Self‐Assembled “Breathing” Grana‐Like Cisternae Stacks

Membranes in cells display elaborate, dynamic morphologies intimately tied to defined cellular functions. Cisternae stacks are a common membrane morphology in cells widely found in organelles. However, compared with the well‐studied spherical cell membrane mimics, cisternae stacks as organelle membrane mimics are greatly neglected because of the difficulty of fabricating this unique structure. Herein, the grana‐like cisternae stacks are assembled via the reorganization of stacked microsized bicelles to mimic grana functions. The cisternae stacks are connected by fusion regions between adjacent cisternae. The number of cisternae can be controlled from ≈4 to 15 by the variation of ethanol volume percentage. Under the stimulation of solvent or negatively charged nanoparticles, the cisternae stacks can reversibly compress and expand, similar to the “breathing” property of natural grana. During the “breathing” process, nanoparticles are reversibly captured and released. Frequency resonance energy transfer is realized on the cisternae stacks trapped with two kinds of quantum dots. The cisternae stacks provide advanced membrane model for cell biotechnology, and clues for the shaping of organelles composed of cisternae. The ability of the cisternae stacks to capture materials enables them to possibly be applied in biomimetics and the design of advanced functional materials.     

Developing a “Water‐Defendable” and “Dendrite‐Free” Lithium‐Metal Anode Using a Simple and Promising GeCl4 Pretreatment Method

Lithium metal is an ultimate anode in “next‐generation” rechargeable batteries, such as Li–sulfur batteries and Li–air (Li–O₂) batteries. However, uncontrollable dendritic Li growth and water attack have prevented its practical applications, especially for open‐system Li–O₂ batteries. Here, it is reported that the issues can be addressed via the facile process of immersing the Li metal in organic GeCl₄–THF steam for several minutes before battery assembly. This creates a 1.5 µm thick protection layer composed of Ge, GeO_x, Li₂CO₃, LiOH, LiCl, and Li₂O on Li surface that allows stable cycling of Li electrodes both in Li‐symmetrical cells and Li–O₂ cells, especially in “moist” electrolytes (with 1000–10 000 ppm H₂O) and humid O₂ atmosphere (relative humidity (RH) of 45%). This work illustrates a simple and effective way for the unfettered development of Li‐metal‐based batteries.     

Zero Linear Compressibility in Nondense Borates with a “Lu‐Ban Stool”‐Like Structure

Discovering materials that exhibit zero linear compressibility (ZLC) behavior under hydrostatic pressure is extremely difficult. To date, only a handful of ZLC materials have been found, and almost all of them are ultrahard materials with densified structures. Here, to explore ZLC in nondense materials, a structural model analogous to the structure of the “Lu‐Ban stool,” a product of traditional Chinese woodworking invented 2500 years ago, is proposed. The application of this model to borates leads to the discovery of ZLC in AEB₂O₄ (AE = Ca and Sr) with the unique “Lu‐Ban stool”‐like structure, which can obtain a subtle mechanical balance between pressure‐induced expansion and contraction effects. Coupled with the very wide ultraviolet transparent windows, the ZLC behavior of AEB₂O₄ may result in some unique but important applications. The applications of the “Lu‐Ban stool” model open a new route for pursuing ZLC materials in nondense structural systems.