Soft Materials Design

By understanding the molecular underpinnings of solvation (of water and other liquids) adjacent to complex nanoscopic surfaces, that is, surfaces with nanoscopic pattern and/or texture, our goal is to inform the design of the next generation of advanced materials.

One example is the design of robust superhydrophobic surfaces (left). Surface texture can transform hydrophobic surfaces into “superhydrophobic” surfaces, endowed with properties like water-repellency, self-cleaning, and fouling resistance. However, superhydrophobicity is fragile, and depends on water being excluded from the surface texture. Thus, fully realizing its promise requires an understanding of the underpinnings of wetting-dewetting transitions on nanotextured surfaces.

Other examples of interest to our group include the design of superhydrophilic surfaces with superior protein non-fouling properties (center), nanoparticle membranes for desalination (right), and polymer electrolytes for batteries.

As part of a previous Penn MRSEC project, we explored the use of liquid crystalline (LC) solvents to drive the tunable and reconfigurable self-assembly of nanocrystalline (NC) particles with interesting optical and/or plasmonic properties. To sculpt the NC assembly landscape and organize the particles into well-defined arrangements, we first needed to understand how nanocrystals and their functional groups perturb (anchor) the LC solvent in their vicinity.

By combining atomistic simulations with novel enhanced-sampling techniques, we worked toward a molecular-level understanding of the relationship between the chemistry of the NC functional groups and how strongly they polarize interfacial LC molecules.