Change in relaxation scenario at the order-disorder transition of a colloidal fluid of hard spheres seen from the Gaussian limit of the self-intermediate scattering function.
نویسندگان
چکیده
Self-intermediate scattering functions (ISFs) are measured by dynamic light scattering for the colloidal fluid of hard spheres for both equilibrium and nonequilibrium (undercooled) conditions, i.e., for volume fractions below and above the known freezing transition of the hard-sphere system. The delay time tau(m) where the mean-squared displacement, or the low wave-vector limit of the ISF, exhibits its maximum stretching is identified as a characteristic of the non-Markovian process(es) and is used to separate the ISF into fast (tau < tau(m)) and slow (tau > tau(m)) contributions. Each of these contributions exposes qualitative differences in the dynamics of the particles between the equilibrium and nonequilibrium colloidal fluids. These changes in the relaxation scenario signal the colloidal fluid's awareness of its traversal of the freezing volume fraction.
منابع مشابه
On the Gaussian approximation in colloidal hard sphere fluids.
We study the behaviour of the self-intermediate scattering function and self-van Hove correlation function for quasi-two-dimensional colloidal hard sphere fluids at a range of area fractions. We compute these functions first directly from the particle coordinates and secondly from the mean squared displacement via the Gaussian approximation. This allows us to test the validity of this approxima...
متن کاملSimulation study of nonergodicity transitions: gelation in colloidal systems with short-range attractions.
Computer simulations were used to study the gel transition occurring in colloidal systems with short-range attractions. A colloid-polymer mixture was modeled and the results were compared with mode coupling theory (MCT) expectations and with the results for other systems (hard-spheres system and Lennard-Jones system). The self-intermediate scattering function and the mean squared displacement w...
متن کاملAgeing and ultra-slow equilibration in concentrated colloidal hard spheres
Abstract We study the dynamic behaviour of concentrated colloidal hard spheres using time resolved correlation, a light scattering technique that can detect the slow evolution of the dynamics in out-of-equilibrium systems. Surprisingly, equilibrium is reached a very long time after sample initialization, the nonstationary regime lasting up to three orders of magnitude more than the relaxation t...
متن کاملAging and ultra-slow equilibration in concentrated colloidal hard spheres
We study the dynamic behaviour of concentrated colloidal hard spheres using Time Resolved Correlation, a light scattering technique that can detect the slow evolution of the dynamics in out-of-equilibrium systems. Surprisingly, equilibrium is reached a very long time after sample initialization, the non-stationary regime lasting up to three orders of magnitude more than the relaxation time of t...
متن کاملمحاسبه سطح مقطع جزیی انتقال حالت به حالت بار به روش فادیف
A second-order approximation to the Faddeev-Watson-Lovelace treatment of the rearrangement channel is used in a three-body scattering cross sections. In this formalism, the Three-body wave function is expressed by three coupled integral equations, the Faddeev equations, which contian the two-body (off-shell) transition amplitudes, and proved the uniqueness of their solutions. This amplitude c...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Physical review. E, Statistical, nonlinear, and soft matter physics
دوره 72 3 Pt 1 شماره
صفحات -
تاریخ انتشار 2005