Transition from Confined to Bulk Dynamics in Symmetric Star–Linear Polymer Mixtures

Abstract

We report on the linear viscoelastic properties of mixtures comprising multiarm star (as model soft colloids) and long linear chain homopolymers in a good solvent. In contrast to earlier works, we investigated symmetric mixtures (with a size ratio of 1) and showed that the polymeric and colloidal responses can be decoupled. The adopted experimental protocol involved probing the linear chain dynamics in different star environments. To this end, we studied mixtures with different star mass fraction, which was kept constant while linear chains were added and their

Entropy-Induced Separation of Binary Semiflexible Ring Polymer Mixtures in Spherical Confinement

“…Nevertheless, much less attention has been paid to the confinement of SRPs inside the spherical container, especially considering SRP mixtures with polydispersity. The physical effects from the topological constraints and confinements play significant roles in the structure and function of individual genetic materials [34][35][36][37][38], such as chromosome shape in elongated bacterial cells [39], DNA (or DNA-actin filament mixtures) self-organization in a cell-size confinement [40], and drug delivery from spherical vesicles [41,42], etc.…”

Static and dynamic properties of block copolymer based grafted nanoparticles across the non-ergodicity transition

“…Such a value is much lower than that of a typical colloidal glass of (other) soft particles investigated in the literature. 18,19,29,[77][78][79] This simple observation is reminiscent of the behavior of hard sphere suspensions 80 which reveals that a colloidal crystal is characterized by lower dynamic moduli compared to the respective repulsive glass. Whereas this is a simple observation, it certainly motivates more investigations in the direction of linking the viscoelastic response of soft colloidal crystals and their respective glasses.…”

“…83 Star polymers with higher functionality (f~362) are more efficient osmotic compressors than linear chains since the osmotic pressure increases with functionality. 18,111 Osmotic pressure in high-functionality stars can also favor crystalline order. 1,28,112,113 In the present case, the shrinkage of the particles was estimated through the reduction of Brush needed to obtain good agreement between the simulated and experimental correlation functions when using the brush potential.…”

“…Figure 12 depicts the shrinkage of the soft particles as a function of the volume fraction, using present data and star data from the literature. 18,29 Although only few data points are available, it is clear that the dependence of the particle size on the volume fraction () is much stronger for PGNPs compared to low functionality stars, and very similar to high-functionality stars, with a slope around -0.2. Figure 12.…”

“…Examples of spherical soft colloidal systems are vesicles, dendrimers, 2 microgels, [3][4][5] block copolymer micelles, [6][7][8][9] polymer-grafted nanoparticles (PGNPs), [10][11][12][13][14] and star polymers. [15][16][17][18][19] Unlike hard-spheres, for which the phase diagram and associated dynamic properties have been exhaustively investigated, 20 the respective consequences of softness have not been fully explored. For instance, bridging the gap between ultrasoft stars and polymer-grafted nanoparticles by identifying similarities and distinct features in the behavior still presents formidable challenges.…”