Real Time Study of Detergent Concentration Influence on Solid Fatty Acid Film Removal Processes

Abstract

International audienceCleaning in an aqueous solution is a complex mechanism which depends on several parameters. The quartz crystal microbalance (QCM) technique was used to investigate the detachment, using an anionic and a nonionic detergents, of stearic acid (C18H36O2) films deposited on gold-coated quartz surfaces. The cleaning mechanism was observed in real time by measuring the frequency of a quartz crystal during the fatty acid film removal. These observations reveal two successive phenomena: firstly, adsorption and absorption of water and detergent on the stearic acid layer and, secondly, the detachment of the fatty acid layer. A relationship between removal time and detergent concentration was highlighted: fatty acid removal time decreases as detergent concentration increases until an asymptotic value is reached. Initial contamination greatly influences cleaning duration. Increased sample contamination actually leads to increased removal time. However, no real correlation between the two parameters can be established. As a result, optimal parameters can be determined for each detergent, thus the QCM technique appears to be of great interest in monitoring and optimising cleaning protocol

Dynamic Analysis of the Removal of Fatty Acid from a Pet Surface Using a Quartz Crystal Microbalance

“…In this study, from a practical viewpoint of detergency, the soil removal was observed immediately after the moment when the soiled substrate was immersed into the detergent solution from atmosphere, as reported by Favrat et al [20].…”

“…Other researchers [16][17][18][19] have recorded the QCM frequency after injecting a given amount of the concentrated detergent solution into a bath of ultrapure water, which enables to observe the effect of the detergent by switching the bath liquid from water to detergent solution. In this study, from a practical viewpoint of detergency, the soil removal was observed immediately after the moment when the soiled substrate was immersed into the detergent solution from atmosphere, as reported by Favrat et al [20].…”

“…There have been some reports on the in situ frequency tracking of QCM for analyzing soil removal processes [16][17][18][19][20]. Weerawardana et al have reported that the QCM technique can be used to identify several distinct stages in the soil removal process and to rank surfactants in terms of their ability to remove solid organic soils [16].…”

Identification of residual nano-scale foulant material on stainless steel using atomic force microscopy after clean in place

“…Other research has evaluated extremely sensitive instrumentation for detecting deposit formation and removal on the nano lengths scale. Chen et al, (2010) and Favrat et al, (2012) used a quartz crystal microbalance (QCM) which allows for real time determination of nano-gram amounts of deposit on various substrates determined by changes in vibrational properties of the substrate itself.…”

Analysis of Cleaning Process for Several Kinds of Soil by Probability Density Functional Method

“…In order to analyze the mechanism of oily soil removal during washing, many studies have been conducted by applying various methods such as molecular dynamics simulations 22 , combined molecular dynamics and quantum mechanics 23 , lattice Monte Carlo simulations 24 , confocal laser scanning microscopy 25 , a scanning fluid dynamic gauging device 26 , and the quartz crystal microbalance technique 27 .…”