Posts

Showing posts from February, 2012

Nanoclusters

Image
Study of nanoclusters provides insight into the mesoscopic regime between single molecules and bulk crystals. Nanoclusters exhibit strong quantum confinement and surface effects. Using nanoclusters as “building blocks” for novel materials offers an opportunity to understand how atomic structure can lead to physical and chemical properties of macroscopic materials. It is possible to produce Nan clusters with atomic arrangements that do not normally exist in nature, leading to novel optical and magnetic properties. ZnO semiconductor sources ZnO is a wide band gap semiconductor that has attracted tremendous interest as blue light emitting materials, gas sensors and transparent conductors in solar cells. Unlike other semiconductor compounds that contain cadmium, arsenic, or other environmental toxins, zinc and oxygen are “environment friendly” elements. In fact, ZnO is used as a dietary supplement in animal feed. The stability of excitons in ZnO results in a very high quantum efficiency a

Nanocoating for quick boiling

Image
Copper bottom cookware Copper bottom cookware is the best option available nowadays for those who are looking for a quality cookware. Copper Cookware has tin, aluminum, or stainless steel cookware with a copper core having a layer of metal in between other layers of non-copper or with a copper exterior. Copper bottom cook wares are used because copper disperses heat fast and help cook food fast and keep the surface heat even. This is because the heat conductivity of copper metal is double that of aluminum metal and is ten times more than the stainless steel. Many cookware products produced nowadays do not serve the purpose perfectly as these types of cookware are not ideal in the material they are made up of and because of pool boiling. Boiling In boiling, bubbles carry away large amounts of heat from solid surfaces, but the bubbles also act as an insulator, preventing the liquid from rewetting the surface and thereby interrupting heat transfer. Pool boiling is the most common and fam

Pay loaded dendrimer to treat retinal diseases

Image
Retinal disease The retina is a thin layer of tissue on the inside back wall of human eye and contains millions of light-sensitive cells and other nerve cells. These cells receive and organize visual information and the retina sends this information to the brain through the optic nerves enabling one to see. Retinal diseases can affect the area of the retina that serves the central vision namely the macula and the fovea at the center of the macula. Many retinal diseases show common symptoms but with unique characteristics. The goal of retinal disease treatments is to stop or slow disease progression and preserve, improve or restore vision. Retinal pigment epithelium is the cell layer that contains the photoreceptors and its degeneration is a disease, especially is a function of age. Drugs have been developed for the prevention and treatment of age-related macular degeneration and the degenerative retinal diseases such as retinitis pigmentosa but with limitations. An effective treatment

Zeolite nanosheets

Image
During the production of fuel, plastics and various chemicals separation processes such as distillation for purifying gasoline and polymer precursors is an important step which consumes considerable amounts of energy. Currently nearly 15% of the total energy consumption goes as waste due to process inefficiencies. Ultra-thin zeolite nanosheets of thin films have been developed by University of Minnesota team of researchers to speed up the filtration process with less energy. Zeolite Zeolites are micro porous aluminosilicate minerals. Zeolite can be used as catalyst. Zeolite can diffuses through the micro channel system with size and shape selection based on channel dimensions. Production of very thin slices of zeolite is difficult due to interference of Ostwald ripening, the well-known process in which the larger crystals always grow at the expense of the smaller ones. Zeolite membranes Energy-efficient separations process involves high-resolution molecular separation with membranes f

Q-dots

Image
Semiconductor nanoparticles Semiconductor nanoparticles also referred to as Q-dots exhibit unique physical properties that give rise to many potential applications in areas such as nonlinear optics, luminescence, electronics, catalysis, solar energy conversion, and optoelectronics. Semiconductor nanoparticles are generally considered to be particles of material with diameters in the range of 1 to 20 nm. Large surface to volume ratio and the second factor is the quantum confinement effect is responsible for these unique properties. This is because the large relative fraction of surface atoms in nanoparticles determines the size dependences of the melting temperature and pressure at which the crystal lattice of a semiconductor rearranges. Because of the comparable size of nanoparticles and the delocalization radii of charge carriers non-linear optical effects arise. The explanation for the effect is that as the diameter of the particle approaches the exciton Bohr diameter, the charge car

Core-Shell Nanoparticles

Image
Nanoparticles have been subjected to a variety of surface engineering for various applications such as self-assembly of organic components and bioactive species, and dielectric-metal core-shell nanostructures. Core-shell structures can be grown epitaxially and the shell can be considered as an extension of core structure with different chemical compositions. Nanoshells The inherent nature of core/shell nanoparticles make them potentially very useful in many areas such as biomedical applications. For example, using a silica core, the plasmon becomes very sensitive to the shell thickness and with silica/gold nanoshells and an 800 nm plasmon, using NIR laser light (808 nm) focused on tumors, nanoshells can be accumulated to localized heat to selectively kill the tumors cells. AuNi core shell nanocrystals AuNi core shell nanocrystals can be prepared using a two-step reduction method. First, mixtures of octahedral, triangular and hexagonal plate like, decahedral, and icosahedral Au core see

Colloidal nanocrystal synthesis

Image
Colloidal nanocrystals Colloidal nanocrystals are solution-grown, nanometre-sized, inorganic particles that are stabilized by a layer of surfactants attached to their surface. The inorganic cores possess useful properties that are controlled by their composition, size and shape, and the surfactant coating ensures that these structures are easy to fabricate and process further into more complex structures. This combination of features makes colloidal nanocrystals attractive and promising building blocks for advanced materials and devices. Colloidal quantum dot synthesis The synthesis of colloidal quantum dot nanoparticles is usually an organo- metallic precursor, high temperature, solvent based, airless chemical procedure that begins with the raw materials, a high boiling point ligand, and a Setrioctylphosphine conjugate. The three component system synthesis of colloidal quantum dots composes of precursors, organic surfactants, and solvents. On heating reaction medium to a sufficiently