The structural and optical properties of thermosensitive particles, nanogels, are studied by light scattering and refractometry as a function of temperature. Nanogels are composed of poly- N-Isopropopylacrylamide, a polymer that shrinks at temperatures higher than its lower critical solution temperature, 33 °C. The internal nanogel structure obtained by light scattering is well modeled by assuming a constant radial mass density profile convoluted with a Gaussian function. Moreover, we introduce a simple method that allows us to describe the measured temperature-dependent index of refraction of these complex nanoparticles by using their structural information, core dimension and external radius
