Wiktor Lewandowski

Ordered materials at the nano-scale:
metal nanoparticle superlattices and graphene derivatives

Wiktor Lewandowski, UW
Supervisor: prof. Józef Mieczkowski (UW)

Nanoparticle (NP) superlattices (SL) are long-range ordered structures made of NP. Due to their unique, collective properties and perspective applications in electronic and optoelectronic devices they have lately become a hot-topic in nanoscience research.
One of the most promising approaches yielding well defined metal nanoparticle superlattices is covalent attachment of liquid crystalline ligands to NPs’ surface (Fig.1.). My research focused on the design and synthesis of new mesogenic molecules that would lead to 3D ordered nanoparticle assemblies and finding key factors influencing the self-assembly modes. Results indicate that the distance between rigid mesogenic core and metal nanoparticle surface as well as overall soft-corona volume play major role in establishing relative nanoparticle positions. Throughout the research I was able to obtain reconfigurable, 3D ordered NP aggregates which is a step towards obtaining tunable metamaterials.

Fig.1. Synthesis of gold nanoparticles and the schematic picture of smectic structure made of nanoparticles.

Another promising, Nobel prize winning material that could find a wide variety of applications is graphene. Due to technological reasons solvent-processable derivatives of graphene are of interest. I will shortly present our research on developing a new synthetic strategy leading to carboxy-functionalized graphene and discuss its physicochemical properties (Fig.2.).

Fig.2. Synthesis of carboxy-functionalized graphene from graphite oxide.

Discussion