Physical chemistry of surface phenomena. Basics of adsorptive therapy

SURFACE PHENOMENA

 are phenomena associated with the existence of interphase boundaries.
SURFACE PHENOMENA

Surface phenomena

Inside the fluid forces are balanced
From the side of

Surface phenomena

The increased surface area of the phase separation is associated

Surface tension σ is the work required for the creation of

Surface tension
Surface tension depends on:
the nature of fluid
σ(Н2О)=72,8 J/m2; σ(serum)=45,4 J/m2).
temperature

SORPTION

Medical & biological importance:

Assimilation of nutrients and drugs
Transfer of

Sorption -change in the concentration of one or more components in

Adsorption

Adsorption is spontaneous change of component concentration in the surface layer

Gibbs Equation

G - the amount of adsorbed substance [mole/m2]
а – equilibrium

Surface activity

The ability of the solute to change surface tension is

Traube-Duclos rule:

When extending the chain-CH2 - in homological series of surface

SAS, SIS, SNS

Surface-active substances (SAS): reduce σ solvent. σ solution <

The isotherm of surface tension

The dependence of σ on the concentration
the

The structure of SAS molecules:

SAS molecule consists of:
non-polar hydrophobic hydrocarbon group

ADSORPTION ON THE SOLUTION-GAS
BORDER

Calculation of the adsorption isotherm G= ƒ(с)

For the calculation of the

Gibbs’ isotherm of adsorption

1. Low С

1

2

G

c

gas

water

2. High С

gas

water

«Langmuir’s palisade»

G

ADSORPTION ON THE SOLID-GAS
BORDER

Adsorption by solids

The adsorption value depends on:
1. The size of the

Freundlich equation

А = x/m = k · p1/n G = x/m

Determination of the constants in the Freundlich equation

lg A = lg

The theory of Langmuir

1) On each absorption place on the surface

The theory of Langmuir

According to this theory localization adsorption can be

Langmuir equation

А = А КС for gases : G = G

Langmuir’s isotherm of adsorption

с

G

Theory of polymolecular adsorption BET (Brunauer, Emmett, Teller)
Many experimental evidence suggests

ADSORPTION ON THE BORDER OF
SOLID – SOLUTION
In the study of

Molecular adsorption

Experimentally determined value of the adsorption of knowing the initial

Molecular adsorption

So, in the adsorption of aliphatic carboxylic acids from aqueous

Conclusion

From the above that is confirmed, that:
For adsorption SAS from

The ion exchange adsorption

The ion exchange adsorption - a process in

Chromatography

Chromatography is dynamic method of analysis based on multiply repeated processes

Chromatography is physical chemical method
used to separate substances

analytical objectives formulations

From the history of chromatography

Mikhail Semenovich Tsvet (1872—1919)

Birthday of chromatography

«No other discovery had such a huge long lasting effect in

The principle of chromatographic separation of substances

The stationary phase

The mobile phase

Molecules

Column chromatography

the stationary phase is in the column;
the technique used in

Identification by GLC

For Identification of compounds in the mixture, its retention

HPLC Agilent Technologies

HPLC Milichrom

HPLC HP

GLC “Agilent Technologies”

Enterosorption

It is method of treatment of various diseases, based on the

Enterosorbents

Polyphepan (lignin)

Activated carbon (sorbex, carbolong, carbolen)

Enterosorbents

Smecta

Silicon organic sorbent Enterosgel

Enterosorption

Enterosorption is part of efferent therapy (from the Latin word efferens

Hemodialysis

Hemodialysis (from hemo-and διάλυσις - decomposition, office) is extrarenal method of

Peritoneal dialysis

Peritoneal dialysis (dialysis Greek expansion, separation) is method of cleansing

Plasmapheresis

Membrane plasma filter contains a chamber for the flow of blood