TY - JOUR
T1 - Protic Ionic Liquids
T2 - A General Strategy for Enhancing Electrical Conductivity and Stretchability of Conducting Polymer Thin Films
AU - Kim, Kyungjin
AU - Han, Minwoo
AU - Ahn, Hyungju
AU - Kim, Minji
AU - Noh, Jiyun
AU - Noh, Eunseo
AU - Choi, Haemin
AU - Lee, Seoung Ho
AU - Lee, Byoung Hoon
N1 - Publisher Copyright:
© 2024 Wiley-VCH GmbH.
PY - 2024
Y1 - 2024
N2 - Ionic liquids (ILs) are promising materials for enhancing the electrical conductivity and stretchability of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)-based stretchable transparent conductors. However, the relationship between the chemical structures of ILs and the electrical and mechanical properties of PEDOT:PSS/IL composites remains unclear. In this study, the impact of protic ILs (p-ILs) on the electrical conductivity and stretchability of PEDOT:PSS/IL thin films is investigated via a comparative analysis with aprotic ILs (ap-ILs). By synthesizing a series of p-ILs and ap-ILs based on imidazolium (IM) and bis(trifluoromethanesulfonyl)imide ions, it is demonstrated that p-ILs significantly enhance electrical conductivity and stretchability, outperforming ap-ILs. In addition, these properties further improve with decreasing alkyl chain length of IM cations, achieving maximum electrical conductivity and stretchability of ≈2200 S cm−1 and 65%, respectively. Notably, the crystalline structures of PEDOT:PSS/IL thin films are elucidated, revealing that p-ILs with shorter alkyl chains facilitate the formation of PSS crystallites due to hydrogen bonding between p-ILs and PSS, which in turn enhance electrical conductivity and stretchability. Leveraging these insights, PEDOT:PSS/p-IL-based strain sensors with broad dynamic ranges and tunable gauge factors are developed. The findings of this study provide valuable design guidelines for developing high-performance ILs in stretchable and wearable electronics.
AB - Ionic liquids (ILs) are promising materials for enhancing the electrical conductivity and stretchability of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)-based stretchable transparent conductors. However, the relationship between the chemical structures of ILs and the electrical and mechanical properties of PEDOT:PSS/IL composites remains unclear. In this study, the impact of protic ILs (p-ILs) on the electrical conductivity and stretchability of PEDOT:PSS/IL thin films is investigated via a comparative analysis with aprotic ILs (ap-ILs). By synthesizing a series of p-ILs and ap-ILs based on imidazolium (IM) and bis(trifluoromethanesulfonyl)imide ions, it is demonstrated that p-ILs significantly enhance electrical conductivity and stretchability, outperforming ap-ILs. In addition, these properties further improve with decreasing alkyl chain length of IM cations, achieving maximum electrical conductivity and stretchability of ≈2200 S cm−1 and 65%, respectively. Notably, the crystalline structures of PEDOT:PSS/IL thin films are elucidated, revealing that p-ILs with shorter alkyl chains facilitate the formation of PSS crystallites due to hydrogen bonding between p-ILs and PSS, which in turn enhance electrical conductivity and stretchability. Leveraging these insights, PEDOT:PSS/p-IL-based strain sensors with broad dynamic ranges and tunable gauge factors are developed. The findings of this study provide valuable design guidelines for developing high-performance ILs in stretchable and wearable electronics.
KW - PEDOT:PSS
KW - protic ionic liquids
KW - strain sensors
KW - stretchable transparent conductors
KW - wearable electronics
UR - http://www.scopus.com/inward/record.url?scp=85212813865&partnerID=8YFLogxK
U2 - 10.1002/adfm.202420607
DO - 10.1002/adfm.202420607
M3 - Article
AN - SCOPUS:85212813865
SN - 1616-301X
JO - Advanced Functional Materials
JF - Advanced Functional Materials
ER -