Investigation of Coalescence-Induced Droplet Jumping on Mixed-Wettability Superhydrophobic Surfaces
Round 1
Reviewer 1 Report
In the article entitled: "Study of coalescence-induced drop jumps on superhydrophobic surfaces of mixed wettability," authors Ming-Jun Liao and Li-Qiang Duan presented the results of numerical simulation of the effect of solid substrate morphology on the coalescence dynamics of two droplets. The simulation was carried out on the assumption that the system meets the thermodynamic equilibrium conditions throughout the transformation. For this reason, the presented solutions can be treated as boundary solutions for such a transformation.
The formulation of the model (the set of equations applied) and the methodology of its solution are not objectionable. Therefore, also the correctness of the obtained results does not raise any doubts.
The text is fairly well written. Although I am not a linguist, some English phrases seem to conflict with the applicable rules. I also found two or three sentences that should be changed to improve the readability of their content. It is also worth paying attention to the terminology used. This applies in particular to relatively new terms which (apart from their abbreviated form) should have the most precise physical meaning possible.
A detailed list of shortcomings noticed:
lines 55-61
I suggest that the text contained in lines 55-61 starting with the words: "On the basis of ..." put in a separate paragraph so that it would constitute a strictly formulated aim of this work.
line 63
I suggest replacing “the box” with “the volume in which numerical simulation is carried out”.
line 64
I suggest replacing “solid Au (100)” with “solid gold (100%)”.
line 67
I suggest replacing “universally used for” with “universally applied for”.
lines 69-70
I suggest replacing “spherical argon droplets are placed on the substrate with equal radius of 8 nm” with “spherical argon droplets with equal radius of 8 nm are placed on the substrate”.
line 73
I suggest replacing “two Ar droplets” with “two argon droplets”. Please avoid placing chemical symbols in the text of the paper. The exception is the indication of inter-molecular interactions. However, in the text, the substances applied are indicated by their names. This makes the text easier to read.
line 81
In my opinion, the interaction coefficient cij should be clearly explained (or described) or an appropriate formula should be added.
line 84
I suggest replacing “will be performed” with “can be performed”.
line 87
I suggest replacing “system keeps an” with “system achieves an”.
line 89-90
I suggest replacing “velocity is applied to two droplets” with “velocity is given to the droplets”.
line 90
I suggest replacing “The velocity is tried from 1 to 5 m s-1.” with “The droplet velocities in the range of 1 to 5 m s-1 were tested.”.
line 90
I suggest replacing “thar 3 m s-1” with “that 3 m s-1”.
line 98
I suggest replacing “width is different” with “width are different”.
line 101
I suggest replacing “changeable, which” with “variable and it”.
lines 103-104
I suggest replacing “moving lengths of the center of two nanodroplets” with “distances of the center of two moving nanodroplets”. The meaning of this term (moving lengths) is crucial when discussing the presented results and therefore it should be very precisely described in the paper.
line 105
I suggest replacing “under” with “for”.
line 107
I suggest replacing “and two droplets” with “its distance between two droplets”.
line 108
I suggest replacing “is placed at the center of the plate forever” with “is always placed at the center of the plate”.
lines 108-111
This sentence should be rewritten “Secondly, under the condition that the relative contact angle is 160°/180°, when two droplets are seen as a whole and the center of it is moved to the right hand, the moving length is shown in Table 2.”. It is very hard to find out what is going on.
lines 112
I suggest replacing “moving length” with “distance between moving droplets”.
lines 114-115
I suggest replacing “of one is fixed, which is placed” with “is fixed for the one, which is placed”.
line 115
I suggest replacing “other is” with “other are”.
line 121
I suggest replacing “moving lengths” with “Initial distance between droplets”.
line 131
For this value (Lb=Ll≥8 nm), there is no result curve in Figure 3b. Therefore, when providing this result, one cannot refer to this graph or it should be emphasized that the result was not shown in this chart.
lines 143-144
Please rewrite part of the sentence “nevertheless the energy dissipation caused by adhesion is larger than that surface, which makes the velocity decrease at the smaller strip width (Lb=Ll≤4 nm)” or split so long sentence into shorter ones.
line 182
Missing description of Figure 4 i in caption.
line 184
I suggest replacing " right hand" with “right side”.
line 210
Please consider replacement “deviate” with “bounce”.
line 220
I suggest replacing “left line denotes” with “left ordinate of yellow region denotes”.
Comments for author File: 
Comments.pdf
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 2 Report
I think the manuscript is nicely written. The overall planning of the experiment, from design to investigation of parameters are good. However though, there is lacking of connectivity from the study for its potential application thought authors explained briefly in the introduction section. Such manuscript might be good in terms of its finding, but it might create a lack of interest to the readers in the field.
I proposed this manuscript to be accepted once proper formatting, grammatical errors being corrected throughout the manuscript.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
