Different from classic polyelectrolytes, poly(ionic liquid)s (PILs) bearing hydrophobic counterions show high electrorheological (ER) effect in dry state. This opens a way to develop new generation of anhydrous polyelectrolyte ER fluids. However, PILs with linear backbone are limited in practical applications due to low glass transition temperature. Herein, we present self-crosslinked PILs-based ER materials with good temperature stability. The influence of counterions and alkyl spacer on ER effect are studied in order to understand the structure-property relationship. It shows that as alkyl spacer length increases, the ER effect increases but the working temperature range becomes narrow. As the size increases, the ER effect decreases (i.e. BF₄^- > PF₆^- > TfO^- > TFSI^-). Different from the linear PILs system, however, the self-crosslinked PILs with inorganic counterions shows stronger ER effect compared to self-crosslinked PILs with organic counterions. Meanwhile, the influence of counterions on temperature dependence of ER effect of the self-crosslinked PILs system is also different from the linear PIL system.

 

ER effect,poly(ionic liquid)s,self-crosslinking