Hybrid Nanochannel Research Articles

Nanochannels: Organic/Inorganic Hybrid Nanochannels Based on Polypyrrole‐Embedded Alumina Nanopore Arrays: pH‐ and Light‐Modulated Ion Transport (Adv. Funct. Mater. 14/2015)

On page 2091 conductive polypyrrole is integrated by Z. Liu, J. Zhai, and co-workers into alumina nanopore arrays to construct organic/inorganic hybrid nanochannels. The protonation and deprotonation of surface groups upon pH variation contributes to the pH-tunable ion rectification. Positive charges in polypyrrole layer induced by the cooperative effect of light and protons are used to regulate the channel flux, which results in a light-responsive ion current.

Organic/Inorganic Hybrid Nanochannels Based on Polypyrrole‐Embedded Alumina Nanopore Arrays: pH‐ and Light‐Modulated Ion Transport

Inspired by the asymmetric structure and responsive ion transport in biological ion channels, organic/inorganic hybrid artificial nanochannels exhibiting pH‐modulated ion rectification and light‐regulated ion flux have been constructed by introducing conductive polymer into porous nanochannels. The hybrid nanochannels are achieved by partially modifying alumina (Al2O3) nanopore arrays with polypyrrole (PPy) layer using electrochemical polymerization, which results in an asymmetric component distribution. The protonation and deprotonation of Al2O3 and PPy upon pH variation break the surface charge continuity, which contributes to the pH‐tunable ion rectification. The ionic current rectification ratio is affected substantially by the pH value of electrolyte and the pore size of nanochannels. Furthermore, the holes (positive charges) in PPy layer induced by the cooperative effect of light and protons are used to regulate the ionic flux through the nanochannels, which results in a light‐responsive ion current. The magnitude of responsive ionic current could be amplified by optimizing this cooperation. This new type of stimuli‐responsive PPy/Al2O3 hybrid nanochannels features advantages of unique optical and electric properties from conducting PPy and high mechanical performance from porous Al2O3 membrane, which provide a platform for creating smart nanochannels system.

Dynamic silica assembly for fabrication of nanoscale polymer channels

Nanoscale polymer silica hybrid nanochannel array of average channel size of ∼50 nm were fabricated by electrokinetically induced silicification reaction within a polymer template. The uniform growth of silica can be realized by appropriate combination of reactant concentration and electric field strength. The formed silica leads to the reduction in channel size, and provides substantial reinforcement to the polymer nanostructure. Such nanochannel arrays may be a useful platform for a variety of biomedical applications.