Spatiotemporal Evolution in Morphogenesis of Thermoreversible Polymer Gels with Fibrillar Network

Abstract

A scattering modeling approach is used to clarify the formation of the thermoreversible polymer gel with a fibrillar network. We find that the gelation has to do with the spatiotemporal evolution of the so-called "coherent structure"-the nonlocalized, fibril nucleation via the fluctuation instability and fibril growth coupled with a cooperatively coarsening concentration wave-and is a direct consequence of the spinodal crystallization far from equilibrium in the solution. The present result rejects the common opinion that the gelation is nothing more than the percolation problems and poses an interesting question about the entropy-driven crystallization.

Nanofibrous, Emulsion-Templated Syndiotactic Polystyrenes with Superhydrophobicity for Oil Spill Cleanup

“…The nanofibrous structures within the sPS- X - Y are well-aligned with the increasing Y (diverging from the bottom of voids to their edges), perhaps because the sPS crystallization grew along the drawing direction of TCB solution, similar to a two-dimensional thin film . The formation of the nanofibers could be ascribed to the crystallization of sPS . The assumption has been confirmed by the fibrous structures from sPS- X -bulk (Figure S4, Supporting Information), but the fiber diameters for the sPS- X - Y were much smaller.…”

“…43 The formation of the nanofibers could be ascribed to the crystallization of sPS. 44 The assumption has been confirmed by the fibrous structures from sPS-X-bulk (Figure S4, Supporting Information), but the fiber diameters for the sPS-X-Y were much smaller.…”

Morphogenetic Transition in Weak Gelation of Crystallizable Linear Polymers

“…18 Recently, we have identified the instability of the fringed-micelle formation (a process called "coherent evolution", the nonlocalized, fibril nucleation via the fluctuation instability and fibril growth coupled with a cooperatively coarsening concentration wave); at this point, we further speculated that the fibrillar networks might represent the "observable" spinodal crystallization of polymers. 9 In contrast to the fibrillar networks, because the polymer chain folds into a crystalline grain, the self-assembling mechanism provides the only available means to form a "network" without the topological entanglement. The cartoon in Figure 1 shows the process.…”

“…The last two terms are the structural description of the fibrillar network in our previous work. 9 Two simple assumptions underlie the model: First, the crystalline grain and the fibril can coexist and follow the conservation law; Second, for the sake of simplicity, only the spherical clusters were assumed. Of course, there is a difference between the spherical and the fractal cluster, particularly near the pseudospinodal point.…”

“…Thus, many experiments have been focused on the microstructures (microcrystal, helical structure, molecular compound, etc.) associated with the cross-links in an imaginary disordered network. , However, the vast observation of diverse, hierarchical gel morphologies shows that the polymer self-organization/assembly seems to be a reasonably realistic description. − …”