RESUMEN
Composite polymer electrolytes (CPEs) with smart, stimuli-responsive characteristics have gained considerable attention owing to their noninvasive manipulation and applications in future technologies. To address this potential, in this work, we demonstrate photoresponsive composite polymer electrolytes, consisting of gel polymer electrolyte (GPE) and spiropyran-immobilized nanoporous anodic aluminum oxide (SP-AAO) templates. Under UV irradiation, the close SP form isomerizes to the open merocyanine (MC) form, creating extremely polarized AAO surfaces; whereas, under visible light irradiation, the MC form reverts to the SP form, creating neutral surface conditions. The electrostatic interactions between ions and AAO surfaces are investigated by attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy. Moreover, the behavior of ionic conductivity of the GPE@SP-AAO is found to be consistent with the kinetics of isomerization tracked by UV-Vis spectroscopy. This work provides a promising platform for developing next-generation photoelectronic smart devices.
Asunto(s)
Nanoporos , Polímeros , Benzopiranos , Electrólitos , Indoles , NitrocompuestosRESUMEN
Ordered arrays of polymer nanostructures have been widely investigated because of their promising applications such as solar-cell devices, sensors, and supercapacitors. It remains a great challenge, however, to manipulate the shapes of individual nanostructures in arrays for tailoring specific properties. In this study, an effective strategy to prepare anisotropic polymer nanopillar arrays via photo-fluidization is presented. Azobenzene-containing polymers (azopolymers) are first infiltrated into the nanopores of ordered anodic aluminum oxide (AAO) templates. After the removal of the AAO templates using weak bases, azopolymer nanopillar arrays can be prepared. Upon exposure of linearly polarized lights, azobenzene groups in the azopolymers undergo trans-cis-trans photoisomerization, causing mass migration and elongation of the nanopillar along with the polarization directions. As a result, anisotropic nanopillar arrays can be fabricated, of which the deformation degrees are controlled by the illumination times. Furthermore, patterned nanopillar arrays can also be constructed with designed photomasks. This work presents a practical and versatile strategy to fabricate arrays of anisotropic nanostructures for future technical applications.
Asunto(s)
Óxido de Aluminio , Nanoporos , Electrodos , Rayos Láser , PolímerosRESUMEN
1D polymer nanomaterials have attracted significant interest in recent years because of their unique properties and promising applications in various fields. It is, however, still a challenge to fabricate polymer nanoarrays with desired sizes and controlled morphologies. Here, an unprecedented approach, the laser-assisted nanowetting (LAN) method, to selectively fabricate polymer nanoarrays is presented. Polystyrene (PS) is blended with gold nanorods (AuNRs), which are used to absorb the energy from the laser. After the blend films are brought in contact with AAO templates, the AuNRs at regions shone by the laser beams absorb the energy and heat the surrounding polymer chains, resulting in the formation of PS/AuNRs arrays in selected areas. This work paves a new research direction for developing template-based polymer nanomaterials.
Asunto(s)
Óxido de Aluminio/química , Oro/química , Rayos Láser , Nanoestructuras/química , Poliestirenos/química , Electrodos , Tamaño de la Partícula , Propiedades de Superficie , HumectabilidadRESUMEN
Surface properties are essential for substrates exhibiting high sensitivity in surface-enhanced Raman scattering (SERS) applications. In this work, novel SERS hybrid substrates using polystyrene-block-poly(methyl methacrylate) and anodic aluminum oxide templates is presented. The hybrid substrates not only possess hierarchical porous nanostructures but also exhibit superhydrophilic surface properties with the water contact angle ≈0°. Such surfaces play an important role in providing uniform enhanced intensities over large areas (relative standard deviation ≈10%); moreover, these substrates are found to be highly sensitive (limit of detection ≈10-12 m for rhodamine 6G (R6G)). The results show that the hybrid SERS substrates can achieve the simultaneous detection of multicomponent mixtures of different target molecules, such as R6G, crystal violet, and methylene blue. Furthermore, the bending experiments show that about 70% of the SERS intensities are maintained after bending from ≈30° to 150°.
Asunto(s)
Óxido de Aluminio/química , Polímeros/química , Rodaminas/análisis , Humectabilidad , Electrodos , Tamaño de la Partícula , Espectrometría Raman , Propiedades de SuperficieRESUMEN
Lateral thyrotomy and strap muscle transposition have been used independently before. However, the published literature does not record the coordinated use of both procedures in the treatment of Teflon granuloma. In this paper, we present a case of vocal fold paralysis that had been treated successfully by Teflon injection in 1999. Two years later, however, the patient developed a host of symptoms that included a husky voice, shortness of breath and suffocation, which indicated Teflon granuloma. He underwent surgery to excise the Teflon granuloma via a lateral thyrotomy. The affected paraglottic space was then reconstructed using strap muscle transposition. One year postoperatively, the glottis had closed completely on phonation, and the voice retained a moderate roughness due to a scarring change from the earlier Teflon reaction. The patient had no problems with aspiration or shortness of breath during speaking. Our experience indicates that a physician can remove the entire granuloma and create a smooth, straight vibratory surface with complete glottic closure during phonation by using a combination of lateral thyrotomy and strap muscle transposition.