Snell's Law of Refraction Observed in Thermal Frontal Polymerization

Authors

John A. Pojman, University of Southern MississippiFollow
Veronika Viner, University of Southern Mississippi
Burcu Binici, University of Southern Mississippi
Shanna Lavergne, University of Southern Mississippi
Melanie Winsper, University of Southern Mississippi
Dmitry Golovaty, University of Akron
Laura Gross, University of Akron

Document Type

Article

Publication Date

9-1-2007

Department

Chemistry and Biochemistry

School

Mathematics and Natural Sciences

Abstract

We demonstrate that Snell’s law of refraction can be applied to thermal fronts propagating through a boundary between regions that support distinct frontal velocities. We use the free-radical frontal polymerization of a triacrylate with clay filler that allows for two domains containing two different concentrations of a peroxide initiator to be molded together. Because the polymerization reaction rates depend on the initiator concentration, the propagation speed is different in each domain. We study fronts propagating in two parallel strips in which the incident angle is 90°. Our data fit Snell’s law v_r/v_i = sin θ_r/sin θ_i, where v_r is the refracted velocity, v_i is the incident velocity, θ_r is the angle of refraction, and θ_i is the incident angle. Further, we study circular fronts propagating radially from an initiation point in a high-velocity region into a low-velocity region (and vice versa). We demonstrate the close resemblance between the numerically simulated and experimentally observed thermal reaction fronts. By measuring the normal velocity and the angle of refraction of both simulated and experimental fronts, we establish that Snell’s law holds for thermal frontal polymerization in our experimental system. Finally we discuss the regimes in which Snell’s law may not be valid.

Comments

Published by Chaos at https://doi.org/10.1063/1.2784386.

Publication Title

Chaos

Volume

17

Issue

3

Recommended Citation

Pojman, J., Viner, V., Binici, B., Lavergne, S., Winsper, M., Golovaty, D., Gross, L. (2007). Snell's Law of Refraction Observed in Thermal Frontal Polymerization. Chaos, 17(3).
Available at: https://aquila.usm.edu/fac_pubs/9009