Synthesis and application of ionic molecular and polymeric materials

Materials are built from atoms and molecules through different interactions. Few artificial material is built primarily with ionic interaction despite its ubiquitous existence in living systems. My research has focused on filling this void by developing novel ionic molecular and polymeric materials for both fundamental understandings of the systems and various applications such as self-healing. With one theme of ionic functional materials, my research has broadly evolved into three areas: Chapters 2-3 focus on the development of structure-property relationship of network-forming ionic glasses and liquids; Chapter 4 focus on the application of network-forming ionic liquids for the cause of shockwave absorption; Chapter 5 extends the exploration into the realm of polymeric ionic rubber and its application as self-healing materials. The network-forming ionic glass is a stable glassy organic network that is primarily connected by ionic interaction. It was found that the glass transition temperature of ionic glass series with increasing alkyl backbone length showed an intriguing odd-even effect. The mechanism was revealed by inelastic neutron scattering as different dynamics of odd- and even-numbered cations in liquid state. Structurally, thanks to the nano-segregation, the network-forming ionic liquid proved to be an excellent shockwave absorption material. Further investigation indicated that a shock-induced ordering in network-forming ionic liquids contributed to its overall shockwave absorption performance. Similar to the small molecule ionic glass and liquids, an oligomeric anion, a carboxylate-terminated copolymer of polybutadiene(PBD) and polyacrylonitrile(PAN), was chosen as the counterion for multivalent cations to build a polymeric amorphous ionic network. An ionic rubber that combines competitive mechanical properties and full reprocessibiltiy was successfully prepared where ionic interaction plays the key role of the dynamic crosslink. The reversible ionic crosslink renders excellent properties including high plateau modulus, rate-dependent stress releasing and super-fast self-healing at room temperature. These studies on the ionic glass and ionic rubber have advanced the development of artificial ionic materials in the aspect of both fundamental knowledges on structure-property relationship and practical application including shockwave absorption and self-healing.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Materials Science & Engr

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2016

Author dc:creator

• Yang, Ke

Contributors dc:contributor

• Moore, Jeffrey S.
• Schweizer, Kenneth S.
• Zhang, Yang
• Chen, Qian
• Kilian, Kristopher A.

• ionic materials
• ionic glass
• odd-even effect
• shockwave absorption
• ionic rubber
• self-healing

Statement dc:rights

• Copyright 2016 Ke Yang

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/90782

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/90782