#Spring isolator free#

#Spring isolator free#

Molecular dynamics simulations are employed to investigate the process of water into/out of hydrophobic microporous materials and the free volume of the zeosil unit cells is deemed to make a difference in the volume of water being intruded. However, the model is not valid for the mechanism of the extrusion pressure. For hydrophobic mesopores (MCM-41 materials), a macroscopic capillary model is proved to be applicable to the interpretation of the intrusion process. The Laplace–Washburn equation is used to account for the Laplace capillary pressure and verified through experiment and simulation methods. Intrusion of water into hydrophobic nanopores. Otherwise, many other hydrophobic zeolite materials could be used as working medium of molecular springs, too. Zeolitic imidazolate frameworks were considered as an attempt to realize engineering applications after understanding the underlying water intrusion and extrusion mechanisms. From a microscopic viewpoint, the process of forced intrusion can be elucidated by the development of new intermolecular bonds between water molecules and zeolites’ framework. And then the mixture is named molecular spring. During the processes of loading and unloading, the mechanical performance of the mixture comprising water and silicalites-1 zeolite presents the same function as a spiral spring. And a stable reciprocal transformation between mechanical energy and interfacial energy is found.

However, some research findings have suggested that storage or release of energy is realized during the process of liquid water intruding into or escaping from ZIF-8′ hydrophobic nanopores (see Figure 1). Hydrophobic nanoporous materials have been extensively used for gas absorption, separation, heterogeneous catalysis, sewage treatment, etc. So, it is still valuable to study the new passive vibration isolation technology. However, these technical solutions usually face some kinds of problems, such as complex structure, stability, and device’ geometrical nonlinearities. By imitating the principle of a molecular spring, a mechanical molecular spring isolator with HSLD stiffness was mentioned. X-shaped vibration isolation was investigated because of its nonlinear stiffness advantages and damping dissipation characteristics.

However, negative stiffness is commonly found in these kinds of nonlinear passive vibration isolation techniques. Based on the cam-roller-spring mechanism, an HSLDS isolator was built and proved to possess superior performance to traditional linear isolators. An ultra-low-frequency vibration isolation (quasizero-stiffness isolators) was proposed in the face of neonatal transport. An HSLD stiffness suspension used in helicopter seats was studied to reduce the vibration in both vertical and lateral directions. Īs one solution to the above-mentioned contradiction, kinds of high-static-low-dynamic (hereinafter referred to as HSLD) stiffness isolators have been progressed. However, novel passive vibration isolators have been attracting engineers’ attention all the time because of their lower cost, higher reliability, and simpler structure, especially the nonlinear passive vibration isolation technique. For traditional linear isolators, the contradiction between wide frequency bandwidth vibration absorption and static deflection cannot be resolved. Vibration control technologies have been a hot issue. Vibration isolation has been more and more demanding in various industrial areas, such as varieties of vehicles, precise instruments, and megastructures. Finally, a vibration isolation test indicated that the inherent frequency of the isolator is as low as 1.3 Hz. Furthermore, the energy transmissibility is used to estimate its vibration isolation capability. An averaging method is devoted to computing the primary resonance response and its accuracy is proved by the fourth-order Runge–Kutta method. After that, the result of water infiltrating a great deal of hydrophobic pores is revealed by theoretical analysis and an experiment.

The Laplace–Washburn equation is used to describe the force equilibrium of a single water column in a micropore. This behavior is similar to a coil spring. The stored energy, meanwhile, is released. And once the external pressure is withdrawn, spontaneous capillary evaporation will occur. In the meantime, mechanical energy is stored. Liquid water can be intruded into the micropores of ZIF-8 under critical pressure. A molecular spring isolator comprising ZIF-8 with hydrophobic micropores, water, and a cylinder/piston unit is introduced.