The evaporation mechanism of miscible binary nanodroplets from heated homogeneous surfaces was studied by molecular dynamics simulations, which has never been studied before. The binary droplets contain a hydrophilic component (type-2 particles) and a hydrophobic component (type-3 particles). It is shown that liquid–liquid interaction strength (ε₂₃) and hydrophilic particle number fraction (φ) have great influence on the surface tension, wetting characteristics, evaporation patterns, evaporation rate, and local mass flux. It is observed that when ε₂₃ ≥ 1, or φ ≈ 0.5, the evaporation mode is the constant-contact-angle mode. Otherwise, it is the mixed mode. We found that the evaporation rate becomes faster when φ and ε₂₃ increase. The droplets become more hydrophilic when φ increases, which promotes heat transfer efficiency between the liquid–solid interface. Besides, a larger ε₂₃ promotes the heat transfer inside the droplet. The mass transfer to the vapor phase occurs preferentially in the vicinity of TPCL (three phase contact line) in the hydrophilic systems (θ < θ_c), where θ_c is the critical contact angle, while in most hydrophobic systems (θ > θ_c), the mass flux close to the TPCL is suppressed. We found that θ_c ∈ (102°–106°), which is different from the theoretical one, θ_c = 90°. The discrepancy is attributed to the existence of the adsorption layer near the TPCL.

中文翻译：

---

受热均质基底上二元纳米液滴蒸发的分子动力学研究

通过分子动力学模拟研究了可混溶的二元纳米液滴从受热均匀表面蒸发的机理，这是以前从未研究过的。二元液滴包含亲水性组分（2型颗粒）和疏水性组分（3型颗粒）。结果表明，液-液相互作用的强度（ε ₂₃）和亲水性颗粒数量分数（φ）对表面张力很大的影响，润湿特性，蒸发图案，蒸发速率，和局部质量通量。据观察，当ε ₂₃ ≥1，或φ≈0.5，蒸发模式是恒定接触角模式。否则，它是混合模式。我们发现，蒸发速度变快时，φ和ε ₂₃增加。当φ增大时，液滴变得更加亲水，从而提高了液固界面之间的传热效率。此外，较大的ε ₂₃促进了液滴内部的热传递。质量传递到气相中TPCL（三相接触线）的亲水性系统附近（θ优先发生<θ _Ç），其中θ _Ç是临界的接触角，而在最疏水的系统（θ>θ _Ç），可以抑制接近TPCL的质量通量。我们发现，θ _Ç ∈（102°-106°），这是从在理论上一个不同，θ _{c ^} = 90°。差异归因于TPCL附近的吸附层的存在。