Magneto-Hydrodynamic Mixing: a New Technique for Preparing Carbomer Hydrogels

Abstract Magnetohydrodynamic mixing was evaluated as an alternative to conventional high shear mixing in the preparation of carbomer hydrogels containing 1.22 wt.% Carbopol? 980 NF. Neutralization of the carbomer dispersion (pH = 2.74) with triethanolamine (TEA) enabled to adjust the pH of the mixture and tune the viscosity of the hydrogel. Using high shear mixing, this approach was limited to 0.2 wt.% TEA (pH = 3.83) as the gel became too viscous and the recirculation flow dropped from 12 to 0.3 m3/h. Magnetohydrodynamic mixing enabled to reach TEA concentrations up to 1.0 wt.% (pH = 5.31). Apparent viscosity measurements on samples having 0.2 wt.% TEA revealed lower viscosities for carbomer hydrogels prepared with high shear mixing, i.e. 6,800 mPa·s versus 8,800 mPa for magneto-hydrodynamic mixing. Based on 1H NMR evidence, this decrease in apparent viscosity was attributed to structural damage to the carbomer backbone in combination with mechanochemical degradation of the added TEA.

Jaar van publicatie:2022

Toegankelijkheid:Open