Self-assembly and Design of Tunable Soft Materials
- Author(s): Pandolfi, Ronald J.
- Advisor(s): Hirst, Linda S
- et al.
Soft materials are a diverse and rich field of interest. Materials which form structure by their own self-assembly are of special interest. New material properties can be achieved by the self-assembly of constituent soft matter. Two soft matter systems are investigated in this dissertation from different perspectives. An in silico approach is applied to explore semiflexible polymers; X-ray scattering is applied to probe QD-LC composites.
Semiflexible polymers can generate a range of filamentous networks significantly different in structure from those seen in conventional polymer solutions. Our coarse-grained simulations with an implicit cross-linker potential show that networks of branching bundles, knotted morphologies, and structural chirality can be generated by a generalized approach independent of specific cross-linkers. Network structure depends primarily on filament flexibility and separation, with significant connectivity increase after percolation. Results should guide the design of engineered semiflexible polymers.
Thermotropic liquid crystal provides an active basis for organization of nanoparticles. Using a bottom-up approach, nanoparticles well dispersed in the isotropic phase can be self-assembled by exclusion from the nematic phase as the material cools from the isotropic phase. A ligand exchange reaction can be used to create nanoparticles with mesogenic ligand coatings to allow better dispersion and assemble novel structures. Small angle X-ray scattering is used to inform the structure of a variety of materials which apply this design concept. These metamaterials have tunable properties with applications in quantum dot based electro-optic devices and more.