Method for the preparation of metal colloids in inverse micelles and product preferred by the method

A method for producing colloidal metal alloy particles, comprising the steps of:

• forming a homogeneous inverse micelle solution of a first metal salt in a metal-salt organic solvent containing a surfactant,
• reducing the first metal salt by a first reducing agent such that colloidal first elemental metal particles are formed,
• adding a solution of a second metal salt, and
• reducing the second metal salt by a second reducing agent such that the elemental second metal is formed on the surface of the colloidal first elemental metal particles, whereby colloidal particles of an alloy of the first and second elemental metals is formed.

A method for producing colloidal metal particles, comprising the steps of:

• forming a homogeneous inverse micelle solution of a metal salt in a metal-salt solvent at or above a first temperature such that the solution is a single phase, the metal-salt solvent containing a surfactant and a hydrocarbon solvent,
• reducing the metal salt such that colloidal elemental metal particles are formed, whereby the colloidal particles are suspended in the single phase metal-salt solvent,
• permitting the metal-salt solvent to cool to a second temperature at which two phases form, an upper phase and a lower phase, the colloidal elemental metal particles and the hydrocarbon solvent substantially being in the upper phase, and the surfactant substantially being in the lower phase, and
• separating the upper phase from the lower phase.

A method for producing colloidal metal particles, comprising the steps of:

• forming a homogeneous inverse micelle solution of a metal salt in a first metal-salt solvent system such that the solution is a single phase, the metal-salt solvent containing a cationic surfactant and a first organic solvent,
• reducing the metal salt such that colloidal elemental metal particles are formed, whereby the colloidal particles are suspended in the single phase metal-salt solvent,
• adding a second organic solvent such that two phases form, a first phase and a second phase, the colloidal elemental metal particles and the first solvent substantially being in the first phase, and the cationic surfactant substantially being in the second phase, in the second solvent, and
• separating the first phase from the second phase.