FTIR Measurements Research Articles

Polysaccharide-potato protein coacervates for enhanced anthocyanin bioavailability and stability

Anthocyanins (ACNs) possess strong antioxidants, anti-cancer, anti-obesity, anti-diabetic, and anti-inflammatory properties but are limited use by their susceptibility to environmental factors. This study aims to overcome these limitations by developing and assessing a novel coacervate system, consisting of potato protein isolate (PPI) combined with various polysaccharides, to stabilize and encapsulate anthocyanins from black carrot concentrate The polysaccharides included in this system include inulin, gum Arabic, guar gum, pectin, and soluble fiber. The coacervate system's effectiveness in maintaining stability and increasing the bioavailability of anthocyanins was evaluated compared to conventional soybean protein-based systems. The results show that pH considerably influences potato protein solubility, with maximum solubility at strongly acidic (pH 2) conditions. Hygroscopicity and moisture content analysis of the coacervates showed significant variations, with potato protein-guar gum (PPIGG) microcapsules having the lowest moisture content and potato protein gum Arabic (PPIGA) microcapsules having the highest moisture content. SEM imaging illustrated distinct microcapsule morphologies, while FT-IR measurement verified the successful integration of proteins and polysaccharides. The significance of the research reflects its proof that potato protein isolate (PPI) based coacervate systems consists of potato protein with polysaccharides, particularly those containing gum Arabic and pectin, have significant potential for improving anthocyanin stability and bioavailability. These findings guide future studies to investigate other polysaccharides, improve coacervation processes, and explore applications in the food and nutraceutical sectors. It also offers valuable insights for creating efficient encapsulation techniques for bioactive substances.

Elaboration of a new 4-(4-nitrophenyl)piperazin-1-ium tetrakis(thiocyanato)-cobalt hydrate: Crystal structure, optical properties, quantum computational investigation, electrical and biological study

The preparation, spectroscopic, biological, and electrical characterization, in addition to the X-ray crystal structure investigation of a novel three-dimensional compound (C10H14N3O2)2 [Co(NCS)4].H2O ((NPP)2[Co(NCS)4].H2O) is reported. The synthesized compound crystallizes in the Pna21 space group. The structure comprises layers of cobalt (II) bridged by terminally bound thiocyanate-N ligand achieving distorted MN4 tetrahedron surroundings around the metal center. The vibrational modes of the functional groups were investigated using FT-IR measurements. Hirshfeld surface (HS) analysis and electronic structures calculations reveal the excellent reactivity and intermolecular interactions in stabilizing complex. The change transfer and NLO parameters were also computed using the DFT method. The study of the optical behavior reveals a high optical property. Explorations of impedance spectroscopy on (NPP)2[Co(NCS)4].H2O reveals fascinating electrical behavior which reveals that the Co complex component can be used as an electronic chip under certain conditions. The thermal analysis was used to confirm the crystal’s thermal stability. The compound’s antimicrobial activity suggested that the Cobalt complex acts as an inhibitor Agent against different types of bacteria.

Innovative discovery on the impact of hydration on the alternative flotation of smithsonite and calcite under benzohydroxamic acid system

Currently, it is still lacking of deep understanding of the alternative of benzohydroxamic acid (BHA) on smithsonite and calcite flotation. We hypothesize that the presence of hydration films plays a significant role. Therefore, this paper aims to uncover the impact of hydration on the alternative flotation of smithsonite and calcite with BHA, utilizing flotation experiments, DFT calculations, Zeta potential tests, FTIR measurements, and XPS analyses. The results of the flotation experiments confirmed the effective separation of smithsonite from calcite with BHA. DFT calculations innovatively discovered that Zn on the surface of smithsonite can interact with BHA− but the Ca on the surface of calcite was easier to interact with the H2O instead of BHA−, thus BHA was incapable of repelling the hydrated layer from the surface of calcite to interact with the calcium ions. Zeta potential tests, FTIR measurements, and XPS analyses further provided experimental support that BHA was selectively chemically adsorbed onto the surface of smithsonite via forming Zn-BHA complex, whereas no such interaction occurred with the surface of calcite by generating Ca-BHA complex, which validated the DFT calculation results. This study provides valuable insights into the role of hydration in the beneficiation of smithsonite and calcite.

Jade powder/PLGA composite microspheres for improved performance as potential bone repair drug carrier

Poly (lactic-co-glycolic acid) (PLGA) has been widely used as drug delivery carrier or scaffold for bone repair due to its good biocompatibility, biodegradability, and degradation rate controllability. However, defects, like acidic degradation by-products, are associated with PLGA and restrict its practical applications. Jade powder, leftover from jade polishing process, is a natural material rich in elements of Ca, Si, and Mg while biocompatible and antibacterial. Herein, jade powder/PLGA composite microspheres with different mass ratios were prepared by emulsion solvent evaporation method under the optimized conditions. Characterization from SEM, EDS, FTIR, and surface water contact angle measurements indicated jade powder was successfully combined with PLGA and improved the surface wettability of the microspheres. Moreover, it was proved, through in vitro simulated body fluid test as well as adipose stem cell osteogenesis analysis, that jade powder addition enhanced the pH buffering capacity of the composite microsphere for simulated body fluid, and promoted the in vitro osteogenic activity of adipose stem cells at a certain amount. This study provides new ideas to employ jade powder, a natural material otherwise thrown away as solid waste, for improvement on PLGA performance in bone repair or potentially other biomedical fields.

Polycaprolactone-zinc oxide biocomposite membranes for wastewater treatment by ultrafiltration process: Synthesis, characterization and removal of inorganic pollutants

The severe droughts impacting North Africa have intensified the pressure on potable water supplies and agricultural irrigation, highlighting the urgent need for sustainable water management solutions. This study explores the potential of poly(ε-caprolactone)/zinc oxide (PCL/ZnO) biocomposites as ultrafiltration membranes for treating urban wastewater, with the goal of enabling water reuse in agriculture. PCL/ZnO membranes, fabricated using the solvent-casting method, were thoroughly characterized using FTIR, XRD, EDAX, SEM, AFM, DSC, TGA, and water contact angle (WCA) measurements. Key findings revealed that increasing ZnO content (1–4 wt%) significantly enhanced membrane thickness, crystallinity, mechanical robustness, and surface roughness, while lowering WCA values to improve hydrophilicity. These enhanced properties are critical for ultrafiltration, as they contribute to higher contaminant rejection and improved water permeability. Performance tests demonstrated ion retention rates of 32–61 % post-filtration, including for toxic metals, effectively reducing pollutant levels. Notably, the treated water met the Food and Agriculture Organization (FAO) standards for irrigation quality, indicating its suitability for agricultural applications. This work highlights the efficacy of PCL/ZnO membranes in facilitating sustainable wastewater recycling under drought conditions, presenting a promising, adaptable solution for water reclamation in water-scarce regions. The results underscore the potential of these biocomposite membranes to advance sustainable water treatment practices, supporting both environmental resilience and agricultural productivity.

Investigation of the effects of an excess of Ca2+ and Mg2+ ions in low salinity water in the process of oil removal, dissolution, and solvation in calcites

The transition from an oil-wet to a water-wet calcite surface is crucial for enhanced oil recovery and can be influenced by low salinity (LS) water. While previous studies have explored the effects of LS water or single-ion solutions on rock-oil interfaces, the impact of excess active ions in LS on wettability remains uncertain. This work aims to determine whether Ca2+ or Mg2+ ions are more effective in altering wettability and oil recovery and to identify the optimal salinity for the Nujol-calcite system. Oil-wet calcite surfaces were characterized before and after treatment with LS water rich in Ca2+ or Mg2+, diluted 25, 50, 75, and 100 times (LS25, LS50, LS75, and LS100) compared to formation water. LS75, with a salinity of 3173 ppm, was the most effective for oil removal, achieving 81 % oil recovery. LS75Mg removed 75 % of the oil, and LS75Ca removed 65 %, as confirmed by ATR-FTIR and contact angle measurements. LS75Mg also showed a larger contact angle (∼160°) than LS75Ca (145°), indicating better oil detachment. Surface changes, including dissolution and oil fragmentation (especially with LS75Mg and LS100Mg), were observed via topographical analysis. XPS results revealed higher Na+, Cl−, and Mg2+ levels on treated surfaces, with LS50Mg showing the most significant reduction of surface carbon content. While a combination of Ca2+ and Mg2+ at optimal salinity enhances oil removal, excess Mg2+ alone is less effective. The competitive mechanisms behind oil removal and their dependence on brine composition are discussed.

A Simple Regeneration Process Using a CO2-Switchable-Polarity Solvent for Cellulose Hydrogels.

Cellulose is one of the main components of plant cell walls, abundant on earth, and can be acquired at a low cost. Furthermore, there has been increasing interest in its use in environmentally friendly, carbon-neutral, sustainable materials. It is expected that the applications of cellulose will expand with the development of a simple processing method. In this study, we dissolved cellulose in aqueous N-butyl-N-methylpyrrolidinium hydroxide solution ([C4mpyr][OH]/H2O) and investigated the cellulose regeneration process based on changes in solubility upon application of CO2 gas. We investigated the effect of transformation of the anion chemical structure on cellulose solubility by flowing CO2 gas into [C4mpyr][OH]/H2O and conducted pH, FT-IR, and 13C NMR measurements. We observed that the changes in anion structure allowed for the modulation of cellulose solubility in [C4mpyr][OH]/H2O, thus establishing a simple and safe cellulose regeneration process. This regeneration process was also applied to enable the production of cellulose hydrogels. The hydrogel formed using this method was revealed to have higher mechanical strength than an analogous hydrogel produced using the same dissolution solvent with the addition of a cross-linker. The ability to produce cellulose-based hydrogels of different mechanical properties is expected to expand the possible applications.

Spent tea leaves and tea bags - promising biofuels?

The spent tea leaves used after the extraction of liquid from processed tea are insufficiently utilized waste, rich in essential amino acids, polyphenols, alkaloids, and minerals, produced in large quantities, e.g., in tea houses, hospitals, school canteens, etc. Therefore, this study is aimed at characterizing this waste, how it is processed into pellets and how it subsequently increases its energy potential by torrefaction. The influence of the method of tea packaging, i.e., loose tea leaves or tea bags, was also considered. Several types of tea waste were processed using a pilot plant pelletizing press and torrefaction stand. The prepared pellets were characterized by mechanical parameters, such as the pellet durability index, the wettability index, water resistance, hardness, or specific bulk density, and were integrated by FTIR measurements. Furthermore, pellet’s energy parameters, such as higher heating value, lower heating value, and elemental analysis, were compared. The results show that non-torrefied pellets have an average combustion heat of 19 KJ.kg-1, while torrefied pellets have a value of 9 KJ.kg-1 higher. Overall, the study demonstrates that spent tea leaves can be converted into a sustainable source of bioenergy and presents a solution for the treatment of this waste, as well as a renewable energy option.

Efficient synthesis of novel phenanthroline-dimedone derivatives using Pd@HQBI-SPION as a versatile palladium-immobilized catalyst

This paper presents the synthesis and application of a novel catalyst for carbon–carbon bond formations, comprising palladium immobilized on 2-(5-hydroxyquinolin-8-yl)-1H-benzo[d]imidazole-5-carboxylic acid modified superparamagnetic iron oxide nanoparticles (Pd@HQBI-SPION). The synthesis involved the attachment of HQBI ligands to SPION using APTES, followed by the immobilization of palladium. Characterization techniques, including FTIR, TEM, and magnetic measurements, confirmed the successful synthesis and structural integrity of Pd@HQBI-SPION. The catalytic activity of Pd@HQBI-SPION was evaluated in various carbon–carbon bond formation reactions, demonstrating high efficiency and reusability. 8 different derivatives bearing several electron withdrawing and electron donating functionalities were used as starting materials and the products were obtained in high isolated yields (75–97%). The catalyst exhibited excellent performance in one-pot synthesis of phenanthroline-dimedone polycyclic derivatives via C-alkylation followed by intramolecular O-alkylation of phenanthroline with dimedone. The products are obtained in high to excellent yields is described. This protocol presents a highly selective synthetic method for the construction of polycyclic aromatic compounds containing nitrogen and oxygen atoms.

Photoresponse enhanced CsPbBr3 quantum dots quantum-confined in mesoporous PCN-600 single crystal microwires

In this work, the CsPbBr3 quantum dots (QDs) are encapsulated into the mesoporous iron-based metal-organic framework (PCN-600) by using a two-step solvothermal method. The success formation of CsPbBr3@PCN-600 composite is confirmed via SEM, TEM, XRD, FTIR, EDS and other measurements. Besides, the characterization of fluorescence lifetime of CsPbBr3@PCN-600 composite reveals the presence of the electron transfer between PCN-600 and CsPbBr3 QDs. Especially, CsPbBr3@PCN-600 exhibits a prominent emission peak at 473 nm due to the quantum confinement effect, and the photoluminescence quantum yield of CsPbBr3 QDs protected by the mesoporous PCN-600 increases to 71% compared to 52% of the pristine CsPbBr3 QDs. Also, the protection of CsPbBr3 QDs by the PCN-600 channel enhances the luminescence stability, thermal stability and blue-light stability of CsPbBr3. In fact, under light illumination, the photogenerated carriers from the encapsulated CsPbBr3 QDs could be captured by catalytically active sites on the inner surface of the PCN-600 channel. This charge capture effect can increase the photocurrent and implies much effective separation of electron-hole pairs of the CsPbBr3@PCN-600 composite. These results make this composite a promising candidate for high-performance photoelectronic devices.

Silica conversion of polysilazanes by low-temperature plasma jet generated from Ar and water-vapor mixed gas

Perhydropolysilazane (PHPS), which contains no organic catalyst, chemically reacts with H2O in the atmosphere by heating it at 450 °C for more than 1 h to turn it into a SiO2 film. If silica conversion can be achieved at temperatures below 100 °C, which plastics can withstand, it may be applicable to a wide range of applications, such as flexible electronics. Here, we report a technique for forming SiO2 films with leakage current characteristics very close to those of thermally oxidized (THOX) films that works at a very low temperature of 52 °C with high speed. Using a 9-kV, 30-kHz power supply, a low-temperature plasma jet containing a gas mixture of Ar and water vapor irradiated an 8 nm thick PHPS thin film, inducing silica conversion at a maximum substrate temperature of 52 °C. The current density-electric field strength (J-E) characteristics of metal oxide semiconductor capacitors fabricated with this SiO2 film showed characteristics very close to those of THOX films. In addition, the mechanism of silica conversion of PHPS through low-temperature plasma jet irradiation using this gas mixture was clarified in real-time FT-IR measurements.

Temperature dependent radiative and non-radiative recombination lifetimes of luminescent amorphous silicon oxynitride systems

In our previous work, we deeply researched the absolute photoluminescence (PL) quantum yields of luminescent modulating a-SiNxOy films with various N/Si atom ratios under different measurement temperatures. In this work, we further systematically studied the temperature dependent kinetic processes of radiative and non-radiative recombinations in a-SiNxOy systems in the visible light range. First, we investigated the structure of a-SiNxOy films and obtained the concentrations of both trivalent Si and N-Si-O defects related dangling bonds through XPS, FTIR and EPR measurements. Then we further tested the transient fluorescence attenuation of a-SiNxOy films detected at different emission wavelengths. We found that the PL lifetimes of a-SiNxOy films vary with the change of N-Si-O defect state concentrations, which is different from the typical PL decay characteristics of band tail related a-SiNx films previously reported. By combining the resulting PL IQE values with the ns-PL lifetimes, we further intensively redetermined the radiative and non-radiative recombination lifetimes of a-SiNxOy systems. The related radiative recombination rates were obtained (kr∼108 s−1), which can be compared to the results in the direct band gap.

Synthesis and characterization of silica-supported cobalt acylpyrazolone complex and its catalytic performance in ethylbenzene oxidation

A novel β-diketone-containing acylpyrazolone (2-(3-chlorophenyl)-3‑hydroxy-5-methyl-2,3-dihydro-1H-pyrazole-4-yl) (4-nitrophenyl) methanone [HLC] ligand and its cobalt complex [Co(HLC)2(H2O)2] were synthesized and characterized. A silica-supported cobalt complex was synthesized as a heterogeneous catalyst to investigate the cobalt complex's catalytic activity. The characterization techniques used for the synthesized compounds are CHN analysis, SC-XRD, FT-IR, TGA, DRS spectra, BET and BJH measurements, ICP-MS, XPS, powder XRD and SEM. Without any solvent, the cobalt complex catalytic impact on the oxidation of ethylbenzene was investigated with tert‑butyl hydroperoxide (70 % TBHP) as an oxidant. The catalyst exhibited good conversion (88 % conversion) and selectivity (83 % acetophenone) in the oxidation of ethylbenzene. The catalyst shows no leaching occurred under the reaction conditions because it is stable and reusable for further reaction.

Tridentate N-donor Schiff base metal Complexes: Synthesis, Characterization, computational Studies, and assessment of biomedical applications in cancer Therapy, Helicobacter pylori Eradication, and COVID-19 treatment

A unique Schiff base ligand (BCA), 4-(2-((1E,2E)-1-(2-(p-tolyl)hydrazono)propan-2-ylidene)hydrazinyl)quinazoline, was synthesized and complexed with Mn [II], Co [II], Cu [II, and Cd [II] ions, with 1,10-Phenanthroline (PHN) as an auxiliary ligand. The unique Schiff base ligand BCA and its metal complexes were characterized using multiple analytical techniques, including elemental analysis, UV–visible spectroscopy, FT-IR, mass spectrometry, and conductometric measurements. These methods provided detailed insights into the compounds’ structural and electronic properties. Density Functional Theory (DFT) computations complemented the experimental data, elucidating electronic configuration stability, HOMO-LUMO energy gaps, chemical hardness, and dipole moments. The computational results confirmed the distorted octahedral structure of the complexes. Antimicrobial testing against various bacterial and fungal strains revealed that the Cd (II) complex exhibited the highest activity, with inhibition zones ranging from 19.7 ± 0.6 mm to 35.0 ± 1.0 mm, surpassing the activity of standard antibiotics in some cases. Notably, the compounds displayed significant efficacy against Helicobacter pylori, with the Cd (II) complex showing an inhibition zone of 32.67 ± 0.58 mm and a minimum inhibitory concentration (MIC) of 7.8 μg/ml. Anticancer properties were evaluated against MCF-7 (Breast carcinoma) cells, with the [(BCA)(PHN)Cd(H2O)].2Cl·2H2O complex demonstrating superior activity (IC50 = 29.97 μg/ml) compared to the free ligand (IC50 = 183.96 μg/ml) and other metal complexes. Notably, the Cd(II) complex showed reduced cytotoxicity towards normal VERO cells, suggesting potential selectivity for cancer cells. Molecular docking simulations evaluated the complexes’ binding interactions with protein targets associated with Helicobacter pylori, MCF cancer cells, and the COVID-19 virus. The main objective of this research was to design and synthesize a unique Schiff base ligand and its new corresponding Ternary metal complexes and then investigate their potential medical applications. Specifically, the study aimed to evaluate the compounds’ effectiveness as antibiotics, antitumor agents, and possible treatments for COVID-19.

Preparation and Characterization of Au Quantum Dots Using Laser in Benzene and Study of the Pulse Energy effect on Quantum Size

Here, findings from a study on pulsed laser ablating of noble Au targets submerged in benzene solvent and a study on the effect of pulse energy on quantum size are presented. Three samples of gold quantum dots (AuQDs) are synthesized at pulse fluence of 4, 8, and 12 J/cm2, which is referred to as F1, F2, and F3, respectively. The prepared AuQDs were characterized by UV-Vis, HR-TEM, XRD, XPS, EDX, FTIR, Raman spectroscopy and Photoluminescence measurement. AuQDs that were synthesized have monocrystalline and cubic (FCC) structure, according to XRD patterns. It was found that the direct optical energy gap of AuQDs is enhanced to 2.6 eV. The emission peak of AuQDs photoluminescence emission spectra is at roughly 481, 445, and 437 nm, for F1, F2, F3 samples, respectively. The quantum size was reduced to 2 nm for sample F3. This strategy has the ability to prepare pure AuQDs in one step, with promising biosensor and bioimaging applications.

Synthesis and Spectral Studies of New Azomethine Metal Complexes With Biological Activity and Docking Studies Utilizing 3‐Methylpyridin‐2‐Amine as a Complexing Agent

ABSTRACTThe novel Schiff base, (Z)‐2‐(1‐((3‐methylpyridin‐2‐yl)imino)ethyl)phenol (HL), was synthesized by reacting 1‐(2‐hydroxyphenyl)ethanone with 3‐methylpyridin‐2‐amine. Metal complexes [M (L)n (H2O)2] (M = Co and Cu, n = 2) were synthesized and characterized utilizing various analytical techniques including UV–visible spectroscopy, FTIR, elemental analysis, molar conductance, 1H NMR, thermal analysis, and magnetic moment measurement. The findings indicated that the Co+2 and Cu+2 complexes exhibited octahedral geometries. In vitro biological activity testing was conducted to evaluate the antimicrobial potential of the complexes against Bacillus subtilis (B. subtilis) and Escherichia coli (E. coli) bacteria strains. Similarly, molecular docking was conducted to elucidate the interactions between the active sites of protein–metal complexes and dihydrofolate reductase as well as ferrochelatase.

A Novel Approach for Nanosponge: Wool Waste as a Building Block for the Synthesis of Keratin-Based Nanosponge and Perspective Application in Wastewater Treatment.

Wool waste is a huge environmental problem that needs to be addressed in order to avoid the continuous accumulation of biohazardous waste in landfills. In recent years, wool has proven to be an excellent source of keratin that can be used for various purposes. But never before has keratin from wool waste been used as a building block to synthesize a well-known class of biopolymers called nanosponges. Typically, nanosponges are produced by the reaction of cyclodextrins with an appropriate cross-linker to obtain an insoluble hyper-cross-linked polymer, which has applications in various fields. For this reason, a novel, affordable approach for the synthesis of a novel class of nanosponge using wool keratin as the building block has been presented. The keratin nanosponge was synthesized by reacting keratin with pyromellitic dianhydride as a cross-linking agent. The formation of a cross-linked polymer was successfully confirmed by CHNS-elemental analysis, TGA, DSC, FTIR-ATR, SEM, and water absorption capacity measurements. Surprisingly, the keratin-based nanosponge showed ∼50% uptake of heavy metals after only 24 h of contact time. The adsorption kinetics was also evaluated, indicating a pseudo-second-order model fit and the mechanism is predominantly the intraparticle diffusion process. The novel synthesized nanosponge proved to be a possible alternative for wastewater treatment.

In Situ IR Spectroscopy Studies of Atomic Layer-Deposited SnO2 on Fullerenes for Perovskite Photovoltaics.

In recent years, atomic layer deposition (ALD) has established itself as the state-of-the-art technique for the deposition of SnO2 buffer layers grown between the fullerene electron transport layer (ETL) and the ITO top electrode in metal halide perovskite-based photovoltaics. The SnO2 layer shields the underlying layers, i.e., the fullerene-derivative materials such as C60 and PCBM, as well as the perovskite absorber, from water ingress and damage induced by the sputtering of the transparent front contact. Our study undertakes a comprehensive investigation of the impact of SnO2 ALD processing on fullerenes by means of in situ spectroscopic ellipsometry (SE) and transmission infrared spectroscopy (FTIR). While no difference in SnO2 bulk properties is observed and the perovskite absorber degradation is nearly entirely avoided during exposure to heat and vacuum, when the absorber is introduced beneath the organic ETLs, a SnO2 growth delay of about 50 ALD cycles is measured on PCBM, whereas the delay is limited to 10 cycles in the case of growth on C60. Notably, FTIR measurements show that while C60 remains chemically unaffected during SnO2 ALD growth, PCBM undergoes chemical modification, specifically of its ester groups. The onset of these modifications corresponds with the detection of the onset, after the initial delay, of ALD SnO2 growth. It is expected that the modification that the PCBM layer undergoes upon ALD SnO2 processing is responsible for the systematic lower photovoltaic device performance in the case of PCBM-based devices, with respect to C60-based devices.

Methanol steam reforming over copper supported on apatites

Low-temperature methanol steam reforming (MSR) over Cu is an efficient process for releasing H2 from this promising liquid hydrogen carrier but the Cu contents of commercial catalysts are often exceedingly high. Here we show that Sr-exchanged fluoro and hydroxyapatites with 1 wt% Cu exhibit very high methanol turnover frequencies up to 386 h−1 and H2 production rates up to 6569 mol H2 kgCu−1 h−1 with CO selectivity as low as ∼0.25 % at 250 °C. Formaldehyde and methyl formate are the only other byproducts which are especially observed over catalysts with low Sr/P ratio in the hydroxyapatite. The reforming proceeds through methoxy, formaldehyde and formate species according to in situ FTIR and mass spectrometric measurements. The spectroscopic analyses further reveal the involvement of apatitic HPO42- ions in the catalytic sequence. Thus, the catalytic synergy between Cu and apatites provides a basis for highly efficient, bifunctional MSR catalysts with low copper content.

Innovative upcycling cigarette filters into high-performance cellulose nanofiber-epoxy composites

This research introduces a novel upcycling method for transforming cigarette filters—an abundant and persistent environmental waste—into high-performance epoxy composites reinforced with cellulose nanofibers. The innovation lies in extracting cellulose acetate nanofibers from used cigarette butts via a multi-step purification and electrospinning process, followed by their conversion into regenerated cellulose nanofibers through alkaline hydrolysis. This dual-fiber approach allows us to fabricate four distinct epoxy composites, each reinforced by different nanofiber types: recycled cellulose acetate nanofibers, regenerated cellulose nanofibers from recycled cigarette filters, and their commercial counterparts. Notably, this is the first time regenerated nanofibers derived from waste cigarette filters have been utilized for epoxy composite reinforcement, demonstrating a sustainable, high-value use for a major pollutant. Comprehensive characterizations, including FTIR, XRD, SEM, and contact angle measurements, confirmed the successful regeneration of cellulose nanofibers, showing improved hydrophilicity, reduced crystallinity, and uniform nanofiber morphology with diameters between 200 and 300 nm. The innovation further extends to the mechanical performance of these composites: tensile tests revealed that those reinforced with regenerated cellulose nanofibers exhibited superior tensile strength (49.5–53.8 MPa), significantly outperforming both cellulose acetate nanofiber composites (40.1–42.6 MPa) and neat epoxy resin (31.4 MPa). This marked improvement is attributed to enhanced nanofiber dispersion and interfacial adhesion within the epoxy matrix, an essential advancement over traditional composites. In addition, thermal analysis showed that all composites maintained thermal stability in the 300–400 °C range, comparable to commercial alternatives. The regenerated nanofiber-reinforced composites also displayed enhanced optical transparency due to reduced light scattering, making them ideal candidates for applications requiring both mechanical strength and optical clarity. By pioneering the use of cigarette filter waste for fabricating advanced cellulose nanofiber composites, this study presents an eco-friendly approach to addressing environmental pollution while creating sustainable materials with superior mechanical, thermal, and optical properties.