Hydrodynamic radii and diffusion coefficients of particle aggregates derived from the bead model

Streaming potential studies of colloid, polyelectrolyte and protein deposition

“…Obviously for solid spheres 〈R H 〉 is equal to the sphere radius a. For a solid sphere doublet 〈R H 〉 = 1.39a [78], for a triplet (linear aggregate) 〈R H 〉 = 1.73a [79,80] and for a linear aggregate composed of n s equal sized spheres one has [81] 〈R H 〉 = n s ln2n s −0:25 a = 1 ln2λ−0:25…”

“…Numerical solution of the Stokes equation [81] Solid sphere linear aggregate 〈R H 〉 = 1 ln2λ−0:25 λa Asymptotic expression for 100 ≤ n s ≤ 300 λ = n s [81] Prolate spheroid À Á λ = L / 2b approximate solution, valid for λ ≫ 1 [14] validity can be derived using various RSA approaches discussed in the next section.…”

“…It is interesting to note that the RSA model is applicable for particles of various shape and various dimensionality like a quasi one À Á Approximate solution, λ = L / 2b valid for λ ≫ 1 [128] Half circle approximated by n s spheres 〈R H 〉 = 1 11 12 ln2λ + 0:084 λa Numerical solution valid for 100 ≤ λ ≤ 400 [81] Bent spheroid [128] Circle (ring) made of n s spheres 〈R H 〉 = 1 11 12 ln2λ + 0:67 λa λ = ns numerical solution valid for 100 < λ < 450 [81] Disk 〈R H 〉 = 2 π a Analytical, valid for d / a ≪ 1, d -disk thickness [14] dimensional (1D) adsorption on a line segment, a two-dimensional (2D) adsorption on planar surfaces of finite (surface features) or infinite extension and three-dimensional (3D), adsorption (referred to as random addition) in the space. It is advantageous for analyzing these results to introduce the dimensionless coverage, which for the 2D case (adsorption at a surface), can be defined as…”

Fibrinogen conformations and charge in electrolyte solutions derived from DLS and dynamic viscosity measurements

“…In this work, using the new bead model of fibrinogen, numerical calculations are performed enabling one to determine the mobility tensors and intrinsic viscosities for various conformations the molecule. The efficient multipole expansion method [29][30][31][32][33][34][35] is applied to solve fluid velocity fields governed by the linear Stokes equation.…”

Hydrodynamic radius approximation for spherical particles suspended in a viscous fluid: Influence of particle internal structure and boundary

“…the DLS measurements of the translational self-diffusion coefficients of dilute suspensions, combined with the Stokes-Einstein relation [6], or viscometric measurements of the intrinsic viscosity, supplemented by the Einstein's theory [5]. This concept is often also applied to non-spherical particles [7]. However, in this work we analyze the concept of the hydrodynamic radius only in the context of spherical particles, and we * Electronic address: mekiel@ippt.pan.pl show how to apply it to account for the hydrodynamics of particles with a different internal structure and boundaries.…”