Materials Science/Useful Formulas

Table of Formulas Name Equation Notes Subject Attractive Force = = Bonding Forces and Energies Repulsive Force Bonding Forces and Energies Net Energy = Where A= and B is found using an empirical plot Bonding Forces and Energies % Ionic Character A ionic B Covalent X electronegativity Bonding Density, Metal Density of Metals and Ceramics Density, Ceramic Density of Metals and Ceramics Atomic Packing Factor APF= Ceramic Crystal Structures Degree of Polymerization Polymer Structures Molar Weight Polymer Polymer Structures Molar weight substituent Polymer Structures number repeat units/ cell Crystallinity % Crystallinity Crystallinity Number of Vacancies Defects Error function Diffusion Table of Symbols Glossary Term Definition Notes Subject Bonding Energy Energy required to separate two atoms to and infinite separation Example Bonding Polymer Having Many Mer Polymer Structures Mer Base atom or structure that repeats Polymer StructuresCeramic nonmetallic, w/ %IC BondingCovalent Shares electrons BondingIonic Gives up/ gains electrons Bonding Electronegativity How much electrons wanted Bonding Crystal single ordered form Crystallinity Linear Density Ceramic Crystal Structures Planar Density Ceramic Crystal Structures Number-average based off size of chain Polymer Structures Weight-average based off weight of chain Polymer Structures Thermoplastics Linear+branched w/ minimal cross linking, heat malliable Polymer Structures Thermoset network w/ crosslinks, covalent bonds, decomposes under heat Polymer Structures Copolymer Different repeat units Polymer Structures Monopolymer Same repeat units Polymer Structures Atomic Packing Factor Atoms/ unit cell Ceramic Crystal Structures Unit Cell Smallest crystal pattern constituent Ceramic Crystal Structures Cation Positive ion Bonding Anion Negative ion Bonding Coordination number Number of nearest neighbors Ceramic Crystal Structures Stacking Sequence Ceramic Crystal Structures Ceramic Bonding Degree of Polymerization Average number of repeat units per chain Polymer Structures crystalline material periodic array of atoms over large atomic distances Ceramic Crystal Structures unit cells small, repeating entities of crystalline material Example Ceramic Crystal Structures mer unit cell of a polymer Polymer StructuresPolymorphism when metal or nonmetal may have more than one crystal structure see: allotropy Ceramic Crystal StructuresAllotropy polymorphism for elemental solids specifically see: Polymorphism Ceramic Crystal Structures Random copolymers No pattern AABABBABBBABAA Polymer Structures Alternating copolymers Directly alternating units ABABABABA Polymer Structures Block copolymers One block identical, block other AAAABBBBAAAA Polymer Structures Graft copolymers Main homopolymer chain with grafted homopolymer side branches Polymer Structures Homopolymer Polymer Structures Linear Polymer repeat units joined end-to-end in one chain Polymer Structures Branched Polymer Has side-branch chains connected to main chains Polymer Structures Crosslinked Polymer Adjacent linear chains connected at various positions by covalent bonds Polymer Structures Network Polymer 3D network of multifunctional monomers Polymer Structures Isotactic Polymer All substituents on same side of monomolecular backbone Polymer Structures Syndiotactic Polymer alternating positions along chain (down/up) Polymer Structures Atactic Polymer substituents placed randomly on chain Polymer Structures Tacity Polymer Structures Interdiff