A General and Simple Method of Preparing Molybdenum- Incorporated Silica Nanoparticles as Potential Catalysts for Epoxidation of Alkenes

AbstractWe describe a simple method for the preparation of gold-decorated silica (SiO2) nanoparticles (NPs) by the in situ precipitation method using simple BH4− ions reduction as a procedure, where BH4− ions are adsorbed onto PEI-functionalized SiO2 NPs for stabilizing and reducing gold ions onto PEI-SiO2 surface in water under ambient conditions. The result was 3-nm gold nanoshell NPs attached to SiO2 core (~ 75 nm) with a surface plasmon resonance (SPR) at ~ 680 nm. SPR band is associated with Au NP aggregates that arise from strong interparticle interaction. This is an alternative to the gold-seeding methods and the use of anionic gold species for the obtention of gold-decorated SiO2 NPs with an important red-shift in UV–Vis absorption and with potential applications in biosensors and photothermal therapy.

Download Full-text

Facile Synthesis Silica Nanoparticles from Indonesia Silica Sand and their Physico-Chemical Properties

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.862.35 ◽

2020 ◽

Vol 862 ◽

pp. 35-39

Author(s):

Agus Ismail ◽

Ariffinisa Lintang Widyaningtyas ◽

Bambang Heru Susanto ◽

Mohammad Nasikin

Keyword(s):

Silica Nanoparticles ◽

Sodium Silicate ◽

Sol Gel ◽

Chemical Properties ◽

Spherical Shape ◽

Sodium Silicate Solution ◽

Silicate Solution ◽

Silica Sand ◽

Easy Method ◽

Simple Method

Silica nanoparticles are a very promising functional material when purified from silica sand for wide application. In addition, a low cost and easy method to obtain the material will be increasing the value of silica sand. To synthesize of nanoparticles using an easily scalable, cheap and simple method, we suggest a sodium silicate solution as a precursor that silica sand was diluted on the NaOH. After that, the sodium silicate solution under various alcohols (methanol and ethanol) in the acid medium was conducted by sol gel method to obtain silica nanoparticles. The synthesized of silica nanoparticles was observed to the non-agglomerate, homogeneous and spherical shape with an average size about 200 nm. We also noted the existence of NaNO3 by side product of reaction on the system, which may be the amorphous silica unidentified on the XRD results.

Download Full-text

‘Overloading’ fluorescent silica nanoparticles with dyes to improve biosensor performance

Journal of Materials Chemistry B ◽

10.1039/c7tb01284e ◽

2017 ◽

Vol 5 (28) ◽

pp. 5564-5572 ◽

Cited By ~ 12

Author(s):

Colin J. Moore ◽

Giorgia Giovannini ◽

Filip Kunc ◽

Andrew J. Hall ◽

Vladimir Gubala

Keyword(s):

Silica Nanoparticles ◽

Proof Of Concept ◽

Target Concentration ◽

Simple Method ◽

Fluorescent Signal ◽

Fluorescent Silica Nanoparticles

Using dye-doped silica nanoparticles (DSNP) as reporter probes, we describe a simple method of enhancing fluorescent signal and the extension of the detectable target concentration range in a proof-of-concept ‘dissolution immunoassay’.

Download Full-text

An Alternative and Simple Method for the Preparation of Bare Silica Nanoparticles Using Sugarcane Waste Ash, an Abundant and Despised Residue in the Brazilian Industry

Journal of the Brazilian Chemical Society ◽

10.21577/0103-5053.20190049 ◽

2019 ◽

Cited By ~ 3

Author(s):

Suzimara Rovani ◽

Jonnatan Santos ◽

Paola Corio ◽

Denise Fungaro

Keyword(s):

Silica Nanoparticles ◽

Simple Method

Download Full-text

Pd@Py2PZ@MSN as a Novel and Efficient Catalyst for C-C Bond Formation Reactions

10.21203/rs.3.rs-661021/v1 ◽

2021 ◽

Author(s):

Mohammad Hossein Sayahi ◽

Mansoureh Toosibashi ◽

Mehdi Bahmaei ◽

Hosein Lijan ◽

Leila Maˈmani ◽

...

Keyword(s):

Mesoporous Silica ◽

Silica Nanoparticles ◽

Mesoporous Silica Nanoparticles ◽

Bond Formation ◽

Significant Loss ◽

Efficient Catalyst ◽

Simple Method ◽

Carbon Carbon Bond ◽

Novel Catalyst ◽

Bond Formation Reactions

Abstract In this paper, a novel catalyst is introduced based on the immobilization of palladium onto dipyrido[3,2-a:2',3'-c]phenazine modified mesoporous silica nanoparticles. Dipyrido[3,2-a:2',3'-c]phenazine (Py2PZ) ligand is synthesized in a simple method from the reaction of 1,10-phenanthroline-5,6-dione and 3,4-diaminobenzoic acid as starting materials. The ligand is used to functionalize mesoporous silica nanoparticles (MSN) and to modify its surface chemistry for immobilization of palladium. The palladium immobilized dipyrido[3,2-a:2',3'-c]phenazine modified mesoporous silica nanoparticles (Pd@Py2PZ@MSN) are synthesized and characterized by several characterization techniques, including TEM, SEM, FTIR, TGA, ICP, XRD, and EDS analysis. After the careful characterization of Pd@Py2PZ@MSN, the activity and efficiency of this catalyst is examined in carbon-carbon bond formation reactions. The results are advantageous in water and the products are obtained in high isolated yields. In addition, the catalyst shows very good reusability and did not show significant loss in activity after 10 sequential runs.

Download Full-text

A simple way for producing holographic filters suitable for image improvement

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100108271 ◽

1978 ◽

Vol 36 (1) ◽

pp. 226-227

Author(s):

K.-H. Herrmann ◽

E. Reuber ◽

P. Schiske

Keyword(s):

Transfer Functions ◽

Diffraction Order ◽

Lateral Position ◽

Simple Method ◽

Spatial Frequencies ◽

Resolution Electron ◽

Wiener Filters ◽

Image Improvement ◽

Optical Reconstruction ◽

Set Up

Aposteriori deblurring of high resolution electron micrographs of weak phase objects can be performed by holographic filters [1,2] which are arranged in the Fourier domain of a light-optical reconstruction set-up. According to the diffraction efficiency and the lateral position of the grating structure, the filters permit adjustment of the amplitudes and phases of the spatial frequencies in the image which is obtained in the first diffraction order.In the case of bright field imaging with axial illumination, the Contrast Transfer Functions (CTF) are oscillating, but real. For different imageforming conditions and several signal-to-noise ratios an extensive set of Wiener-filters should be available. A simple method of producing such filters by only photographic and mechanical means will be described here.A transparent master grating with 6.25 lines/mm and 160 mm diameter was produced by a high precision computer plotter. It is photographed through a rotating mask, plotted by a standard plotter.

Download Full-text

Rotary Beveling for In Situ Thin-Section Microscopy of Cell Cultures

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100099192 ◽

1981 ◽

Vol 39 ◽

pp. 550-551

Author(s):

Dean A. Handley ◽

Jack T. Alexander ◽

Shu Chien

Keyword(s):

Cell Growth ◽

Cell Cultures ◽

Molecular Interactions ◽

Convenient Method ◽

Petri Dish ◽

Simple Method ◽

Thin Section Microscopy ◽

Thin Sectioning ◽

Organic Fluids

In situ preparation of cell cultures for ultrastructural investigations is a convenient method by which fixation, dehydration and embedment are carried out in the culture petri dish. The in situ method offers the advantage of preserving the native orientation of cell-cell interactions, junctional regions and overlapping configurations. In order to section after embedment, the petri dish is usually separated from the polymerized resin by either differential cryo-contraction or solvation in organic fluids. The remaining resin block must be re-embedded before sectioning. Although removal of the petri dish may not disrupt the native cellular geometry, it does sacrifice what is now recognized as an important characteristic of cell growth: cell-substratum molecular interactions. To preserve the topographic cell-substratum relationship, we developed a simple method of tapered rotary beveling to reduce the petri dish thickness to a dimension suitable for direct thin sectioning.

Download Full-text