Coalescence-Induced Jumping of Nanodroplets on Textured Surfaces

Abstract

Conducting experimental studies on nanoscale droplet coalescence using traditional microscopes is a challenging research topic, and views differ as to whether the spontaneous removal can occur in the coalescing nanodroplets. Here, a molecular dynamics simulation is carried out to investigate the coalescence process of two equally sized nanodroplets. On the basis of atomic coordinates, we compute the liquid bridge radii for various cases, which is described by a power law of spreading time, and these nanodroplets undergo coalescence in the inertially limited-viscous regime. Moreover, coalescence-induced jumping is also possible for the nanodroplets, and the attraction force between surface and water molecules plays a crucial role in this process, where the merged nanodroplets prefer to jump away from those surfaces with lower attraction force. When the solid-liquid interaction intensity and surface structure parameters are varied, the attraction force is shown to decrease with decreasing surface wettability intensity and solid fraction.

Enhanced catalysis of ultrasmall Au-MoS 2 clusters against reactive oxygen species for radiation protection

“…In addition, toxicity should still be the main focus. Some researchers in the field used small-sized clusters that can be cleared through renal excretion, while their surface modification allows precise control of toxicity and improvement of biocompatibility [55][56][57][58][59][60][61][62][63][64]. It is meaningful to follow emerging strategies of reduction of toxicity.…”

Size distribution theory for jumping-droplet condensation

“…2(a)]. Most of the contact and coalescence between two adjacent droplets will trigger the jumping removal process [29][30][31][32][33][34] (see supplementary material S1 for details).…”

Molecular physics of jumping nanodroplets

“…The influence of interfacial thermal fluctuations has often been overlooked in the literature, even in molecular simulations, 33,36 where, as revealed here, its impact is non-negligible. For instance, the extreme normalised jumping speed shown in Fig.…”

“…as high as Oh l ≈ 0.17). 27 The precise mechanism of coalescence-induced droplet jumping 9,17,[30][31][32] and how to enhance the jumping speed [33][34][35] have been studied across length scales. It is now generally understood that coalescence-induced jumping results from the excess surface energy released after coalescence being partially converted into translational kinetic energy of the resulting droplet.…”