Directed self-assembly of nanoscale building blocks through coded bonding potentials

 

Submitter: Jason J. Benkoski*

Mentor: Alamgir Karim

Category: Materials

 

Polymers Division, MSEL

Building 224, Room A225

Ph.: 301-975-8556   Fax: 301-975-3928

100 Bureau Dr., Stop 8541

Gaithersburg, MD 20899-8541

jason.benkoski@nist.gov

* not a Sigma Xi member

 

 

We present a novel platform for the formation of 2-D assemblies from nanoscale building blocks.  The system consists of an oil-water interface in which the oil can be flash cured upon UV exposure.  Mixed with a radical photoinitiator, 1,12-dodecanediol dimethacrylate solidifies in less than 5 seconds when exposed to UV light at an intensity of 8 mW/cm2.  The rapid crosslinking allows one to obtain a “snapshot” of the self-assembly process for particles that segregate to the oil/water interface.  Among the particles investigated were 400 nm PMMA latex spheres, 10 nm quantum dots, magnetite nanoparticles, and colloidosomes.  The agglomerates formed by this process were typically either globular or fractal-like in appearance.  By comparing with simulation, we find that the morphology of the aggregates is coded directly in the particles through the symmetry of the bonding potentials and the relative strengths of the interactions.