RESUMEN

Super-porous hydrogels are considered a potential drug delivery network for the sedation of gastric mechanisms with retention windows in the abdomen and upper part of the gastrointestinal tract (GIT). In this study, a novel pH-responsive super-porous hybrid hydrogels (SPHHs) was synthesized from pectin, poly 2-hydroxyethyl methacrylate (2HEMA), and N, N methylene-bis-acrylamide (BIS) via the gas-blowing technique, and then loaded with a selected drug (amoxicillin trihydrate, AT) at pH 5 via an aqueous loading method. The drug-loaded SPHHs-AT carrier demonstrated outstanding (in vitro) gastroretentive drug delivery capability. The study attributed excellent swelling and delayed drug release to acidic conditions at pH 1.2. Moreover, in vitro controlled-release drug delivery systems at different pH values, namely, 1.2 (97.99%) and 7.4 (88%), were studied. These exceptional features of SPHHs-improved elasticity, pH responsivity, and high swelling performance-should be investigated for broader drug delivery applications in the future.

RESUMEN

An Sb2S3-sensitized TiO2 (Sb2S3/TiO2) photo-anode (PA) exhibiting a high photo-electrochemical (PEC) performance in water oxidation has been successfully prepared by a simple chemical bath deposition (CBD) technique. Herein, the Raman spectra and XPS spectrum of Sb2S3/TiO2 confirmed the formation of Sb2S3 on the TiO2 coatings. The Sb2S3/TiO2 photo-anode significantly shifted the absorption edge from 395 nm (3.10 eV) to 650 nm (1.90 eV). Furthermore, the Sb2S3/TiO2 photo-anode generated a photo-anodic current under visible light irradiation below 650 nm due to the photo-electrochemical action compared with the TiO2 photo-anode at 390 nm. The incident photon-to-current conversion efficiency (IPCE = 7.7%) at 400 nm and -0.3 V vs. Ag/AgCl was 37 times higher than that (0.21%) of the TiO2 photo-anodes due to the low recombination rate and acceleration of the carriers of Sb2S3/TiO2. Moreover, the photo-anodic current and photostability of the Sb2S3/TiO2 photo-anodes improved via adding the Co2+ ions to the electrolyte solution during photo-electrocatalysis.

RESUMEN

Heat dissipation efficiency and electromagnetic interference (EMI) shielding performance are vital to integration, miniaturization, and application of electronic devices. Flexible and designable polymer-based composites are promising candidates but suffer from unavoidable interfacial thermal resistances, anisotropic thermal conductivity, and low shielding of EMI limiting application. Herein, multifunctional epoxy resin (EP)-based composites with an interconnected carbon fibers (CFs) network structure containing a low thermal resistance interfacial were prepared by high-temperature calcination and infiltration. The coherent heat and electron transfer pathways constructed with self-oriented CFs cloth connected by carbon nanotubes (CNTs) converted from leaf-shaped zeolitic imidazolate frameworks (ZIF-L) and stable magnetic property provided by cobalt nanoparticles contained in the CNTs made composites to an integrated in-plane thermal conductivity of up to 7.50 W m-1 K-1, a through-plane thermal conductivity of 1.96 W m-1 K-1, and an EMI shielding effectiveness of 38.4 dB. Furthermore, the mechanical properties of CFs and the junction effect of CNTs endowed the composites with stability of mechanical property, thermal conductivity, and EMI shielding effectiveness after multiple bendings. The finite element simulation further verified the advantage of CFs network linked by CNTs on heat transfer. This work provides the desired design for the construction of a multifunctional polymer-based composite used in advanced electronic equipment.

RESUMEN

Ion-exchange membranes are the core elements for an electrodialysis (ED) separation process. Phase inversion is an effective method, particularly for commercial membrane production. It introduces two different mechanisms, i.e., thermal induced phase separation (TIPS) and diffusion induced phase separation (DIPS). In this study, anion exchange membranes (AEMs) were prepared by grafting a quaternized moiety (QM,2-[dimethylaminomethyl]naphthalen-1-ol) through brominated poly (2,6-dimethyl-1,4-phenylene oxide) (BPPO) via the TIPS method. Those membranes were applied for selective bisulfite (HSO3-) anion separation using ED. The membrane surface morphology was characterized by SEM, and the compositions were magnified using a high-resolution transmission electron microscope (HRTEM). Notably, the membranes showed excellent substance stability in an alkali medium and in grafting tests performed in a QM-soluble solvent. The ED experiment indicated that the as-prepared membrane exhibited better HSO3- separation performance than the state-of-the-art commercial Neosepta AMX (ASTOM, Japan) membrane.

Asunto(s)

RESUMEN

It remains a challenge to develop highly polymer-based nanocomposite thermal interface materials, which can effectively remove heat developed during the miniaturization of electronic instruments. It has been reported that a large number of graphene-based nanocomposites exhibit excellent performance. However, it is still an issue to construct thermal conductive pathways by orientation arrangements with a low filler volume fraction. Herein, a high-thermal conductivity filler of magnetic carbon nanotube-grafted graphene polyhedra (Co@Co3O4-G) was exploited via the annealing of metal-organic frameworks (ZIF-67). Co@Co3O4-G can improve the thermal conductivity of nanocomposites obviously by forming oriented pathways for phonon transport in an external magnetic field. Therefore, the resulting nanocomposite displayed a high thermal conductivity of 2.11 W m-1 K-1 for only 8.7 vol%, which is 10 times higher than that of the pure epoxy resin. Core-shell magnetic cobalt oxide (Co@Co3O4) was encapsulated in situ in the nanoarchitecture to avoid falling off. Moreover, the equilibrium molecular dynamics (EMD) simulation verifies that Co@Co3O4-G had high thermal conductivity to effectively improve the heat dissipation of nanocomposites. This strategy provides an approach for developing high-performance thermal management materials and opens up the possibility for the pioneering applications of encapsulated magnetic-oriented thermal conductive fillers.