Mark–Houwink–Sakurada coefficients determination for molar mass of silk fibroin from viscometric results. SEC-MALLS approach

Abstract

The results on the changes of average molar masses inBombyx morifibroin with use of size exclusion chromatography and viscometry are presented in terms of the determination of Mark–Houwink–Sakurada coefficients, which are lacking in the literature.

Flexible Methyl Cellulose/Polyaniline/Silver Composite Films with Enhanced Linear and Nonlinear Optical Properties

“…For that purpose, four different concentrations (namely; 0.5, 0.25, 0.2, and 0.1 g/dL in concentrated sulphoric acid) were prepared. The obtained inherent viscosity was used to estimate the MW of PANI using the Mark–Houwink–Sakurada equation [ 14 ]. The average MW of PANI was 29 KD.…”

The Effect of Molecular Weight on the Solubility Properties of Biocompatible Poly(ethylene succinate) Polyester

“…The theoretical consideration (see ESI file) is in good agreement with the experimental values of K η and α constants for PES in DMSO (see Figure 9 B), found to be equal to 8.22 × 10 −2 and 0.52, respectively. The value of α that characterized the macromolecules conformation in the solvent was around 0.52 in the same range of 0.5 < α < 0.8 to a flexible chain [ 34 ]. The mentioned findings indicate that DMSO constitutes a near theta solvent for PES polymer and thus the DMSO/water binary mixture is ideal for the precipitation of the polymer which enables the drug encapsulation.…”

“…The intrinsic viscosity for each PES sample was determined by measuring the viscosity (proportional to the flow times, Equation (5)) of PES solution (in DMSO) with the variation of the concentration that was ranged between 0.1–0.3 g/mL using the Ostwald viscometer at room temperature, then the reduced viscosity ( η red ) that was determined by using (Equation (6)) was plotted against the concentration (g/mL) and the intrinsic viscosity ( η ) was estimated from the intercept value. The logarithm of determining intrinsic viscosity ( η ) for three different PES was plotted against the logarithm of relative molecular weights, and the K η was obtained from the intercept value and exponent α was determined from the slope from the curve fitting equation [ 34 ]. where t is the flow time of the solution, t o is the flow time of pure DMSO, c is the concentration, K η is the KMH coefficient relevant to a given polymer-solvent system, and α is the KMH exponent which characterizes the conformation of macromolecules in a solvent [ 34 ].…”

“…The logarithm of determining intrinsic viscosity ( η ) for three different PES was plotted against the logarithm of relative molecular weights, and the K η was obtained from the intercept value and exponent α was determined from the slope from the curve fitting equation [ 34 ]. where t is the flow time of the solution, t o is the flow time of pure DMSO, c is the concentration, K η is the KMH coefficient relevant to a given polymer-solvent system, and α is the KMH exponent which characterizes the conformation of macromolecules in a solvent [ 34 ].…”

“…where t is the flow time of the solution, t o is the flow time of pure DMSO, c is the concentration, K η is the KMH coefficient relevant to a given polymer-solvent system, and α is the KMH exponent which characterizes the conformation of macromolecules in a solvent [34].…”