How does a polymer chain pass through a cylindrical pore under an elongational flow field?

Experimental Validation on Average Conformation of a Comblike Polystyrene Library in Dilute Solutions: Universal Scaling Laws and Abnormal SEC Elution Behavior

“…In addition to the above thermodynamic origin, initially, we also suspected that the flow-induced forced penetration may be the other origin from the dynamic point of view. In our previous studies of polymer translocation through nanopores, we have revealed that the deformability of macromolecules with different architectures is not determined by the chain size but by the entropy penalty. − In particular, we have proved that hyperbranched chains with a much larger R h but a lower branching density can enter nanopores more easily. , …”

“…74−76 In particular, we have proved that hyperbranched chains with a much larger R h but a lower branching density can enter nanopores more easily. 77,78 To verify the possibility of a dynamic origin, we systematically studied whether the column type and elution flow rate will change the elution order of samples with different grafting densities. It is well-known that the packing materials of SEC columns from different companies may possess different pore geometries, size distributions, and pore densities, which absolutely will result in different average microscopic flow rates inside a nanopore and different shear rates.…”

Ultrafiltration of single-chain polymer nanoparticles through nanopores and nanoslits

“…Understanding the translocation of macromolecules with different topologies through confinement geometries such as a cylindrical pore of diameter D or a rectangular slit of width H both smaller than the macromolecular size, R, (i.e., ultrafiltration regime) is of great interest for both theoretical and practical point of views. [1][2][3][4][5][6][7][8][9] From an application perspective, understanding how confinement alters the conformation of topological complex polymers is of interest for increasing our comprehension of several biological processes such as endocytosis, extravasation or renal filtration, 9,10 to improve new polymeric drug delivery systems, 11,12 and for the development of innovative nanoanalytical devices, 13 to name only a few relevant examples. Complementary, extensive theoretical efforts have been carried out to predict scaling regimes of noncharged chains with complex topologies in nanochannel and nanoslit geometries, [1][2][3][4][5][6] as well as the corresponding critical flux rates for ultrafiltration under an elongational flow field 14 since the successive works by Peterlin, 15 Casassa and Tagami, 16 de Gennes, 17 Pincus, 18 and Daoudi and Brochard 19 related to the translocation of a (neutral) flexible linear polymer chain through a small cylindrical pore under a specific flow field.…”

“…In addition to the classical and relevant problem of ultrafiltration of linear polymers through nanopores, other more complex scenarios involving translocation of intricate chain topologies such as those displayed by randomly branched [2][3][4][5]20 and star 2,6,21 polymers have also been theoretically addressed. In particular, the conformational properties of macromolecules under confinement and the critical flow rate for ultrafiltration have been the subject of a variety of theoretical approaches (e.g., Flory-type treatment of the free energy under confinement, 1,22 "blob" model of confined polymers, 1 balance of hydrodynamic drag and confinement forces on an individual blob 14 ).…”

“…When compared to theoretical achievements, however, experimental progress in this field has been significantly delayed due to the difficulty in preparation of uniform polymers with complex topologies and well-defined ultrafiltration membranes as well as to guarantee a complete elongational flux at nanopore entrance, although significant advances have been observed in recent years. 4 Interestingly enough, a unified description of transportation of polymer chains with different topologies (linear, branched, star) through a small cylindrical pore has been recently established by Wu and Li, 14 paving the way to consider the case of even more complex topologies, such as those displayed by so-called single-chain polymer nanoparticles (SCNPs) (i.e., individual intrachain cross-linked polymer chains). 23 In recent years, the self-folding of an individual linear polymer chain (precursor) to a SCNP via intrachain covalent, noncovalent or dynamic covalent bonds [24][25][26][27][28][29][30][31][32][33] has attracted significant interest due to the potential applications of these nano-objects with complex topology in nanomedicine, [34][35][36][37] biosensing, [38][39][40] and catalysis, [41][42][43][44][45] among other different fields.…”