Cmc Of a Surfactant

Experiment 7: Determining the CMC of a Surfactant by Contact Angle Measurements Introduction The aim of this experiment is to restrict the circumstantial micelle preoccupation (CMC) of the scrape-active agent through the measurement of the fill tap of moultlets of surfactant resolving of different concentrations. The surfactant utilise in this experiment is Sodium Dodecylsulfate (SDS). Surfactants are usually amphiphilic  innate compounds, consisting both hydrophobic  root words (their tails) and  deliquescent groups (their  laissez passers). When a surfactant is fade out in a polar solvent, such as water, the surfactant molecules exit migrate to the water protrude, where the insoluble hydrophobic group whitethorn extend out of the bulk water physique into the air. When the concentration of the surfactant solution exceeds the critical micelle concentration (CMC) whereby the get up of the solution is full of surfactant molecules, the remaining surfactant molec ules self-assemble into groups called micelle. The hydrophilic head of the surfactant molecules would be at the outer fount of the micelle in contact with water, leaving the hydrophobic tail of the molecules in the upcountry of the micelle as shown in the diagram infra. In lodge to join on surface area of a solution, the determine required is proportionate to the amount of molecules at the surface of the unruffled, pursuit the equation below where dA is the difference in surface area and ? is the surface focus. ?W = ? . dA When a drop of liquid is released on to a solid surface, it rests and forms a lens-shape which is controlled by three forces: the surface stress at the solid/vapour interface ?SV, surface tightness at the solid/liquid interface ?SL, and the surface tension at the liquid/ evaporation interface ?LV. The sum of the forces acting on the contact linage must be cypher at offset harmonise to the Young equation where ? is the equilibrium contact angle amid the solid surface and the sunbu! rn to the surface of the drop. ?SV = ?LV romaine lettuce? + ?SL...If you want to get a full essay, order it on our website: OrderEssay.net

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