Browsing by Author "Tiittanen, Laura"

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    The effect of nonpolar phase and surfactants on the critical micelle concentration of lecithin
    (2016-10-31) Tiittanen, Laura; Lehtimaa, Tuula; Nugroho, Robertus; Kemian tekniikan korkeakoulu; Österberg, Monika
    Lecithin is a mixture of phospholipids that have surface active properties. Lecithin is obtained as a by-product of water degumming of vegetable oil. Degumming is a part of vegetable oil purification in which an emulsion is formed to solubilize impurities in oil. The understanding of aggregation behaviour of lecithin and various other surfactants present in oils and fats is crucial for their efficient removal. Moreover, various surfactants may have synergistic effects which affect their removal from oils and fats. Lecithin and various other surfactants in nonpolar solvents can form reverse micelles and other reverse structures. In this thesis, lecithin micelle formation in four different nonpolar organic solvents was compared. The aim was to evaluate how the nonpolar phase affects lecithin micelle formation and behaviour. This was done by determining the critical micelle concentration of lecithin in these solvents using the TCNQ solubilization method, as well as investigating the effects of adding polar solvent E to these systems. Critical micelle concentration (CMC) is the surfactant concentration at which micelle formation is initiated. Further aim was to study the effect of adding monoglyceride or diglyceride to lecithin-solvent system, and investigate how their addition affects the concentration at which lecithin forms micelles. For this, TCNQ solubilization method was also used. The CMC value determined for lecithin were 0.07 wt.-% in solvent A, 0.01 wt.-% in solvent B, 0.09 wt.-% in solvent C, and 0.09 wt.% in solvent D. The solvent E added to solvent D was observed to have a drastically different effect as in other three solvents (A, B, C). Thus, it was concluded that lecithin micelle behaviour is very different in solvent D as in other solvents. Both monoglyceride and diglyceride were observed to increase the CMC of lecithin in solvent D, and the effect of monoglyceride was more pronounced.
  • No Thumbnail Available
    Item
    Fosforipohjaiset biopolymeerit
    (2012) Tiittanen, Laura; Korhonen, Harri; Sähkötekniikan korkeakoulu; Turunen, Markus