Polymer Wrapping onto Nanoparticles Induces the Formation of Hybrid Colloids

Round 1

Reviewer 1 Report

Overall, the manuscript presents a study on the wrapping of nanoparticles by polymers, and the factors that control the stability and efficiency of the resulting hybrid colloids. The thermodynamic model proposed in the paper is interesting and the conclusions provide useful insights into the behavior of these systems. However, the manuscript needs improvement in the following aspects:

1.      The abstract is not very clear and does not provide enough information about the problem studied, the methods used, and the results obtained. The author should revise the abstract and include more specific information, such as the type of nanoparticles and polymers used, the specific interactions considered in the model, and the main conclusions of the study.

2.      The manuscript would benefit from a more detailed explanation of the methods used to calculate the wrapping energy and the different interaction energies. The author should provide more information about the assumptions and approximations made in the model, and how they affect the results obtained.

3.      The author should also provide more information about the ad hoc experiments suggested to validate the approach, and how they would complement the thermodynamic model presented in the paper.

4.      The language and writing style of the manuscript need improvement. Some sentences are difficult to understand, and the use of technical terms and acronyms is not always clear. The author should revise the manuscript to ensure that it is written in clear and concise language, and that technical terms and acronyms are defined or explained when first introduced.

Overall, the manuscript has the potential to contribute to the field of nanoparticle-polymer composites, but it needs to be revised and improved to provide a clearer and more detailed description of the study and its results.

Author Response

Thanks for expression of interest on this contribution. The following are my replies. I tried not to change too much the inner core of the manuscript, to respect what my coauthor did before his death. Anyhow, the paper has been substantially changed.

1. The abstract has been rewritten, according to your suggestions. 
2. The introduction has been slimmed and the methods used to calculate were clarified.
3. Experiments based on isothermal titration calorimetry (ITC), were recently reported by Schroffenegger and others (Ref. 42). They were mentioned here. 
4. Language has been cleaned and clarified.

Reviewer 2 Report

 

1-      The authors should explain what makes this work unique and how it differs from similar research.

2-      It is necessary for the authors to discuss in detail the used model.

3-      It is necessary for the authors to discuss in the text each figure in detail.

4-      Nothing is mentioned in the text about the uncertainty in the measurements, so please discuss this issue in the text.

5-      Please provide more information regarding the potential applicability of the work presented.

Author Response

Thanks for expression of interest on this contribution. The following are my replies. I tried not to change too much the manuscript, to respect what my coauthor did before his death.

1. The statistical thermodynamic model we introduced was never applied to Polymer-NP systems: in this sense it is unique and original.    

2-    Many parts of the model have been clarified. Note that the Model section has been implemented. 

3-      As mentioned in the captions Figure 1 is a surface projection of wrapping modes, that is dense, loose and without wrapping units. Figure 2 indicates the polymer protrusion outside the particle (medusa’s head). Figure 3 deals with the binding probability calculated assuming different exponents. Figure 4, conversely, was normalized in such a way, and such conditions, to put in evidence the location of the maximum.

4-      Nothing is mentioned in the text about the uncertainty in the measurements, so please discuss this issue in the text. We never made measurements, we only introduced a model and made calculations based on it. Anyhow, the uncertainties on energy terms are reported: see the Results section. 

5-      Please provide more information regarding the potential applicability of the work presented. We did experiments along this line some years ago and noticed how hard is to get detailed information on wrapping density from experiments only. Studies reported to date suffer from the fact that forces at work in the wrapped layer are badly defined. We are personally convinced that finely developed and refined statistical approaches to wrapping could help getting more details on the process efficiency.

Reviewer 3 Report

The authors forecast the wrapping/protruding ratio using a simple thermodynamic model, which is useful in broadening the applications of polymers/nano-particles hybrid colloids. This working is suitable for Coatings. However, before its publication, there are issues to be addressed:

1.     Too many sentences describe the development of hybrid and hybrid colloids. This is suitable for a review paper, but not a research paper.

2.     The authors should state the significance of their research in Introduction.

3.     In line 120, the meaning of X_b is absent.

4.     In line 155, what is the Eq. 1’？

5.     Please clarify why α = (1-P)/P is used for Eqs. 4-6. It seems to be an assumption from current version.

Author Response

Thanks for expression of interest. The following are our replies

The authors forecast the wrapping/protruding ratio using a simple thermodynamic model, which is useful in broadening the applications of polymers/nano-particles hybrid colloids. This working is suitable for Coatings. However, before its publication, there are issues to be addressed:

1.     Too many sentences describe the development of hybrid and hybrid colloids. This is suitable for a review paper, but not a research paper. This has been done; compare the present version with the former one. 

2.     The authors should state the significance of their research in Introduction. The research line is original. Wrapping is modeled in such a way to be user friendly, without introducing too many additional conditions.

3.     In line 120, the meaning of Xb is absent. It has been added. 

4.     In line 155, what is the Eq. 1’？ Eq.s 1a and 1b refer to wrapped and not wrapped terms. 

5.     Please clarify why α = (1-P)/P is used for Eqs. 4-6. It seems to be an assumption from current version. If you rearrange Eq. 3, then you get Eq. 4-6. 

Round 2

Reviewer 1 Report

Accept

Reviewer 2 Report

In response to my previous suggestions and concerns, the authors have made reasonable changes to the manuscript. Overall, the manuscript reads well and clarifies the authors' work. In my opinion, the manuscript contains currently all information and is ready for publishing in the Journal " Coatings " as a regular article. 

Reviewer 3 Report

The authors answered my question well. I recommand to accept it at present form.