Chem

• Metal is an element, compound or alloy that is a good conductor of both electricity and heat.
• Metal crystal structure and specific metal properties are determined by holding together the atoms of a metal.
• Ferrosus metals contain any amount of iron in its basic form, possess magnetic properties that makes them prone to corrosion, and have high tensile strength.
• Non-ferrous metals do not contain any amounts of iron in its basic form, do not possess magnetic properties but resist corrosion much better than ferrous metals, have typically lighter weights, higher melting points and are basically resistant to corrosion.
• Metals can be classified as brittle, ductile, hard, malleable, soft, tough, and occur naturally from minerals.
• Most metals come from minerals, which are naturally occurring substances with a range of chemical composition.
• An ore is a mineral deposit concentrated enough to allow economic recovery of a desired metal.
• Metals exist in various forms such as in the Earth's surface, as ions in seawater, and in the ocean floor.
• Aluminum, Iron, Calcium, Magnesium, Sodium, Potassium, Titanium and Manganese are the most abundant metals which exists as minerals in the Earth’s crust.
• Seawater is a rich source of some metal ions, such as Na+, Mg 2+, and Ca 2+.
• Vast areas of the ocean floor are covered with manganese nodules which are made up mostly of manganese, along with iron, nickel, copper, and cobalt in a chemically combine state.
• The basic step of extracting metals is called concentration of ores, which can be done by gravity separation or hydraulic washings, or froth flotation process.
• Nanotechnology in electronics includes nanotechnology RAM (Random Access Memory) based on carbon nanotubes, nano-opto-mechanical SRAM (Static RAM), and nano-batteries.
• Nanotechnology in agriculture and food includes nano-fertilizers, hybrid polymers used in packaging and to reduce spoilage, sensors for food-borne pathogens, and nano-emulsions to reduce bacteria on produce.
• Bottom-up processes must be supplemented by the self-organization of individual particles to obtain ordered structures.
• Nanotechnology is used in electronics, healthcare and medicine, energy, agriculture and food, and other fields.
• All compounds that crystallize in layered structures show a tendency to form nanotubes.
• Formation of carbon nanotubes can be achieved through layered structures, where the crystal structure is built from layers held together with van der Waals forces rather than by electrostatic attraction.
• Nanotechnology in healthcare and medicine includes detectors for heart attack, nano-chips to check plaque in arteries, nano-carriers for eye surgery, chemotherapy, etc., diabetic pads for regulating blood sugar levels, nanoparticles for drug delivery to the brain for therapeutic treatment of neurological disorders, and nano-sponges which are polymer nanoparticles coated with a red blood cell membrane, can be used for absorbing toxins and removing them from the bloodstream.
• Nanotechnology in energy includes solar paints or photovoltaic paint, wind power generations, and nano-batteries.
• Formation of nanomaterials involves the formation of rods and plates, with the influence of surface energy being considered for non-spherical nanostructures, especially in the case of anisotropic (non-cubic) structures.
• Graphite and fullerenes are special modifications of carbon.
• Froth flotation is a process where the ore is physically separated from a liquid phase as a result of differences in the ability of air bubbles to selectively adhere to the surface of the particles, based upon their hydrophobicity.
• Sulphur impurities can escape as gas during the process of roasting.
• Polyethylene (PE) has properties similar to Low Density Polyethylene (LDPE) but is more rigid, tougher, and slightly denser.
• Polyethylene Terephthalate (PETE/ PET) has properties such as being transparent, strong, shatter-resistant, and impervious to acids and atmospheric gases.
• Polyvinyl Chloride (PVC) has variable properties, being rigid if not softened with a plasticizer, clear and shiny, but often pigmented, and resistant to most chemicals, including oils, acids, and bases.
• Polyvinyl Chloride (PVC) is used in rigid applications such as plumbing pipe, house siding, charge cards, and hotel room keys.
• Polyethylene Terephthalate (PETE/ PET) is used in soft-drink bottles, clear food containers, beverage glasses, fleece fabrics, carpet yarns, and fiber-fill insulation.
• Polyethylene (PE) is used in opaque milk, juice, detergents, and shampoo bottles, and is also used in buckets, crates, and fencing materials.
• Calcination is a process where the ore is converted into oxides by heating strongly in the presence of excess air.
• Metallurgy is the science and technology of separating metals from their ores and of compounding alloys.
• A diblock copolymer contains two homopolymer blocks whereas a triblock copolymer contains three distinct blocks of homopolymers.
• An example of a diblock copolymer is acrylonitrile butadiene styrene, commonly referred to as SBS rubber.
• The first – and broadest – definition of nanomaterials states that, these are materials where the sizes of the individual building blocks are less than 100 nm (a very small scale), at least in one dimension (nm; equivalent to the diameter of approximately 500 atoms).
• The main chain or the side chains of these polymers can be copolymers or homopolymers.
• High impact polystyrene is an example of a graft copolymer.
• “Top-down” means starting from large pieces of material and producing the expected structure by mechanical or chemical methods.
• Crystal structures can be specified in terms of unit cells, which are often quite complex.
• Although such processes provide exceptional freedom among the resulting products, the number of possible structures to be obtained is comparatively small.