A major challenge in the synthesis of porous metal oxides is the control of pore size and/or wall thickness that may affect the performance of these materials. Herein, nanoporous β-MnO₂ samples were prepared using different hard templates, e.g., ordered mesoporous silica SBA-15 and KIT-6, disordered mesoporous silica, and colloidal silica. These samples were characterized by Powder X-Ray Diffra...

This article describes a simple microfluidic method to fabricate chitosan-silica hybrid microspheres in one step. We dissolved tetraethoxysilane (TEOS) into a chitosan/acetic acid aqueous solution to form a chitosan-silica sol, and then emulsified it in an organic phase mainly containing n-octanol and an organic base triotylamine (TOA) via a co-axial microfluidic device. The formed aqueous drop...

In this study, fluorescent dye-conjugated magnetic resonance (MR) imaging agents were investigated in T mode. Gadolinium-conjugated silica nanoparticles were successfully synthesized for both MR imaging and fluorescence diagnostics. Polyamine and polycarboxyl functional groups were modified chemically on the surface of the silica nanoparticles for efficient conjugation of gadolinium ions. The d...

the photocatalytic coatings were prepared via incorporating the modified titania nanoparticles into epoxy-based inorganic-organic hybrid coatings. titania nanoparticles were first synthesized from tetra-n-butyl titanate using sol-gel methods by two different calcination treatments, i.e., in mild condition (80°c) and 500°c. the formed anatase nanoparticles were further modified as titania-silica...

Mesoporous silica nanoparticles are used as pesticide carries in plants, which has been considered as a novel method to reduce the indiscriminate use of conventional pesticides. In the present work, mesoporous silica nanoparticles with particle diameters of 200-300 nm were synthesized in order to obtain pyrimethanil-loaded nanoparticles. The microstructure of the nanoparticles was observed by s...

Titania coated silica spheres (SiO2@TiO2) prepared by heterocoagulation of silica and titania nano-particles were investigated as catalyst in he photodegradation of rhodamine B (RB) in aqueous solution. The silica spheres were prepared by the well-known Stöber method and titania ol by a hydrolysis–condensation reaction in acidic media. The uncoated and coated particles were characterized by zet...

We have examined the superfluidity of 3He in 98.2% porous silica aerogel with up to 34% 4He at 21.6 bars. The mixture is phase separated for 4He fractions between ,11% and 34%, and the 4Herich phase preferentially occupies the regions of highest silica density in the aerogel, thus modifying the distribution of the correlated disorder seen by superfluid 3He. The 3He Tc increases slightly with 4H...

Functionalized arrays of silica nanochannels (ASNCs) were prepared by post-condensation of amino-functional alkoxysilanes (NH-silanes). The method of post-condensation combines postsynthetic grafting and co-condensation - the classical pathways for the functionalization of mesoporous silica - to afford a convenient one-pot reaction in aqueous medium. The structure of the NH-silanes determines t...

A new strategy to obtain a single-mode fiber with a flattened intensity profile distribution is presented. It is based on the use of an OVD-made high index ring deposited on a silica rod having a refractive index slightly lower than the silica used for the microstructured cladding. Using this strategy, we realized the first single-mode fiber with a quasi-perfect top-hat intensity profile around...

Mesoporous silica SBA-15 in the form of 10-30 μm sized sheets with unusually large ordered pores has been synthesized using heptane as a cosolvent in the presence of NH4F. The resulting morphology of 400 nm thick sheets that contain easily accessed, hexagonally arranged, 18 nm sized pores running parallel to sheet normal has not been previously reported. The material has a BET surface area of 5...