Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Negative pressure characteristics of an evaporating meniscus at nanoscale | Maroo and Chung Nanoscale Research Letters 2011 6 72 http content 6 1 72 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access Negative pressure characteristics of an evaporating meniscus at nanoscale Shalabh C Maroo1 2 JN Chung1 Abstract This study aims at understanding the characteristics of negative liquid pressures at the nanoscale using molecular dynamics simulation. A nano-meniscus is formed by placing liquid argon on a platinum wall between two nanochannels filled with the same liquid. Evaporation is simulated in the meniscus by increasing the temperature of the platinum wall for two different cases. Non-evaporating films are obtained at the center of the meniscus. The liquid film in the non-evaporating and adjacent regions is found to be under high absolute negative pressures. Cavitation cannot occur in these regions as the capillary height is smaller than the critical cavitation radius. Factors which determine the critical film thickness for rupture are discussed. Thus high negative liquid pressures can be stable at the nanoscale and utilized to create passive pumping devices as well as significantly enhance heat transfer rates. Introduction The physical attributes of phenomenon associated with the nanoscale are different from those at the macroscale due to the length-scale effects. In nature transport processes involving a meniscus are usually associated with nano- and micro-scales. Capillary forces are of main importance in micro- and macro-scale fluidic systems. However at nanoscale disjoining forces can become extremely dominant. These disjoining forces can cause liquid films to be under high absolute negative pressures. A better insight into negative liquid pressures can be gained from the phase diagram of water which shows the stable metastable and unstable regions 1 . Usually in such cases cavitation is observed . vapor bubbles form when a liquid is stretched. However for the formation of a .
