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Eco-friendly porous ceramics based on zeolite and bentonite: Preparation and assessment of adsorption efficiency toward lead, nickel, and cobalt ions
No full textIn this study, eco-friendly porous ceramics with reinforced mechanical properties based on available and cost-effective raw material, natural zeolite and bentonite clay, were synthesized and their adsorption capacity towards Co2+, Ni2+, and Pb2+ ions from aqueous solutions was investigated. The synthesis was carried out using the foaming method with sodium dodecyl sulfate as the foaming agent and hydrogen peroxide (H2O2) as the blowing agent. The obtained samples of the porous ceramics based on natural zeolite and bentonite clay were prepared with 4 and 8 % H2O2. The increasing amount of H2O2 led to an increase in total porosity. The obtained green and sintered samples of porous ceramics were characterized in detail by thermogravimetric analysis, scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. The heavy metal ions adsorption kinetics and isotherms fit the Pseudo-Second-Order and Langmuir models, confirming chemisorption (ion exchange reaction). The adsorption capacity of both sintered samples toward ions of heavy metals decreased in following order: Pb2+>Ni2+>Co2+. The thermodynamic parameters showed that adsorption is a spontaneous and endothermic process favored at higher temperatures
Photodeposition of Noble and Non-Noble Metals on Pristine vs. Plasma-Treated g-C3N4
No full textHeterogeneous photocatalysis is considered a promising, cost-effective, and eco-friendly alternative to conventional methods for the photocatalytic reduction of Cr(VI) [1]. Graphitic carbon nitride (g-C3N4, CN), known for its excellent photocatalytic performance, appeared as a reasonable solution for this application. However, its effectiveness in aquatic systems is limited by its hydrophobic properties and high electron-hole recombination rate despite its excellent chemical durability, visible-light response (Eg ~ 2.7 eV), and appropriate redox potential [2]. To address these limitations, metal nanoparticles (NPs) are often loaded onto CN to form M/CN heterostructures, which enhance charge separation via a Schottky barrier and improve visible light absorption through the localized surface plasmon resonance (LSPR) effect. The key to these enhancements is effective interfacial contact. A common method of improving CN’s surface properties is plasma treatment, known for surface functionalization, defect introduction, and morphological alteration [3]. Therefore, we anticipated that plasma treatment of CN would provide improved, tighter M/CN contact and consequently an effective heterostructure.
In this study, we synthesized urea-derived CN using the direct thermal polymerization method and applied DBD plasma treatment for surface modification (CN-pt). For the deposition of Ag and Cu, AgNO3 and CuCl2 were used as precursors, respectively. Photodeposition method was used for the synthesis, which is considered a promising approach for obtaining well-dispersed metal NPs on CN with strong adhesion [4]. Here, we present a systematic study of Ag- and Cu-dispersed CN and CN-pt using various characterization methods: XRD, FTIR, FESEM, EDS, PL and DRS. It was revealed that visible light absorption and charge separation were enhanced after NPs deposition (). Ag was deposited in greater amounts on CN than Cu for a shorter period. When tested for photocatalytic reduction of Cr(VI), all samples exhibited enhanced activity compared to CN, with Ag-based samples being superior
Exploring green proteins from pumpkin leaf biomass: assessing their potential as a novel alternative protein source and functional alterations via pH-Shift treatment
No full textAs sustainability continues to be a major global focus, the use of agro-industrial waste as a renewable resource presents a promising solution. In this study, the potential of pumpkin leaf biomass, a type of agro-industrial waste, will be explored as an alternative protein source using thermal coagulation. A key challenge is the accumulation of green proteins, a protein-rich byproduct. This waste fraction, which has been insufficiently investigated due to its limited functional properties, is the main focus of this research, aimed at enabling complete biomass utilization. The novelty of this research lies in the application of combined pH-shift and controlled heat treatment to improve the solubility of green proteins isolated from pumpkin leaf biomass – an underexplored protein fraction derived from agro-industrial waste. The obtained crude green protein powder, with a yield of 47.95 g/kg of leaf dry biomass, exhibited a satisfactory composition, containing 53.58% protein, a high-quality amino acid profile, and notable antioxidant properties. On the other hand, it exhibited low solubility, below 25%, across the pH range of 2–10, with the isoelectric point at pH 4.4. Following the application of an optimized pH-shift and heat treatment, green proteins solubility increased significantly, reaching 89.74% at pH 8, nearly 4.5 times higher than before treatment, showing low solubility only at the isoelectric point and excellent stability maintained in salt concentrations up to 1 M NaCl. A notable decrease in particle size was observed, from 1883 nm to 192 nm, leading to a more uniform particle size distribution. SDS-PAGE and FTIR deconvolution analyses indicated structural changes, possibly involving disulfide bond formation. The promising findings of this research, not only ensure complete biomass utilization, but also highlight the need for further investigation regarding the potential of green modified proteins, as the observed improvements open up numerous biotechnological applications. One potential direction is green protein-stabilized emulsions, supported by a significant increase in alpha-helix content associated with enhanced functional properties, which offers new possibilities for future research on stable and functional emulsions
Profiling of Disubstituted Chloroacetamides’ Potential Biological Activity by Liquid Chromatography
No full textModern agriculture relies heavily on the use of pesticides, with one-third of them being herbicides. Chloroacetamides are the most widely used herbicides because of their high effectiveness, but their extensive use poses environmental challenges and threatens the health of living organisms due to toxicity risks. Since the pharmacokinetic behavior and toxicity of a compound are influenced by its lipophilicity, this essential physicochemical parameter for disubstituted chloroacetamides was determined in silico and experimentally through thin-layer chromatography on reversed phases (RPTLC C18/UV254s) in mixtures of water and distinct organic modifiers. The pharmacokinetic profile of chloroacetamides was analyzed by using the BOILED-Egg model. The correlation between the obtained chromatographic parameters and software-based lipophilicity, pharmacokinetic, and ecotoxicity predictors of the studied chloroacetamides was assessed by using linear regression, but more comprehensive insight was obtained through multivariate methods—Cluster Analysis and Principal Component Analysis. It was observed that the total number of carbon atoms in the structure of their molecules, along with the type of hydrocarbon substituents, are the most important factors affecting lipophilicity, pharmacokinetics, and potential toxicity to non-target organisms
Design of a rechargeable hybrid cell utilizing seawater electrolyte
No full textThe growing global demand for energy necessitates the development of sustainable and
cost-effective storage systems. Among the promising candidates, seawater-activated
batteries are particularly attractive due to their high operating voltage and ability to
deliver power at elevated current densities [1,2]. However, the instability of cathode
materials remains a critical limitation. In this study, a novel hybrid electrochemical cell
was developed with a rechargeable composite cathode composed of functionalized
carbon felt (FCF) and electrochemically synthesized polypyrrole (PPy), further coated
with silver chloride (AgCl) using a modified successive ion layer adsorption and reaction
process (SILAR). The FCF/PPy–AgCl electrode demonstrated stable electrical and
electrochemical properties. When paired with an AZ63 magnesium alloy anode, which
functioned as a sacrificial electrode during discharge and as a hydrogen-evolving
electrode during charge, the cell achieved specific energy values ranging from 120 to 32
mWh g⁻¹ and specific power outputs between 52 and 450 mW g⁻¹. These findings
emphasize the potential of the AZ63 | 3.5% NaCl | FCF/PPy–AgCl system for practical
applications such as emergency power sources in lifeboats and short-term monitoring of
shallow seawater environments
Citizen Science and Astroinformatics
No full textCitizen science plays an important role in modern astroinformatics, enabling the public to collaborate with professional scientists in large-scale projects like Galaxy Zoo and Planet Hunters. Volunteers classify astronomical objects, detect exoplanets (the planets that orbit stars outside our solar system), and monitor transient events, contributing to major discoveries. With the rise of big data, AI, and machine learning, the integration of automated systems and human input creates a powerful synergy that improves data analysis. Despite the challenges in data quality and ethical issues, citizen science continues to thrive, providing a platform for global participation and encouraging public interest in scientific discovery
From Nature to Function: Green Composites Using Camphoric Acid-Based Unsaturated Polyester Resin and Bamboo/Flax Non-Woven Reinforcements
No full textUnsaturated polyester resins (UPRs) were synthesized from camphoric acid and diluted with styrene, partially replaced (up to 30%) by trimethylolpropane triacrylate (TMPTA). Rheological tests showed increased but sustainable viscosity due to TMPTA’s higher polarity. These UPRs served as matrices for composites reinforced with non-woven bamboo and flax mats from recycled waste. Mechanical testing revealed that Cf-UPR/TMPTA30 exhibited the highest tensile strength (25.2 MPa) and modulus (0.96 GPa), compared to 18.7 MPa and 0.74 GPa for the styrene-based resin, respectively, attributed to greater cross-link density. Bamboo composites showed lower tensile properties (13.6 MPa) due to random fiber orientation and porosity, while flax-reinforced systems, especially Cf-UPR/TMPTA30–FLAX, reached 42.7 MPa tensile and 95.5 MPa flexural strength, indicating synergy between TMPTA-modified resin and flax fibers. Dynamic-mechanical analysis confirmed stable thermo-mechanical behavior, and water uptake tests showed reduced absorption (by ~10%), suggesting improved fiber/matrix adhesion. SEM images revealed brittle fracture and fiber pull-out in styrene systems, but fiber breakage and ductile textures in TMPTA-based ones, proving better stress transfer. Thermal analysis indicated slightly earlier degradation onset for TMPTA-modified resins but higher char yield in fiber composites. Overall, TMPTA substitution and flax reinforcement enhance the mechanical, interfacial, and thermal properties of bio-based UPRs, supporting sustainable high-performance composites
Interfacial halogen bonding with charge-transport layers for operational stability of hybrid perovskite solar cells
No full textHybrid metal halide perovskites have emerged as some of the leading
semiconductors in photovoltaics. Despite their remarkable power
conversion efficiencies, these materials remain unstable under device
operating conditions. One of the main instabilities relates to the interface with the contact layers in photovoltaic devices, such as metal
oxides. We rely on halogen bonding (XB) using 1,4-diiodotetrafluorobenzene (TFDIB) to modulate the interface of the TiO2
electron-transport layer, demonstrating the improvement of perovskite solar cell operational stability. Furthermore, we complement this
strategy with the use of iodo-functionalized Zn–phthalocyanine modulator of the hole-transporting material, which passivate the interface
while enhancing the power conversion efficiency, showcasing the
potential of XB in hybrid photovoltaics
Modification of microemulsion-assisted sol–gel method to control the composition of multi-ion-doped mesoporous bioactive glass particles
No full textThe microemulsion-assisted sol–gel method, combined with a cationic surfactant, is widely used to
synthesize spherical mesoporous bioactive SiO2–CaO glass particles (MBGs), which have various
biomedical applications owing to their biocompatibility, bioactivity and mesoporous structure with
surface properties suitable for drug loading. The biological properties of MBGs can be tailored by
optimizing the calcium content, as calcium plays a critical role in MBGs bioactivity and pro-osteogenic
properties. Additionally, incorporating an optimal quantity of so-called therapeutic ions promotes
specific biological responses upon release, such as: osteogenic (Mg2+ and Sr2+), angiogenic (Cu2+ and
Mg2+) and antimicrobial (Cu2+ and Zn2+) effects. Previous investigations have shown that the
incorporation of high amounts (>20 mol%) of calcium, as well as strontium, into highly dispersed MBGs
is challenging, resulting in a significant discrepancy between the nominal and actual composition. The
problem stems from the synthesis process itself, as insufficient amounts of the ions are adsorbed on
the surface of the silica particles, which initially form within oil droplets in water.
The aim of this study was to optimize or modify microemulsion-assisted sol–gel synthesis to better
control the content of Ca, Mg, Sr, Cu and Zn in multi-ion-doped spherical MBGs. The main parameter
varied was the pH value, specifically the ammonia content, which influences hydrolysis and
condensation rates of tetraethyl orthosilicate (the silica precursor), as well as ions adsorption. The
synthesis modification involved impregnating pure silica particles with ions after synthesis rather than
relying on adsorption during the synthesis. The morphology and chemical composition of MBGs were
analyzed by FESEM and EDS analysis, while an MTT assay was performed on mouse bone marrowderived
stem cells (mBMSCs) to assess in vitro biocompatibility. The specific surface area was
determined by BET method. The results indicate that pH variations slightly influence MBGs size and
composition. Furthermore, ions whose hydroxides are poorly soluble (Cu, Zn, Mg) were found to bind
much better to silica than ions whose hydroxides are more soluble (Ca, Sr). The synthesis modification
demonstrated a much greater potential for controlling the composition of MBGs compared to pH
adjustments.
Acknowledgements: This research was funded by the Science Fund of Republic of Serbia #GRANT
No.7470, Novel hybrid biomimetic macroporous composites with tuned biodegradability, improved
osteointegration and anticancer properties for bone tissue regeneration – HyBioComBone and by
Ministry of Science, Technological Development and Innovations, Republic of Serbia (No. 451-03-
65/2024-03/200135, 451-03-66/2024-03/20028
Development and In Vitro Evaluation of Starch–Gelatin Hydrogels for Potential Cartilage Repair
No full textThe development of bioactive and affordable scaffolds for cartilage repair remains a key
challenge in regenerative medicine. In this study, starch–gelatin (SG) hydrogels were fabricated
via aqueous casting, lyophilization, and subsequent annealing, and evaluated in vitro alongside
commercial references HyaloFast® and ChondroGide®. The resulting SG hydrogels exhibited
a macroporous, highly interconnected structure with sufficient mechanical integrity for
handling and implantation. Swelling behavior, mechanical properties, and degradation in PBS
at 37 °C demonstrated balanced water uptake and gradual degradation, influenced by
crosslinking parameters such as time and temperature. Human mesenchymal stromal cells
(hMSCs) were seeded onto the hydrogels to assess cell retention and proliferation. A CTB assay
on day one showed that SG hydrogels retained significantly more cells than ChondroGide® and
comparably to HyaloFast®. Over 42 days, cell proliferation displayed an inverse relationship
with initial retention, with SG hydrogels supporting moderate but sustained cell growth.
Overall, SG hydrogels offer a promising combination of porosity, biodegradability, mechanical
performance, and cytocompatibility. Their high cell retention and low-cost formulation
position them as attractive candidates for scalable and accessible cartilage tissue engineering
applications