Dear Rachel McMurray, you'd better to give the methods for film preparation. Under this magnification, it seems that PCL films are rough, and have some pores. The addition of graphene improve the surface quality by reducing the roughess of the film and the two materials are compatible. Reagrds

Dear Rachel,

I believe that some minor experimental differences in preparation of films by solvent casting (using acetone as solvent) could explain somewhat the porous aspect of the neat PCL film. You know all the details of experimental procedure (e.g., Did you use similar amounts of solution of PCL? the thickness of films was similar? /other parameters).

To evidence better graphite particles will be necessary to use higher SEM magnifications, and eventually to have the help of TEM analysis. The loading of graphene is not so high, maybe you have the possibility to test other solvents or to repeat the first experiment regarding the producing of neat PCL and PCL/graphite films.

Good luck in your study and best regards,

Marius

Dear Rachel,

For eventual help and interest some papers. Best regards, Marius

Open Access

Morphology, Crystallinity, and Molecular Weight of Poly(ε-caprolactone)/Graphene Oxide Hybrids

Polymers 2019, 11(7), 1099; https://doi.org/10.3390/polym11071099

Surface properties and biocompatibility of solvent-cast poly[-caprolactone] films

September 2004Biomaterials 25(19):4741-8

DOI: 10.1016/j.biomaterials.2003.12.003

Dottori, M., Armentano, I., Fortunati, E. and Kenny, J.M. (2011), Production and properties of solvent‐cast poly(ε‐caprolactone) composites with carbon nanostructures. J. Appl. Polym. Sci., 119: 3544-3552. doi:10.1002/app.33033

How to get uniform thickness films by solvent casting method?

https://www.researchgate.net/post/How_to_get_uniform_thickness_films_by_solvent_casting_method

Antibacterial performance of solvent cast polycaprolactone (PCL) films containing essential oils

Food Control, Volume 34, Issue 1, November 2013, Pages 214-220

https://doi.org/10.1016/j.foodcont.2013.04.025