Mesoporous aluminophosphate thin films with cubic pore arrangement

Area of Science:

• Materials Science
• Nanotechnology
• Inorganic Chemistry

Background:

• Mesoporous materials offer high surface area and tunable pore sizes, crucial for catalysis and separations.
• Aluminophosphates (AlPOs) are versatile framework materials with diverse applications.
• Developing ordered mesoporous thin films is challenging but highly desirable for device integration.

Purpose of the Study:

• To synthesize, for the first time, mesoporous aluminophosphate thin films with a 3D cubic (Im3m) pore structure.
• To investigate the formation and structural ordering of these thin films during synthesis.
• To evaluate the thermal stability of the mesoporous structure.

Main Methods:

• Thin film synthesis via dip-coating using Pluronic F127 and F108 block copolymer templates on glass substrates.
• In situ Small-Angle X-ray Scattering (SAXS) to monitor mesostructure formation.
• Transmission Electron Microscopy (TEM) for structural characterization.
• Thermogravimetric analysis (TG) and Fourier-Transform Infrared Spectroscopy (FT-IR) for template removal monitoring.
• Magic-Angle Spinning Nuclear Magnetic Resonance (MAS NMR) to observe framework transitions.

Main Results:

• Successful synthesis of mesoporous aluminophosphate thin films with a highly ordered 3D cubic (Im3m) mesostructure.
• In situ SAXS confirmed the formation of the ordered mesostructure during the dip-coating process.
• The cubic mesostructure demonstrated significant thermal stability, remaining intact up to at least 670 K.
• TEM confirmed the cubic mesostructure, and MAS NMR indicated a transition from an amorphous gel to a well-defined aluminophosphate framework.

Conclusions:

• The study reports the first synthesis of ordered mesoporous aluminophosphate thin films with a 3D cubic structure.
• The dip-coating method with block copolymer templating effectively yields ordered mesostructures with good thermal stability.
• These findings open avenues for utilizing ordered mesoporous aluminophosphate thin films in various technological applications.