Dynamic behavior of a rotary nanomotor in argon environments

Self-Scrolling of a Graphyne Ribbon Near a CNT in Multiphysical Environments

Graphyne nanoscrolls (GNSs) have attracted significant research interest because of their wide-ranging applications. However, the production of GNSs via a self-scrolling approach is environment dependent. Here, molecular dynamics simulations are conducted to evaluate the self-scrolling behavior of an α-graphyne (α-GY) ribbon on a carbon nanotube (CNT) within various multiphysical environments, accounting for the interactions among temperature, electric field, and argon gas. The results demonstrate that the fabrication of an α-GNS lies in the interplay of van der Waals (vdW) forces among the components in a vacuum. Notably, the α-GY ribbon is easier to scroll onto a thicker CNT. The electric field attenuates the vdW interaction, necessitating thicker CNTs for successful self-scrolling under a stronger electric field. In argon, both the vdW interaction and nanoscale pore contribute to the overlap formation. At 300 K, increasing argon density prolongs the time required for α-GNS formation, with self-scrolling failing beyond a critical gas density threshold. Moreover, the self-scrolling becomes easier at higher temperatures. In multiphysical environments, the interplay between the electric field and the gas density dictates the self-scrolling at low temperatures. Finally, reasonable suggestions are given for successful self-scrolling. The conclusions offer valuable insights for the practical fabrication of α-GNS.

Dynamic Behavior of Rotation Transmission Nano-System in Helium Environment: A Molecular Dynamics Study

The molecular dynamics (MD) method is used to investigate the influence of the shielding gas on the dynamic behavior of the heterogeneous rotation transmission nano-system (RTS) built on carbon nanotubes (CNTs) and boron nitride nanotube (BNNT) in a helium environment. In the heterogeneous RTS, the inner CNT acts as a rotor, the middle BNNT serves as a motor, and the outer CNT functions as a stator. The rotor will be actuated to rotate by the motor due to the interlayer van der Waals effects and the end effects. The MD simulation results show that, when the gas density is lower than a critical range, a stable signal of the rotor will arise on the output and the rotation transmission ratio (RRT) of RTS can reach 1.0, but as the gas density is higher than the critical range, the output signal of the rotor cannot be stable due to the sharp drop of the RRT caused by the large friction between helium and the RTS. The greater the motor input signal of RTS, the lower the critical working helium density range. The results also show that the system temperature and gas density are the two main factors affecting the RTS transmission behavior regardless of the size of the simulation box. Our MD results clearly indicate that in the working temperature range of the RTS from 100 K to 600 K, the higher the temperature and the lower the motor input rotation frequency, the higher the critical working helium density range allows.

Efficiency of CNT-based rotation transmission nanosystem in water

Carbon nanotubes (CNTs) have been widely used as the motor and rotor in a rotational transmission nanosystem (RTnS), whose function is to transfer the input rotational frequency of the motor into the output frequency of the rotor through motor-rotor interactions. A wide range of techniques has been explored to achieve a CNT-based RTnS with a stable and adjustable transmission. In this work, a CNT-based rotor is partly immersed into a water box and the associated water-rotor interaction leads to effective manipulation of the transmission efficiency of RTnS. Molecular dynamics simulations are performed on this new RTnS to investigate the dynamic response of the rotor and the local flow field near the water-rotor interface. Various parameters, including ambient temperature, tubes' radii, and volume fractions of water in the box (V_f) are examined for their effects on the rotational transmission efficiency. This study offers useful guidelines for the design of stable RTnS with controllable transmission efficiency.

Recent development of autonomously driven micro/nanobots for efficient treatment of polluted water

Autonomously propelled micro/nanobots are one of the most advanced and integrated structures which have been fascinated researchers owing to its exceptional property that enables them to be carried out user-defined tasks more precisely even on an atomic scale. The unique architecture and engineering aspects of these manmade tiny devices make them viable options for widespread biomedical applications. Moreover, recent development in this line of interest demonstrated that micro/nanobots would be very promising for the water treatment as these can efficiently absorb or degrade the toxic chemicals from the polluted water based on their tunable surface chemistry. These auto propelled micro/nanobots catalytically degrade toxic pollutants into non-hazardous compounds more rapidly and effectively. Thus, for the last few decades, nanobots mediated water treatment gaining huge popularity due to its ease of operation and scope of guided motion that could be monitored by various external fields and stimuli. Also, these are economical, energy-saving, and suitable for large scale water treatment, particularly required for industrial effluents. However, the efficacy of these bots hugely relies on its design, characteristic of materials, properties of the medium, types of fuel, and surface functional groups. Minute variation for one of these things may lead to a change in its performance and hinders its dynamics of propulsion. It is deemed that nanobots might be a smart choice for using these as the new generation devices for treating industrial effluents before discharging it in the water bodies, which is a major concern for human health and the environment.