Colloidal systems relaxation function

Car-Parrinello techniques have been used to describe classical variables whose behavior, like quantum electrons in the Born-Oppenheimer approximation, is nearly adiabatic with respect to other variables. In simulations of a colloidal system consisting of macroions of charge Ze, each associated with Z counterions of charge —e, Lowen et al. [192] eliminated explicit treatment of the many counterions using classical density functional theory. Assuming that the counterions relax instantaneously on the time-scale of macroion motion, simulations of the macroion were performed by optimizing the counterion density at each time step by simulated annealing. 

Measurements of spin-lattice relaxation rate as a function of the magnetic field/resonance frequency are commonly referred to as nuclear magnetic relaxation dispersion, NMRD. Measurements of this kind, when performed over a broad range, are an invaluable source of information on frequency-resolved molecular motions in complex biological or colloidal systems. Several years ago, Halle proposed a theory for relaxation of quadrupolar spins in dynamically heterogeneous systems... 

Field-flow fractionation (FFF) is a reliable technique for separation and characterization of colloids and polymers. It is a dynamic separation technique based on the differential elution of the sample constituents by a laminar flow, in a flat ribbon-like channel, according to their sensitivity to an external field applied in the perpendicular direction to that of the flow. Resolution in the FFF system is a function of the time allowed to equihbrate (or relax) the sample within the channel under the force field, with the mobile phase not flowing prior to fractionation. 

---