Self-assembly behavior in systems containing surfactants and chelating agents
Typ
Examensarbete för masterexamen
Master's Thesis
Master's Thesis
Program
Materials chemistry (MPMCN), MSc
Publicerad
2024
Författare
Nero, Emelie
Jacobsson, Frida
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
Cleaning products play a crucial role in effectively maintaining a healthy and
hygienic living environment. In all cleaning formulations ingredients like chelating
agents and surfactants are essential for the products’ performance. This study
investigates the self-assembly of surfactants in the presence of chelating agents and
their influence on the physicochemical properties and cleaning efficiency of
cleaning formulations. The formulations consist of a nonionic surfactant, a
chelating agent and a secondary surfactant. Three amine-based secondary
surfactants were evaluated, including an amphoteric surfactant, an amine oxide,
and a quaternary ammonium compound (quat). The chelating agents evaluated
were L-glutamic acid N,N-diacetic acid tetrasodium salt (GLDA), methylglycine
N,N-diacetic acid trisodium salt (MGDA), ammonium citrate and citric acid.
The study focuses on how these components affect clouding temperature, viscosity,
foaming, wettability, and surface tension. Results show that clouding temperature,
viscosity, and foaming are notably impacted by the choice of secondary surfactant
and chelating agent, whereas surface tension remains unchanged. Amphoteric
surfactants, in particular, reduce the salting-out effect of chelating agents like
MGDA and GLDA, likely due to the similarity between their molecular structures.
This interaction is hypothesized to lower the critical packing parameter (CPP),
leading to smaller, more spherical micelles that increase solubility, raise clouding
temperature, decrease viscosity, and improve foaming. These changes could enable
higher concentrations of active ingredients, resulting in more concentrated,
energy-efficient products with reduced packaging needs.
Cleaning performance tests on model soils revealed that formulations combining
amphoteric or amine oxide surfactants with GLDA or MGDA were most effective
across various surfaces and soil types, especially at higher concentrations of chelating
agents. These findings suggest that combining amphoteric surfactants with GLDA
or MGDA could lead to the development of more concentrated, sustainable cleaning
products.
Beskrivning
Ämne/nyckelord
Surfactants , Chelating agents , Surface cleaning , MGDA , GLDA , Citric acid , Ammonium citrate , Quat , Amine oxide , Amphoteric