Effect of Connectivity on the Structure and the Liquid–Solid Transition of Dense Suspensions of Soft Colloids

Abstract

Aqueous solutions of multiarm flower-like poly(ethylene oxide) (PEO) were formed and connected to various degrees by self-assembly. The structure was rendered permanent by in situ UV-irradiation. Dense suspensions of these single and connected soft colloids were studied by static and dynamic light scattering and viscosity measurements. The concentration dependence of the osmotic compressibility, the dynamic correlation length, and the viscosity of single flowers was shown to be close to that of equivalent PEO star-like polymers demonstrating that the effect of forming loops on the interaction is small. It was found that the osmotic compressibility and the dynamic correlation length of dense suspensions are not influenced by the bridging. However, when flower polymers are connected into clusters, motion in dense suspensions needs to be collective over larger length scales. This causes a much stronger increase of the viscosity for dense suspensions of interpenetrated clusters compared to single-flower polymers.

Size Separation Techniques for the Characterisation of Cross-Linked Casein: A Review of Methods and Their Applications

“…For homogeneous hard sphere the ratio is equal to 0.775, for linear random coil is between 1 and 2, and for elongated conformations the ratio is up to 2 [200]. The determination of the diffusion coefficient and thus the hydrodynamic radius is also possible from the AF4 elution time (see Section 5.1, Equation (3)); however, both approaches possess advantages and limitations that were treated in depth in the bioconjugation of synthetic macromolecules and proteins [177,[201][202][203][204][205].…”

Synthesis of Flower‐Like Polybutadiene

“…Increasing the irradiation time did not improve the incorporation rate of unimers in the crosslinked flowers (see Figure S11, Supporting Information). As previously observed for PEO‐based flowers, increasing the concentration from 0.5 to 2 g L −1 led the bridging of flower‐like micelles that formed aggregates of micelles ( t el < 10 min) . Deconvolution of the chromatograms allowed the estimation of the fractions of the different populations (see Table ).…”

“…As previously observed for PEO-based flowers, increasing the concentration from 0.5 to 2 g L −1 led the bridging of flower-like micelles that formed aggregates of micelles (t el < 10 min). [26,39] Deconvolution of the chromatograms allowed the estimation of the fractions of the different populations (see Table 1). A solution of copolymer at 0.5 g L −1 in THF was irradiated in the same conditions.…”