Hydrotropes in cleaning formulations
- Reference number
- ID20-0039
- Project leader
- Bordes, Romain
- Start and end dates
- 210601-260531
- Amount granted
- 2 500 000 SEK
- Administrative organization
- Chalmers University of Technology
- Research area
- Materials Science and Technology
Summary
To improve cleaning formulations performance, novel surfactants have attracted most of the industrial focus. Water soluble additives, such as hydrotropes, have been nearly exclusively used to regulate the solubility of surfactant, leaving their proven cleaning efficiency and mechanism of action largely not understood. The aim of this proposal is therefore to correlate the bulk activity of hydrotropes to their behavior at interfaces in relation to cleaning efficiency, through the study of the molecular interactions between hydrotopes, surfactants and other additives in cleaning formulations. This will be achieved by conducting bulk spectroscopic studies of systems where hydrotropes are actively improving the efficiency. These interactions will help rationalizing the behavior at interfaces of formulations and will guide the development of new families of hydrotropes using natural building blocks. The newly developed systems will be challenged in known hard-to-clean applications identified by Nouryon. The gained understanding will directly impact the business area by giving an alternative path to realize environmentally benign cleaning formulations while providing new tools to help maintaining the company at the forefront of the cleaning activity. By linking the concepts of weak amphiphilicity, that is currently emerging in surface chemistry, and cleaning efficiency, we hope to clarify the role of water-soluble additives in the behavior of surfactant at interfaces.
Popular science description
Behind a simple appearance, the efficiency of detergents relies on the complex blending of several active chemicals, that have to work together to remove soil from surfaces. The main ingredient, that has been optimized through the years by the chemical industry, is the surfactant. It is the molecule that effectively clean surfaces. With an annual world production close to 15 million tons, of which 40% goes into household detergents and cleaning products, it is naturally referred to as commodity chemicals. The second most important compound in a cleaning formulation and that often makes a difference is the hydrotrope. In industrial applications, hydrotropes are defined as organic compounds that increase the solubility of a surfactant in a formulation. Traditional hydrotropes, such as sodium cumene sulfonate, bring no additional value to the cleaning process. On the contrary, modern hydrotropes are molecular species that aim at bringing additional value to formulations in synergy with the primary surfactant. This enables, among other improvements, higher performance at lower surfactant concentration, better control of the cleaning, and minimal impact on the environment and low human and aquatic toxicity. In a word hydrotropes offer the chance of designing better cleaning formulations, more sustainable by, for instance, reducing surfactant consumption. Unfortunately, these observed improvements rely mostly on empirical understanding, with poor rationalization of the mechanism of action. Contrary to surfactants, hydrotropes have been much less optimized as their interactions with the other components of the cleaning formulation is poorly understood. This constitutes the aim of this project. By using spectroscopy in combination to surface analysis techniques, we will correlate molecular interactions between hydrotropes, surfactants and other additives in cleaning formulations to their cleaning efficiency. This rationalization will enable the design of cleaning formulations that will outperform the current technology in both efficiency and environmental impact by allowing a reduction of the quantity of surfactants used. Furthermore, it will provide guidelines for making new hydrotropes using natural building blocks. For the Nouryon, this project will yield new tools to keep the company at the forefront of the cleaning business.