Macromolecular Symposia最新文献

The quest for alternative energy sources has been spurred by the drawbacks and environmental risks of fossil fuels, with hydrogen emerging as a viable contender. But finding materials that can effectively store hydrogen with the best adsorption energy is a major obstacle to building a hydrogen-based economy. As a result, a significant amount of research has been conducted worldwide to examine fullerene's (C60) potential for hydrogen adsorption. The results of extensive DFT calculations are presented here, pertaining to the adsorption of hydrogen molecules onto fullerenes doped with alkali metals, namely Rubidium (Rb), Ceasium (Cs), and Fransium (Fr). The study analyzes a number of parameters, such as global properties, electronic, optical, and surface annihilation energy. These analyses are performed using the Gaussian 09 simulation package with the 6–31G/B3LYP level of theory DFT methodology. The findings show that an exothermic process is involved in the adsorption of hydrogen onto fullerene doped alkali elements, as evidenced by the negative adsorption energy. The attractive interactions between the polarized dipole of hydrogen molecules and the surface dipole of doped fullerenes can be the cause of this exothermicity. These results imply that fullerenes decorated with alkali metals are promising as likely hydrogen storage media.

CeO₂ nanoparticles are synthesized hydrothermally using CTAB as a surfactant, cerium nitrate hexahydrate (Ce(NO₃)₃·6H₂O) as a precursor and urea. The synthesized CeO₂ nanoparticles are characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction peak profile analysis (XRD), Scanning electron microscopy (SEM), and UV–vis. The X-ray diffraction results revealed that the sample is crystalline with a face centered cubic (fcc) phase having cubic fluorite structure. The structural elements of prepared samples have been investigated by various methods. The Monshi, W–H analysis, size–strain plot, and H–W methods are used to study crystallite sizes and lattice strain on the peak broadening of CeO₂ nanoparticles. Further, the lattice constant of the cubic fluorite has also been estimated from the Nelson–Riley plot. The parameters, including strain, stress, and energy density value, are calculated for all the reflection peaks of X-ray diffraction corresponding to cubic fluorite phase of CeO₂ lying in the range 20°–80° and at different temperatures.

The fuel cell carries the promise of being ecologically beneficial and being one of the renewable energy choices. Solid acids have super-protonic behavior, allowing them to act as conductors. It can operate at high temperatures. Hydration, on the other hand, can be employed to increase the solid acid and performance. Furthermore, the size of the electrolyte membrane influences the conductivity, stability, and crystal structure of the fuel cell solid acid compounds. Very few studies have been conducted on solid acid fuel cells, which are still being researched in order to make them feasible as well as a trustworthy alternative to clean renewable energy. This review presents an outline of the variables or attributes and current challenges that influence the technical efficacy and performance of the unique super-protonic conductors for solid acid fuel cells.

Tuberculosis (TB) is a deadly disease of global concern. The previous work studies the geometric optimization, vibrational analysis, TDDFT, and electronic properties of the TB pathogen drug isoniazid (ISO). This communication will discuss the changes in geometry, electronic properties, and shielding parameters of ISO-absorbed carbon nanotube (CNT) (CNT-ISO, C₅₆H₁₆). This study has used the DFT/B3LYP/6–311G (d, p) method for the first time to report ISO's electronic structure and interaction parameters on the CNT surface. The same level theory is used to discuss the thermodynamic stability of CNT-ISO. The calculated UV spectra of CNT are compared with UV spectra of CNT-ISO by using the same level theory in a water solvent, which provides a better comprehension of CNT as a drug delivery system after absorption of the ISO in the human body. The nature and strength of interactions have been discussed with the help of NBO and AIM analysis, and the frontier orbital highest occupied molecular orbital–lowest unoccupied molecular orbital (HOMO-LUMO) gap, chemical softness, and chemical hardness have been calculated to understand its complete chemical properties. The characters of the frontier molecular orbitals are discussed and analyzed by comparing the DOS spectra of CNT with CNT-ISO. It has also examined the scan plot of interaction with time using ab-initio dynamics simulation (ADMP) calculations.

Olivacine, a semisynthetic isomer of ellipticine, belongs to the family of natural alkaloids; which possess analgesic, antibacterial, and antipyretic properties. It is a model anticancer drug acting as topoisomerase II inhibitor. The mechanism of action and antineoplastic properties of olivacine are ascribed to its intercalative binding into DNA helices. The present paper reports DFT investigation of the molecular structure, electronic properties, and global reactivity descriptors of the drug. Frontier orbitals (HOMO and LUMO) and MEP surface of the olivacine molecule have been examined. Furthermore, inhibition activity and binding sites of olivacine with kinase protein (PDB Id: 3OG7) have been explored by molecular docking technique. Results have been used to elucidate physico-chemical aspects and preferred binding patterns of the olivacine drug.

In the present study, an effort is made to record the thermoelectroluminescence (TEL) glow curves and electroluminescence (EL) spectra for anthracene, acridine, and anthracene doped with acridine to determine the trap depth and escape frequency in these materials. For recording the TEL glow curves, the EL cell is heated at the study rate after 500 V_rms (RMS) of AC is supplied between the plates. At various field frequencies, the light output is recorded. To comprehend the luminescence processes and mechanisms in these films, three methods have been employed to determine the trap energy and escape frequency.

Bisphenol A is an oil-derived, large market volume chemical with a wide spectrum of applications in plastics, adhesives, and thermal papers. However, bisphenol A and its derivative are not considered safe due to its endocrine disrupting properties and reproductive toxicity. A nontoxic alternative of bisphenol analogus has been proposed in this study using plant biomass. A study of different DFT-based QSAR approaches has been done to show the significance of the conceptual DFT-based selected descriptors with different QSAR models in the prediction of toxicity and to establish meaningful correlations between the molecular structure of the proposed compounds and their toxicological properties. Multiple regression analysis and ANN model are also suggested to use to relate the biological activity with the global and local reactivity descriptors.

A second-generation HIV protease enzyme inhibitor, darunavir is used in combination therapy for patients with history of prior antiretroviral treatments. It inhibits the cleavage of HIV encoded gag-pol polyprotein in cells contaminated by a virus and thereby hinders the development of mature and infectious new virions. In this paper, optimization of molecular geometry of darunavir has been obtained by Density Functional Theory based B3LYP and ωB97XD methods with 6–311+G(d,p) basis set. The electro-optical, global reactivity descriptors, and UV–visible spectrum of the drug have been examined using both the functionals. Further, binding affinity of darunavir at different sites of protein receptor (PDB ID: 5b18) has been analyzed using molecular docking technique. Results have been used to discuss electro-optical and electronic properties of the drug along with its binding affinities with protein receptors.

Cold cathode emission or cold field emission (CFE) is a purely quantum mechanical phenomenon and a phenomenon of wonder. The exact science behind the observed current (I)–voltage (V) is yet to be pin pointed. For instance, a good cold emitter is very reasonably supposed to have low work function and good conductivity whereas a carbon allotropes like diamonds have just the reverse in both the cases, i.e., it is insulating in nature having very wide band gap as well as high work function yet it is considered to be an efficient field emitter. Since early of 20th century, till its middle a number of groups have suggested different equations or relations that can adequately describe the experimental CFE I–V characteristics adequately. Although they all fundamentally follow an exponential law, but so far, the relation suggests by Fowler and Nordheim (F–N) is the most accepted one. However, there is another relationship suggested by Millikan and Lauritsen (M–L) which is in spite of being reasonable not so common now a day to use. This work revisits different popular approaches for analyzing cold emission data. With this aim, the experimental CFE data obtained for chemically synthesized zinc oxide nanorods are chosen. The proper phase formation of ZnO is confirmed by XRD study whereas FESEM shows the rod like morphology. EDX confirms the proper stoichiometric ratio for the sample. After detail analysis it is confirmed that the theoretically proposed relation between F–N and M–L experimentally holds good as well and thus it would not be wrong to analyze the CFE data by simple M–L theory.

With the escalating global energy demand, the exploration of alternative, easily accessible, and cost-effective energy sources has become imperative. The diminishing reserves of conventional energy resources underscore the urgency to transition towards renewable energy. Solid polymer electrolytes (SPEs) have gained prominence for energy storage electrochemical devices due to their high flexibility and favorable electrode–electrolyte interactions. This study focuses on synthesizing nano cuprous oxide (CuO) semiconductors via the precipitation method. The prepared CuO nanofiller is homogeneously dispersed into a polymer electrolyte solution. Utilizing the solution cast method, free-standing polymer electrolyte films are fabricated, exhibiting commendable mechanical stability. Polyvinyl alcohol (PVA) serves as the host material, with potassium iodide (KI) salt, forming the basis for the polymer electrolyte. The resultant electrolyte films underwent comprehensive characterization for their electrical and optical properties. The investigation aims to identify the optimal composition of the electrolyte film with superior conductivity. The selected composition will be employed in the fabrication of various electrochemical devices, demonstrating the potential for enhanced energy storage applications. This work not only contributes to the synthesis of advanced solid polymer electrolyte films but also paves the way for the development of efficient and sustainable energy storage solutions in the realm of renewable energy technologies.