Smart hydrogels are one kind of soft materials adopting water as the dispersion medium
which could respond to the external changes in the surrounding environment
such as temperature
pH value
pressure
solvent
light or electric/magnetic field
and further induce reversibly continuous or discontinuous volume phase transitions by absorbing or squeezing several-fold water out of themselves.In recent years
chiral hydrogel emerges as a new research field and will find broad applications in chiral recognition
enantiomeric separation
controlled drug release and microfluid devices
which have become one of the research focuses in the interdisciplinary fields among material sciences
chemistry and biomedicines.However
how to obtain chiral hydrogels with sensitive and accurate responsiveness
well-defined nano- and micro-structures
as well as the controllable formation process
have become the critical points of research.In this review
recent progresses in chiral hydrogels are summarized
including various preparation methods to construct polymer hydrogels with three-dimensional network structures or small molecular hydrogels with helical structures
as well as some vagarious gel formation process in which chirality is transferred from singular molecules to nanoscale architectures and macroscopic behavior of hydrogels.Finally
the applications and tendency of future development of these materials are introduced.