1 Powder synthesis processes Approach strategy to Nanoparticle Top-Down appr. Bottom-up appr. Top-Down appr. Milling technique Involves mechanical thermal cycles yields Broad size distribution (10-1,000 nm) Varied particles shape or geometry Impurities Bottom-up appr. Precursor based chemical reaction Phase classification: Gas (Vapor) phase: - Pyrolysis, Inert gass condensation, … Liquid phase: - Solvothermal reaction - Sol-gel reaction - Micoremulsion method **Solid-sate phase (Intermediate appr.) ** = Self-assembly appr. Powder synthesis method Co-precipitation method Uniform distribution of size distribution, homogeneous powder Easy to manufacture due to low firing temperature Mass production possible Powder size not adjustable Handling process such as impurity control (washing) Hydrothermal (Solvothermal) method Fast reaction speed, excellent dispersibility: Easy to manufacture uniformly Possible to control particle shape, size composition and purity High facility cost, operation cost Slow Growth Rate Sol-Gel method Spontaneous mixing of multicomponent solutions: uniform Low temperature synthesis possible Increase production efficiency Drying process time, cost High cost of materials Sensitive to moisture Solid State Reaction method Simple process Economics Requires high thermal energy due to low solid reaction Mixing, pulverizing by mechanical method: heterogeneity such as size, shape↑ Application of Ceramic Powder_YSZ Cubic Zirconia Implants Solid Oxide Fuel Cell Oxygen sensor Thermal Barrier Coating of high Efficiency gas turbine Application of Ceramic Powder_MgO Semiconductor Heat resistance cable Bio ceramic Metal oxide catalyst Solid oxide fuel cell Refractory
