Structural and Dynamic Approach of Early Hydration Steps in Erodable Polymers by ATR−FTIR and Fluorescence Spectroscopies

Abstract

The understanding of mechanisms involved in the controlled release of active molecules from the polymer matrix requires the study of hydration phenomenon. Fluorescence and attenuated total reflection Fourier transform infrared (ATR−FTIR) spectroscopies were used to analyze the earlier steps of hydration in acrylic copolymers. The effect of hydration on the anisotropy of the PRODAN fluorescent probe showed a change in the dynamics of the macromolecular chains. By using ATR−FTIR spectroscopy, the structure of dissolved water in polymers was studied. The evolution of this structure was performed as hydration proceeds by band decomposition of the νOH vibration on the basis of the four-state model which allows discriminating bound from free molecules: in the “early” stages of hydration, the water network appears drastically perturbed as compared to that of bulk pure water, this perturbation vanishing in the “later” stages of hydration. Besides, this study reveals that the polymer carbonyl groups constitutes the major water binding sites as it was deduced from their progressive engagement in H bonds in the time course of hydration. The rate and extent of this process was observed to be correlated with the hydrophobicity of polymers. The present findings, obtained on similar time scales from noninvasive techniques, indicate that both dynamic and structural consequences of hydration are correlated in most of the polymers here studied.

Tin-free self-polishing marine antifouling coatings

“…For example, the spectroscopic technique ATR-FTIR combined with a mathematical model (second Fick's law) enables the calculation of kinetic constants such as diffusion coeffi cients (Thouvenin et al, 2002c). The uptake and diffusion rates of water into binders can be also quantifi ed by electrochemical impedance spectrometry (EIS) measurements.…”

“…Fluorescence spectroscopy, a second non-destructive method, was used to evaluate the impact of hydration on macromolecular cohesion (Thouvenin et al, 2002c). The results obtained for rosin-based binders (blends of an acrylic polymer and rosin) indicate that the chain fl uctuations are highly enhanced as water diffuses.…”

Interaction of the excited state intramolecular proton transfer probe 3-hydroxy-2-naphthoic acid with poly N-vinyl-2-pyrrolidone polymer in water: An insight into the water structure in the binding region

“…The structure and the behavior of water absorbed in polymers has been the subject of much concern in recent times [2,[5][6][7][8][9][10]. Xu et al [10] have been able to recognize type I water (n O-H o3300 cmÀ1), type II water (n O-H between 3300 and 3500 cm À 1 ) and type III water (n O-H between 3500 and 3800 cm À 1 ) using FTIR in attenuated total reflection (ATR) and transmission mode on PVP and its copolymers and also by theoretical calculation using DFT.…”

Synthesis of zinc-based acrylate copolymers and their marine antifouling application

“…5,28 Hydrophilic swelling behaviour increased the movement of the copolymer chains and led to an erosion mechanism that was inhomogeneous across the overall coated surface. In the same way, the water-soluble pigment and biocide components enhanced the permeation of water in the lm, which increased the effective contact area of the ZnPs and ller that reacted with seawater.…”