Translocation of Micelles through a Nanochannel

Abstract

Flow-driven translocation of micelles self-assembled from amphiphilic diblock copolymers through a nanochannel is studied by using hybrid lattice-Boltzmann molecular dynamics simulations. It is discovered that the structure of the translocating micelles depends on their initial sizes. Intact translocation occurs for small micelles, whereas fragmented translocation takes place for large micelles. The fragmented micelles reassemble to form an intact micelle after translocation. Coexistence of these two translocation modes is observed when the size of the initial micelle core is similar to that of the nanochannel. The critical translocation flow flux, at which the probability of translocation equals to 0.5, is found to increase rapidly with the aggregation number of the initial micelles in the intact translocation regime, whereas it remains approximately a constant in the fragmented translocation regime. The number of fragmented translocating micelles is found to be a linear function of the aggregation number. These findings provide an understanding of the dynamics of micelle translocation.

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

“…Our previous work has shown that the critical flow flux can be used to characterize the stability of the micelle by indicating the minimum flow flux that is just enough to allow the micelle to be disrupted and squeezed into a small nanochannel smaller than its size. 13 Thus, we calculate the translocation probability [ P ( J )] in Fig. 2, where (a)–(c) are the comb-like copolymer micelles and (d)–(f) are the corresponding diblock copolymer micelles, and the critical flow flux ( J c ) is defined as the flow flux when P ( J ) = 0.5, denoted by the auxiliary dashed lines.…”

“…11,12 In our previous work, we have demonstrated that the stability of micelles can be well characterized by their flow inside a nanochannel through the flow-driven translocation; that is, the translocation of micelles, including intact and fractured modes, is dependent on their initial size. 13…”

“…In this work, using a coarse-grained model from previous work by our group and other researchers, 13,27–29 and coupled with self-consistent field theory (SCFT), 30 we investigate the flow-driven translocation of micelles through a nanochannel, in particular, making a detailed comparison between the micelles formed by comb-like block copolymers and those formed by diblock copolymers. Our article is structured as follows: in Section 2, we display the details and parameters of the simulations.…”

“…11,12 In our previous work, we have demonstrated that the stability of micelles can be well characterized by their flow inside a nanochannel through the flow-driven translocation; that is, the translocation of micelles, including intact and fractured modes, is dependent on their initial size. 13 For the micelles formed by block copolymers, the stability is closely related to the chain topology of their constituent copolymers. 14 To distinguish from linear copolymers, each graft block copolymer structurally consists of a main chain and several branching side chains; it should be noted that the two types are composed of different structural units, i.e., hydrophobic and hydrophilic monomers, respectively.…”

Adsorption Kinetics of Poly(benzyl acrylate) Chains onto Alumina Interface during the Flow-Driven Translocation through Cylindrical Nanochannels

“…As for the former, as long as the drag force from the fluid is sufficiently high to overcome the confinement force imposed by the channel interface, the conformational transition and translocation event occur simultaneously. Such a topic has received much attention in the previous theoretical and experimental studies. − …”