RESUMO
As an n-type semiconductor material, tungsten oxide (WO3) has good application prospects in the field of gas sensing. Herein, using oxalic acid (OA), citric acid (CA) and tartaric acid (TA) as auxiliary agents, three homogeneous tungsten oxide nanosheets were prepared by the rapid microwave-assisted hydrothermal method. The potential exhaled gases of various diseases were screened for the gas sensitivity test. Compared with WO3-OA and WO3-TA, WO3-CA exhibits significant sensitivity to formaldehyde, acetone and various alkanes. Photoluminescence (PL) chromatography and photoelectric properties show that its excellent gas sensitivity is due to its abundant oxygen vacancies and high surface charge migration rate, which can provide more preferential reaction sites with gas molecules. The experiment is of great significance for the sensor selection of the large disease exhaled gas sensor array.
RESUMO
Targeted release of anticancer drugs to tumor sites has a pivotal role in clinical oncology. pH-responsive drug delivery systems, with an intelligent and targeted release of anticancer drugs in a controllable manner based on sensitivities to the weakly acidic environments of tumor cellular microenvironments, are desirable. Herein, the design of such a pH-responsive drug delivery system is detailed using in situ amino-functionalized hollow mesoporous silica nanoparticles as carriers. The drug release behavior of the pH-responsive delivery system was evaluated under an in vitro simulation of tumor cellular microenvironments. The drug delivery system has efficient drug loadings and targeted release. Zorubicin hydrochloride releasing percentage is almost up to 100% at a buffer pH of 5.0. The drug release systems described demonstrating great potential in anticancer therapy.
RESUMO
A novel bioinspired approach for ordered mesoporous silica was developed on the basis of the synergic coassembly between polyamine and an anionic surfactant as a template. With the help of cationic polyamine, anionic surfactant micelles could be utilized as a mesostructure template, whereas with the aid of the anionic surfactant micelles the cationic polyamine chains underwent aggregation to exert their ability to induce silica condensation. Mesoporous silicas with well-ordered mesostructure of Fd-3m symmetry and 3D hexagonal close-packed mesostructure (hcp) were fabricated. Because of the abundant types of anionic surfactants and polyamines, the synthesis approach can be regarded as a general method for anionic-surfactant-templated mesoporous silica, and new mesostructures and morphologies are expected.
Assuntos
Poliaminas/química , Dióxido de Silício/química , Tensoativos/química , Ânions/química , Tamanho da Partícula , Porosidade , Propriedades de SuperfícieRESUMO
Mesoporous silica with three-dimensional (3D) bicontinuous cubic Ia-3d structure and fascinating caterpillar-like morphology was synthesized by using anionic surfactant N-lauroylsarcosine sodium (Sar-Na) as the template and 3-amionpropyltrimethoxysilane (APS) as the co-structure-directing agent (CSDA) with the aid of acetate. A phase transformation from high interfacial curvature 2D hexagonal to low interfacial curvature 3D cubic Ia-3d occurred in the presence of a proper amount of acetate. Other species of salts (excluding acetate) had the ability to induce the caterpillar-like morphology, but failed to induce the cubic Ia-3d mesostructure. Furthermore, [3-(2-aminoethyl)-aminopropyl]trimethoxysilane (DAPS) was also used as the CSDA to synthesize Ia-3d mesostructured silica under the aid of sodium acetate. After extraction of the anionic surfactants, amino and di-amine functionalized 3D bicontinuous cubic Ia-3d mesoporous silicas were obtained and used as supports to immobilize Pd nanoparticles for supported catalysts. The catalytic activity of the catalysts was tested by catalytic hydrogenation of allyl alcohol.
