SureDenSolutions and their Classification
Solution is that type of colloidal system which has solid as dispersed phase and liquid as dispersion medium e.g. paints, muddy water etc. Sols may be classified as Lyophilic means liquid living. These are those sols may be classified as Lyophilic and Lyophobic sols.
Lyophilic Solutions:- The word Lyophilic means liquid loving. These are those sols which are formed by limply dissolving the dispersed phase into the dispersion medium. e.g. sols of Gum, starch etc.
Lyophobic Solutions:- The word Lyophobic means liquid – hating. These are the sols which are not formed by simply mixing the dispersion medium and dispersed phase, but some special methods are employed for the preparation of these sols. e.g. sols of metals, their sulphides etc.
Difference between Lyophilic and Lyophobic Sols:-
|
Property |
Lyophilic sol |
Lyophobic sol |
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Lyophilic sols are prepared easily by directly mixing the dispersed phase with dispersion medium. |
Lyophobic sols can not be prepared directly. They are prepared by special methods. |
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These are quite stable and are not easily precipitated or coagulated. They are highly hydrated. |
These are easily precipitated by adding suitable electrolytes. |
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They are reversible in nature i.e. once |
They are not much hydrated |
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Precipitated can reform the colloidal solution by simply remixing with dispersion medium |
They are irreversible in nature i.e. once precipitated can not from colloidal sol. By simply addition of the dispersion medium |
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These are usually formed by the organic substances like starch, gum, proteins etc. |
These sols are usually formed by inorganic materials like metals and their sulphides etc. |
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The viscosity is much higher than medium |
The viscosity is almost same as that of medium |
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The surface tension is usually lower than that of the dispersion medium. |
The surface tension is nearly same as that of dispersion medium |
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The particles are neither visible nor detected easily by the ultra microscope. |
The particles are through not visible, can be detected by the ultra microscope. |
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The particles may migrate in either direction or may not migrate at all. |
Their particles migrate in only one particular direction in electric field. |