FTIR Analysis Research Articles

Application of a Green Deep Eutectic Solvent for Preconcentration and Determination of Copper and Cadmium in Food, Cosmetic, and Water Samples

Background:: Determination of environmental pollutants is important due to their harmful effects on the health of living organisms. However, direct measurement of many of these pollutants is not possible due to their low concentrations, which necessitates the need for sample preparation methods. One of the rapid and simple sample preparation methods is the Air-Agitated Liquid-Liquid Microextraction (AALLME) method, which requires toxic organic solvents that can lead to environmental pollution. Therefore, finding green solvents like Deep Eutectic Solvents (DESs) to replace them can be investigated. Methods:: A novel Deep Eutectic Solvent (DES) was synthesized from a combination of choline chloride and 2-phenylethanol with a molar ratio of 1:4, and it was examined using FT-IR analysis. This solvent was used in an AALLME method for measuring copper and cadmium heavy metal ions in complex real samples with Flame Atomic Absorption Spectroscopy (FAAS). Results:: The influential parameters of this method, such as solution pH (5.4), extraction cycles (12), and extraction solvent volume (440 μL), were optimized utilizing central composite design (CCD). Underneath the optimized circumstances, the detection limits for Cu2+ and Cd2+ were 0.14 and 0.09 ng mL-1, and the linear dynamic range was 0.47-50.0 and 0.32-22.5 ng mL-1, respectively. The preconcentration factors for these cations were 139.7 and 133.4, respectively. Conclusion:: Combining this novel green solvent and rapid sample preparation method for the preconcentration and determination of the studied heavy metal ions has shown promising results in terms of enrichment factors and detection limit values.

Retentive bio-based chemical gel for removing glues from water-sensitive wooden artworks

Aged animal glues degrade and weaken over time, resulting in flakes and cracks on the material employed by wooden manufacturers and luthiers. Because of this deterioration, conservators and restorers remove aged water-soluble glues with a water swab, smoothing enough to clean them mechanically and putting on new reversible glues. However, it raises the question of whether a water swab can control moisture delivery while removing glue from wood, a hygroscopic and water-sensitive material.This study formulated a chemically crosslinked film-forming hydrogel based on sodium alginate (SA) with (3-Glycidoxypropyl)trimethoxysilane (GPTMS) and calcium chloride, named as CA-GPTMS to construct a retentive gel. Synthesized gel materials were characterized using several methods: liquid state NMR, FTIR-ATR, and SEM-EDS analyses were involved in examining the cross-linking process, while moisture and mechanical properties were examined to understand its suitability for the cleaning application process. The strategies for applying the CA-GPTMS gel on wood surface were to selectively soften the glue and to remove it as well as leave no residues on the wood surface. The cleaning process was investigated by using different techniques, i.e., stereomicroscopy, reflection-FTIR, and SEM-EDS. Compared to traditional rigid Agar gel, the CA-GPTMS gel appeared successfully resistant to destruction and was suitable for application on highly water-sensitive surfaces.

Isotactic-polypropylene (iPP) wettability modified by surface DBD plasma

In this paper, atmospheric pressure plasma of ambient air was generated by a surface dielectric barrier discharge (SDBD) device for the purpose of modifying the surface of isotactic-polypropylene (iPP). The effect of SDBD treatment time on the chemical and physical properties of iPP was studied using various analytical techniques including, water contact angle (WCA), attenuated total reflection (ATR), Raman spectroscopy, x-ray diffraction (XRD), and atomic force microscopy (AFM). The results indicate that the hydrophilicity and the C=O bonds of the treated iPP were improved as observed, respectively, through WCA and ATR analysis. The crystal structure was evaluated by Raman spectroscopy and XRD. It was found that the iPP chain was under microscopic stress, which affected its crystallinity degree depending on the duration of the treatment. Furthermore, the AFM analysis revealed that the surface roughness was substantially modified.

Influence of the Extraction Process on the Mechanical and Morphological Properties of Technical Fibers from Typha domingensis

ABSTRACT Typha is a fast-growing and invasive plant that spreads in the humid areas. Its proliferation has a negative impact on the local ecosystems. This study aims at the valorization of the by-products of this plant as biocomposites’ reinforcements. A mechanical extraction technique and retting in distilled water and sea water processes were developed to extract fibers from the leaves and stems of the Typha plants. SEM, FTIR analyses and monotonic tensile tests have been carried out to assess fibers’ properties. Morphological observations revealed that fibers extracted from the leaves were on average 48% finer than those from the stems. This fineness was more significant for the fibers retted in distilled water, that presented a smoother surface. The leaf fibers tensile properties (502, 247 and 372 MPa for the strength, 20.5, 14.2 and 12.8 GPa for the Young’s modulus and 2.47, 1.68 and 2.73% for maximum strain, respectively for the mechanical, distilled water and sea water retting processes) were on average 50% higher than for stem fibers, regardless of the extraction method. The results showed that the fibers elaborated had promising properties for biocomposite reinforcement. The extraction methods developed are low cost and without the use and generation of polluting chemicals

Accelerating healing of infected wounds with G. glabra extract and curcumin Co-loaded electrospun nanofibrous dressing.

This study aimed to construct a nanofibrous wound dressing composed of polyvinyl alcohol (PVA) and chitosan (CS) containing curcumin and Glycyrrhiza glabra root extract to inhibit infection and accelerate wound healing. Loading 10wt% of G. glabra extract-curcumin (50:50) by electrospinng technique resulted in the formation of nanofibers (NFs) with diameter distribution 303 ± 38 and had a uniform and defect-free morphology. FTIR analysis confirmed the loading of the components without adverse interactions. Also, the results showed extremely high porosity, extraordinary liquid absorption capacity, and complete wettability. In addition, G. glabra extract-curcumin showed significant antioxidant activity and their release profile from NFs was continuous and sustained. Also, the prepared NF could inhibit the growth of both Gram-positive Saureus and Gram-negative E. coli strains. Wound healing evaluation in the infected animal model showed that the NFs caused full wound closure and accelerated skin regeneration. The studies on inhibiting the bacteria growth at the wound site also revealed complete inhibitory effects. Moreover, histopathology studies confirmed the complete regeneration of skin layers, formation of collagen fibers, and angiogenesis. Finally, PVA/CS NFs containing G. glabra extract-curcumin as a multifunctional bioactive wound dressing presented a promising approach for promoting the healing of infected wounds.

6-Benzylaminopurine mediated augmentation of cadmium phytostabilization potential in Strobilanthes alternata

This study unveiled the cadmium phytoremediation potential and its augmentation using 6-Benzylaminopurine in Strobilanthes alternata. Cadmium stress was provided by applying 250 mg/kg cadmium chloride in soil and 25 ppm of 6-BAP (25 ml) was administered to the plants as foliar spray. The results revealed high bioconcentration factor (BCF) (18.82 ± 0.54) and low translocation factor (TF) values (0.055 ± 0.002) for the plant based on which we strongly recommend S. alternata as a promising candidate for Cd phytoremediation. The phytostabilization potential of the plant was further enhanced by applying 6-BAP, which augmented its BCF to 22.09 ± 0.64 and reduced the TF to 0.038 ± 0.001. Cd toxicity caused a reduction of plant growth parameters, root volume, adaxial-abaxial stomatal indices, relative water content, tolerance index, moisture content, membrane stability index, and xylem vessel diameter in S. alternata. However, Cd + 6-BAP treated plants exhibited an increase of the same compared to Cd-treated plants. FTIR analysis of Cd + 6-BAP treated plants revealed increased deposition of hemicellulose, causing enhanced retention of Cd in the root xylem walls, which is largely responsible for increased phytostabilization of Cd. Therefore, 6-BAP application in S. alternata can be exploited to restore Cd-contaminated areas effectively.

The effect of mixing sequence on synthesis of PP-g-GMA compatibilizer for multilayer packaging (MLP) compounding

Melt recycling Multilayer Packaging (MLP) waste is difficult due to challenging separation procedures. However, blending techniques with compatibilizers can simplify MLP waste melt recycling. PP-g-GMA is a common compatibilizer in polyolefin and PET blends. PP-g-GMA compatibilizer was synthesized by utilizing an internal mixer at 175℃, 50 rpm, and 10 min using styrene as a comonomer. Titration was a method to examine effect of three different sequences of adding the BPO initiator on GMA grafting. Each sequence's PP-g-GMA samples were compounded with MLP waste using a twin-screw extruder and injection molded to make tensile test specimens. FTIR analysis shows that the GMA and Styrene monomers had grafted onto the PP polymer backbone, with the GMA grafting degree by varying mixing sequence. Sequence 3, which introduced initiator, GMA, and styrene simultaneously to PP melt, yielded PP-g-GMA with the most significant GMA grafting degree of 5.11%. Adding PP-g-GMA produced from sequence 3 into the MLP melt enhanced the highest increase in tensile strength and elongation at break of the MLP/PP-g-GMA compound.

Development of antioxidant film based on gelatin and carboxymethylcellulose incorporated with Tecoma stans (L.) Juss. ex Kunth Petals extract for biodegradable food packaging

The aim of this research was to develop a novel combination of antioxidant blended film for use as biodegradable packaging in the food industry. The antioxidant film was prepared based on gelatin (G) and carboxymethyl cellulose (CMC) incorporated with Tecoma stans (L.) Juss. ex Kunth petals extract (TKE) at various concentrations (0.5, 1.0, and 2.0 mg∙L‒1) via solution casting method. The structural and surface morphology of G/CMC-TKE film were characterized using FTIR spectrometry technique and scanning electron microscopy (SEM), including determining antioxidant activity, water solubility, water vapor permeability, and biodegradability. According to FTIR analysis, the significant interaction between the gelatin and CMC chain is associated with hydrogen bonding. Adding TKE into the blended films significantly increased their roughness, thickness and antioxidant activity while decreasing their water solubility and water vapor transmission. Likewise, the biodegradability of the films containing antioxidants exhibited greater degradation values than the pure G/CMC film, and all of the biofilms was entirely degraded (>80%) in 14 days. The G/CMC-TKE 2.0 demonstrated the best antioxidant (74.47%), biodegradable activity (95.85% in 14 days), and the lowest water solubility (61.80%) and water vapor transmission rate (3.2483 g∙m‒2∙day‒1), which could be a feasible candidate for the food active packaging.

Innovative Approaches for Manufacturing Epoxy-Modified Wood and Cellulose Fiber Composites: A Comparison between Injection Molding and 3D Printing.

The current study focused on improving the properties of polylactic acid (PLA) for wider application in load-bearing scenarios. Various methods were explored to optimize the interaction between PLA and natural fibers, particularly wood fibers (WFs). Alkalized and epoxy-impregnated WFs were evaluated against untreated WFs and cellulose fibers in both injection molding (IM) and fused deposition modeling (FDM). FTIR analysis revealed the removal of hemicellulose and lignin in alkalized WFs and uniform epoxy curing. Addition of fibers reduced PLA's thermal stability while acting as nucleating agents. Additionally, fibers augmented the storage modulus of biocomposites, with alkalized fibers exhibiting the highest tensile modulus in IM. FDM samples with a 0° raster angle showed superior impact resistance compared to IM counterparts. Moreover, raster angle significantly influenced FDM biocomposite properties, enhancing the tensile strength and modulus of untreated WF and cellulose fibers at 0°. Although FDM did not produce alkalized WF samples, epoxy impregnation emerged as a promising method for enhancing PLA/WF composite mechanical properties in the IM process, offering valuable insights for composite material development.

Structural, Mechanical and Tribological Properties of Hydroxiapatite Reinforced Ti13Nb13Zr/HA Composite Produced by Friction Stir Process (FSP)

AbstractMany modification methods are applied to produce Ti-based biomedical materials. In this study, the structural, mechanical and tribological properties of unreinforced Ti13Nb13Zr alloy and Ti13Nb13Zr/HA composites with different contents of hydroxyapatite (HA) reinforcement were investigated by friction stir processing (FSP) to Ti13Nb13Zr alloy. SEM, FTIR and EDS analyzes were performed to determine the structural properties. Surface roughness values were determined using a 3D optical microscope. Surface wettability properties were investigated with a contact angle. Microhardness and wear test devices were used to determine the mechanical and tribological properties, respectively. Wear tests were carried out in a dry environment and phosphate buffered saline solution (PBS). The wear tracks were analyzed by SEM and 3D optical microscope. As a result of FTIR analysis, HA has PO43−, HPO42−, CO32− and OH− bonds. All samples exhibited hydrophilic surfaces suitable for cell adhesion. The FSP process increased the hardness and wear resistance of the Ti13Nb13Zr alloy in both atmospheres. In addition, Ti13Nb13Zr/HA composites significantly increased the hardness and wear resistance of Ti13Nb13Zr alloy and Ti13Nb13Zr alloy modified by FSP.

Controlled porosity intelligent aerogel based on chitosan nanofiber, anthocyanins and starch nanoparticles: Preparation, characterization and application in monitoring food spoilage

The aim of this study was to design a food freshness colorimetric aerogel with controlled porosity based on chitosan nanofibers (CHNF), Ixiolirion tataricum anthocyanins (ITA), and starch nanoparticles (SNPs). Two size-controlled SNPs were produced via nanoprecipitation (133.3 nm; SNP-A) and H2SO4 hydrolysis methods (86.2 nm; SNP-B) and were used for controlling the porosity and morphological characteristics of aerogel solid support. According to FE-SEM images, the porosity of smart aerogels improved after SNPs incorporation, and SNP-B was able to decrease the disrupting effect of ITA on 3D porous network of aerogels. The formation of hydrogen bonds between the CHNF and ITA molecules was confirmed by FT-IR analysis and the absence of obvious change in the FT-IR spectra approved the physical entrapment of SNPs. The improvement in the crystallinity and thermal stability of the aerogels after SNPs loading was confirmed by the XRD and TGA tests, respectively. The SNPs loaded aerogels showed color variation from red to green over the pH range of 2–12. In addition, the SNP-B-incorporated aerogel exhibited high sensitivity to ammonia vapor and good color response reversibility. The CHNF/SNP-B/ITA aerogel with the best porosity and sensitivity was used for monitoring food spoilage and could differentiate minced beef into three stages: fresh, medium fresh, and spoiled, facilitating simple observation of freshness-spoilage progression. This research opens a new insight to develop advanced and highly sensitive indicators capable of monitoring freshness/spoilage in protein-based food products.

Synthesis and characterization of composite membranes based on bacterial cellulose and coral powder

Preparation of bacterial cellulose and coral powder composite membranes has been carried out. Composite membranes were made by mixing bacterial cellulose with coral powder at different mass ratios at temperatures of 25 ºC, 40 ºC, 60 ºC and At 80 ºC, the composite membrane was evaluated for Fourier Transformation of Infrared, X-Ray Diffraction, degree of swelling, proton conductivity and methanol permeability. From the FT-IR analysis it was found that in the absorption area around 1461.385 – 911cm-1 showing the Si-O-Si stretching functional group, and in the absorption area around 3000 - 3500 cm-1 showing the (O-H) group which shows the semicrystalline composite membrane for each mass variation, according to the results of X-Ray Diffraction. The maximum proton conductivity has been measured as 3.32 x 10-3 S.cm-1 at 60°C, produces a degree of swelling of 31.14% and methanol permeability of 3.72 × 10-9 mol/cm.s for a mass ratio of bacterial cellulose:coral powder composite membrane 4:1.

Aloe-inspired eco-friendly synthesis of Ag/ZnO heterostructures: boosting photocatalytic potential

The current research focuses on the development of Ag–ZnO heterostructures through a “bottom-up” approach involving the assembly and extraction of Aloe barbadensis Miller gel. These heterostructures composed of metals/semiconductor oxide display distinct and notable optical, electrical, magnetic, and chemical properties that are not found in single constituents and also exhibit photocatalytic applications. These synthesized heterostructures were characterized by XRD, FTIR, SEM, and UV–visible spectroscopy. The high peak intensity of the Ag/ZnO composite shows the high crystallinity. The presence of Ag–O, Zn–O, and O–H bonding is verified using FTIR analysis. SEM analysis indicated the formation of spherical shapes of Ag/ZnO heterostructures. The Zn, O, and Ag elements are further confirmed by EDX analysis. Ag–ZnO heterostructures exhibited excellent photocatalytic activity and stability against the degradation of tubantin red 8BL dye under visible light irradiation.

Microplastics in multi-environmental compartments: Research advances, media, and global management scenarios

During the past decades, microplastics (MPs) have become an emerging concern due to their persistence and potential environmental threat. MP pollution has become so drastic that it has been found in the human food chain, breast milk, polar regions, and even the Himalayan basin, lake, etc. Inflammation, pulmonary hypertension, vascular occlusions, increased coagulability and blood cell cytotoxicity, disruption of immune function, neurotoxicity, and neurodegenerative diseases can all be brought on by severe microplastic exposure. Although many MPs studies have been performed on single environmental compartments, MPs in multi-environmental compartments have yet to be explored fully. This review aims to summarize the muti-environmental media, detection tools, and global management scenarios of MPs. The study revealed that MPs could significantly alter C flow through the soil-plant system, the structure and metabolic status of the microbial community, soil pH value, biomass of plant shoots and roots, chlorophyll, leaf C and N contents, and root N contents. This review reveals that MPs may negatively affect many C-dependent soil functions. Different methods have been developed to detect the MPs from these various environmental sources, including microscopic observation, density separation, Raman, and FT-IR analysis. Several articles have focused on MPs in individual environmental sources with a developed evaluation technique. This review revealed the extensive impacts of MPs on soil-plant systems, microbial communities, and soil functions, especially on water, suggesting possible disturbances to vital ecological processes. Furthermore, the broad range of detection methods explored emphasizes the significance of reliable analytical techniques in precisely evaluating levels of MP contamination in various environmental media. This paper critically discusses MPs' sources, occurrences, and global management scenarios in all possible environmental media and ecological health impacts. Future research opportunities and required sustainable strategies have also been suggested from Bangladesh and international perspectives based on challenges faced due to MP's pollution.

The Impact of Different Catalysts on Heterogeneous Hydrogenation of Hydroxyl‐Terminated Polybutadiene

AbstractHydroxyl‐terminated polybutadiene (HTPB) is hydrogenated using catalytic hydrogenation with HTPB as a precursor using various catalysts. The hydrogenation is carried out using iso‐propyl alcohol (IPA) and toluene as an active solvent media. The present paper used (a) charcoal, (b) palladium supported by charcoal (Pd−C), (c) palladium supported by zirconium oxide (Pd‐ZrO2), and (d) copper chromite (CC) as catalysts for hydrogenation of HTPB to study the influence on the degree of hydrogenation with respect to each catalyst. The experimental data shows that hydrogenated HTPB (HHTPB) formation is predominantly controlled by physisorption and chemical reaction with a catalyst. Various techniques like NMR, FTIR and chemical analysis are used to characterize HTPB and HHTPB. Degree of hydrogenation of HTPB is found to be higher with copper chromite when compared to other catalysts in this work. Post‐hydrogenation, no significant change in hydroxyl value and a marginal increase in molecular weight is noticed with all catalysts. HTPB and HHTPB samples are analyzed using FTIR, 1H‐NMR, and 13C‐NMR and TG‐DSC studies, and inferences are derived with respect to the change in the olefinic region, microstructural changes, molecular weight, and thermal decomposition characteristics.

The valorization of Prunus mahaleb shell through acid modification for the sorption of Pb2+ removal from aqueous solution

AbstractThis study aimed to investigate the biosorption performance of acid-modified waste Prunus mahaleb (PMA) shells in the removal of Pb2+ ions from aqueous solutions. Changes in the morphological properties and functional components of PMA biosorbent were characterized using SEM–EDX, FT-IR, BET, and PZC analyses. The effect of various parameters such as initial Pb2+ concentration, pH, PMA dosage, contact time, and temperature on biosorption was investigated using a batch biosorption procedure. The maximum biosorption capacity, determined using the Langmuir isotherm, was calculated to be 119 mg g−1. It was found that the biosorption kinetic mechanism followed pseudo-second-order kinetics and intraparticle diffusion model. According to the determined thermodynamic parameters, the biosorption mechanism was found to be endothermic (ΔH° > 0), spontaneous (ΔS° > 0), and entropy-increasing (ΔG° < 0). The outcomes of the experiment were evaluated in comparison to other sorbents that have been previously commonly used in the literature. It was demonstrated that PMA could be a promising, environmentally friendly, cost-effective, and sustainable potential biosorbent for the removal of Pb2+ ions.

Heterogeneous electro-Fenton removal of polyacrylamide in aqueous solution over CoFe2O4 catalyst

ABSTRACT Polyacrylamide (PAM) in environmental water has become a major problem in water pollution management due to its high molecular mass, high viscosity and non-absorption by soil. CoFe2O4 with strong magnetic properties was prepared by solvent-thermal synthesis method and used as the catalyst for the removal on PAM in heterogeneous Electro-Fenton (EF) system. It showed that the removal efficiency of PAM by the heterogeneous EF system using CoFe2O4 catalyst was 92.01% at pH 3 after 120 min. Further studies indicated that ·OH was the most significant active species for the removal of PAM, and the contribution of ·O2− and SO4·− for the removal of PAM was less than 15%. The reusability test and XRD, XPS, FTIR analyses proved that the catalyst had good stability. After a repeated use for five times, the catalyst still had a high PAM removal rate and stable structure. The valence distribution and functional groups of the phase components of the catalyst did not change significantly before and after the reaction. The possible mechanism of catalyst activation of H2O2 was deduced by mechanism investigation. The CoFe2O4 is an efficient and promising catalyst for the removal of PAM wastewater.

Creating and evaluating a novel small diameter PCL/PU vascular graft for finger reconstruction: A comprehensive analysis of structural, mechanical, in vitro, and in vivo assessments

This study addresses vascular repair challenges during digital replantation by developing an electrospun nanofibrous scaffold using PCL and PU for small-diameter vascular grafts (<2 mm). Structural validation employed diverse techniques such as FE-SEM, DSC, and FTIR analysis, while mechanical properties like stress and strain were rigorously evaluated. Functionality was assessed through in vitro assays and in vivo experiments, including subcutaneous implantation in rats and femoral artery insertion in rabbits. The scaffold demonstrated favorable mechanical properties and enhanced cell attachment, with minimal lumen fibrosis and good blood compatibility observed. Post-implantation in rabbits showed well-established blood flow and signs of tissue formation, suggesting potential for regenerative medicine. In conclusion, the PU85/PCL15 scaffold exhibited promising outcomes, highlighting its potential in microvascular tissue engineering Level of evidenceLevel V

Synthesis of Polysubstituted Pyridines via Nitrogen-doped Graphene Catalyzed One-Pot Multicomponent Reaction under Solvent-Free Conditions

Abstract: Polysubstituted pyridine derivatives were produced with high to excellent yields in the presence of nitrogen-doped graphene (NDG) as a dual acid-based catalyst. NDG efficiently catalyzes the multicomponent reaction between arylaldehydes, diethyl-acetylene dicarboxylates, malononitrile, and ammonium acetate under solvent-free conditions at 80°C to afford the polysubstituted pyridines in short reaction times. The structures of the synthesized pyridines were established by Ft-IR, 1H, and 13C NMR spectroscopic analysis. The advantages of this method include the in-situ oxidation of prepared 1,4-dihydropyridines, one-pot procedure, solventless system, operational simplicity, and no column chromatography. Additionally, neither toxic solvents nor catalysts are needed, and the procedure can be very reliable among the reported methodologies. The yields and reaction times in the presence of four times recycled catalyst are in comparable to the fresh catalyst.

Characterization, antioxidant and α-amylase inhibition of polysaccharides and phosphorylated derivatives from finger citron (Citrus medica L. var. sarcodactylis Swingle)

In this study, the structure-activity relationship of finger citron polysaccharides (FCPs) and their phosphorylated derivatives (P-FCPs) was investigated. Three FCPs (FCP20, FCP40 and FCP60) were successively fractionated by ethanol, and were phosphorylated modification to obtain P-FCPs (P-FCP20, P-FCP40 and P-FCP60). FCPs and P-FCPs are acidic heteropolysaccharides composed of mannose, rhamnose, glucose, galactose, arabinose and galacturonic acid, and exhibited different content of neutral sugar, uronic acid, proteins, polyphenols and sulfates. FTIR and NMR analyses determined the structures of FCPs and P-FCPs, indicating that the phosphorylation modification was successful. P-FCPs possessed the smaller molecular weight distribution and particle size, with significant changes in microstructure than FCPs. Additionally, P-FCPs showed significantly increased antioxidant and α-amylase inhibitory activities compared to FCPs. The inhibitory mechanisms of FCP40 and P-FCP40 on α-amylase was a mixed-type manner and dynamic fluorescence quenching. The results demonstrate that phosphorylation modification can alter the structural features and bioactivities of FCPs, providing an approach for the further development of finger citron in the field of medicinal and functional foods.