Molecular Simulation of Poly (2-oxazoline) Adsorption on Graphene Nanosheet

Foroutan, Samira; Asadinezhad, Ahmad

Molecular Simulation of Poly (2-oxazoline) Adsorption on Graphene Nanosheet

Document Type : Original Research

Authors

S. foroutan

A. asadinezhad

Isfahan University of Technology

Abstract

Research subject: Poly (2-oxazoline) (PEOX) polymers are a family of synthetic macromolecules with biodegradable and biocompatible features. They resemble polypeptides in structure and therefore, have recently taken put to use in drug delivery. Nonetheless, these polymers suffer from relatively low thermal and mechanical performance and thus are reinforced with nanoparticles as nanocomposites. The molecular details of the reinforcement mechanism of PEOX have not yet been elucidated.

Research approach: This research work was done to reach an understanding on interaction of 2-oxazoline-based polymers with 2D nanoscale reinforcements and to shed light on the mechanism of reinforcing the respective nanocomposites. To this end, conformation and dynamics of poly (2-ethyl-2-oxazoline), as a known representative member of this family, near a functionalized graphene nanosheet were studied via classical molecular dynamics for a period of 10 ns. The effects of various temperatures and polymer chain lengths on polymer conformation and dynamics were assessed.

Main results: Molecular dynamics snapshots exhibited effective interaction of the polymer chain with the graphene nanosheet leading to adsorption, whereby conformation and dynamics of the chain underwent transition. The adsorbed polymer chain adopted a flat, folded arrangement parallel with the graphene plane. Also, the gyration radius was found to increase, when the polymer chain approached the graphene nanosheet. Pair correlation function curves revealed that the adsorption correlation length was on the order of the repeating unit end-to-end distance. Mean-square-displacement of the polymer chain decreased as it moved towards graphene. An increase in temperature led to a change in structure and dynamics of the adsorbed polymer chain.

Keywords

poly (2-oxazoline)

molecular dynamics

Graphene

simulation

Adsorption

Subjects

nano-composite

[1] Asadi R., Farhadi K., Soltaniani M.H. and Ghaffarzadeh M., Investigation of Detonation of Glycidyl triazolium methyl nitrate as a New Energetic Polymer in Propellant Rockets with Molecular Dynamic Simulation, J. Appl. Res. Chem-Polym. Eng., 1, 3, 2018.
[2] Zhang X. Rajaraman X., Liu H. and Ramakrishna S., Graphene's potential in Materials Science and Engineering, RSC Adv., 4, 28987, 2014.
[3] Wang X. and Shi G., An Introduction to the Chemistry of Graphene, Phys. Chem. Chem. Phys., 17, 28484, 2015.
[4] Zhu j., Chen M., He Q., Shao L., Wei S. and Guo, Z., An Overview of the Engineered Graphene Nanostructures and Nanocomposites, RSC Adv., 3, 22790, 2013.
[5] Flynn G.W., Perspective: The Dawning of the Age of Graphene, J. Chem. Phys., 135, 05091, 2011.
[6] Rissanou A.N., Power A.J. and Harmandaris V., Structural and dynamical Properties of Polyethylene/Graphene Nanocomposites through Molecular Dynamics Simulations, Polymers, 7, 390, 2015.
[7] Asadinezhad A. and Kelich P., Effects of Carbon Nanofiller Characteristics on PTT Chain Conformation and Dynamics: A Computational Study, Appl. Surf. Sci., 392, 981, 2017.
[8] Kelich P. and Asadinezhad A., Adsorption of Poly (ethylene succinate) Chain onto Graphene Nanosheets: A Molecular Simulation, J. Mol. Graph. Model. 69, 26, 2016.
[9] Hoogenboom R., Poly (2‐oxazoline)s: a Polymer Class with Numerous Potential Applications, Angew. Chem. Int. Ed., 48, 7978, 2009.
[10] Bernard A.M., Molecular Modeling of Poly (2-ethyl-2-oxazoline), PhD Thesis, Georgia Institute of Technology, 2008.
[11] Boel E., A., Vergaelen M., De la Rosa V.R., Hoogenboom R. and Van den Mooter G., Comparative Study of the Potential of Poly(2-ethyl-2-oxazoline) as Carrier in the Formulation of Amorphous Solid Dispersions of Poorly Soluble Drugs, Eur. J. Pharm. Biopharm., 144, 79, 2019.
[12] Shubha A. and Manohara S.R., Thermal, Conductivity, and Dielectric Properties of Poly(2-ethyl-2-oxazoline)-Polyvinylpyrrolidone Blends, J. Polym. Res., 25, 174, 2018.
[13] Yarahmadi E., Didehban K., Shabanian M., Saeb M.R., Assessing the Crosslinking Behavior of Nanocomposites Based on Epoxy and Starch-modified Graphene Oxide Nanosheets Potent to be Applied as Engineering Coatings, J. Appl. Res. Chem-Polym. Eng., 1, 61, 2017.
[14] Khabiri M., Jafari S.H., Pourhossaini M.R., Khonakdar H.A., Influence of Swelling Phenomenon on Filler Structure in Nitrile-Silica Nanocomposite as Resistant Rubber Compound to Solvent, J. Appl. Res. Chem-Polym. Eng., 1, 51, 2018.
[15] Khonakdar H.A., Ehsani M., Asadinezhad A., Jafari S.H. and Wagenknecht U., Nanofilled Polypropylene/Poly (trimethylene terephthalate) Blends: A Morphological and Mechanical Properties Study, J. Macromol. Sci. Phys., 52, 897, 2013.
[16] Rao C.N. and Sood A.K., Graphene: Synthesis, Properties, and Phenomena, John Wiley and Sons, Weinheim, 2013.
[17] L. Niranjanmurthi, C. Park and Lim K.T., Synthesis and Characterization of Graphene Oxide /Poly (2-ethyl- 2-oxazoline) Composites, Mol. Cryst. Liq. Cryst. 564, 206, 2012.
[18] Wang M., Gustafsson O.J.R., Siddiqui G., Javed I., Kelly H.G., Blin T., Yin H., Kent S.J., Creek D.J., Kempe K., Ke P.C. and Davis T.P., Human Plasma Proteome Association and Cytotoxicity of Nano-graphene Oxide Grafted with Stealth Polyethylene Glycol and Poly(2-ethyl-2-oxazoline), Nanoscale, 10, 10863, 2018.
[19] Kelich P. and Asadinezhad A., Molecular Simulation Study on Brushes of Poly (2-ethyl-2-oxazoline), Mater. Today Commun., 21, 100681, 2019.
[20] Oostenbrink C., Villa A., Mark A.E. and Gunsteren W.F., A Biomolecular Force Field Based on the Free Enthalpy of Hydration and Solvation: the GROMOS Force-field Parameter Sets 53A5 and 53A6., J. Comput. Chem., 25, 1656, 2004.
[21] Jorgensen W.L., Maxwell D.S. and Tirado-Rives J., Development and Testing of the OPLS All-atom Force Field on Conformational Energetics and Properties of Organic Liquids, J. Am. Chem. Soc. 118, 11225, 1996.
[22] Van der Spoel D., Lindahl E., Hess B., Groenhof G., Mark A.E. and Berendsen H.J.C., GROMACS: Fast, Flexible, and Free, J. Comput. Chem. 26, 1701, 2005.
[23] Bussi G., Donadio D. and Parrinello M.J., Canonical Sampling through Velocity Rescaling, J. Chem. Phys.126, 014101, 2007.
[24] Steinhauser M.O., Computational Multiscale Modelling of Fluids and Solids: Theory and Applications, Springer, Heidelberg. 2008.
[25] Humphrey W., Dalke A. and Schulten K., VMD: Visual Molecular Dynamics, J. Mol. Graph., 14, 33, 1996.