How molecular chirality manifests at the nano- to macroscale has been a scientific puzzle since Louis Pasteur discovered biochirality. In general, amphiphilic molecules can organize into a variety of assembly shapes including micelles, spherical vesicles, cylindrical micelles, and planar bilayers. However, when such amphiphilic molecules are chiral, helical ribbons, helicoidal scrolls (cochleates), twisted ribbons and even möbius strips (closed twisted ribbons) appear. These fascinating supramolecular chiral materials have particular properties that make them useful for applications in drug delivery, biosensors, nanoelectronics, and chiral recognition devices. Controlling the shape and internal architecture of the assemblies is critical for these technologies, but the structure, and thus the function, of these hierarchical assemblies reconfigure in response to stimuli, via mechanisms that are often elusive. In this study, we observe and explain how molecular reordering driven by variations in electrostatic interactions can induce micrometer-scale structural changes in membranes of charged, chiral molecules. The size, shape, and charge of soft assembled nano-structures, like those in biology, respond in an interconnected manner to solution ionic conditions, providing a pathway to shape control of chiral materials. This study combines experimental, theoretical, and computational approaches to elucidate key principles in analyzing the coupling of electrostatics and nano-scale details of soft nano-structures. These preliminary efforts have led to development of an electrostatics-based approach for assembly shape selection and nano-scale structure control in chiral assemblies.

Creator

• McCourt, Joseph

DOI

• https://doi.org/10.21985/n2-vpr8-sg35

Subject

• Physical chemistry
• Physics
• Materials Science

Language

• en

Alternate Identifier

• http://dissertations.umi.com/northwestern:16654
• etdadmin_upload_1000771

Keyword

• self-assembly
• soft mattter
• electrostatics
• membranes
• chiral
• charge

Date created

• 2023-01-01

Resource type

• Dissertation

Rights statement

• In Copyright