Programming Colloidal Crystal Habit with Anisotropic Nanoparticle Building Blocks and DNA Bonds

Area of Science:

• Materials Science
• Nanotechnology
• Crystallography

Background:

• Colloidal crystallization offers programmability using nanoparticle building blocks with DNA linkers.
• Current methods primarily yield single crystals with well-defined habits only from spherical nanoparticles with BCC symmetry.
• A limitation exists in controlling the macroscopic shape of colloidal single crystals.

Purpose of the Study:

• To overcome limitations in controlling colloidal crystal habits.
• To utilize low-symmetry, anisotropic nanoparticles for novel crystal engineering.
• To demonstrate the ability to access different equilibrium Wulff shapes in colloidal single crystals.

Main Methods:

• Employing anisotropic nanoparticles (cubes, octahedrons, rhombic dodecahedrons) as building blocks.
• Utilizing DNA bonds to direct colloidal crystallization.
• Analyzing the resulting crystal structures and their equilibrium Wulff shapes.

Main Results:

• Achieved single crystals with controllable Wulff shapes using anisotropic nanoparticles.
• Cube-shaped nanoparticles yielded cubic crystal habits.
• Octahedron-shaped nanoparticles yielded rhombic dodecahedron habits.
• Rhombic dodecahedron-shaped nanoparticles yielded octahedron habits.

Conclusions:

• Demonstrated control over the microscopic shape of single crystals by selecting nanoparticle building block shape and crystal symmetry.
• This control has significant implications for fundamental understanding and technological applications of colloidal matter.
• Opens new avenues for designing colloidal materials with specific macroscopic properties.