A Transparent, Highly Stretchable, Solvent‐Resistant, Recyclable Multifunctional Ionogel with Underwater Self‐Healing and Adhesion for Reliable Strain Sensors

• Published in: Advanced materials (Weinheim) Vol. 33; no. 51; pp. e2105306 - n/a
• Main Authors: Xu, Liguo, Huang, Zhenkai, Deng, Zhishuang, Du, Zhukang, Sun, Tao Lin, Guo, Zi‐Hao, Yue, Kan
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01-12-2021
• Subjects: Acrylamide; Bonding strength; Chemical bonds; Dipole interactions; Fluorine; Healing; Hydrogen bonding; Ionic liquids; Materials science; multifunctional ionogels; Muscles; Recyclability; Room temperature; self‐healing materials; Sensors; solvent resistance; Solvents; strain sensors; Stretchability; Substrates; Underwater; underwater adhesion; Wearable technology; multifunctional ionogels; solvent resistance; strain sensors; underwater adhesion; self-healing materials
• ISSN: 0935-9648; 1521-4095
• DOI: 10.1002/adma.202105306

Ionogels have gained increasing attentions as a flexible conductive material. However, it remains a big challenge to integrate multiple functions into one gel that can be widely applied in various complex scenes. Herein, a kind of multifunctional ionogels with a combination of desirable properties, including transparency, high stretchability, solvent and temperature resistance, recyclability, high conductivity, underwater self‐healing ability, and underwater adhesiveness is reported. The ionogels are prepared via one‐step photoinitiated polymerization of 2,2,2‐trifluoroethyl acrylate and acrylamide in a hydrophobic ionic liquid. The abundant noncovalent interactions including hydrogen bonding and ion–dipole interactions endow the ionogels with excellent mechanical strength, resilience, and rapid self‐healing capability at room temperature, while the fluorine‐rich polymeric matrix brings in high tolerance against water and various organic solvents, as well as tough underwater adhesion on different substrates. Wearable strain sensors based on the ionogels can sensitively detect and differentiate large body motions, such as bending of limbs, walking and jumping, as well as subtle muscle movements, such as pronunciation and pulse. It is believed that the designed ionogels will show great promises in wearable devices and ionotronics.
A physically crosslinked multifunctional ionogel is designed and prepared via a simple one‐step photoinitiated polymerization of a fluorinated monomer and a hydrogen bond enabling comonomer in a hydrophobic ionic liquid. The ionogels possess excellent comprehensive performance, including high transparency, robust mechanical properties, self‐healing and self‐adhesion in air/underwater, easy recyclability, solvent tolerance, and sensitive and reliable strain sensing.