Nanotechnology has become one of the most promising new approaches for pest control in recent years. In our screening program, laboratory trials were conducted to determine the effectiveness of silica nanoparticles (SNP) and silver nanoparticles (AgNP) on larval stage and adults of Callosobruchus maculatus on cowpea seed. Nanoparticles of silica and silver were synthesized through a solvotherma...

The solid-liquid phase transition of silica encapsulated bismuth nanoparticles was studied by in situ transmission electron microscopy (TEM). The nanoparticles were prepared by a two-step chemical synthesis process involving thermal decomposition of organometallic precursors for nucleating bismuth and a sol-gel process for growing silica. The microstructural and chemical analyses of the nanopar...

Effects of calcination temperatures varying from 400 to 1000°C on structural and magnetic properties of nanocomposites formed by Co-ferrite dispersed in the sol-gel silica matrix using tetrakis(2-hydroxyethyl) orthosilicate (THEOS) as water-soluble silica precursor have been investigated. Studies carried out using XRD, FT-IR, TEM, STA (TG-DTG-DTA) and VSM techniques. Results indicated that magn...

The synthesis of bulk imprinted silica using colloidal gold as a functional template is demonstrated. The imprinting approach relies on the isolation of colloidal gold in gold@silica nanoparticles synthesized via a 3-aminopropyltrimethoxysilane (APS) route. Gold@silica nanoparticles are then condensed within a silica framework for the synthesis of a composite gold-silica material containing ~30...

Today, by using half of the oil reserves of the world, natural production of oil has decreased drastically. Gas and water injection for maintaining reservoir pressure is not responsive for oil production.At first, we dispersed silica nanoparticles in low salinity and after two weeks, there was no change in its stability. Then we mixed the nanoparticles in low salinity. After a while, we found o...

The antimicrobial effects of silver nanoparticles were studied. Silver nanoparticles were synthesized through wet chemistry method, and were dispersed in an aqueous suspension. With nanoscale silica particles serving as heterogeneous nucleation sites, silver nanoparticles were formed on the silica surface. Suspensions were found to be stable at high silver concentrations as well as over a broad...

Monodisperse, spherical, polyethylene glycol (PEG)-coated silica nanoparticles have been prepared at room temperature and characterized for the purpose of biomedical applications. The particles were synthesized by the hydrolysis of tetramethyl orthosilicate (TMOS) in alcohol media under catalysis by ammonia, and their size can range from about 50-350 nm in diameter. We studied the particle size...

We investigate by scattering techniques the structure of water-based soft composite materials comprising a crystal made of Pluronic block-copolymer micelles arranged in a face-centered cubic lattice and a small amount (at most 2% by volume) of silica nanoparticles, of size comparable to that of the micelles. The copolymer is thermosensitive: it is hydrophilic and fully dissolved in water at low...

By controlling the interaction between cationic surfactant micelles and ammonium metatungstate during the formation of mesoporous silica structure, highly dispersed tungsten carbide (WC) nanoparticles of 2.0 nm in diameter on mesoporous silica nanospheres were synthesized at lower concentration of ammonium metatungstate. With additional ammonium metatungstate, a novel mesoporous silica nanobamb...

Mesoporous silica nanoparticles coencapsulating gadolinium oxide and horseradish peroxidase (HRP) have been synthesized in the aqueous core of sodium bis-(2-ethylhexyl) sulfosuccinate (AOT)-hexane-water reverse micelle. The average diameter of these silica particles is around 25 nm and the particles are spherical and highly monodispersed as depicted using transmission electron microscopy. The e...