Download or read book Toward Hierarchical Material Design Via Block Copolymers in a Protic Ionic Liquid written by Ru Xie and published by . This book was released on 2018 with total page 430 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ionic liquids and block copolymers are two representative classes of “designer compounds”, which are known for tunability and controllability of their physical and chemical properties via careful selection of their components. Hierarchically structured functional materials are synthesized by self-assembly of block copolymers in ionic liquids, where the block copolymer imparts mechanical strength to the material via self-assembly into long ranged ordered structure, and the ionic liquid imparts electrical conductivity to the system via concomitant free mobile ions. ☐ Understanding the structure-property relationship of complex fluids comprised of self-assembled block copolymer in ionic liquid paves the foundation for rational design and engineering of hierarchically structured functional materials and smart devices. Thus, the goals of this dissertation are threefold: firstly, to develop structure-property relationships for complex fluid model systems composed of self-assembled non-ionic block copolymers in a protic ionic liquid at rest and under ow deformations; secondly, to synthesize and characterize a novel hierarchically structured stretchable ion-conducting material system utilized the structure-property relationship; and lastly, with the fundamental understanding of the structure-property relevancy of the materials, to design and engineer commercializable device prototypes based on the insights extracted from customer discovery interviews. ☐ A non-ionic, spherical micellar ionic liquid complex fluid model system and a non-ionic polymerlike micellar ionic liquid complex fluid model system are explored in this dissertation using a combination of advanced rheological and neutron techniques. In the spherical micellar model systems, it was found that polymer blending is an effective route to create self-assembled complex fluid model systems with tunable microstructure and rheological properties. The study of the polymerlike micellar system reveals that non-ionic polymerlike micelles have di_erent rheological signatures than non-shear banded shear thinning surfactant wormlike micelle solutions. The structure-property relationships determined for the two model systems serve as a reference for formulating and processing non-ionic block copolymer/ionic liquid complex fluids to achieve specific structures that can be crosslinked to create new functional materials. ☐ A simplified two-step manufacturing process has been developed in this dissertation to create an ultra-stretchable conductive iono-elastomer, by self-assembly of concentrated solutions of end-functionalized block copolymers in a protic ionic liquid, followed by chemical crosslinking. The resultant iono-elastomers exhibits an unprecedented combination of high stretchability (3000% elongation and 200 MPa tensile strength at break) and mechano-electrical response. To our knowledge, the strechability is about 10 times higher than reported elastomers. Importantly, the resistance of the material decreases with extension, a unique and non-trivial material response, whose origin is postulated to be the microstructural rearrangement of the micelles. Furthermore, the incorporation of water in the ionic liquid precursor leads to estimated 8.5 times less stretchability, and strikingly, the resistance of iono-elastomer increases with increasing strain. The contrary mechano-electrical response was postulated to be due to different ion binding and transport mechanism in the presence of water. ☐ Based on the material property and customer discovery interviews, a potential application of the iono-elastomer is identified as a motion strain sensor. Significant efforts are made to develop three generations of large strain amplitude, stretchable resistive strain sensor patch prototypes. They should enable customers (e.g., athletes, patients undergoing physical therapy, physical trainers, biomechanicians, etc.) to accurately track motion and performance of specific joints and/or muscles on their smart phone, tablet or computer via Bluetooth wireless communication, with applications in motion capturing, sports performance tracking and rehabilitation monitoring. ☐ Together, advanced rheological and neutron techniques provide a platform for creating structure-property relationships that predict rheological and structural phenomena in soft materials. This research is part of a broader effort to design, synthesize and characterize novel self-assembled non-ionic polymers in ionic liquids by material scientists and engineers. Finally, this work spans interests in both fundamental investigations and technical applications of non-ionic block copolymer self-assembly in ionic liquids, suggesting that the wealth of possible chemistries and ability to create a plethora of hierarchically self-assembled microstructures should lead to many new discoveries.
Download or read book Molecular Design of Polymerized Ionic Liquids written by Gabriel Eduardo Sanoja and published by . This book was released on 2016 with total page 105 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polymerized ionic liquids are an emerging class of functional materials with ionic liquid moieties covalently attached to a polymer backbone. As such, they synergistically combine the structural hierarchy of polymers with the versatile physicochemical properties of ionic liquids. Unlike other ion-containing polymers that are typically constrained to high glass transition temperatures, polymerized ionic liquids can exhibit low glass transition temperatures due to weak electrostatic interactions even at high charge fractions. Promising applications relevant to electrochemical energy conversion and CO2 capture and sequestration have been demonstrated for polymerized ionic liquids, but a molecular design strategy that allows for elucidation of their structure-property relationships is yet to be developed. A combination of anionic polymerization, click chemistry, and ion metathesis allows for fine and independent control over polymer properties including the number of repeat units, fraction of ionic liquid moieties, composition, and architecture. This strategy has been exploited to elucidate the effect of lamellar domain spacing on the ionic conductivity of block copolymers based on hydrated protic polymerized ionic liquids. The conductivity relationship demonstrated in this study suggests that a mechanically robust material can be designed without compromising its ability to transport ions. The vast set of ion pair combinations in polymerized liquids provides a unique opportunity to develop functional materials where properties can be controlled with subtle changes in molecular structure via ion metathesis. We illustrate the case of a polymerized ionic liquid that combines the low toxicity and macromolecular dimensions of poly(ethylene glycol) with the magnetic functionality of ion pairs containing iron(III). This material can yield novel theranostic agents with controlled residence time within the human body, and paramagnetic functionality to enhance 1H nuclei relaxation rate required for medical imaging. Finally, the molecular design strategy is expanded to incorporate ion pairs based on metal-ligand coordination bonds between cations and imidazole moieties tethered to the polymer backbone. This illustrates a general approach for using chelating polymers with appropriate metal-ligand interactions to design high conductivity and tunable modulus polymer electrolytes.
Download or read book Solution Self assembly of Block Copolymers written by Nitin Sharma and published by . This book was released on 2011 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Design of Advanced Materials by Exploiting Hierarchically structured Liquid Crystalline Block Copolymers written by Yuxiang Zhou and published by . This book was released on 2011 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt:
