As a result of elevated inherent flammability of polyethylene (PE) matrices during fire condition and their increasing applications in heat and fire prone sectors, it has become imperative to alleviate and mitigate their inherently high flammability in order to enlarge their scope of applications. Herein, the cone calorimetric parameters of PE including rapid time to ignition (Tign), elevated smoke production rate (SPR), high peak heat release rate (PHRR), high total heat release rate (THR), low limiting oxygen index (LOI), rapid heat release rate (HRR), high carbon dioxide (CO2) and carbon monoxide (CO) release rates, high fire growth index (FGI), and UL-94-V-0 status, and so on, are analyzed to ascertain the degree of flame retardancy achieved for expanded multifunctional applications due to the inclusion of nanoparticles (graphene and derivatives, carbon nanotubes and derivatives, nanoclay and derivatives, and so on) within the polymeric matrices. However, this work is limited to interpretation of cone calorimetric parameters relative to thermal and flame retardant properties. Therefore, this paper investigates the thermal and flame retardant (FR) calorimetric parameters of PE nanocomposites for multifunctional applications especially in segments where heat inhibition and flame retardancy are essential.
In view of the research-substantiated comparative efficiency of nontoxic and bioavailable nanomaterials synergic with human systems for drug delivery, this work was aimed at studying the comparative efficiency of transition metal (Au, Os, and Pt)-decorated B12N12 nanocages in the adsorption of fluorouracil (5Fu), an antimetabolite-classed anticarcinogen administered for cancers of the breast, colon, rectum, and cervix. Three different metal-decorated nanocages interacted with 5Fu drug at the oxygen (O) and fluorine (F) sites, resulting in six adsorbent-adsorbate systems whose reactivity and sensitivity were investigated using density functional theory computation at the B3LYP/def2TZVP level of theory with special emphasis on the structural geometry, electronic, and topology analysis as well as the thermodynamic properties of the systems. While the electronic studies predicted Os@F as having the lowest and most favorable Egp and Ead of 1.3306 eV and -11.9 kcal/mol, respectively, the thermodynamic evaluation showed Pt@F to have the most favorable thermal energy (E), heat capacity (Cp), and entropy (ΔS) values as well as negative ΔH and ΔG while the adsorption studies showed that the greatest degree of chemisorption with Ead magnitude of -204.5023 kcal/mol was observed in energies ranging from -12.0 to 138.4 kcal/mol with Os@F and Au@F at the lower and upper borders. The quantum theory of atoms in molecules results show that the six systems had noncovalent interactions as well as a certain degree of partial covalency but none showed covalent interaction while the noncovalent interaction analysis corroborated this by showing that the six systems had favorable interactions, though of varying degrees, with very little trace of steric hindrance or electrostatic interactions. Overall, the study showed that notwithstanding the good performance of the six adsorbent systems considered, the Pt@F and Os@F showed the most favorable potential for the delivery of 5Fu.
ABSTRACT The growing demand for environmentally responsible materials has accelerated research into green composites that utilize recycled polymers and waste‐derived fillers. However, balancing mechanical strength, thermal stability, and compatibility among multiple fillers remains a key challenge. This study addresses this by formulating recycled high‐density polyethylene (rHDPE) composites reinforced with wood powder (WP) and calcium carbonate (CaCO3), and modified with ground tyre powder (GTP) and maleic anhydride grafted polyethylene (MAPE). The wood powder serves as a renewable lignocellulosic reinforcement to improve stiffness and reduce material cost, while calcium carbonate acts as an inorganic filler enhancing thermal stability and rigidity. Ground tyre powder is incorporated primarily as a waste valorization strategy to address the environmental challenge of end‐of‐life tyres. MAPE (5 wt%) functions as a compatibilizer to strengthen interfacial bonding between the hydrophilic and hydrophobic phases. Composites containing 0–25 wt% WP were prepared with fixed levels of CaCO3 (5 wt%), GTP (5 wt%), and MAPE (5 wt%) via extrusion and injection molding. The 0 wt% WP formulation serves as an internal baseline (rHDPE +5% MAPE +5% CaCO3 + 5% GTP), not neat rHDPE. Mechanical testing revealed marked increases in tensile strength, stiffness, and modulus with higher WP content, with optimal performance at 25 wt% WP. Elongation at break decreased accordingly, indicating the expected stiffness–ductility trade‐off. Thermogravimetric analysis (TGA) demonstrated notable improvements in char yield attributed to the cumulative contributions of CaCO3 and tyre‐derived residues, while differential scanning calorimetry (DSC) indicated reduced crystallinity. Fourier transform infrared spectroscopy (FTIR) confirmed the presence of constituent materials and showed spectral features consistent with enhanced interfacial compatibility, although covalent bond formation could not be definitively confirmed without complementary techniques (e.g., XPS). The findings demonstrate that combining lignocellulosic and inorganic fillers with recycled polymers and waste rubber yields composites with superior rigidity, strength, and thermal stability. This work provides a foundational formulation and processing protocol for sustainable composite development, while explicitly acknowledging that mechanistic interpretations of interfacial chemistry and filler synergy require further validation through controlled experimental designs and direct morphological/spectroscopic evidence.
Theoretical examination of hydroxyurea adsorption capabilities toward the cyclodextrin surface for proper drug delivery systems was carried out utilizing DFT simulations. The study aims to assess the efficacy of doped cyclodextrin (doped with boron, nitrogen, phosphorus, and sulfur atoms) in increasing its stability and efficiency in intermolecular interactions, hence facilitating optimal drug delivery. The adsorption energies were found to follow a decreasing order of B@ACD-HU>N@ACD-HU>P@ACD-HU>S@ACD-HU with energies of −0.046, −0.0326, −0.015, and 0.944 kcal/mol, respectively. The S@ACD-HU complex, unlike previous systems, had a physical adsorption energy. The N@ACD-HU and B@ACD-HU complexes had the shortest bond lengths of 1.42 Å (N122-C15) and 1.54 Å (B126-C15), respectively. The HOMO and LUMO values were also high in identical systems, −6.367 and −2.918 eV (B@ACD-HU) and −6.278 and −1.736 eV (N@ACD-HU), respectively, confirming no chemical interaction. The N@ACD-HU has the largest energy gap of 4.54 eV. For the QTAIM analysis and plots, the maximum electron density and ellipticity index were detected in B@ACD-HU, 0.600 au (H70-N129) and 0.8685 au (H70-N129), respectively, but N@ACD-HU exhibited a high Laplacian energy of 0.7524 a.u (H133-N122). The fragments' TDOS, OPDOS, and PDOS exhibited a strong bond interaction of greater than 1, and they had different Fermi levels, with the highest value of −8.16 eV in the N@ACD-HU complex. Finally, the NCI analysis revealed that the complexes were noncovalent. According to the literature, the van der Waals form of interactions is used in the intermolecular forces of cyclodextrin cavities. The B@ACD-HU and N@ACD-HU systems were more greenish in color with no spatial interaction. These two systems have outperformed other complexes in intermolecular interactions, resulting in more efficient drug delivery. They had the highest negative adsorption energies, the shortest bond length, the highest HOMO/LUMO energies, the highest energy gap, the highest stabilization energy, the strongest bonding effect, the highest electron density, the highest ellipticity index, and a strong van der Waals interaction that binds the drug and the surface together.
This study investigates how welding parameters affect weld bead geometry and microstructural characteristics of duplex stainless steel (DSS) using shielded metal arc welding (SMAW), highlighting the importance of process control for weld quality. The work examines heat input, controlled by welding current and electrode type, on bead geometry and microstructure. Welding was performed under direct current with electrode positive polarity (DCEP) at 90 and 110 A, with a constant voltage of 23.0 V, using DSS electrodes E1, E2, and C. Weld bead height and width were measured, and surface topography was analyzed with a stereomicroscope. High heat inputs of 1.52 and 1.51 kJ/mm produced wide weld beads exceeding 12.00 and 11.5 mm, while bead heights remained 1.60 and 2.21 mm. Microstructural analysis confirmed ferrite and austenite phases, and proper heat input promoted good fusion, whereas excessive or insufficient heat input impaired bead geometry and fusion quality.
