1 Materials in Human History Historical perspective: New materials bring advancement to societies • Stone age • Bronze age • Iron age • Silicon age Crescent Axes. The top Syrian, the bottom Egyptian. about 1900 BC 2 Materials in Human History 50 000 B.C. Iron oxide pigments Lascaux, Altamira 24 000 B.C. Ceramics – fat, bone ash, clay 3 500 B.C. Cu metallurgy Glass, Egypt and Mesopotamia 3 200 B.C. Bronze 1 600 B.C. Iron metallurgy, Hittites 1 300 B.C. Steel 1 000 B.C. Glass production, Greece, Syria 105 B.C. Paper, China 590 A.D. Gun powder, China 700 A.D. Porcelain, China 3 Materials in Human History - Metals 4 Materials in Human History - Ceramics 5 Development of Materials in Human History 6 Materials Chemical compounds - single use pharmaceuticals, fertilizers, fuels Materials - repeated or continual use - shaping 7 Materials Ceramics (oxides, carbides, nitrides, borides) Glasses (oxides, fluorides, chalcogenides, metallic) Metals, Alloys, Intermetallics Polymers - inorganic, organic, hybrid Semiconductors (Si, Ge, 13/15, 12/16 compounds) Composites, Hybrid Materials Zeolites, Layer and Inclusion Materials Biomimetic Materials Carbon-based Materials: Fullerenes, Fullerene Tubes, Graphene 8 Properties of Materials Property = a material trait, the kind and magnitude of response to a specific stimulus Properties Mechanical Electrical Thermal Magnetic Optical Deteriorative (corrosion) Catalytic Biocompatibility 9 Metals Ceramics Polymers Strong Strong Usually not strong Ductile Brittle Very ductile Electrical Conductor Electrical Insulator Electrical Insulator Heat Conductor Thermal Insulator Thermal Insulator Not transparent May be transparent Not transparent Shiny Heat Resistant Low Densities 10 Materials Science Materials Science: Studies relationships between the structure and properties of materials Materials Engineering: Designing and engineering the structure of a material to produce a predetermined set of properties 11 Materials Science Processing Structure Properties Function 12 atomic bonding crystal structure microstructure properties final product Natural sciences Materials science Engineering ApplicationsBasic research F Materials Chemistry among Natural and Technical Sciences 13 Materials Chemistry Role of Materials Chemistry • Synthesis of new materials – new atom architecture • Preparation of high purity materials • Fabrication techniques for tailored shapes, morphologies, and size 14 Natural and Synthetic Single Crystals Calcite CaCO3 15 Materials Chemistry Single crystals, defects, dopants, non-stoichiometry Monoliths Coatings Thin or thick films - singlecrystalline, polycrystalline, amorphous, epitaxial Fibers, Wires, Tubes Powders – primary particles, aggregates, agglomerates polycrystalline, amorphous, nanocrystalline (1-100 nm) Porous materials micropores (< 20 Å), mesopores (20-500 Å), macropores (> 500 Å) Micropatterns Nanostructures – spheres, hollow spheres, rods, wires, tubes, photonic crystals Self-assembly – supramolecular chemistry: rotaxenes, catenanes, cavitands, carcerands 16 Direct reactions of solids – „heat-and-beat“ Precursor methods Chimie douce, soft-chemistry methods, synthesis of novel metastable materials, such as open framework phases Ion-exchange methods, solution, melt Intercalation: chemical, electrochemical, pressure, exfoliation-reassembly Crystallization techniques, solutions, melts, glasses, gels, hydrothermal, molten salt, high P/T Vapor phase transport, synthesis, purification, crystal growth, doping Materials Chemistry 17 Electrochemical synthesis, redox preparations, anodic oxidation, oxidative polymerization Preparation of thin films and superlattices, chemical, electrochemical, physical, self-assembling mono- and multilayers Growth of single crystals, vapor, liquid, solid phase chemical, electrochemical High pressure methods, hydrothermal, diamond anvils Combinatorial materials chemistry, creation and rapid evaluation of gigantic libraries of related materials Materials Chemistry 18 Si3N4 Hexagonal a modification b modificationSi N Si N • Strong covalent bond (4.9 eV) • Hardness (a-monocrystal, Vickers 21 GPa) • Tensile Strength 1.5 GPa (b-whisker) • Young modulus 350 GPa • Decomposition temp. 1840 °C/1 atm N2 • Density 3.2 g cm-3 19 Si3N4 Ceramics 20 Microstructure of Materials SiC/Si3N4 nanocomposite Glass phase 21 Microstructure vs. Material Properties tens.str. tensile stress SiC inclusion Sliding of grains slowed down improved mechanical properties Si3N4tensile stressSi3N4 Sliding of grains 150 nm SiC inclusion