Journals
2025 EN
Yousef Ayman · Hameed R. M. Abdel · Maafa Ibrahim M.
+1 more
ABSTRACT Selecting a suitable carbon support for electrodepositing metallic‐based complex films significantly enhances the electroactivity of fabricated electrocatalysts. In this work, curcumin [1,7‐bis[4‐hydroxy‐3‐methoxyphenyl]‐1,6‐heptadiene‐3,5,dione] was modified with nickel electrodeposition using activated carbon (AC), graphene (Gr), and N‐doped graphene (N‐Gr) as carbonaceous surfaces. A homogeneous distribution of nickel‐curcumin (NiCur) deposits onto the N‐Gr substrate could be identified by SEM images. This might explain the increased surface area of this composite in relation to the formed layers onto AC and Gr. A promoted electrocatalytic activity was measured for NiCur films onto different carbon surfaces for the ethylene glycol electro‐oxidation reaction in alkaline electrolyte. Electrochemical experiments demonstrated that the encouraging alcohol oxidation rate was detected by NiCur/N‐Gr. The performance of NiCur/N‐Gr was appreciably affected by the chosen alcohol concentration and the study scan rate. Steady‐state current densities of 1.996, 2.407, and 3.798 mA cm −2 were recorded at the end of the chronoamperometry test for NiCur/AC, NiCur/Gr, and NiCur/N‐Gr electrocatalysts, respectively. This study showed the encouraging attitude of nitrogen‐doped graphene as a highly conductive surface with an outstanding active area to provide promising electrocatalysts for fuel cells applications.
Journals
2025 EN
Salah Nesma · Adly Omima M. I. · Ibrahim Magdy A.
+2 more
ABSTRACT A new Schiff base ligand, HNMPC , was prepared and reacted with some metal ions, including Cu(II), Ni(II), Co(II), Mn(II), and VO(IV). The infrared, electronic, mass, electron spin resonance, nuclear magnetic resonance, thermal and elemental analysis, molar conductance, and magnetic susceptibility measurements were used to characterize the metal complexes. The HNMPC ligand acts as a monoanionic tridentate ONO donor in all complexes, and the coordinating sites are C=O pyridone , C=N, and the phenolate anion. All metal complexes exhibit octahedral configurations, and the results showed that the metal ion:ligand ratio was 1:2. The molecular structural parameters of the ligand and its metal complexes were determined based on the DFT level implemented in the Gaussian 09 program B3LYP/GENECP method at the 6‐311G(d,p) basis set for C, H, N, and O atoms and the SDD (Stuttgart/Dresden) basis set for the metal atoms. The theoretical data were correlated with the experimental results. Gram‐positive bacteria, Gram‐negative bacteria, yeast, and fungi were used to test the current compounds' antimicrobial activity. Investigating the antitumor activity of the ligand and its complexes against the HepG2 cell lines showed encouraging IC 50 values that were on par with those of cisplatin . In order to determine the affinity and binding pattern for the synthesized compounds toward the VEGFR‐2 active site, molecular docking studies were conducted, and the results were correlated with antitumor data. Based on the obtained results, future work aimed to synthesize a new category of Schiff bases and their metal complexes derived from the current aminopyridine derivative with diverse aldehydes and ketones.
Journals
2025 EN
Afify Donia G. · Hameed R. M. Abdel · Mohamed Aya M.
+1 more
ABSTRACT The rational design of noble metal‐free electrocatalysts represents one of the basic stones for fuel cell development. With the exploration of eco‐friendly nanomaterials for the investigated alcohol oxidation process, nickel‐based electrodes have been recognized as the most auspicious anodes with promoted activity and stability. In this work, a series of NiCo 2 O 4 nanoparticles were deposited onto graphite sheets (NiCo 2 O 4 /T) introducing varied proportions of cobalt oxide species. Co‐precipitation protocol of the respective metallic hydroxides onto the carbonaceous support was followed with consecutive annealing in an air atmosphere at 400°C. The fabricated mixed metallic oxide nanopowder was physically studied using X‐ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X‐ray analysis (EDX), X‐ray photoelectron spectroscopy (XPS), and selected area electron diffraction (SAED). Uniformly arranged nanoparticles were observed on graphite surface as evidenced by SEM and TEM. The cubic lattice structure of formed NiCo 2 O 4 crystals was also confirmed by XRD through the defined peaks of binary metallic oxides clarifying their successful preparation scheme. The electrocatalytic properties of these NiCo 2 O 4 /T nanocatalysts were evaluated for oxidizing ethanol molecules in basic solution. Pronounced oxidation current densities were remarkably measured at NiCo 2 O 4 /T electrodes in relation to that at NiO/T. Differing the introduced cobalt oxide content into the synthesized nanocatalyst significantly controlled its catalytic performance. NiCo 2 O 4 /T‐20 exhibited the highest activity and stability among the prepared nanomaterials. Much decreased charge transfer resistances were also recorded at this electrode demonstrating its promoted electron transfer characteristics. This work could provide a reasonable route for the simple synthesis of comparable transition metallic oxides with promising attitudes for energy generation purposes.
Journals
2025 EN
Ibrahim Ahmed B. M. · Cordes David B. · Slawin Alexandra M. Z.
+1 more
ABSTRACT Tin complexes, Sn(IV)‐TSC 1·MeOH and Sn(IV)‐TSC 2 , with thiosemicarbazones possessing an N 2 S ligation system [ TSC 1 = 4‐(4‐nitrophenyl)‐1‐((pyridin‐2‐yl)methylene)thiosemicarbazide and TSC 2 = 4‐(2‐methoxyphenyl)‐1‐((pyridin‐2‐yl)methylene)thiosemicarbazide] were prepared and structurally characterized. These complexes are found in the space groups P1 ¯ $$ {1} $$ and P 2 1 / n , respectively, with their tin atoms in octahedral environments established by three chlorine atoms and an anionic thiosemicarbazone ligand. All compounds (20 mg/mL in DMSO) were tested for their antibacterial [against Bacillus subtilis , Staphylococcus aureus , Escherichia coli , and Pseudomonas aeruginosa ] and antifungal [against Aspergillus flavus and Candida albicans ] properties. The ligand TSC 2 displayed inhibitions in the S. aureus and E. coli cultures (with zones of 11 and 10 mm, respectively), whereas Sn(IV)‐TSC 1·MeOH and Sn(IV)‐TSC 2 inhibited all bacteria with 11–15 and 14–16 mm, respectively. In the fungal cultures, only Sn(IV)‐TSC 1·MeOH (10 mm) showed an inhibition zone against A. flavus . The ligands' antiproliferative activities were determined against human cancer cells of the lung, breast, liver, and colon, and both ligands afforded the highest activity against the breast MCF‐7 cells. The complexation enhanced the ligands' activities as TSC 1 , TSC 2 , Sn(IV)‐TSC 1·MeOH , and Sn(IV)‐TSC 2 afforded respective IC 50 values of 52.4, 153.7, 18.3, and 63.9 μM. However, against normal baby hamster kidney (BHK) cells, these compounds showed IC 50 data of 54.8, 82.7, 16.1, and 15.3 μM, respectively.
Journals
2025 EN
Ucar Okan · Ozturk Ibrahim I. · Grześkiewicz Anita M.
+3 more
ABSTRACT In this study, we report the synthesis, characterization, and biological investigation of antimony(III) halide complexes with various coordination architectures constructed from thiophene thiosemicarbazones. Antimony(III) thiophene‐2‐carbaldehyde thiosemicarbazone complexes ( 1 , 2 , 4 , and 5 ) exhibit a square pyramidal geometry, with ligands coordinated to the central antimony atom in two distinct binding modes. In contrast, antimony(III) 2‐acetylthiophene thiosemicarbazone complexes ( 3 , 6 , and 7 ) adopt a seesaw geometry. These complexes ( 1 – 7 ) represent the first reported examples of antimony(III) halide thiosemicarbazone compounds. The unique coordination environments observed in these complexes are of significant importance within the realm of antimony chemistry. These synthesized complexes exhibit different coordination geometries as well as potential biological activities. The antiproliferative activity against the human breast adenocarcinoma (MCF‐7) cell line and antimicrobial activity against Gram‐positive and Gram‐negative bacteria were assessed. Antimony(III) thiophene‐2‐carbaldehyde thiosemicarbazone complexes ( 1 , 2 , 4 , and 5 ) showed significant antiproliferative activity with IC 50 values ranging from 8.5 to 19.1 μM, while antimony(III) 2‐acetylthiophene thiosemicarbazone complexes ( 3 , 6 , and 7 ) had higher IC 50 values. Additionally, the antimony complexes demonstrated selective antimicrobial activity against Gram‐negative bacteria.
Journals
2025 EN
Shawky Amal · Sayed Asmaa · ElSayed Ibrahim E. T.
+1 more
ABSTRACT This study presents a novel gamma irradiation‐based synthesis of CoFe 2 O 4 ‐integrated CAR/PNIPAm nanogels, offering distinct advantages over conventional nanogel systems. The unique incorporation of magnetic cobalt ferrite nanoparticles into a κ‐carrageenan/poly(N‐isopropylacrylamide) matrix yields nanogels with uniform nanoparticle distribution, tunable size, and adjustable surface charge, which collectively enhance targeted drug delivery. Comprehensive characterization by XRD, SEM, AFM, and TEM revealed a crystalline size of 50.63 nm and particle sizes ranging from 30 to 116 nm, confirming effective nanoparticle distribution within the nanogels. Dynamic light scattering (DLS) and zeta potential analyses confirmed stable dispersion, with tunable size and surface charge beneficial for drug delivery applications. Antibacterial studies demonstrated the efficacy of these nanogels against Klebsiella and Enterococci strains, with inhibition zones of 17 ± 1 mm and 12.3 ± 1.57 mm at 1.5 wt% CoFe 2 O 4 , suggesting potential use as antimicrobial agents. Furthermore, in vitro cytotoxicity assays revealed selective anticancer activity against HepG‐2 and MCF‐7 cell lines, with low IC 50 values indicating potent anticancer effects. Importantly, the nanogels showed minimal toxicity toward normal WI‐38 fibroblast cells, with a CC 50 value of 115.27 ± 3.72 μg/mL, underscoring a favorable safety profile.
Journals
2025 EN
Karagöz İdris · Duyar Halil İbrahim · Çavuşoğlu Aysu
+1 more
ABSTRACT In this study, the thermal, mechanical, and morphological properties of high‐density polyethylene composites reinforced with wal1nut shell and nano‐CaCO 3 were investigated. Composites with a fixed walnut shell content (20%) and varying nano‐CaCO 3 concentrations (1%, 3%, and 5%) were prepared by extrusion and injection molding. The results showed that increasing filler content raised crystallization temperatures, while melting temperatures (T m ) slightly decreased, and crystallinity was lower compared to pure HDPE. The lowest T m (128.2°C) and crystallinity (27.3%) were found in the PECCWS4 and PECCWS5 composites. Thermogravimetric analysis (TGA) revealed that the initial degradation temperature (T 5 ) increased from 452°C to 457.8°C, and the temperature for 50% weight loss (T 50 ) shifted from 481.8°C to 486.5°C. Residual weight at 600°C increased from 1.1% for PECCWS1 to 9.5% for PECCWS5, indicating improved char formation. Scanning Electron Microscopy and Transmission Electron Microscopy showed improved filler distribution and enhanced filler‐matrix interaction. The combination of walnut shell and nano‐CaCO 3 improved certain mechanical properties such as tensile strength and modulus; however, elongation at break decreased in tensile testing, indicating reduced ductility. These findings highlight the synergistic effect of walnut shell and nano‐CaCO 3 in enhancing HDPE composites' thermal and mechanical properties, showing potential for improved performance.
Journals
2025 EN
Akin Sahbaz Deniz · Aydogdumu Elif Can · Koybasi Zehra
+4 more
ABSTRACT The valorization of glass production waste (GPW) as a functional additive in rubber‐based composites presents a sustainable approach to waste management and material enhancement. In this study, GPW was ground into fine powder and incorporated into rubber formulations at 5, 10, and 15 phr. The effects of GPW on curing behavior, rheological, and mechanical performance of the rubber composites (RCs_GPW) were evaluated. Rheometric analysis revealed that the incorporation of GPW accelerated the vulcanization process, reducing cure time and increasing the cure rate index. Physico‐mechanical tests demonstrated that GPW addition into the rubber compounds improved hardness while maintaining acceptable tensile strength and elongation at break. However, excessive GPW loading led to particle agglomeration, adversely affecting mechanical properties. The morphological, compositional, and thermal properties of GPW and rubber composites were investigated using SEM, EDX, FTIR, TGA, and DSC analyses, confirming the dispersion of GPW particles and their interaction with the rubber matrix. The findings suggest that GPW can serve as a cost‐effective, eco‐friendly functional additive in rubber composite production, promoting circular economy principles in the rubber industry. Among the tested formulations, 10 phr of GPW was identified as the optimal loading level, providing the best balance between mechanical performance and thermal stability.
Journals
2025 EN
Hemida Mohamed H. · Moustafa Hesham · Mehanny Sherif
+3 more
ABSTRACT Humidity surveillance is a requirement for several applications, including medical, pharmaceutical, food storage, and agriculture. This work describes the fabrication of humidity sensors from cellulose nanocrystals (CNCs) and ZnO nanoparticles (ZnO NPs) integrated inside a polyvinyl alcohol (PVA)/polyvinylpyrrolidone (PVP) blend created by a solvent‐casting method. A 10 wt.% of CNCs were used with variable quantities of ZnO NPs (i.e., 3, 7, and 15 wt.%) to prepare PVA/PVP nanocomposite films. The films were characterized using X‐ray diffraction, Raman spectroscopy, as well as mechanical, thermal, and antibacterial properties. In all cases, ZnO NPs improved morphology, thermal stability, and antibacterial properties. The tensile properties were slightly reduced compared to unfilled matrix (~33 MPa), but their tensile stress values were still higher than filled film‐based CNCs (P/CNC, 22.60 MPa). Whereas the outcomes from the antibacterial experiment illustrated that the halos of inhibition were observed for film‐based ZnO NPs with different diameters ranging from 3 to 16 nm, depending on the microbe and the film type. These results indicate that these films could be used in active packaging and the biological area because these materials prolong shelf life. Correspondingly, a P/CNC moisture sensor possessed higher sensitivity with low hysteresis over a wide range of relative humidity (11%–97%) and at 300 Hz.
Journals
2025 EN
Malek Nur Syahrul Nizam Abdul · Zawawi Engku Zaharah Engku · Romli Ahmad Zafir
+1 more
ABSTRACT This study explores the fused particle method as a potential approach to mitigating the negative effects of filler agglomeration on composite properties. Composites are fabricated with 3%, 9%, and 15% filler loadings, and the cured samples are subjected to fusion at 195°C and 205°C for 20, 60, and 100 min to promote particle fusion. Indentation compression tests evaluate surface hardness, while stress relaxation analysis assesses viscoelastic behavior. Pristine epoxy shows the highest indentation stress and lowest stress relaxation due to its highly crosslinked structure. At 3% loading, voids and weak filler–matrix interactions reduce stress resistance, but extended fusion improves performance. Nine percent filler loading provides the most stable mechanical performance, maintaining consistent stress before and after fusion due to optimal filler distribution, reduced shrinkage effects, and enhanced filler–matrix adhesion. In contrast, 15% loading results in excessive agglomeration and early‐stage weakness, with limited improvement even after fusion. Fusion at 205°C yields slightly lower stress than 195°C, likely due to epoxy softening and shrinkage‐induced voids. Stress relaxation decreases with increasing filler content and fusion time, as chain mobility becomes restricted by the semi‐crystalline filler network. However, at 15% loading, shrinkage and incomplete fusion counteract these benefits, leading to minimal improvement in relaxation behavior.