The corrosion behavior of six choline chloride-based eutectic solvents namely, ChCl-Ur, ChCl-EG, ChCl-Gl, ChCl-MA, ChCl-Ph and ChCl-TG towards copper, mild steel and stainless steel 316 have been investigated. The effect of temperature and moisture content was evaluated. The corrosion rates of the three materials increased with an increase in the temperature and moisture content. Stainless steel was found to be the most resistant under all experimental conditions. The experimental results demonstrated ChCl-Ph and ChCl-Gl to have high inhibition efficiency suggesting these to be a suitable candidate as green corrosion inhibitors for metal and alloys under extreme environments.

Phase-field models are relatively inexpensive field-based models capable of capturing the nonequilibrium multiphase behavior of polymers and other soft materials. With their rise in popularity over the past several years, questions have arisen concerning the thermodynamic consistency of some model formulations. In doing so, researchers have employed several different forms of the Gibbs–Duhem equationa classical thermodynamic relationship used to assess consistencyleading to questions about the correct form of this expression for inhomogeneous mixtures. In this paper, we derive a generalized Gibbs–Duhem relation that is valid for phase-field models. The key to the derivation is the recognition that the functional derivatives used with phase-field models give exchange chemical potentials, in contrast to the classical chemical potentials commonly used in homogeneous thermodynamics. We use this derivation to demonstrate that a phase-field model that generalizes the Flory–Huggins model satisfies the Gibbs–Duhem expression and is therefore thermodynamically consistent. In addition, we find that the Gibbs–Duhem relationship provides some unique insights into the relationship between the traditional chemical potentials, the exchange chemical potentials, and the osmotic stress tensor.

Nonsolvent-induced phase separation (NIPS) is a popular method for creating polymeric particles with internal microstructure, but many fundamental questions remain surrounding the kinetics of the complex coupled mass transfer and phase separation processes. In this work, we use simulations of a phase-field model to examine how (i) finite domain boundaries of a polymer droplet and (ii) solvent/nonsolvent miscibility affect the NIPS process. To isolate the effects of phase separation kinetics and solvent/nonsolvent mass transfer on the NIPS process, we study two different cases. First, we investigate droplet concentrations that originate inside the two-phase region, where phase separation kinetics alone governs the microstructure. Second, we investigate the effects of solvent/nonsolvent mass transfer by studying droplet concentrations that begin outside the two-phase region, where both phase separation kinetics and mass transfer play a role. In both cases, we find that qualitative NIPS behavior is a strong function of the relative location of the initial droplet composition with respect to the phase diagram. We also find that polymer/nonsolvent miscibility competes with solvent/nonsolvent miscibility in driving NIPS kinetic behavior. Finally, we examine polymer droplets undergoing solvent/nonsolvent exchange and find that the model predicts droplets that shrink with nearly Fickian diffusion kinetics. We conclude with a brief perspective on the state of simulations of NIPS processes and some recommendations for future work.

While hierarchical ordering is a distinctive feature of natural tissues and is directly responsible for their diverse and unique properties, research efforts to synthesize biomaterials have primarily focused on using molecular-based approaches without considering multiscale structure. Here, we report a bottom-up self-assembly process to produce highly porous hydrogels that resemble natural tissues both structurally and mechanically. Randomly oriented, physically crosslinked nanostructured micelles form the walls of aligned, polymer-rich pore walls that surround water-rich cavities. Extremely soft elastic modulus (< 1 kPa), highly stretchability (greater than 12-times), strain-hardening, and completely reversible deformation result from the hierarchical structure. Independent control of nano and macroscales is realized through the combination of polymer macromolecular parameters and processing conditions, directly impacting the resulting phase behavior. Here, we demonstrate precise control of the material structure and structure orientation over many orders of magnitude (e.g., nm – µm), and reveal how the multiscale structure directly impacts mechanical properties.