Lebedev Physical Institute, Russian Academy of Sciences, 119991 Moscow, Russia.
Lebedev Physical Institute, Russian Academy of Sciences, 119991 Moscow, Russia.
J Colloid Interface Sci. 2022 Dec;627:774-782. doi: 10.1016/j.jcis.2022.07.073. Epub 2022 Jul 14.
The problem of the development of miniature motors able to move on the air-liquid interface at low Reynolds numbers is a crucial challenge due to dominating role of viscous force. To solve this problem the chemical generation of gas can be used. Generated gas pushes liquid out from the surfer surface, so the resistance force is reduced.
Surfer composed of TiO nanoparticles and ferromagnetic cobalt microparticles moves at the interface of an aqueous solution of hydrogen peroxide under the action of magnetic force. After irradiation with UV or visible light, the gas cavern is formed at the surfer surface due to photo-catalytic decomposition of hydrogen peroxide. As a result, the area of surfer contact with liquid is reduced.
The resistance force acting on the surfer is reduced due to the liquid pushing out from the surfer surface. This effect is strengthened with the increase in the intensity of gas generation. The resistance force is increased when increasing the liquid viscosity or using a surfactant. The proposed method allows control of the velocity of the motors in a rather wide range by changing the gradient of the magnetic field and parameters of light.
由于粘性力的主导作用，能够在低雷诺数下在气液界面上移动的微型马达的发展问题是一个关键挑战。为了解决这个问题，可以利用气体的化学生成。生成的气体将液体从冲浪者表面推出，从而降低阻力。
由 TiO 纳米粒子和铁磁钴微粒子组成的冲浪者在磁场的作用下在过氧化氢水溶液的界面上移动。在紫外线或可见光照射后，由于过氧化氢的光催化分解，在冲浪者表面形成气穴。结果，与液体接触的冲浪者面积减小。
由于液体从冲浪者表面推出，作用在冲浪者上的阻力减小。随着气体生成强度的增加，这种效果得到加强。当增加液体粘度或使用表面活性剂时，阻力会增加。通过改变磁场梯度和光的参数，可以在相当宽的范围内控制电机的速度。
