Wilcoxlowery1179

As an example of molecular design of new polymers, structures and properties of poly(ethylene thionoterephthalate) (PET[S2]) and the related polymers have been predicted from calculations of ab initio molecular orbital (MO) theory, rotational isomeric state (RIS) scheme, and periodic density functional theory (DFT). The MO calculations were confirmed by NMR experiments and introduced to the RIS scheme for PET[S2] to yield its configurational properties, which are compared herein with those of analogous polyester, polythioester, and polydithioester. Configurational properties of randomly thiono-substituted poly(ethylene terephthalate) (PET), PET[S z O1-z ], were also evaluated as a function of sulfidity (z). On the assumption that the crystal of PET[S2] can be expressed as an isomorphic replacement of the PET crystal, the crystal structure was optimized by a periodic DFT simulation and its Young's moduli in the a-, b-, and c-axis directions were, respectively, evaluated to be Ea = 0.94(7.20) GPa, E b = 19.58(22.26) GPa, and E c = 142.1(182.4) GPa, where the parenthetic values are those of the PET crystal. There is a possibility that properties of PET[S z O1-z ] will be controlled between those of PET and PET[S2] by adjusting the sulfidity. The potential practical applications of the polythionoesters are also discussed herein. By purely theoretical computations, the structures and properties of the not-yet synthesized polymers were predicted quantitatively; that is, the theoretical molecular design of new polymers has been achieved. Copyright © 2020 American Chemical Society.Inspired by the rampant digestive disorders and the vast bacterial infections, this study aimed at fabricating nanofibers made of inulin/polyvinyl alcohol (PVA) composite nanofibers (CNFs) using the electrospinning technique and testing their prebiotic and antibacterial activities. The inulin/PVA CNFs were tested for prebiotic activity with Lactobacillus species while Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were used to assess the antibacterial potentiality. During the fabrication of the CNFs, different electrospinning parameters have been carefully controlled, in order to produce nanofibers with relatively uniform diameter, fewer beads, and high integrity. The different parameters included variable solution concentration (material ratio varied from 14 to 20 wt %), applied voltage (varied from 15 to 25 kV), and solution flow (ranged between 0.005 and 0.5 mL/min). The chemical characteristics, thermal stability, and morphology of the formed CNFs were comprehensively characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy. Selected CNFs, showing the best diameter uniformity and integrity, were tested for the prebiotic and antimicrobial activity. A 38% increase in prebiotic activity of CNFs, compared to their bulk solution, was observed. The antibacterial activity of the selected CNFs was enhanced, from ∼40% (pure inulin) to 70% (inulin/PVA CNFs) against E. coli and 45% against S. aureus. This study investigates the prebiotic and antibacterial activities of PVA/inulin CNFs and provides the foundation for inulin/PVA CNF use in the healthcare sector, as in disinfectants and/or digestive disorders. Copyright © 2020 American Chemical Society.In this work, we propose using periodic Au nanoparticles (NPs) in indium selenide-based optoelectronic devices to tune the optical absorption of indium selenide. Electromagnetic simulations show that optical absorption of indium selenide can be manipulated by tuning plasmonic resonance. The effect on the plasmonic resonance of the size, period of NPs, the thickness of silicon oxide, and the insulator spacer is systematically analyzed. A high absorption enhancement over the visible spectrum is achieved through systematic optimization of nanostructures. Copyright © 2020 American Chemical Society.Investment in wearable monitoring systems is increasing rapidly for realizing their practical applications, for example, in medical treatment, sports, and security systems. However, existing wearable monitoring systems are designed to measure a real-time physical signal and abnormal conditions rather than harmful environmental characteristics. In this study, a flexible chemical sensor electrode based on a three-dimensional conductive nanofilm (3D CNF) is fabricated via facile polymerization with temperature control. The morphology and chemical state of the 3D CNF are modified via electrochemical doping control to increase the carrier mobility and the active surface area of the sensor electrode. The sensor electrode is highly sensitive (up to 1 ppb), selective, and stable for an analyte (NH3) at room temperature owing to the three-dimensional morphology of polypyrrole and the oxidation-level control. Copyright © 2020 American Chemical Society.Ni is widely used in the field of corrosion protection because of its stability, hardness, and ductility. Selonsertib Inspired by the excellent hydrophobicity of walnut wood, imparted by its porous structure, we synthesized a morph-genetic, porous Ni sheet. A pyrolyzed walnut template was immersed in a Ni2+ solution, allowing Ni to be electroplated on the surface and to enter the skeleton's pores. After calcination and surface modification, a template-free, low-surface-energy Ni sheet was obtained and accurately investigated by scanning electron microscopy and contact angle goniometry to evaluate its morphology and hydrophobicity. The results show that the Ni sheet inherited the complementary structure of the template, and, in turn, its water-repelling ability. We were able to measure contact angles as large as 150°, demonstrating that the new surface morphology endowed Ni with superhydrophobicity. Copyright © 2020 American Chemical Society.Dendrimer nanocarriers are unique hyper-branched polymers with biomolecule-like properties, representing a promising prospect as a nucleic acid delivery system. The design of effective dendrimer-based gene carriers requires considering several parameters, such as carrier morphology, size, molecular weight, surface chemistry, and flexibility/rigidity. In detail, the rational design of the dendrimer surface chemistry has been ascertained to play a crucial role on the efficiency of interaction with nucleic acids. Within this framework, advances in the field of organic chemistry have allowed us to design dendrimers with even small difference in the chemical structure of their surface terminals. In this study, we have selected two different cationic phosphorus dendrimers of generation 3 functionalized, respectively, with pyrrolidinium (DP) and morpholinium (DM) surface groups, which have demonstrated promising potential for short interfering RNA (siRNA) delivery. Despite DP and DM differing only for one atom in their chemical structure, in vitro and in vivo experiments have highlighted several differences between them in terms of siRNA complexation properties.