Integral transformation method for sedimentation behaviours of aggregates: Part I. α-Cyclodextrin/poly(ethyrene glycol)/water system

We tried to investigate concentration profiles of colloidal particles diffusing and settling down in aqueous media with a digital image processing and an integral transformation method. We proposed this method as an original one in previous papers. The definition of the method is shown as: I(t)=∫i(t,τ)×D(τ) dt, where I(t),i(t,τ) and D(τ) are phenomenological (response), elementary and distribution functions, respectively. The distributions of the characteristic length of concentration profiles were given by this method based on digital graphical image data. We have applied this method to sedimentation behaviours of α-cyclodextrin (α-CD)/poly(ethylene glycol) (PEG)/water systems. The obtained distribution curves of aggregates between CD–PEG complexes were changed as a function of time. In this paper, we could discuss also about relaxation times, τsed for a sedimentation equilibrium of latex particles at various temperatures. We will briefly discuss about the different sedimentation behaviours between latex particles and CD–PEG complexes.