Synthesis and characterization of graphene based composites for non-linear optical applications


Rachel H. Rai

Date of Award


Degree Name

M.S. in Chemical Engineering


Department of Chemical and Materials Engineering


Advisor: Christopher Muratore


Graphene shows remarkable non-linear optical behavior, where above an incident light intensity threshold, transmission is attenuated. Unfortunately, capitalizing on the unique properties of graphene can be a challenge because the material itself is hard to handle unless graphene is integrated with other materials. The objective of the work presented here is development of premium graphene-based nano-composites for non-linear optical applications. Few and single layer graphene flakes were synthesized through liquid phase exfoliation of graphite in 1-Methyl-2-pyrrolidinon (NMP). The structure of the resultant flakes was then examined using Raman spectroscopy and transmission electron microscopy. Additionally, since the exfoliated graphene had to remain in solution prior to incorporation into the polymer, a study of the segregation behavior of the suspended flakes with respect to time was obtained via analysis of the solution by UV-Visible transmission spectroscopy. Noting the difference in the light transmission through a sample of graphene in suspension as a function of time was a convenient method to obtain the flakes shelf-life, or time at which the homogeneity of the flake concentration drops below acceptable thresholds. The fabricated graphene was incorporated to a Polymethyl methacrylate (PMMA) matrix via spin coating. As means to understand how the spin coating parameters affect the dispersion of graphene, samples where studied under Raman spectroscopy. After determining the optimum synthesis parameters promoting uniform graphene distribution in a heterogeneous matrix, sol-gel/graphene composites were prepared and characterized. The correlation of processing, structure and properties of these novel composites for non-linear optical applications is discussed.


Graphene Synthesis, Graphene Properties, Nonlinear optics Materials, Nanocomposites (Materials), Engineering, Materials Science, Chemical Engineering, Nanoscience, graphene, non-linear optics, optical limiter, nano-composites, graphene synthesis, graphene characterization

Rights Statement

Copyright 2016, author