title: Electric Field-Controlled Ion Transport In TiO2 Nanochannel.
abstract: On the basis of biological ion channels, we constructed TiO2 membranes with rigid channels of 2.3 nm to mimic biomembranes with flexible channels; an external electric field was employed to regulate ion transport in the confined channels at a high ionic strength in the absence of electrical double layer overlap. Results show that transport rates for both Na+ and Mg2+ were decreased irrespective of the direction of the electric field. Furthermore, a voltage-gated selective ion channel was formed, the Mg2+ channel closed at -2 V, and a reversed relative electric field gradient was at the same order of the concentration gradient, whereas the Na+ with smaller Stokes radius and lower valence was less sensitive to the electric field and thus preferentially occupied and passed the channel. Thus, when an external electric field is applied, membranes with larger nanochannels have promising applications in selective separation of mixture salts at a high concentration.
authors.affiliation: State Key Lab of Material-Oriented Chemical Engineering, National Engineering Research Center for Special Separation Membrane, College of Chemistry and Chemical Engineering, Nanjing Tech University, Nanjing, Jiang Su 210009, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Li
authors.affiliation: State Key Lab of Material-Oriented Chemical Engineering, National Engineering Research Center for Special Separation Membrane, College of Chemistry and Chemical Engineering, Nanjing Tech University, Nanjing, Jiang Su 210009, China.
authors.forename: Wenheng
authors.initials: W
authors.lastname: Jing
authors.affiliation: State Key Lab of Material-Oriented Chemical Engineering, National Engineering Research Center for Special Separation Membrane, College of Chemistry and Chemical Engineering, Nanjing Tech University, Nanjing, Jiang Su 210009, China.
authors.forename: Shuaiqiang
authors.initials: S
authors.lastname: Li
authors.affiliation: State Key Lab of Material-Oriented Chemical Engineering, National Engineering Research Center for Special Separation Membrane, College of Chemistry and Chemical Engineering, Nanjing Tech University, Nanjing, Jiang Su 210009, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Shen
authors.affiliation: State Key Lab of Material-Oriented Chemical Engineering, National Engineering Research Center for Special Separation Membrane, College of Chemistry and Chemical Engineering, Nanjing Tech University, Nanjing, Jiang Su 210009, China.
authors.forename: Weihong
authors.initials: W
authors.lastname: Xing
mesh_terms: D040761:Biomimetic Materials / Q000737:chemistry*; D004574:Electromagnetic Fields; D018274:Electroporation / Q000379:methods; D017136:Ion Transport / Q000528:radiation effects*; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000528:radiation effects / Q000648:ultrastructure*; D058608:Nanopores / Q000648:ultrastructure*; D014025:Titanium / Q000737:chemistry* / Q000528:radiation effects
chemical_list: C009495:titanium dioxide; D014025:Titanium
keywords: TiO2 membrane; TiO2 nanochannel; confined channel; electric field; ion transport