What is a topotactic process?

What is a topotactic process?

A topotactic reaction is a chemical solid-state reaction such that the orientations of the product crystals are determined by the orientation of the initial crystal. The same symmetry rules apply for the domains as for phase transitions.

What is topotactic and Epitactic reaction?

Epitactic and topotactic reactions Epitactic: structural similarity restricted to the surface / interface. between two crystals layer. Topotactic: Structural similarity through the crystal.

What is meaning of topotactic?

Filters. (chemistry) Describing a transformation, within a crystal lattice, involving the displacement or exchange of atoms.

What is topotactic intercalation?

Introduction. Topotactic reactions are typically used in order to synthesize novel materials using solid-state chemistry routes. Among the possible hosts used for topotactic reactions by intercalation, graphite is a noteworthy host material, especially in the case of the insertion of metals and metallic alloys.

What is solid state reaction method?

The solid-state reaction method is a high-temperature synthesis method for preparing phosphor material. The reaction starts spontaneously during the mixing process, accompanied by the release of heat and water vapor. Sometimes, acetone is used as a mixing medium to get a homogeneous mixture.

Why are solid state reactions difficult?

The solid state reactions are difficult because the reactants have limited access to each other and this reduces the contact between the reactants. Also, chemical properties and morphological properties affect the solid state reactions. These are surface area, temperature, pressure, and reactivity.

What is Tamman’s rule?

Tamman’s Rule suggests a temperature of about two-thirds of the melting point (K) of the lower melting reactant is needed to have reaction to occur in a reasonable time.

Can two solids chemically react?

Despite both substances being solids, due to melting point depression (and relatively low melting points of the two substances), the two substances melt when mixed together and react.

Why are solid state reactions faster?

Generally, solid state reactions may have the following advantages over solution phase reactions: These reactions are often faster, taking just a few minutes rather than hours to complete because the reactants are in intimate contact with each other [2].

What is sol-gel method?

In materials science, the sol–gel process is a method for producing solid materials from small molecules. The process involves conversion of monomers into a colloidal solution (sol) that acts as the precursor for an integrated network (or gel) of either discrete particles or network polymers.

Why do solids not react?

Pure solids or liquids are excluded from the equilibrium expression because their effective concentrations stay constant throughout the reaction. The concentration of a pure liquid or solid equals its density divided by its molar mass.