Effect of grafting density on the adsorption of end-grafted polymer chains

Height-Switching Dynamics of Mixed Polymer Brushes with Polymers of Different Stiffnesses

“…After long time of evolution, the brushes reach a new equilibrium state, and < h > R , < h > C , and δ h tend to be constant. We would like to point out that, since the critical adsorption point is dependent on the grafting density of polymer brush, we only present the critical adsorption of a single polymer chain in this paper.…”

“…After long time of evolution, the brushes reach a new equilibrium state, and <h> R , <h> C , and δh tend to be constant. We would like to point out that, since the critical adsorption point is dependent on the grafting density of polymer brush, 47 we only present the critical adsorption of a single polymer chain in this paper. Figure 3 also shows that δh changes from an initial positive value to a negative saturated value with time, indicating that the mixed polymer brushes undergo a switch from a "hard" surface (inset (a) of Figure 3) where the stiff polymers are at the top of the brushes to a "soft" surface (inset (b) of Figure 3) where the flexible polymers are at the top of the brushes.…”

Height-Switching in a Mixed Polymer Brush Induced by the Collapse Transition of Attractive Polymer Chains

“…It is well-known that the critical grafting density f c , which separates the mushroom state and the polymer brush state, can be expressed as f c ( N ) = 1/ N 2ν with ν = 0.588 for a polymer brush consisting of identical polymers of length N in the good solvent condition. , That is, f c is lower for longer polymers. In the present work, we have implemented a strategy where N A > N R in order to exhibit the height-switching phenomenon.…”

“…Previous studies have shown that the mean height of the polymer brush is proportional to Nf 1/3 . − Thus, we plot the dependence of values ⟨ h c ⟩, ⟨ h max ⟩, ⟨ R Gz ⟩, and ⟨ h ⟩ on the rescaled N R f R 1/3 at low temperature T = 0.5, as shown in Figure . Indeed, the height of the repulsive R-chain brush shows a scaling relation of N R f R 1/3 , which is consistent with the previous results. − However, the values of the attractive A-chain globule are roughly independent of N R and f R , which means that the property of a globule is determined by itself.…”

Interplay of Grafted and Adsorbed Chains at the Polymer–Particle Interface in Tuning the Mechanical Reinforcement in Polymer Nanocomposites

“…When the grafting density exceeds a certain value (e.g., 1.67 nm –2 ), the matrix chains cannot penetrate the grafted chains, and the interface is composed of grafted chains only (Figure c) . Structure and thermodynamics of PGNCs consisting of grafted and adsorbed chains at polymer–particle interface have been studied through computer simulations ,,,, and experiments. ,, However, the interplay of the grafted and adsorbed chains on mechanical properties in PGNCs has been little explored in the past. ,, …”