Estimating the Refractive Index of a Hydrated Superabsorbent Polymer Sphere

• Autores: Matthew Stephen Nee
• Localización: The Physics Teacher, ISSN 0031-921X, Vol. 62, Nº. 4, 2024, págs. 262-265
• Idioma: inglés
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• Resumen

  • Superabsorbent polymers (SAPs) are known for their amazing ability to absorb at least 100 times their dry weight in water and, once hydrated and having no added coloration, are nearly invisible to the naked eye when immersed in water with ambient lighting. Here we develop a method for estimating the refractive index of fully hydrated SAP spheres. Leveraging a computer model of refraction of light through a sphere, we use the results of a simple, low-cost experiment to estimate the refractive index as ns = 1.3354 ± 0.0001, or within 0.23% of the average index of water for yellowish light and room temperatures. The procedure described below could easily be incorporated into a classroom laboratory activity.