Probing the Utmost Distance of Polymer Dynamics Suppression by a Substrate by Investigating the Diffusion of Fluorinated Tracer-Labeled Polymer Chains

Abstract

A facile method was developed to measure the utmost distance of polymer dynamics suppressed by a solid substrate by investigating the diffusion of a fluorinated tracerlabeled polymer in the bottom layer of bilayer samples. Here, a labeled layer of fluorinated tracer-labeled at the polymer chain end of variable thickness was supported on a substrate, and the corresponding homopolymer layer of fixed thickness was deposited on top of the bottom layer. From the critical time (t*) required for the fluorinated component to diffuse from the bottom layer to the bilayer film surface as a function of the thickness of the bottom layer, a critical thickness of the bottom layer (h c *), corresponding to the thickness at which t* started to increase, was obtained. This thickness was related to the distance over which polymer dynamics were altered by the substrate. The results showed that h c * was very sensitive to the surface chemistry of the substrate and exhibited both molecular weight and temperature dependencies.

The Glass-Transition Temperature of Supported PMMA Thin Films with Hydrogen Bond/Plasmonic Interface

“…To further understand the surface effect in molecule mobility behavior, we investigated the T g of TC1-labeled PMMA thin film sandwiched between the substrate (quartz or silver) and PMMA bulk layer. From free surface to polymer/substrate interface, the polymer chain in thin film with different deepness could exhibit different molecule mobility [17,18,43]. Therefore, structure-B and structure-D (Figure 1) were prepared to study the free surface effects on the samples.…”

The role of the molecular weight of the adsorbed layer on a substrate in the suppressed dynamics of supported thin polystyrene films

“…The diffusion of polymer chains with fluorinated tracer-labeled multilayer films was used to detect the propagation depth of the substrate effect with various adsorbed layers, as in our previous work. 32 The multilayer films were produced by combining spin-coating and floating techniques as previously reported. 33,34 In the present study, the bottom layer is an adsorbed layer of PS.…”

Effect of Local Chain Conformation in Adsorbed Nanolayers on Confined Polymer Molecular Mobility

“…Taken together, the data presented above demonstrate that the height of loops in flattened layers can be controlled by altering f HS , provided 0.024 < f HS < 0.14. The influence of adsorbed layer chain topology on diffusion in PS thin films was obtained using a multilayer film geometry [34] recently developed to detect gradients of chain mobility near the interface by investigating the diffusion of a fluorinated tracer-labeled polymer. [34] A multilayer film [Inset of Fig.…”

“…The influence of adsorbed layer chain topology on diffusion in PS thin films was obtained using a multilayer film geometry [34] recently developed to detect gradients of chain mobility near the interface by investigating the diffusion of a fluorinated tracer-labeled polymer. [34] A multilayer film [Inset of Fig. 3(a)] composed of a bottom flattened layer of P(S-r-HS), a variable-thickness middle layer of polystyrene end-capped with 2-perfluorooctylethyl methacrylate (FMA) units (PS 402 -ec-FMA 2 , M W = 43 kg/mol, PDI = 1.12), and a top layer of PS (h up = 50 nm, M w = 40 kg/mol, PDI = 1.08), was fabricated (see section S5 of SM [27] for sample preparations).…”