Soft Matter 13(10):2040–2053Īlmohammadi H, Amirfazli A (2017b) Asymmetric spreading of a drop upon impact onto a surface. Langmuir 31(36):10100–10111Īlmohammadi H, Amirfazli A (2017a) Understanding the drop impact on moving hydrophilic and hydrophobic surfaces. Graphical abstractĪboud DGK, Kietzig A-M (2015) Splashing threshold of oblique droplet impacts on surfaces of various wettability. Using our method, one can predict the spreading of both low and high surface tension liquids over stationary and moving surfaces (i.e., when in-plane velocity exists). We developed a method and related equations to describe the time evolution of the lamella as drop spreads on a hydrophilic surface. We observed that on a moving surface, the position of the maximum width shifts more to the center of the lamella for low surface tension liquids, compared to that of high surface tension liquids, and this shifting increases with an increase in in-plane velocity. Also, compared to high surface tension liquids, the stretching of lamella in the direction of the in-plane velocity vector, is more pronounced for low surface tension liquids. It was observed that low and high surface tension liquids spread in a different manner on both stationary and moving surfaces with different outcomes regarding the time to the maximum spreading diameter, and the maximum spreading factor. High-speed imaging was used to capture the spreading phenomenon from side and overhead views. Furthermore, it examines the role of the in-plane velocity ( V P) on the time evolution of spreading phase of the impact phenomena V P is seen when the surface is inclined, or when the surface is moving in the horizontal direction, for impact of a free-falling droplet. Also available in English translations.This paper examines the time evolution for spreading of low surface tension liquids upon impact onto a surface, and highlights the differences with the same, for high surface tension liquids. Zarzycki,J (1982): Les Verres et l'état vitreux.Götze,W (2009): Complex Dynamics of glass forming liquids.This theory describes a slowing down of structural relaxation on cooling towards a critical temperature Tc, typically located 20% above Tg. The microscopic dynamics at low to moderate viscosities is addressed by a mode-coupling theory, developed by Wolfgang Götze and collaborators since the 1980s. More recently, the fragility has been quantitatively related to the details of the interatomic or intermolecular potential, and it has been shown that steeper interatomic potentials lead to more fragile liquids. Materials with a higher enthalpy of configuron formation compared with their enthalpy of motion have a higher Doremus fragility ratio, conversely melts with a relatively lower enthalpy of configuron formation have a lower fragility. Bond breaking modifies the properties of an amorphous material so that the higher the concentration of broken bonds termed configurons the lower the viscosity. Fragility is related to materials bond breaking processes caused by thermal fluctuations. Strong melts are those with (R D-1) < 1, whereas fragile melts are those with (R D-1) ≥ 1. The fragility of amorphous materials is numerically characterized by the Doremus’ fragility ratio R D=Q H/Q L. Amorphous materials are classified accordingly to the deviation from Arrhenius type behaviour of their viscosities as either strong when Q H-Q L
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