Polydopamine layer formation at the liquid – gas interface

Abstract

The surface properties of a polydopamine layer at the air-water interface were studied by dilatational surface rheology, ellipsometry and Brewster angle microscopy (BAM). A significant increase of the dynamic surface elasticity was discovered when the concentration changed from 0.75 g/l to 2 g/l with the maximum value of about 60 mN/m at a concentration of 1 g/l. The obtained results indicate that the surface film consists of separate domains and the high surface elasticity is a consequence of the interactions between relatively rigid domains of the polymer film. This conclusion was confirmed by Brewster angle microscopy, which demonstrated different steps of the polydopamine film growth. Separate domains appeared at the first step while one can observe a continuous film close to equilibrium. An increase of the initial concentration led to faster polymerization and to the formation of a thicker film. The dynamic surface elasticity decreased in the concentration range from 2 g/l to 5 g/l when the thickness of the polymer film reached about 80 nm. In this case the film could be destroyed in the course of deformation. The cracks in the film resulted in a decrease of the dynamic surface elasticity.

Polydopamine Films with 2D-like Layered Structure and High Mechanical Resilience

“…The majority of the applications of PDA and studies attempt to understand the physicochemical characteristics of PDA layers grown on solid supports or directly address amorphous PDA particulates obtained during polymerization. ,,, However, over the past few years, some studies have explored the possibility of obtaining thin PDA membranes synthesized at the water/air interphase. − The general attractiveness of this methodology relies on the larger area of PDA films, homogeneity, and easily transferability. Despite their applicability and the rather exceptional properties of PDA, a few studies have shown the use of PDA membranes as wound dressing tools and as a calcination template for the oxygen reduction reaction .…”

Characterization of broadband complex refractive index of synthetic melanin coatings and their changes after ultraviolet irradiation

“…1), following a modified film-forming procedure (for experimental details, refer to the supplementary material). 45 Recently, there have been suggestions that intermolecular assembly in melanin could lead to stacked structures along the growth direction. 14 However, we provide evidence that including the uniaxial anisotropic model does not reduce the residuals.…”

Polydopamine Film Self‐Assembled at Air/Water Interface for Organic Electronic Memory Devices

“…[20][21][22][23][24][25] On the contrary, the polymerization of dopamine at the air/water (PDA-a/w) interface arises from a homogeneous nucleation process, which thereby leads to the production of large-area PDA film with controllable thickness and organized morphology. [26][27][28][29] Accordingly, PDA derived materials have been widely used in a variety of fields, including surface modification, [30][31][32][33] biomedical device fabrication, [34][35][36][37][38] and photo(electro-)chemical catalysis. [39][40][41][42][43] However, the direct utilization of PDA films in fabricating memristive devices has not been revealed prior to the work described here.…”