Building on principles of adhesion mechanics, we developed novel PDMS gels with ultra-low adhesion to ice and outstanding mechanical durability.

We used FDA-approved, edible materials to fabricate superhydrophobic coatings in a simple, low cost, scalable, single step process. Our coatings display high contact angles and low roll off angles for a variety of liquid products consumed daily and facilitate easy removal of liquids from food containers with virtually no residue. Even at high concentrations, our coatings are nontoxic, as shown using toxicity tests.

Droplet nucleation and condensation are ubiquitous phenomena in nature and industry. Over the past century, research has shown dropwise condensation heat transfer on nonwetting surfaces to be an order of magnitude higher than filmwise condensation heat transfer on wetting substrates. However, the necessity for nonwetting to achieve dropwise condensation is unclear. This article reports stable dropwise condensation on a smooth, solid, hydrophilic surface ( a = 38°) having low contact angle hysteresis (<3°). We show that the distribution of nano-to micro-to macroscale droplet sizes (about 100 nm to 1 mm) for coalescing droplets agrees well with the classical distribution on hydrophobic surfaces and elucidate that the wettability-governed dropwise-to-filmwise transition is mediated by the departing droplet Bond number. Our findings demonstrate that achieving stable dropwise condensation is not governed by surface intrinsic wettability, as assumed for the past eight decades, but rather, it is dictated by contact angle hysteresis.

Superomniphobic surfaces with macrotextures allow coalescence-induced jumping of droplets at Ohnesorge number >1.

Superomniphobic surfaces are extremely repellent to virtually all liquids. By combining superomniphobicity and shape memory effect, metamorphic superomniphobic (MorphS) surfaces that transform their morphology in response to heat are developed. Utilizing the MorphS surfaces, the distinctly different wetting transitions of liquids with different surface tensions are demonstrated and the underlying physics is elucidated. Both ex situ and in situ wetting transitions on the MorphS surfaces are solely due to transformations in morphology of the surface texture. It is envisioned that the robust MorphS surfaces with reversible wetting transition will have a wide range of applications including rewritable liquid patterns, controlled drug release systems, lab-on-a-chip devices, and biosensors.

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Porous graphene oxide foams were prepared by unidirectional freeze-drying technology and used to investigate the reaction between graphene oxide (GO) and SO 2 . The structure and composition changes of the graphene oxide were monitored by X-ray photoelectron spectrometry (XPS), Raman, X-ray diffraction (XRD), Thermogravimetric analysis (TGA), and ultraviolet-visible spectroscopy (UV-vis), and the product of the reaction was analyzed by an EDTA titration. The results show that SO 2 was oxidized to SO 3 and the GO was reduced. GO not only acts as the oxidant in the reaction, but also as the catalyst to catalyze the reaction of SO 2 and O 2 to form SO 3 . This catalytic action is more active in the aqueous GO suspensions than in the foams. The GO foams can adsorb SO 2 and convert it to SO 3 which then changes to SO 4 2À on contact with water. This offers a new effective method of converting noisome SO 2 gas to SO 3 at room temperature.

Omniphobic membranes are attractive for membrane distillation (MD) because of their superior wetting resistance. However, a design framework for MD membrane remains incomplete, due to the complexity of omniphobic membrane fabrication and the lack of fundamental relationship between wetting resistance and water vapor permeability. Here we present a particle-free approach that enables rapid fabrication of monolithic omniphobic membranes for MD desalination. Our monolithic omniphobic membranes display excellent wetting resistance and water purification performance in MD desalination of hypersaline feedwater containing surfactants. We identify that a trade-off exists between wetting resistance and water vapor permeability of our monolithic MD membranes. Utilizing membranes with tunable wetting resistance and permeability, we elucidate the underlying mechanism of such trade-off. We envision that our fabrication method as well as the mechanistic insight into the wetting resistance-vapor permeability trade-off will pave the way for smart design of MD membranes in diverse water purification applications.