Dynamic molecular ordering in multiphasic nanoconfined ionogels detected with time-resolved diffusion NMR

Molecular motion in nanosized channels can be highly complicated. For example, water molecules in hydrophobic nanopores move rapidly and coherently in a chain, following the so-called single file motion. Surprisingly, fast molecular motion is also observed in viscous charged fluids, such as room temperature ionic liquids (RTILs) confined in a nanoporous carbon or silica matrix. The microscopic mechanism of this intriguing effect is still unclear. Here, by combining NMR diffusion experiments in different relaxation windows with ab-initio molecular dynamics simulations, we show that the imidazolium-based RTIL [BMIM]+[TCM]-, entrapped in the MCM-41 silica nanopores, exhibits a complex dynamic molecular ordering (DMO); adsorbed RTIL molecules near the pore walls orient almost vertically to the walls, while at the center of the pores anion-cation pairs diffuse collectively in a single file (SFD). Enlightening this extraordinary effect is of primary importance in designing RTIL-based composite materials with tuned electrochemical properties.

Novel Quinolizine AIE System: Visualization of Molecular Motion and Elaborate Tailoring for Biological Application

Molecular motions are ubiquitous in nature and they immutably play intrinsic roles in all actions. However, exploring appropriate models to decipher molecular motions is an extremely important but very challenging task for researchers. Considering aggregation-induced emission (AIE) luminogens possess their unique merits to visualize molecular motions, it is particularly fascinating to construct new AIE systems as model to study molecular motion. Herein, a novel quinolizine (QLZ) AIE system was constructed based on the restriction intramolecular vibration mechanism. It was demonstrated that QLZ could act as an ideal model to visualize single-molecule motion and macroscopic molecular motion via fluorescence change. Additionally, further elaborate tailoring of this impressive core achieved highly efficient reactive oxygen species production and realized fluorescence imaging-guided photodynamic therapy applications, which confirms the great application potential of this new AIE-active QLZ core. Therefore, this work not only provides an ideal model to visualize molecular motion but also opens a new way for the application of AIEgens.

Research on fatigue failure mode and failure theory of rubber

The rubber products are usually used in the condition of periodically complicated stresses, and their anti-fatigue function is simultaneously dependent on their viscoelasticity and the emergence and propagation of cracks directly effecting on the life of rubber products. Therefore, the research on fatigue failure of rubber products has important significance to improve their durability and safety. The research on fatigue failure of rubber has important significance to improve the durability and safety of rubber products. The fatigue failure mechanism of natural rubber was explained from the point of molecular motion theory and phenomenological theory. The application of test research methods in the study of rubber fatigue microstructure and the influence of environmental factors on the fatigue properties of natural rubber were studied, and the future development direction of natural rubber fatigue was also forecasted.