Method of making inverse opal structures produces far fewer defects and larger crystalline domains than the conventional process
The inverse opal structures of the invention are made in a two step process of:
1) preparing a colloidal crystal in a solution of matrix material (such as a sol-gel metal oxide precusor), and
2) removing the colloid particles by heating or etching.
Conventional methods add the matrix material by infiltration after the colloidal crystal structure is made. The co-assembly process of the invention results in far fewer defects and larger crystalline domains than the conventional three step process - the improvement is 10,000- 100,000 fold. The size of the crystalline domains can reach 10 cm or more. Such larger crystals have advantages in all the applications of inverse opal structures.
Inverse opal structures are an exciting area in materials science. They are used:
a) to make photonic band-gap materials,
b) as templates for tissue engineering,
c) as chemical sensors, and
d) for catalysis and many other applications.
Intellectual Property Status: A PCT patent application is pending.