A smart temperature and magnetic-responsive gating carbon nanotube membrane for ion and protein transportation

Abstract

Carbon nanotube (CNT) nanoporous membranes based on pre-aligned CNTs have superior nano-transportation properties in biological science. Herein, we report a smart temperature- and temperature-magnetic-responsive CNT nanoporous membrane (CNM) by grafting thermal-sensitive poly(N-isopropylacrylamide) (PNIPAM) and Fe3O4 nanoparticles (Fe3O4-NPs) on the open ends of pre-aligned CNTs with a diameter around 15 nm via surface-initiated atom transfer radical polymerization (SI-ATRP) method. The inner cavity of the modified CNTs in the membrane is designed to be the only path for ion and protein transportation, and its effective diameter with a variation from ~5.7 nm to ~12.4 nm can be reversible tuned by temperature and magnetic field. The PNIPAM modified CNM (PNIPAM-CNM) and PNIPAM magnetic nanoparticles modified CNM (PNIPAM-MAG-CNM) exhibit excellent temperature- or temperature-magnetic-responsive gating property to separate proteins of different sizes. The PNIPAM-CNMs and PNIPAM-MAG-CNMs have potential applications in making artificial cells, biosensors, bioseparation and purification filters.

Transport Phenomena in Nano/Molecular Confinements

“…Over the past few years, the increased availability of CNT membranes for experimental investigations resulted in a significantly improved understanding of transport properties of these materials and their potential utilization for a variety of applications. 325−328 For example, Cong et al 329 developed a CNT membrane for ion and protein transportation with temperature and magnetic-driven gating capability. To this end, they used a surface-initiated atom-transfer radical polymerization method to graft thermal-sensitive poly(Nisopropylacrylamide) (PNIPAM) and Fe 3 O 4 nanoparticles (Fe 3 O 4 -NPs) on the open ends of prealigned CNTs with a diameter around 15 nm.…”

“…g ., MD) as a more accessible tool to study fluid characteristics in CNTs. Over the past few years, the increased availability of CNT membranes for experimental investigations resulted in a significantly improved understanding of transport properties of these materials and their potential utilization for a variety of applications. − For example, Cong et al . developed a CNT membrane for ion and protein transportation with temperature and magnetic-driven gating capability.…”

“…The obtained membrane provides ions and water transport only through CNTs. Adapted from ref . Copyright 2016 Springer Nature.…”

Thermo-responsive polymer–black phosphorus nanocomposites for NIR-triggered bacterial capture and elimination

“…48 In addition, poly(N-isopropylacrylamide) (PNIPAM) is usually used for decorating nanomaterials (e.g., graphene, carbon nanotubes, and silica nanoparticles) to fabricate thermo-responsive nanocomposites. [49][50][51][52] When the nanomaterials have photothermal conversion properties, the hydrophobic-hydrophilic phase transition of PNIPAM can be manipulated by NIR light-triggered temperature change, facilitating the contactless control of nanocomposites' behaviour.…”

Bioinspired nanochannels based on polymeric membranes

“…The application of biological materials is limited due to their low strength and harsh requirements for external working conditions [16]. Inorganic materials, which have the advantages of high strength, stable structure and physicochemical properties, play an important role in the construction of nanochannels [17][18][19]. For example, anodic alumina membrane (AAO) has a pore density up to 10 9 cm −2 , and its shape and size are relatively controllable.…”