Untitled Quiz

Hybrid Materials

• Can be broadly classified into two main classes based on the nature of bonds and interactions between organic and inorganic components
• Class I hybrids: no covalent or iono-covalent bonds between organic and inorganic components; only Van der Waals, hydrogen bonding, or electrostatic forces are present
• Class II hybrids: at least parts of organic and inorganic components are linked through strong covalent or iono-covalent bonds

Condensation Reactions

• Oxolation: leads to an oxo bridge; water or alcohol is eliminated
• Olation: an addition reaction that forms a hydroxo bridge
• Metal centers can have coordination higher than their valence, leading to the growth of structures and aggregation

Hybrid Materials Synthesis Strategies

• Path A: soft chemistry-based routes, including conventional sol-gel chemistry, use of specific bridged and polyfunctional precursors, and hydrothermal synthesis
• Path B: assembling or dispersing well-defined nanobuilding blocks (NBB) that keep their integrity in the final material

Sol-Gel Processing

• Inorganic framework is built by successive hydrolysis and condensation reactions
• Structure, connectivity, and morphology of the final inorganic network depend on the relative contribution of reactions

Control of Hybrid Materials

• Chemical control of activation/polymerization reactions allows tuning of size, shape, and miscibility of inorganic polymers or colloids with organic counterparts
• Functional precursors can be used to co-condense with metal alkoxide or halide precursors or modify the surface of inorganic entities