by phase inversion. The optimization of drying temperature and time was studied along with the variation of ZNPs wt.% to obtain defect-free membranes. The developed ZNPs layered membranes were characterized for membrane morphology, surface roughness, mechanical strength, thermal stability, functional group analysis, and surface hydrophilicity. The chemical characterization of all fabricated membranes was examined by X-ray photoelectron spectroscopy (XPS). An increased water flux of 28.83 L/m2h was obtained whereas the fluoride concentration was reduced to 1.47 mg/L (∼50.33 % reduction) for the optimized PSf/Zeolite-1 wt% membrane. Moreover, other contaminants namely chromium (Cr6+) and manganese (Mn2+) were removed very significantly by utilizing the modified PSf/Zeolite-1 wt% membrane. The regeneration experiment was conducted utilizing an HCl solution through dead-end filtration. The flux recovery of membrane PSf/Zeolite-1 wt% was found to be 85.43 % with an antifouling improvement of 42.70 %.

The removal of Rhodamine B from aqueous solution using manganese oxide modified vermiculite

In this study, we prepared and used manganese oxide-modified vermiculite (Mn–MV) as an adsorbent to sequester Rhodamine B (RhB) dye from aqueous solution. Mn–MV was characterized using a Fourier transform infrared (FT-IR) spectrometer, XRF spectrometry and scanning electron microscope (SEM) to identify the functional groups, components and morphology of the sorbent. Analysis of the adsorbent's functional groups revealed the presence of O–H, C–H, C=C, C–O, and C–O–H groups. The experiments were conducted using a batch adsorption procedure. The optimal removal of Rhodamine B (RhB) was achieved with a dosage of 1.75 g of Mn–MV, a pH of 10, and a duration of 45 min. The study on the effect of temperature demonstrated that an increase in temperature favoured the removal of RhB using Mn–MV. The data from the kinetic and isotherm models were best described by the pseudo-second-order and Langmuir models. The thermodynamic parameters, ∆H = 6.32 kJ/mol and ∆S = 82.12 J/mol/K, indicate that the adsorption process is endothermic and spontaneous. These results indicate that vermiculite clay has the potential to be a cost-effective adsorbent for the removal of RhB dye.

Compositional heterogeneity of insoluble organic matter extracted from asteroid Ryugu samples

AbstractWe report a Fourier transform infrared analysis of functional groups in insoluble organic matter (IOM) extracted from a series of 100–500 μm Ryugu grains collected during the two touchdowns of February 22 and July 11, 2019. IOM extracted from most of the samples is very similar to IOM in primitive CI, CM, and CR chondrites, and shows that the extent of thermal metamorphism in Ryugu regolith was, at best, very limited. One sample displays chemical signatures consistent with a very mild heating, likely due to asteroidal collision impacts. We also report a lower carbonyl abundance in Ryugu IOM samples compared to primitive chondrites, which could reflect the accretion of a less oxygenated precursor by Ryugu. The possible effects of hydrothermal alteration and terrestrial weathering are also discussed. Last, no firm conclusions could be drawn on the origin of the soluble outlier phases, observed along with IOM in this study and in the preliminary analysis of Ryugu samples. However, it is clear that the HF/HCl residues presented in this publication are a mix between IOM and the nitrogen‐rich outlier phase.