Rotational Brownian motion and polarization of the fluorescence of solutions.

TLDR: The chapter discusses the rotational Brownian motion and polarization of the fluorescence of solutions, which involves the translation of the molecules but also their rotational movements.

Abstract: Publisher Summary The chapter discusses the rotational Brownian motion and polarization of the fluorescence of solutions. It is possible to learn something of the size and shape of protein molecules by studying their Brownian motion. Such motion involves the translation of the molecules but also their rotational movements. The Brownian motion is not observed from a study of the physical properties of the solution. When the dissolved molecules are fluorescent, a study of the polarization of the emitted radiation gives important information about rotational motion. At any instant, all possible directions are equally represented, and the molecules are thus randomly disposed. In fact, unity at the initial instant is where there is perfect orientation and reaches zero value when the orientation is random.