To increase the service life and to maintain the visual appearance of textile floor coverings, a frequent basic cleaning (usually annually) is necessary.

In this process, heated cleaning liquor (30 – 50 °C) is introduced into the wear layer of textile floor coverings (cleaning step) and then removed together with detached soil using fresh water (15 – 20 °C, rinsing step).

The use of surfactants in basic cleaning of textile floor coverings is indispensable, especially for the effective removal of oil- and grease-containing soiling. Surfactants are amphiphilic molecules consisting of a hydrophilic (surfactant head) and a hydrophobic (surfactant tail) part.

Due to their amphiphilic structure, surfactants accumulate on water/air, water/material and water/soil interfaces during cleaning process and thus improve wettability of soiled textiles floor coverings with the cleaning liquor, effectively remove soilings from pile fibres and stabilize detached soiling in the cleaning liquor.

However, due to amphiphilic structure and resulting surface-active properties, surfactants are difficult to remove from pile fibers of textile floor coverings in the rinsing step. During basic cleaning, therefore, an extensive rinsing step (use of water, duration) is necessary to reduce residual surfactant content of pile fibers.

Nevertheless, residues of surfactants contained in the cleaning agents cannot be avoided. Since surfactant residues on the pile fibers increase soil adhesion, rapid resoiling of textile floor coverings occurs.

Within the scope of the research project, stimulus-amphiphilic surfactant systems were therefore developed to minimize residual surfactant content of textile floor coverings during basic cleaning and to reduce effort required in rinsing step.

Such stimulus-amphiphilic surfactant systems exhibit reversible switchability between a hydrophilic and an amphiphilic state (hydrophilic/amphiphilic switchability) and thus switchability of their surfactant characteristics (amphiphilicity, wetting behavior, solubilization capacity) as a function of temperature (stimulus).

As a stimulus for hydrophilic/amphiphilic switchability, changes in temperature occurring during basic cleaning are used (see above).

Stimulus-amphiphilic surfactant systems are therefore highly efficient in wetting pile fibers and removing soil in the cleaning step and exhibit a high solubilization capacity for soiling (amphiphilic state of the stimulus-amphiphilic surfactant systems).

In the rinsing step (hydrophilic state of the stimulus-amphiphilic surfactant systems), surfactant systems can be completely detached from pile fibers with little effort (reduced water requirement, duration).

The research report is available on request from FRT.