Luminescence Materials via Pechini-type Sol-Gel Process

Sol-Gel Process

• The sol-gel process is a widely used technique for designing and synthesizing advanced functional and engineering materials.
• It has found extensive application in the production of various materials, including powders, films, fibers, and monoliths of diverse shapes, sizes, and chemical compositions.
• The sol-gel process can also be used to synthesize nanostructures and organic-inorganic hybrids.

Pechini-Type Sol-Gel (PSG) Process

• The PSG process is a type of soft solution process that is widely used for the synthesis of homogeneous multicomponent metal oxide materials.
• It involves a combined process of metal complex formation and in situ polymerization of organics.
• The PSG process can produce luminescence and pigment materials with different forms, such as powders, core-shell structures, and thin films.

Advantages of PSG Process

• The PSG process uses common metal salts (nitrates, acetates, chlorides, etc.) as precursors and citric acid (CA) as a chelating ligand.
• The process uses polyhydroxy alcohols (such as ethylene glycol or polyethylene glycol) as a cross-linking agent to form a polymeric resin on a molecular level.
• The PSG process reduces segregation of particular metal ions and ensures compositional homogeneity.
• It can overcome the difficulties and disadvantages of the alkoxides-based sol-gel process.

Key Features of PSG Process

• The process involves the formation of stable metal complexes using citric acid (CA) or other R-hydroxycarboxylic acids.
• The metal complexes are then polyesterified with polyhydroxy alcohols (such as ethylene glycol or polyethylene glycol) to form a polymeric resin.
• The immobilization of metal complexes in the rigid organic polymer network reduces segregation of particular metal ions, ensuring compositional homogeneity.

Pechini-Type Sol-Gel (PSG) Process

• The PSG process uses common metal salts (nitrates, acetates, chlorides, etc.) as precursors and citric acid (CA) as chelating ligands of metal ions.
• Polyhydroxy alcohol (e.g., ethylene glycol or poly ethylene glycol) is used as a cross-linking agent to form a polymeric resin on a molecular level.
• This process ensures compositional homogeneity and reduces segregation of particular metal ions.

Advantages and Applications

• The PSG process overcomes difficulties and disadvantages of the alkoxides-based sol-gel process.
• It is a well-known soft solution process with extensive applications in designing and synthesizing various advanced functional and engineering materials.
• Materials synthesized using PSG include powders, films, fibers, monoliths, nanostructures, and organic-inorganic hybrids.

Multiform Oxide Optical Materials

• The PSG process is used to synthesize multiform oxide optical materials.
• The authors' laboratories have worked on various kinds of oxide optical materials using the PSG process.

Key Research Article

• Title: Multiform Oxide Optical Materials via the Versatile Pechini-Type Sol-Gel Process: Synthesis and Characteristics
• Authors: Jun Lin, Min Yu, Cuikun Lin, and Xiaoming Liu
• Published in: J. Phys. Chem. C, 2007, 111, 5835-5845
• Received: January 4, 2007; In Final Form: January 26, 2007