Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
THE pH INFLUENCE ON THE CARBOPOL® SOLUTIONS STABILIZATION BY ADDITION OF NaOH
Submission Author:
Fernando Barbosa , PR
Co-Authors:
Fernando Barbosa, Yamid José García Blanco, Eduardo Matos Germer, Admilson Franco
Presenter: Fernando Barbosa
doi://10.26678/ABCM.COBEM2021.COB2021-0902
Abstract
Carbopol® solutions are widely used in experimental investigations as fluid with ideal viscoplastic characteristics. These solutions have an excellent potential for mimicking the gel materials' viscoplastic behavior in different industrial processes, such as the drilling fluid used in the oil and gas industry, explaining its vast application in research projects about fluid dynamics and rheology. Nevertheless, the use of Carbopol® has been limited due to the complexity in preparing large uniform samples, presenting difficulties in assessing its rheology and long stabilization times. The control of the pH level during the preparation of these solutions is essential to guarantee a proper stabilization of the rheological properties and increase the fluid's lifetime, allowing a reduction of time, cost, and resource waste. This paper concerns about the behavior of the pH value during its formulation stage, in which NaOH is added to stabilize the solution. As described by other authors and witnessed by previous works, a nonlinear relationship is depicted between the pH and the NaOH concentration until the stabilization, achieving the neutral value of 7. In such a pH zone, rheological parameters can be better controlled for more extended periods. Three Carbopol® solutions with different concentrations were prepared, and their pH was measured and monitored until neutrality. The aim is to understand and clarify this phenomenon in order to have better control of the process. With the obtained results, it was possible to enlarge the analysis of some variables that are directly involve in the pH evolution and may influence its stability period, such as NaOH solution concentration, rate of addition, and formulation time. By chemical studies on Carbopol® nature and rheological tests, it was possible to justify such phenomenon and support the conclusions achieved. Finally, an experimental correlation was proposed to predict and speed up the neutralization process for future formulations of Carbopol® solutions, standardizing a more efficient one, therefore, a more environmentally friendly one.
Keywords
Carbopol solutions, Viscoplastic fluids, pH behavior, Oil & gas
