Smart Membranes: Positively K+-Responsive Membranes with Functional Gates Driven by Host-Guest Molecular Recognition (Adv. Funct. Mater. 22/2012)

A unique, positively K+‐responsive membrane is reported by Xiao‐Jie Ju, Liang‐Yin Chu, and co‐workers on page 4742. The membrane pores can spontaneously and reversibly switch from the closed state to the open state rapidly by recognizing K+ ions in the environment. Other ions (e.g., Na+, Ca2+) do not trigger such a gating function. The K+‐triggered opening of the membrane gates is driven by a cooperative interaction of crown‐ether‐based host‐guest complexation and poly(N‐isopropylacrylamide)‐based phase transition.