لخّصلي

Polar solvents are good for the swelling of polar polymers, nonpolar solvents are good for the swelling of nonpolar polymers.According to the Lewis theory of acids and bases, hard acids contain electronegative atoms of a small radius and low polarizability that prone to gain lone electron pairs, while hard bases are also made of electronegative atoms with low polarizability that prone to donate lone pairs of electrons.Overall, acids are acceptors of lone electron pairs (they must have empty orbitals), while bases are donors of lone electron pairs. e arrange cations and anions in the order of the increase of their).Figure Lyotropic series of ions: the intense of the concurrence with proteins for water molecules is decreasing from left to right

The influence of pH in water solution on the swelling degree is represented in figure The swelling degree has the lowest value at the certain pH.At this pH a given protein has no overall charge: the total positive charge existing in some regions of a protein is equal to the total negative charge existing in other regions of the same protein.From the point of view of thermodynamics, the enthalpy of solvatation and the enthalpy of the formation of bonds between different chains of a polymer determine the heat effect of the whole process.Viscosity.2.

Polar solvents are good for the swelling of polar polymers, nonpolar solvents are good for the swelling of nonpolar polymers. Swelling may be limited or unlimited. If the swelling is limited, the volume of a polymer stops its growth after some period of time. If the swelling is unlimited, finally the real solution is formed. From the point of view of thermodynamics, the enthalpy of solvatation and the enthalpy of the formation of bonds between different chains of a polymer determine the heat effect of the whole process. That heat effect together with the entropy of the solvatation determines the Gibbs energy of this process at a given temperature.

It is known that the presence of electrolytes influences the process of swelling (and so the dissolving) of polymers.

The swelling degree of a protein decreases with the increase of hardness of Lewis acids and bases added to the solution.

According to the Lewis theory of acids and bases, hard acids contain electronegative atoms of a small radius and low polarizability that prone to gain lone electron pairs, while hard bases are also made of electronegative atoms with low polarizability that prone to donate lone pairs of electrons. Overall, acids are acceptors of lone electron pairs (they must have empty orbitals), while bases are donors of lone electron pairs. Instead of terms "strong" and "weak" acids and bases, Lewis decided to use terms "hard" and "soft". It was done to highlight that "strong" Arrhenius acid doesn't always mean "hard" Lewis acids.

e arrange cations and anions in the order of the increase of their).Figure Lyotropic series of ions: the intense of the concurrence with proteins for water molecules is decreasing from left to right

The influence of pH in water solution on the swelling degree is represented in figure The swelling degree has the lowest value at the certain pH.At this pH a given protein has no overall charge: the total positive charge existing in some regions of a protein is equal to the total negative charge existing in other regions of the same protein. Because of this, that kind of state is called isoelectric point

The value of pH at which a given protein exists in the isoelectric point is called

pl

The influence of pH in water solution on the swelling degree is represented in figure. The swelling degree has the lowest value at the certain pH. At this pH a given protein has no overall charge: the total positive charge existing in some regions of a protein is equal to the total negative charge existing in other regions of the same protein.

2. Viscosity. Solutions of polymers demonstrate high viscosity. Viscosity is expressed with the help of the coefficient of viscosity (n). It is known that different layers of liquid are moving at different speed in a capillary. The closer this layer to the center of a capillary, the faster it moves. The layer situated at the surface of capillary is not moving at all. This situation is known as laminar flow