Optical and thermal characterization of albumin protein solders

The effect of temperature on the optical and thermal properties of pure and indocyanine green-doped albumin protein solders as a function of wavelength has been studied between 25 °C and 100 °C. An increase in the group refractive index by up to 4% and a decrease in absorption coefficient (;800 nm) by up to 8%, after denaturing the solder specimens in a constant-temperature water bath at temperatures of 60–100 °C, were not significant. The reduced scattering coefficient, however, increased rapidly with temperature as the solder changed from being a highly nonscattering medium at room temperature to a highly scattering medium at temperatures close to 70 °C. The thermal conductivity, thermal diffusivity, and heat capacity increased by up to 30%, 15%, and 10%, respectively. Finally, the frequency factor and activation energy were measured to be 3.17 × 1056 s^-1and 3.79 × 105 J mol^-1, respectively, for liquid protein solders (25% bovine serum albumin) and 3.50 × 1057 s^-1and 3.85 × 105 J mol^-1, respectively, for solid protein solders (60% bovine serum albumin). Incorporation of dynamic optical and thermal properties into modeling studies of laser tissue interactions could have a significant influence on the determination of the expected zone of damage.