Fabrication and application of nanoporous polymer ion-track membranes

Abstract

With the development of the nano-fabrication and nanofluidics, nanoporous membranes have shown great potential in applications such as molecular separation, energy conversion, and molecular sensing. However, their performance has often been limited by the trade-off between selectivity and permeability and the lack of scalability. The prospect of overcoming these problems with nanoporous polymer ion-track membranes is promising. Focusing on these membranes, this review provides a comprehensive overview of fabrication methods, including the traditional track-etching technique and the recently developed track-UV technique; characterization methods; transport mechanisms; and major properties and applications.

Prospects of Membrane Science Development

“…To the traditional fields of application of tracketched membranes (TMs)-use in chemical, biochemical, bacteriological, and microbiological analysis; environmental monitoring; medicine; and pharmaceutics [101]-fast growing areas associated with the development of nanofluidics, sensorics, and life sciences have been added. Research-and-development works in these fields require the use of microand nanopores with predetermined geometry and surface properties [102][103][104][105][106][107]. Significant progress in these works was achieved in particular due to the unique procedure for fabrication of membranes with a single track-etched pore [108].…”

“…In the last decade, a wealth of research was performed for the purpose of understanding the mechanism and theoretically describing the nature of the diode effect [114]. Membranes with asymmetric, in particular, cone-shaped nanopores are promising for electric power generation using reverse electrodialysis [103,107].…”

“…Hundreds of publications are devoted to molecular sensors on the basis of membranes with single asymmetric pores. Such sensors operate based on the resistive pulse principle or molecular recognition principle [104,107,[113][114][115][116]. The resistive pulse detection method is based on the fact that a particle, e.g., a macromolecule, passing through an orifice replaces some solution from the sensitive zone and sharply changes the electric resistance of the pore.…”

“…Carboxyl groups on the pore walls are generally used for its grafting. The applicability of the molecular recognition method with the use of asymmetric pores in the membranes made of polyethylene terephthalate and polyimide was demonstrated in a large number of original works (see, e.g., [113,115,116]) and reviews [104,106,107,118]. "Nanopore" sensors for various protein molecules, glucose, metal ions, toxins, and narcotics were proposed.…”

“…MEMBRANES Track-etched nanopores with a diode effect are also considered as functional elements in nanofluidics. Thus, they can serve as ion pumps as well as logic elements [103,107,117]. Grafting DNA oligomers in the pore entrance made it possible to obtain an electromechanical nanovalve that opens and closes depending on the potential difference applied to the membrane and the pH [101,107,118].…”