Liquid–Liquid Phase Separation of Two Non-Dissolving Liquids—A Mini Review

Round 1

Reviewer 1 Report

The manuscript Processes-2266207 with the title "Liquid-liquid phase separation of two non-dissolving liquids – A mini review" presents an interesting contribution to separation of immiscible liquids. However, the manuscript reads more like a technical report than a review article. It is not deserve for publication in Processes, according to the following comments:

-        The abstract must be rewritten. It should present a brief introduction of the subject, the methodology, main results and conclusion. Avoid the use of “etc”

-        “Review” is not a keyword. Provide more innovative keywords.

-        The introduction section lacks references.

-        The justification and objective of the mini-review are not clear. The end of the introduction should be completely rewritten.

-        The manuscript reads more like a technical report than a review article. Authors should build longer paragraphs, with closing ideas. There are several small paragraphs with only one reference with no link between them.

-        There are too many figures that could be compressed to reduce the number of figures.

-        An academic English correction must be performed throughout the manuscript. Avoid overusing "which". There are 18 in the manuscript. Also, avoid excessive use of the word paper.

-        The conclusion section is long enough for a mini-review. It should present the impacts of the research discussed. I suggest it be completely rewritten.

Author Response

We express our gratitude to the reviewer for devoting the required time and energy to evaluate the manuscript.

Author Response File: Author Response.pdf

Reviewer 2 Report

In my opinion, processes-2266207 can be published in Processes after major revision.

The idea of summarizing/reviewing the phase separation of two non-dissolving liquids is interesting and I have not found a similar review in the literature. However, the introduction can be generalized to attract more attention:

liquid-liquid separation has a large application in biology, cancer-related research, hydrometallurgy, and chemical processes. Many methods like solvent extraction need liquid-liquid separation in later steps however such applications are not mentioned in the introduction.

2- membrane for liquid-liquid separation can also be made from inorganic materials (e.g. zeolites and mesoporous silica) however, the text in this review manifest that membranes are made from polymers.

3- in the text, it is mentioned that particles can block the membranes and indeed this is the case when membranes are used for particle separation/when at least one of the solvents has particles but is it the case when membranes are used for pure solvent-solvent separation? Text can be modified to address this-e.g. by mentioning that in industrial applications solvents can have particles.

Author Response

We would like to express our gratitude to the reviewer for dedicating their time and effort to reviewing the manuscript. Please see the attachment. 

Author Response File: Author Response.pdf

Reviewer 3 Report

Mixtures with limited mutual solubility are quite common in different areas of the chemical industry. The question of finding ways to separate such mixtures and the choice of equipment (apparatuses) remains an urgent problem. Review papers devoted to such problem are important because they allow us to assess both the current state of the issue and the achievements of recent years.

Authors write at the abstract: «This paper provides an overview of recent studies on separating mixtures consisting of liquid phases». At the same time, the number of references dated to the last decade does not exceed 20% (13 references out of 64). This is extremely small. Recently, the number of publications devoted to splitting systems has grown significantly (what the authors themselves write about «Over the last decades, with growing interest in environmental and nature resource concerns, the separation of liquid phases has received a renewed level of interest»). This fact indicates that the list of references should be significantly expanded and supplemented with new references (2013-2022).

The «Thermodynamic Basic» section represents well-known information («book» data). The paper is intended for specialists who have an understanding of the thermodynamics of heterogeneous equilibria and methods of separation of splitting systems, and not for students of initial courses of study. The information from this section in this form is usually presented in the textbook for students. In my opinion, this section should be deleted.

The mini-review is mostly devoted to the analysis of equipment that can be used to separate splitting mixtures. In this connection, section 2.4 can be left, since it is directly related to the equipment.

The paper requires major revision.

Author Response

We express our gratitude to the reviewer for dedicating time and effort to review the manuscript. Please see the attachment. 

Author Response File: Author Response.pdf

Reviewer 4 Report

Comments for author File: Comments.pdf

Author Response

We would like to thank to reviewer for taking the time and effort to review this manuscript. Please see the attachment. 

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

A revised version should not be returned to the reviewer with comments and underlining. In this way, it is difficult for the reviewer to evaluate the article. Therefore, this article should not be published in Processes.

Reviewer 3 Report

Despite the fact that the reviewers see the content of the paper differently and have given opposite recommendations, I stand by my opinion, but I will not insist on changing the first part of the paper. The list of references has been significantly expanded, more works of the last decade have been mentioned. There are no other comments. The paper can be accepted