Taichi Ito, Chemical & Biomedical Engineering, Massachusetts Institute of Technology, E25-328, 45 Carleton St., Cambridge, MA 02142 and Takeo Yamaguchi, Chemical System Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.
Molecular recognition ion gating membrane is a synthetic membrane, which can response to a specific ion such as K+ and Ba2+, and can control hydrostatic flux, diffusion of solutes like model drugs, and osmotic pressure. This membrane was prepared to fill the copolymer of N-isopropylacrylamide (NIPAM), a thermosensitive polymer, and benzo [18]crown-6-acrylamide (BCAm) into nanosized-pores, which pore size is 200nm, of porous polyethylene film using plasma graft filling polymerization. Crown ether rings of BCAm catch the specific ion, the size of which fits its cavity, which triggers the swelling and shrinking of NIAPM in the pores. As a result, this membrane can control the above various transport phenomena. In the present study, we will report the nonlinear autonomous oscillation of osmotic pressure using the molecular recognition ion gating membrane. The gating membrane opened and closed its pores autonomously and cyclically in response to Ba2+ under BaCl2 concentration gradient. Using these phenomena, we can design and develop the novel sensors, drug delivery system, and micro fluid device in future.