Study of transportation of atrazine and paraquat through nanochannels

The transportation of paraquat and atrazine through the modified gold nanochannels polycarbonate track etched (PCTE) membrane was described. The gold nanochannels can be electrolessly plated within the pores of PCTE membranes. The gold nanochannels were hydrophobic because of modification of thiol (HSC18H37). They can forbid paraquat and allow atrazine to transport through the membranes. However, these hydrophobic membranes can be switched from an “off” state (no or lower ion-current through the membrane) to an “on” state (higher ion-current) due to the presence of some surfactants. The effects of different surfactants, including cationic surfactant such as C16H29 (CH3)3NH4Br, nonionic surfactant like emulsifier OP, on the transport properties of paraquat through the membrane were investigated. It is found that for some alkyl surfactants with a 12-carbon chain length can switch the membrane to the on state even if their concentrations were lower than critical micelle concentrations. Specially, for a 10-carbon chain alkyl surfactant, 1-decanesulfonic acid sodium has the same function of switching the membrane to the on state as long as its concentration is high enough. But other chemical substances, regardless of cation, anion or molecule, cannot switch the membrane.