Nanofluid Droplet Impact on Rigid and Elastic Superhydrophobic Surfaces.

Ice accumulation on cold surfaces is a common and serious phenomenon that exists in numerous industrial fields, such as power transmission, wind turbines, and aircraft. Despite recent efforts in mitigating ice accumulation on the cold surface, it remains a challenge to achieve robust anti-icing on the cold surface in terms of nanofluid droplet. Here, we report a rigid superhydrophobic Cu surface and an elastic polydimethylsiloxane (PDMS) superhydrophobic surface to enhance water-repellency performance, characterized by a significant reduction in contact time and a decrease in the spreading ratio. As for the rigid superhydrophobic Cu surface, the underlying mechanism is ascribed to the existence of stable air cushions between the micropillar array, which reduce the contact area and further suppress the heat conduction. As for the elastic PDMS superhydrophobic surface, the rapid detachment of the nanofluid droplet relies on superior surface elasticity, which can further suppress the nanofluid droplet splashing at a high impacting velocity. We believe that this work can provide a new view for the improvement of water-repellency for a wide range of applications.

Hierarchical Superhydrophobic Poly(vinylidene fluoride-co-hexafluoropropylene) Membrane with a Bead (SiO2 Nanoparticles)-on-String (Nanofibers) Structure for All-Day Passive Radiative Cooling.

Passive all-day radiative cooling has been proposed as a promising pathway to cool objects by reflecting sunlight and dissipating heat to the cold outer space through atmospheric windows without any energy consumption. However, most of the existing radiative coolers are susceptible to contamination, which may decrease the optical property and gradually degrade the outdoor radiative cooling performance. Herein, we prepared a hierarchical superhydrophobic fluorinated-SiO2/PVDF-HFP nanofiber membrane by a facile and scalable technology of electrospinning and electrostatic spraying. Due to the synergistic effects of the efficient scattering of nanofibers/micropores and the phonon polarization resonance of SiO2 nanoparticles, the membrane achieves up to 97.8% average solar reflectance and 96.6% average atmospheric window emittance. The membrane displays sub-ambient temperature drop values of 11.5 and 4.1 °C in daytime and nighttime outdoor conditions, respectively, exhibiting remarkable radiative cooling performance. Importantly, the unique bead (SiO2 nanoparticles)-on-string (nanofibers) structure forms hierarchical roughness that endows the surface with a superior self-cleaning property. In addition, the obtained membrane exhibits remarkable flexibility and mechanical stability, which are of significant importance in cooling vehicles, buildings, and large-scale equipment.

Pancake Jumping of Sessile Droplets.

Rapid droplet shedding from surfaces is fundamentally interesting and important in numerous applications such as anti-icing, anti-fouling, dropwise condensation, and electricity generation. Recent efforts have demonstrated the complete rebound or pancake bouncing of impinging droplets by tuning the physicochemical properties of surfaces and applying external control, however, enabling sessile droplets to jump off surfaces in a bottom-to-up manner is challenging. Here, the rapid jumping of sessile droplets, even cold droplets, in a pancake shape is reported by engineering superhydrophobic magnetically responsive blades arrays. This largely unexplored droplet behavior, termed as pancake jumping, exhibits many advantages such as short interaction time and high energy conversion efficiency. The critical conditions for the occurrence of this new phenomenon are also identified. This work provides a new toolkit for the attainment of well-controlled and active steering of both sessile and impacting droplets for a wide range of applications.

Investigation into archaeal extremophilic lifestyles through comparative proteogenomic analysis.

Archaea are a group of primary life forms on Earth and could thrive in many unique environments. Their successful colonization of extreme niches requires corresponding adaptations at proteogenomic level in order to maintain stable cellular structures and active physiological functions. Although some studies have already investigated the extremophilic lifestyles of archaeal species based on genomic features and protein structures, there is a lack of comparative proteogenomic analysis in a large scale. In this study, we explored 686 high-quality archaeal genomes (proteomes) sourced from the Pathosystems Resource Integration Center (PATRIC) database. General patterns of genomic features such as genome size, coding capacity (coding genes and non-coding regions), and G + C contents were re-confirmed. Protein domain distribution patterns were then identified across archaeal species. Domains with unknown functions (DUFs) and mini proteins were investigated in terms of their distributions due to their importance in archaeal physiological functions. In addition, physicochemical properties of protein sequences, such as stability, hydrophobicity, isoelectric point, aromaticity and amino acid compositions in corresponding archaeal groups were compared. Unique features associated with extremophilic lifestyles were observed, which suggested that evolutionary adaptations to different extreme environments had intrinsic impacts on archaeal protein features. Taken together, this systematic study facilitates a better understanding of the mechanisms behind the extremophilic lifestyles of archaeal species, which will further contribute to the evolutionary explorations of archaeal adaptations both experimentally and theoretically in the future studies.Communicated by Ramaswamy H. Sarma.