Assimilating hydrophilic hollow polymer spheres (HPS) into Nafion matrix by a loading of 0.5 wt % led to a restructured hydrophilic channel, composed of the pendant sulfonic acid groups (–SO3H) and the imbedded hydrophilic hollow spheres. The tiny hydrophilic hollow chamber was critical to retaining moisture and facilitating proton transfer in the composite membranes. To obtain such a tiny cavi...

Co3O4/NiO@GQDs@SO3H nanocatalyst has been used as an effective catalyst for the preparation of benzopyranopyridines through a four-component reaction of salicylaldehydes, thiols and 2 equiv of malononitrile under reflux condition in ethanol. The catalyst has been characterized by FT-IR, XRD, SEM, EDS, BET, XPS, TGA and VSM. Atom economy, reusable catalyst, low catalyst loading, applicability to...

We discovered a 1,3-dipolar species co-existing in two different structures. Photolysis of matrix-isolated 5-phenyltetrazole generates two forms of phenylnitrile imine: propargylic and allenic. They are not resonance structures but correspond to different energy minima, representing bond-shift isomers. These distinct species were characterized spectroscopically and confirmed by calculations up ...

We present here comparative assessments of murine lung toxicity (biocompatibility) after in vitro and in vivo exposures to carbon (C-SiO2-etched), carbon-silica (C-SiO2), carbon-cobalt-silica (C-Co-SiO2), and carbon-cobalt oxide-silica (C-Co3O4-SiO2) nanoparticles. These nanoparticles have potential applications in clinical medicine and bioimaging, and thus their possible adverse events require...

Engineered amorphous silica nanoparticles (SiO2 NPs), due to simple and low cost production, are increasingly used in commercial products and produced on an industrial scale. Despite the potential benefits, there is a concern that exposure to certain types of SiO2 NPs may lead to adverse health effects. As some NPs can cross the blood--brain barrier and may, in addition, reach the central nervo...

Atactic polystyrene (PS) has an amorphous structure. Compounds such as H2SO4 and SO3 are commonly used as sulfonating agents for various polymers, including PS. The main purpose of this work is to study chemical structural changes in PS arising from sulfonation through DSC analysis and NMR spectroscopy. An increase in the glass transition temperature (Tg) of sulfonated polystyrene and a decreas...

This work presented a novel core-shell MnO2@m-SiO2 for catalyzing the removal of dyes from wastewater. MnO2 nanorods were sequentially coated with polydopamine (PDA) and polyethyleneimine (PEI) forming MnO2@PDA-PEI. By taking advantage of the positively charged amine groups, MnO2@PDA-PEI was further silicificated, forming MnO2@PDA-PEI-SiO2. After calcination, the composite MnO2@m-SiO2 was final...

Novel hierarchical Cd4SiS6/SiO2 based heterostructure nanowire arrays were fabricated on silicon substrates by a one-step thermal evaporation of CdS powder. The as-grown products were characterized using scanning electron microscopy, X-ray diffraction, and transmission electron microscopy. Studies reveal that a typical hierarchical Cd4SiS6/SiO2 heterostructure nanowire is composed of a single c...

Silicon dioxide (SiO2) nanoparticles (NPs) have been widely used in the biomedical field, such as in drug delivery and gene therapy. However, little is known about the biological effects and potential hazards of SiO2. Herein, the colloidal SiO2 NPs with two different sizes (20 nm and 100 nm) and different charges (L-arginine modified: SiO2 (EN20[R]), SiO2 (EN100[R]); and negative: SiO2 (EN20[-]...