Electric field orientation of nucleic acids in aqueous solutions. 2. Dependence of the intrinsic electric dichroism and electric dipole moments of rodlike DNA on molecular weight and ionic strength

Pulsed Electric Linear Dichroism of Triphenylmethane Dyes Adsorbed on Montmorillonite K10 in Aqueous Media

“…It should be noted that the saturated reduced dichroism is not equal to the intrinsic reduced dichroism for the disklike particle, in contrast with the case of rodlike particles, for which both quantities are equal to each other, because the value of (E → ∞) is unity (18,32,33,36,37). If more than one bound dye species exist in a triphenylmethane dye-clay complex in solution, the intrinsic reduced dichroism for the kth bound species can be expressed as (18, 32, 33)…”

“…For this purpose, the field-strength dependence of observed reduced dichroism values was analyzed by the fitting method (19,35) with the theoretical SUSID orientation function, since the MK-10 particle possesses no permanent electric dipole moment in aqueous solution (19,35). The physical meaning of this orientation function (19,35) and the fitting procedure of experimental values to the theoretical function were described in full detail in previous papers (19,32,33,37). Figure 3 shows the isotropic absorption spectra of CV in the absence (dotted line) and the presence (solid and dashed lines) of MK-10 at two D/S values in (c), and the corresponding reduced dichroism spectra at 3 kV/cm in (a) and (b).…”

Electrooptics of β-FeOOH particle in aqueous media

“…(9) approaches unity at infinitely high fields, the optical anisotropy factor ( g/n) obsd is, to be strict, a weight-average quantity, i.e., g/n w , for the polydisperse system [14]. In the past, the quantity g/n has been treated expediently as being independent of the molecular weight or length of particle in solution [8][9][10][11][12][13]19,20].…”

“…Each β-FeOOH particle is a well-defined spindle-like shape, as shown in Part I and also by other workers [1][2][3][4], but the whole system is polydisperse in terms of the shape, length, volume, or size. Thus, the distribution of particles must be taken into account in the analysis of observed physical quantities [15][16][17][18][19][20]. In the present work, the size distribution could be determined from the electron-micrographic data in the dried state.…”

“…Concentrations of NaCl in mM at a fixed β-FeOOH concentration of 0.0111 g/L are 0.056 ("), 0.094 (2), 0.26 (Q), 0.76 (a), and 2.0 (F). Solid lines are the theoretical SUSID orientation function, whereas dotted lines are the PD-SUSID orientation function.and relaxation time distribution of polydisperse colloid particles[17][18][19][20]31,32].…”