From Crystalline to Amorphous Germania Bilayer Films at the Atomic Scale: Preparation and Characterization

A new two‐dimensional (2D) germanium dioxide film has been prepared. The film consists of interconnected germania tetrahedral units forming a bilayer structure, weakly coupled to the supporting Pt(111) metal‐substrate. Density functional theory calculations predict a stable structure of 558‐membered rings for germania films, while for silica films 6‐membered rings are preferred. By varying the preparation conditions the degree of order in the germania films is tuned. Crystalline, intermediate ordered and purely amorphous film structures are resolved by analysing scanning tunnelling microscopy images.     

Self‐Stabilized Amorphous Organic Materials with Room‐Temperature Phosphorescence

The stability of pure organic room‐temperature phosphorescent (RTP) materials in air has been a research hotspot in recent years. Without crystallization or encapsulation, a new strategy was proposed to obtain self‐stabilized organic RTP materials, based on a complete ionization of a photo‐induced charge separation system. The ionization of aromatic phenol 4‐carbazolyl salicylaldehyde (CSA) formed a stable H‐bonding anion–cation radical structure and led to the completely amorphous CSA‐I film. Phosphorescent lifetimes as long as 0.14 s at room temperature and with direct exposure to air were observed. The emission intensity was also increased by 21.5‐fold. Such an amorphous RTP material reconciled the contradiction between phosphorescence stability and vapor permeability and has been successfully utilized for peroxide vapor detection.     

Not Only Columns: High Hole Mobility in a Discotic Nematic Mesophase Formed by Metal‐Containing Porphyrin‐Core Dendrimers

We report a new family of multifunctional liquid‐crystalline porphyrin‐core dendrimers that have coumarin functional groups around the porphyrin core. Porphyrin metalation strongly affects the photophysical properties, and therefore Zn^II and Cu^II derivatives have also been prepared. All the synthesized dendrimers form a nematic discotic mesophase. Their high tendency for homeotropic alignment makes these dendrimers excellent candidates for device applications, owing to their easy processability, spontaneous alignment between electrodes, and self‐healing of defects because of their dynamic nature. The charge mobility values of these materials are the highest ever reported for a nematic discotic phase. Moreover, these values are similar to the highest values reported for ordered columnar mesophases, and this shows that a supramolecular organization in columns is not necessary to achieve high charge mobility.     

Self‐Healable Organogel Nanocomposite with Angle‐Independent Structural Colors

Structural colors have profound implications in the fields of pigments, displays and sensors, but none of the current non‐iridescent photonic materials can restore their functions after mechanical damage. Herein, we report the first self‐healable organogel nanocomposites with angle‐independent structural colors. The organogel nanocomposites were prepared through the co‐assembly of oleophilic silica nanoparticles, silicone‐based supramolecular gels, and carbon black. The organogel system enables amorphous aggregation of silica nanoparticles and the angle‐independent structural colors in the nanocomposites. Moreover, the hydrogen bonding in the supramolecular gel provides self‐healing ability to the system, and the structural colored films obtained could heal themselves in tens of seconds to restore storage modulus, structural color, and surface slipperiness from mechanical cuts or shear failure repeatedly.