Development of QCM-D sensors for detergent studies

Purpose and goal

The detergent industry has been identified to have great potential for the QCM-D technique. To reach this industry, standardized model stains are required. The project goal was to be able to coat the QCM-D sensors with three different soils and to verify the correlation with cleaning measurements with established standard tests to be able to compare with existing evaluation methods. Of the three soils that were selected, one protocol was successfully developed. Cleaning measurements were successfully performed, but the correlation with the established standard tests remain.

Results and expected effects

Of the three model stains that were the target, one reached a protocol and cleaning evaluation. The protocol generates a reproducible film of good quality. However, it could be desirable for it to be harder to remove for better evaluation and segregation of the efficiency between different cleaning agents. The model stain results were presented at 8th International Fresenius Conference on "Detergents and Cleaning Products´, 2014, Germany and were extremely well received. The feedback that model stains are a must in this market shows that we are heading in the right direction.

Approach and implementation

The strategy was to identify three relevant model stain soils, develop protocols for reproducible soil deposition on the QCM-D sensors and then perform cleaning evaluation tests to correlate the QCM-D data with results from methods used today for cleaning efficiency evaluation. To develop protocols for reproducible deposition of high quality stains was a challenge. At delaying success, first one of the stains were abandoned and then a second one in order to reach as far as possible with the third one. In retrospect, we should have aimed for one stain to start with.