Classes_of_solids Solid

1 classes of solids

1.1 metals
1.2 minerals
1.3 ceramics
1.4 glass ceramics
1.5 organic solids

1.5.1 wood
1.5.2 polymers


1.6 composite materials
1.7 semiconductors
1.8 nanomaterials
1.9 biomaterials

classes of solids

the forces between atoms in solid can take variety of forms. example, crystal of sodium chloride (common salt) made of ionic sodium , chlorine, held ionic bonds. in diamond or silicon, atoms share electrons , form covalent bonds. in metals, electrons shared in metallic bonding. solids, particularly organic compounds, held van der waals forces resulting polarization of electronic charge cloud on each molecule. dissimilarities between types of solid result differences between bonding.

metals


the pinnacle of new york s chrysler building, world s tallest steel-supported brick building, clad stainless steel.

metals typically strong, dense, , conductors of both electricity , heat. bulk of elements in periodic table, left of diagonal line drawn boron polonium, metals. mixtures of 2 or more elements in major component metal known alloys.

people have been using metals variety of purposes since prehistoric times. strength , reliability of metals has led widespread use in construction of buildings , other structures, in vehicles, many appliances , tools, pipes, road signs , railroad tracks. iron , aluminium 2 commonly used structural metals, , abundant metals in earth s crust. iron commonly used in form of alloy, steel, contains 2.1% carbon, making harder pure iron.

because metals conductors of electricity, valuable in electrical appliances , carrying electric current on long distances little energy loss or dissipation. thus, electrical power grids rely on metal cables distribute electricity. home electrical systems, example, wired copper conducting properties , easy machinability. high thermal conductivity of metals makes them useful stovetop cooking utensils.

the study of metallic elements , alloys makes significant portion of fields of solid-state chemistry, physics, materials science , engineering.

metallic solids held high density of shared, delocalized electrons, known metallic bonding . in metal, atoms readily lose outermost ( valence ) electrons, forming positive ions. free electrons spread on entire solid, held firmly electrostatic interactions between ions , electron cloud. large number of free electrons gives metals high values of electrical , thermal conductivity. free electrons prevent transmission of visible light, making metals opaque, shiny , lustrous.

more advanced models of metal properties consider effect of positive ions cores on delocalised electrons. metals have crystalline structure, ions arranged periodic lattice. mathematically, potential of ion cores can treated various models, simplest being free electron model.

minerals

a collection of various minerals.

minerals naturally occurring solids formed through various geological processes under high pressures. classified true mineral, substance must have crystal structure uniform physical properties throughout. minerals range in composition pure elements , simple salts complex silicates thousands of known forms. in contrast, rock sample random aggregate of minerals and/or mineraloids, , has no specific chemical composition. vast majority of rocks of earth s crust consist of quartz (crystalline sio2), feldspar, mica, chlorite, kaolin, calcite, epidote, olivine, augite, hornblende, magnetite, hematite, limonite , few other minerals. minerals, quartz, mica or feldspar common, while others have been found in few locations worldwide. largest group of minerals far silicates (most rocks ≥95% silicates), composed largely of silicon , oxygen, addition of ions of aluminium, magnesium, iron, calcium , other metals.

ceramics

si3n4 ceramic bearing parts

ceramic solids composed of inorganic compounds, oxides of chemical elements. chemically inert, , capable of withstanding chemical erosion occurs in acidic or caustic environment. ceramics can withstand high temperatures ranging 1000 1600 °c (1800 3000 °f). exceptions include non-oxide inorganic materials, such nitrides, borides , carbides.

traditional ceramic raw materials include clay minerals such kaolinite, more recent materials include aluminium oxide (alumina). modern ceramic materials, classified advanced ceramics, include silicon carbide , tungsten carbide. both valued abrasion resistance, , hence find use in such applications wear plates of crushing equipment in mining operations.

most ceramic materials, such alumina , compounds, formed fine powders, yielding fine grained polycrystalline microstructure filled light scattering centers comparable wavelength of visible light. thus, opaque materials, opposed transparent materials. recent nanoscale (e.g. sol-gel) technology has, however, made possible production of polycrystalline transparent ceramics such transparent alumina , alumina compounds such applications high-power lasers. advanced ceramics used in medicine, electrical , electronics industries.

ceramic engineering science , technology of creating solid-state ceramic materials, parts , devices. done either action of heat, or, @ lower temperatures, using precipitation reactions chemical solutions. term includes purification of raw materials, study , production of chemical compounds concerned, formation components, , study of structure, composition , properties.

mechanically speaking, ceramic materials brittle, hard, strong in compression , weak in shearing , tension. brittle materials may exhibit significant tensile strength supporting static load. toughness indicates how energy material can absorb before mechanical failure, while fracture toughness (denoted kic ) describes ability of material inherent microstructural flaws resist fracture via crack growth , propagation. if material has large value of fracture toughness, basic principles of fracture mechanics suggest undergo ductile fracture. brittle fracture characteristic of ceramic , glass-ceramic materials typically exhibit low (and inconsistent) values of kic.

for example of applications of ceramics, extreme hardness of zirconia utilized in manufacture of knife blades, other industrial cutting tools. ceramics such alumina, boron carbide , silicon carbide have been used in bulletproof vests repel large-caliber rifle fire. silicon nitride parts used in ceramic ball bearings, high hardness makes them wear resistant. in general, ceramics chemically resistant , can used in wet environments steel bearings susceptible oxidation (or rust).

as example of ceramic applications, in 1980s, toyota researched production of adiabatic ceramic engine operating temperature of on 6000 °f (3300 °c). ceramic engines not require cooling system , hence allow major weight reduction , therefore greater fuel efficiency. in conventional metallic engine, of energy released fuel must dissipated waste heat in order prevent meltdown of metallic parts. work being done in developing ceramic parts gas turbine engines. turbine engines made ceramics operate more efficiently, giving aircraft greater range , payload set amount of fuel. however, such engines not in production because manufacturing of ceramic parts in sufficient precision , durability difficult , costly. processing methods result in wide distribution of microscopic flaws play detrimental role in sintering process, resulting in proliferation of cracks, , ultimate mechanical failure.

glass ceramics


a high strength glass-ceramic cooktop negligible thermal expansion.

glass-ceramic materials share many properties both non-crystalline glasses , crystalline ceramics. formed glass, , partially crystallized heat treatment, producing both amorphous , crystalline phases crystalline grains embedded within non-crystalline intergranular phase.

glass-ceramics used make cookware (originally known brand name corningware) , stovetops have both high resistance thermal shock , extremely low permeability liquids. negative coefficient of thermal expansion of crystalline ceramic phase can balanced positive coefficient of glassy phase. @ point (~70% crystalline) glass-ceramic has net coefficient of thermal expansion close zero. type of glass-ceramic exhibits excellent mechanical properties , can sustain repeated , quick temperature changes 1000 °c.

glass ceramics may occur naturally when lightning strikes crystalline (e.g. quartz) grains found in beach sand. in case, extreme , immediate heat of lightning (~2500 °c) creates hollow, branching rootlike structures called fulgurite via fusion.

organic solids


the individual wood pulp fibers in sample around 10 µm in diameter.

organic chemistry studies structure, properties, composition, reactions, , preparation synthesis (or other means) of chemical compounds of carbon , hydrogen, may contain number of other elements such nitrogen, oxygen , halogens: fluorine, chlorine, bromine , iodine. organic compounds may contain elements phosphorus or sulfur. examples of organic solids include wood, paraffin wax, naphthalene , wide variety of polymers , plastics.

wood

wood natural organic material consisting of cellulose fibers embedded in matrix of lignin. regarding mechanical properties, fibers strong in tension, , lignin matrix resists compression. wood has been important construction material since humans began building shelters , using boats. wood used construction work commonly known lumber or timber. in construction, wood not structural material, used form mould concrete.

wood-based materials extensively used packaging (e.g. cardboard) , paper both created refined pulp. chemical pulping processes use combination of high temperature , alkaline (kraft) or acidic (sulfite) chemicals break chemical bonds of lignin before burning out.

polymers

stm image of self-assembled supramolecular chains of organic semiconductor quinacridone on graphite.

one important property of carbon in organic chemistry can form compounds, individual molecules of capable of attaching 1 another, thereby forming chain or network. process called polymerization , chains or networks polymers, while source compound monomer. 2 main groups of polymers exist: artificially manufactured referred industrial polymers or synthetic polymers (plastics) , naturally occurring biopolymers.

monomers can have various chemical substituents, or functional groups, can affect chemical properties of organic compounds, such solubility , chemical reactivity, physical properties, such hardness, density, mechanical or tensile strength, abrasion resistance, heat resistance, transparency, color, etc.. in proteins, these differences give polymer ability adopt biologically active conformation in preference others (see self-assembly).

household items made of various kinds of plastic.

people have been using natural organic polymers centuries in form of waxes , shellac classified thermoplastic polymer. plant polymer named cellulose provided tensile strength natural fibers , ropes, , 19th century natural rubber in widespread use. polymers raw materials (the resins) used make commonly called plastics. plastics final product, created after 1 or more polymers or additives have been added resin during processing, shaped final form. polymers have been around, , in current widespread use, include carbon-based polyethylene, polypropylene, polyvinyl chloride, polystyrene, nylons, polyesters, acrylics, polyurethane, , polycarbonates, , silicon-based silicones. plastics classified commodity , specialty , engineering plastics.

composite materials

simulation of outside of space shuttle heats on 1500 °c during re-entry



a cloth of woven carbon fiber filaments, common element in composite materials

composite materials contain 2 or more macroscopic phases, 1 of ceramic. example, continuous matrix, , dispersed phase of ceramic particles or fibers.

applications of composite materials range structural elements such steel-reinforced concrete, thermally insulative tiles play key , integral role in nasa s space shuttle thermal protection system used protect surface of shuttle heat of re-entry earth s atmosphere. 1 example reinforced carbon-carbon (rcc), light gray material withstands reentry temperatures 1510 °c (2750 °f) , protects nose cap , leading edges of space shuttle s wings. rcc laminated composite material made graphite rayon cloth , impregnated phenolic resin. after curing @ high temperature in autoclave, laminate pyrolized convert resin carbon, impregnated furfural alcohol in vacuum chamber, , cured/pyrolized convert furfural alcohol carbon. in order provide oxidation resistance reuse capability, outer layers of rcc converted silicon carbide.

domestic examples of composites can seen in plastic casings of television sets, cell-phones , on. these plastic casings composite made of thermoplastic matrix such acrylonitrile butadiene styrene (abs) in calcium carbonate chalk, talc, glass fibers or carbon fibers have been added strength, bulk, or electro-static dispersion. these additions may referred reinforcing fibers, or dispersants, depending on purpose.

thus, matrix material surrounds , supports reinforcement materials maintaining relative positions. reinforcements impart special mechanical , physical properties enhance matrix properties. synergism produces material properties unavailable individual constituent materials, while wide variety of matrix , strengthening materials provides designer choice of optimum combination.

semiconductors

semiconductor chip on crystalline silicon substrate.

semiconductors materials have electrical resistivity (and conductivity) between of metallic conductors , non-metallic insulators. can found in periodic table moving diagonally downward right boron. separate electrical conductors (or metals, left) insulators (to right).

devices made semiconductor materials foundation of modern electronics, including radio, computers, telephones, etc. semiconductor devices include transistor, solar cells, diodes , integrated circuits. solar photovoltaic panels large semiconductor devices directly convert light electrical energy.

in metallic conductor, current carried flow of electrons , in semiconductors, current can carried either electrons or positively charged holes in electronic band structure of material. common semiconductor materials include silicon, germanium , gallium arsenide.

nanomaterials


bulk silicon (left) , silicon nanopowder (right)

many traditional solids exhibit different properties when shrink nanometer sizes. example, nanoparticles of yellow gold , gray silicon red in color; gold nanoparticles melt @ lower temperatures (~300 °c 2.5 nm size) gold slabs (1064 °c); , metallic nanowires stronger corresponding bulk metals. high surface area of nanoparticles makes them extremely attractive applications in field of energy. example, platinum metals may provide improvements automotive fuel catalysts, proton exchange membrane (pem) fuel cells. also, ceramic oxides (or cermets) of lanthanum, cerium, manganese , nickel being developed solid oxide fuel cells (sofc). lithium, lithium–titanate , tantalum nanoparticles being applied in lithium ion batteries. silicon nanoparticles have been shown dramatically expand storage capacity of lithium ion batteries during expansion/contraction cycle. silicon nanowires cycle without significant degradation , present potential use in batteries expanded storage times. silicon nanoparticles being used in new forms of solar energy cells. thin film deposition of silicon quantum dots on polycrystalline silicon substrate of photovoltaic (solar) cell increases voltage output as 60% fluorescing incoming light prior capture. here again, surface area of nanoparticles (and thin films) plays critical role in maximizing amount of absorbed radiation.

biomaterials


collagen fibers of woven bone

many natural (or biological) materials complex composites remarkable mechanical properties. these complex structures, have risen hundreds of million years of evolution, inspiring materials scientists in design of novel materials. defining characteristics include structural hierarchy, multifunctionality , self-healing capability. self-organization fundamental feature of many biological materials , manner structures assembled molecular level up. thus, self-assembly emerging new strategy in chemical synthesis of high performance biomaterials.