Flow-Driven Translocation of a Diblock Copolymer through a Nanopore

Abstract

Using a hybrid molecular dynamic and lattice Boltzmann simulation method, we investigate the flow-driven translocation of a diblock copolymer which is composed of a hydrophilic block and a hydrophobic block through a nanopore. Our results illustrate the nontrivial translocation dynamics of diblock copolymers. We find that the increase in the number of hydrophobic segments requires a larger critical flow rate and a reduced translocation time, which implies that the separation of diblock copolymers with different fractions of hydrophobic segments can be achieved by adjusting the flow rate. Our work deepens the understanding of copolymer translocation through a nanopore and provides an insight into designing related microscaled separation devices.

Flow-Induced Translocation and Conformational Transition of Polymer Chains through Nanochannels: Recent Advances and Future Perspectives

“…In the aspect of simulations, we have demonstrated that the enhancement in homopolymer insolubility results in the increase of q c , indicating that as the conformation collapses, the compressibility of the polymer chain becomes worse. 38 For amphiphilic diblock copolymers, we find that the increase in the number of hydrophobic segments results in a larger q c , 40 and such an observation is similar to our study of the homopolymer system. 38 Obviously, in a poor solvent, the interaction energy of insoluble blocks plays a crucial role in determining the deformability of target chains rather than the entropy origin.…”

“…We cannot simply assume that the physical image of the confined copolymer chain is still a series of blobs with the same properties. Our previous simulations have confirmed that for linear diblock copolymers the hydrophobic part is easier to aggregate, resulting in a completely different capture process from that of linear homogeneous polymers . Therefore, how to calculate the free energy barrier of these copolymers in a nanochannel and be able to correlate with the work done by the shearing fluid at the same time is also an important breakthrough direction in the future.…”

“…Our previous simulations have confirmed that for linear diblock copolymers the hydrophobic part is easier to aggregate, resulting in a completely different capture process from that of linear homogeneous polymers. 40 Therefore, how to calculate the free energy barrier of these copolymers in a nanochannel and be able to correlate with the work done by the shearing fluid at the same time is also an important breakthrough direction in the future. This may bring new analytical methods for the characterization/purification of copolymers, which is essential for the synthesis and properties study of this family of polymeric materials.…”

“…In the past decade, we have been devoted to the understanding of the interactive relationships between fundamental parameter and translocation behavior for polymer chains with various architectures. ,,− In this Perspective, we will tease out and discuss notable advances, highlight key issues and existing controversies, and propose further directions in the field. The Perspective is organized as follows: (i) First, we will start with the presentation of classical results of conformational properties of polymer chains free in solutions, and meanwhile, we will highlight recently achieved key experimental evidence.…”

Flow-driven translocation of comb-like copolymer micelles through a nanochannel

“…For two hydrophobic beads, we set the cutoff value to be r c = 2.5s, which is close to the poor solvent condition. 32,33 Meanwhile, for the other pairwise beads, the cutoff is set to be the minimum r c = 2 1/6 s, which is the good solvent condition and corresponds to a purely repulsive LJ potential. 34 Furthermore, all LJ potentials are shifted to satisfy U LJ = 0 at r c .…”