CAREER: Controlling Chain Conformation in Amorphous Polymers through Soft Nanoscale Confinement

Ohio State University, The, Columbus OH

Investigators

Abstract

NON-TECHNICAL: Polymers play a central role in our everyday lives, particularly those with inherent crystallinity that are widely used in technological, energy, and biomedical applications. However, some of the most widely used polymers lack any sort of crystallinity, which prevents their use in these advanced applications. This research proposes a unique approach to template crystallinity by exploring the use of liquid crystals, common materials found in liquid crystal displays (LCDs), during the creation of polymeric materials. This research aims to understand and control the characteristics of these newly crystalline polymers, potentially unlocking their use in advanced applications such as soft robotics, Li-ion batteries, and solar cells. In addition, the knowledge gained from this research regarding how liquid crystals affect the properties of these polymers will significantly benefit both the polymer-science and liquid-crystal research communities. A significant aspect of this project also incorporates various integrated educational and outreach activities. This research will provide research training in soft matter for graduate and undergraduate students, will offer laboratory experience for high school students, will broaden participation, and will raise public awareness of soft materials through various educational programs. TECHNICAL: The control of polymer chain conformation significantly influences the physicochemical properties of polymers. While various techniques have been employed to align polymer chains in crystalline polymers, such as through in-situ polymerization, external field alignment, or hard geometrical nanoconfinement, aligning intrinsically amorphous polymers such as poly(methyl methacrylate), polystyrene, and poly(butyl acrylate) is particularly challenging. The amorphous polymers tend to rapidly and irreversibly adopt a random coil conformation when heated and lack the necessary structural features to maintain aligned orientations required for reversible chain conformational changes, a key feature for shape memory materials. In this research, a novel approach is proposed, which employs non-reactive thermotropic liquid crystals (LCs), characterized by their anisotropic fluid properties, to achieve “soft” nanoscale confinement during the polymerization of intrinsically amorphous polymers. The primary objective is to align polymer chains by leveraging the orientational order within the LCs. The research will focus on three key goals: (1) Investigation of the influence of LC phase and polymerization temperature on the resulting chain conformations within the LC solvent; (2) Study of how the choice of solvent for LC removal impacts the conformation of polymer chains post-LC extraction; (3) Characterization of the phase behavior and physicochemical properties of the resulting polymeric network. A deep understanding of the effects of soft nanoscale confinement on polymer chain conformation, phase behavior, and properties may enable the optimization of polymer properties and the introduction of advanced functionalities, including for shape-change, relevant to future developments in soft actuators and soft robotics and in polymer electrolytes with enhanced directional ion conductivity. . This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.