Dewetting of Polymer Films Controlled by Protein Adsorption

Abstract

The stability of the film poly( n -butyl methacrylate) (PnBMA) with different tacticities, prepared on silicon oxide and exposed to aqueous phosphate-buffered saline with different concentrations of bovine serum albumin ( C BSA between 0 and 4.5 mg/mL), was examined at temperatures close to the physiological limit (between 4 and 37 °C) with optical microscopy, contact angle measurements, atomic force microscopy, and time-of-flight secondary ion mass spectrometry. For PBS solutions with C BSA = 0, the stability of atactic PnBMA and dewetting of isotactic PnBMA was observed, caused by the interplay between the stabilizing long-range dispersion forces and the destabilizing short-range polar interactions. Analogous considerations of excess free energy cannot explain the retardation of dewetting observed for isotactic PnBMA in PBS solutions with higher C BSA . Instead, formation of a BSA overlayer, adsorbed preferentially but not exclusively to uncovered SiO x regions, is evidenced and postulated to hinder polymer dewetting. Polymer dewetting and protein patterning are obtained in one step, suggesting a simple approach to fabricate biomaterials with micropatterned proteins.

Polymer Fractionation at an Interface in Simple Shear with Slip

“…These instabilities typically result in the rupture of the film, creating holes at locations where the film is thinner. These holes eventually grow laterally over time, resulting in the formation of rims around them. − We rule out dewetting as a possible reason for the holes observed on the films in our study for the following three reasons: (i) the films produced in this study are stabilized by gravity due to their large thickness [Table ]; (ii) the amplitude of modulation of the surface of the film is not equal in magnitude to the thickness of the film, which is required for rupture; and (iii) the kinetics of dewetting of a material is influenced by its molecular weight and the distribution of relaxation times . Therefore, in the unlikely event of the rupture of the film due to surface instability, the lateral growth of the holes to form rims would be very slow.…”

Assessing Polymer-Surface Adhesion with a Polymer Collection

“…Recent trends of integration and portability generate growing demand for miniaturized devices, which brings great opportunity to this field. However, the uncertainty of the polymer-surface adhesion slows down this evolution. , On the one hand, spontaneous dewetting phenomena of polymers on substrates make it hard to generate polymer microstructures with defined morphologies (e.g., size, thickness, and shape). − On the other hand, mismatched polymer–substrate pairs lead to poor adhesion, having a negative impact on device stability. Therefore, it is necessary to get a better control of polymer-surface adhesion.…”

Halloysite nanotubes-based nanocomposites for the hydrophobization of hydraulic mortar

“…17,18 More recently, biopolymers are considered perspective candidates as they have been defined ''intrinsically reversible'' because they are expected to vanish from the stone surface once their action has ceased or to produce nonaggressive residues, and they do not create any issues in subsequent conservation treatments. [19][20][21][22] Actually, biopolymers are widely used in restoration protocols as thickening agents for cleaning formulations and, to some extent, they have been introduced as coatings against sulphation or to enhance water repellency. [23][24][25][26][27][28][29] Their combination with nanoparticles is a promising strategy to further improve the physicochemical properties.…”