Budova Koloidnyh particles. Coagulation, mechanism of coagulation. Give the designation of coagulation, coagulation threshold and coagulation capacity of the electrolyte. Significance of coagulation processes for the life of the organism.
Coagulation processes are often found in nature, for example, in places where a river flows into the sea. Near the river water, there are always columnar particles of mule, clay, dog or soil.
When the river water changes with the salty sea (to avenge the greater number of electrolytes), the coagulation of these particles begins, and the change in the fluidity of the water flow causes the sedimentation of the water at the girl’s river, as a result of which I will huddle miles and islands.
Coagulation is widely used to purify the water, which should be near the water supply line. For this, aluminum sulphate and salt (III) are added to it, as, being good coagulants, moreover, they are hydrolyzed with dissolved sols of hydroxides of metals. The particles of these sols have a charge that is opposite to the sign of the charge of the granules present in the water. As a result, mutual coagulation of the sols and their precipitation is observed.
Koloidnі razchini are found near the waste waters of rich varieties: for example, stable emulsions of naphthoproducts, various other organic meadows. Їх ruinuyut with the processing of sewage waters with salts of meadow-earth metals.
The coagulation processes of the succulent industry are vicarious when the juice of the succulent beets is purified. Before the storage of yoga, cream of sucrose and water, non-blooded speech enters, often in a colloid-dispersed state. For їх vidalennya сік add Ca(OH) 2 . Yogo mass fraction at tsiomu sound does not exceed 2.5%. Houses, which are located in the colloid camp, coagulate and settle. To remove excess Ca (OH) 2 juice, pass carbon dioxide through it. As a result, the siege of CaCO 3 is settling down, and it’s like hoarding a lot of different houses for yourself.
The processes of coagulation play an essential role for a living organism, because biological natives to keep in their warehouses colloidal-dispersed particles, which are found in the dotik to rozchinennyh elektrolitiv. At the norm, these systems sound at the station, and the coagulation processes in them run. Ale tsyu rіvnovagu can be easily destroyed with the introduction of a supplementary amount of electricity. Moreover, introducing them into the body, it is necessary to protect both the concentration in the biological environment, and the charge of the ions. So, the isotonic concentration of NaCl cannot be replaced by the isotonic concentration of MgCl 2, the shards in cis salt, on the water of NaCl, the doubly charged Mg 2+ ions can be removed, + .
When introduced into the bloodstream, the bed of the sumish of salts should shift forward, so that the summish does not have a synergistic effect, so as to avoid coagulation for the body.
The solution to many problems in medicine: the prosthesis of blood vessels, the valves of the heart too thin. - To deposit in the process of blood clotting. You can coagulate erythrocytes. Anticoagulants (heparin, dextran modifications, polyglucin) should be administered to the blood at surgery for an hour of surgery. After the operation, and in case of internal bleeding, navpaki, - electrolytes that can be used to take coagulation overshoot: caproic acid, protamine sulfate.
For the diagnosis of ailments in clinical laboratories, the number of erythrocyte counts (SOE) is determined. In case of various pathologies with low causes, coagulation of erythrocytes is possible, and their occurrence becomes greater, against the norm.
The adoption of zhovchnyh, sichovyh and other stones in the body is also due to the effects of coagulation in pathological coagulation states of cholesterol, bilirubin, salts of sichic acid and due to the weakening of natural zahisnoy dії. The cultivation of the mechanism of these processes in Ukraine is important for the cultivation of paths for the healing of these diseases.
Kіnets roboti -
This topic should be divided:
Global chemistry
Established Grodno State Medical University. Department of Global and Bioorganic Chemistry.
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All topics of which I divided:
Thermodynamic parameters
Physical quantities that characterize whether the power of the system are called thermodynamic parameters. The stench can be microscopic and macroscopic.
Internal energy of the system
The most important characteristic of a thermodynamic system is the value of internal energy. Usі thermodynamic systems є sukupnіstyu any
At the most extreme, it is possible to calculate the internal energy of the system as the sum of potential and kinetic energy of all storage particles
However, the definition does not allow, however, to give an unambiguous opinion on nutrition about those who have the energy of a particular system, which is made up of a single number of structural units, for example, molecules. in Persian
Form of exchange of energy with dovkilliam
During the course of thermodynamic processes, internal energy can either increase or change. For the first person, it seems that the system has rotted away a part of the energy from the outer environment, for another
Izobarny and izochorny processes. Enthalpy. Thermal effects of chemical reactions
Establish such processes, during the course of which such processes are left unchanged, only a few parameters of the system are changed, and other processes change. So, the process that proceeds during the post
In isochoric processes, all the heat, brought to the system or seen by it, is attributed to the changing internal energy of the system
U2 - U1 \u003d U, de U1 - internal energy of the cob mill of the system; U2 - internal energy of the final mill syst
Qi minds are also called standard minds
Designated by such a rank, the enthalpies of the adoption of speeches are called standard enthalpies of illumination (DNo298). The stinks are reduced in kJ/mol. Heat or enthalpy pro
Injection of temperature and pressure on the thermal effect of the reaction
Vikoristovuyuchi dovіdkovі data of warmth of light or burning of chemical speeches, it is possible theoretically to develop the thermal effect of the reaction, which proceeds beyond standard minds. Ale yak bi
Vykoristannya Hess's law in biochemical studies
Hess's law is fair as a daily chemical reaction, but also for complex biochemical processes. Thus, the amount of heat gained during complete oxidation to CO2 and H2O
entropy
On the basis of the first cob of thermodynamics, it is impossible to install, in a way that is directly and to the extent possible, that other process, the connection with the transformation of energy. Z guard
The principle of energy efficiency
Mimovilno flow for tsikh minds reactions are called exergonic; reactions that can occur only with a constant infusion of calls are called
Chemichna ryvnovaga
Werewolves and irreversible reactions. Rivnovagi constant
Danium viraz is also called isothermal chemical reaction
2) ∆ ch.r. = - RTln (to improve what is in the minds of the chemical equation ∆Gх.р. = 0). Whose taste is Krivn. de ca,
Until firm differences and gas sums, the understanding of the retailer and the opening of speech does not stop
Rіdkі razchiny, in yak yak rozchinnik vstupaє H2O, are called water. Like a retailer, like another homeland - non-water.
Reconciliation mechanism
Different places occupy the interim position between the mechanical sums of speeches and individual chemical fields, the power of singing power and quiet and other systems, and water
The infusion of nature speeches on rozchinnist
It was established by the last path, which is in the retailer, the molecules of which are polar, the speeches are best differentiated, made with ionic or covalent polar bonds. And in the retailer, the molecules of which
Injecting a vise into the rozchinnist speech
Having poured into the vice the versatility of hard and rare speeches is little signified, because obsyag system at svoїy zminyuєtsya insignificantly. Only in the presence of a high vice of change of rozchinnosti
Influx of electricity on the speech flow
If a retailer avenges houses, then the retailer of speeches changes for someone else. It is especially noteworthy if the role of such a third-party plant is played by an electrolyte, and speeches that are different.
Mutual rozchinnist rіdin
In case of mixing of rіdin fallow due to their nature, the nature of that force of interaction between molecules, 3 types of diversity are possible: 1) diversity is not obscured; 2) fenced
On the different diversity of one and the same speech in the native countries, which do not hesitate, the foundations
For this method, to a more dilute retailer, add another retailer, so you don’t mix with the retailer in the first retailer, but you better expand your speech, as you see it. With whom from the first
Ways of expressing the warehouse of rozchinіv
Warehouse, whether it be a variety, can be expressed as if it were, and if it were. Ring out with a clear assessment of the difference, make it so clear, as if it was an increase, not an increase
Thermodynamic aspects of the process of differentiation. Ideal retail
Vіdpovіdno to another cob of thermodynamics, in the isobaric-іsoteric minds (p, T = const) speeches can mimicously differ in any kind of retailer, as if in the process
Collegative authorities in the dilution of differences
Decide on a number of authorities, which are called otherwise collective (collective). The stench is afflicted with serious reasons and is signified by a concentration of p
Diffusion and osmosis in retail
In the regions, the parts of the rozchinnik and the rozchinennoi speech are evenly distributed throughout the entire volume of the system in the wake of their fretless thermal rush. This process is called
The role of osmosis in biological processes
Osmosis is of great importance in the life of a person, creatures and growing organisms. Apparently, all biological tissues are composed of clitin, the middle of which is homeland (cytoplasm
Rozchini freeze at lower temperatures, lower net rozchinnik
Let's take a look at their report. Boiling is the physical process of the transition of the radian into the gas-like mill or steam, with which bulbs of gas are settled by the entire volume of the radium.
Kolіgativnі vlastostі razchinіv elektrolitіv. Van't Hoff's isotonic coefficient
The laws of van't Hoff and Raul are fair in ideal cases, tobto. such that there are no chemical interactions between the components of the difference, and also there is no dissociation or association of years
Electrolytic dissociation
Electrolytes and non-electrolytes. The theory of electrical dissociation All speech is divided into 2 great groups: electrical and non-electric
The main characteristic of electrolytes
Some elec- trolytes in rozchinas are more likely to fall into ions. The stinks are called strong. Other electricity is less frequently broken down and they are, tobto. great cha
Weak electricity
For weak electrolytes, the stages of dissociation are more than small (α<<1). Так, для воды при 20оС α ≈ 1 ∙ 10–9. Это означает, что только одна молекула из милли
Stronger electricity
Based on the theory of electrical dissociation by S. Arrhenius, the strongest electrolytes are responsible for the breakdown on ions (α = 1). Ale experimentally assigned the value of the dis
Under the activity of ions, they may be affected by that effective (intelligent) concentration, apparently to such a stench they manifest themselves in different ways
The activity of the ion a is equal to the molar concentration multiplied by the activity coefficient γ a = C γ
dissociation of water. Water display
Pure water is bad for conducting an electric stream, but it still fails to increase electrical conductivity, as explained by the partial dissociation of H2O molecules into water ions and hydroxide-ions:
Theory of acids and bases
It’s easy to understand “acid” and that “base” in the process of development of chemical science has changed, becoming one of the main nutrients of chemistry. In 1778 p. French scholar Lavoisier bula
The less important, the stronger is the basis
For an acidic base in a dilute aqueous solution, the equality is valid: Kw = Ka Kw de K
In this way, whether an acid-base buffer system is an equally important sum, which is composed of a donor and a proton acceptor.
In such a system, which avenges a weak acid in its warehouse, it distinguishes between hot, active and potency acidity: 1) hot acidity is strong
Mechanism of buffer systems
The essence of buffered acid sumish weak acid z її sіllyu can be seen on the butt of buffered acetate solution. When added to a new strong acid (for example, HCl), the following reaction occurs:
The value of the buffer capacity to deposit depending on the concentration of the components in the buffer system and the type of their spacing
What kontsentrirovanіsh є buffer rozchin, more yogo buffer єmnіst, tk. in any case, adding small amounts of strong acid, otherwise you can’t cause a real change
Buffer systems of the human body
In human organisms, as a result of the overshoot of various metabolic processes, large quantities of acidic products are gradually absorbed. The average standard of their vision is 20-30 liters
Kinetics of chemical reactions
Concepts about chemical processes are composed of two parts: 1) chemical thermodynamics; 2) chemical kinetics. Yak has already been shown earlier, chemist
The order and molecularity of simple chemical reactions
In the head kinetic equal chemical reaction aA + bB + … → u = k · · · … a, b, … –
Simple reactions can be seen to trimolecular ones, in the elementary act of which three parts collide and change
Fallow in the nature of these particles (so the same stinks are different) kinetically equal such a reaction can be seen three different ways: u = k (there are three different particles absolutely the same
Understanding about folding chemical reactions
The following are similarities, which are both simple mono-, and bimolecular reactions in an independent, pure-looking, also appear infrequently. The greater vipadkiv stench is a warehouse part so
So, in the presence of those same speeches, at once reacting to each other, they make various products
The butt of this type of reaction is the reaction of the deposition of berthollet salt KClO3, which works for singing minds in two straight lines
Chemical methods are grounded on an uninterrupted designated amount of speech or concentration in a reaction vessel
The most common way to see vicory is to see the analysis, like titrimetry and gravimetry. If the reaction proceeds correctly, then to control the staining of reagents
The speed constant is calculated according to the formula
k = (–) її numerical value to deposit depending on the concentration of speeches in some units
Influx of temperature on the speed of the chemical reaction
The frequency of chemical reactions to occur in the form of various factors, the main ones are the concentration and nature of the outgoing speeches, the temperature of the reaction system and the presence of a catalyst
The multiplier A reflects the frequency of effective gaps between the molecules of the outer speeches in their number
It is obvious that the value of the blame should be changed in the interval from 0 to 1. When A = 1, all the faults are effective. At A \u003d 0, the chemical reaction does not proceed, regardless of the zіtknennya mizh mole
General provisions and laws of catalysis
The speed of the chemical reaction can be regulated by catalysts. They are called speeches that change the speed of the reaction, ale, on the vіdmіnu vіd reagents, do not stain
The mechanism of homogeneous and heterogeneous catalysis
The mechanism of homogeneous catalysis should be explained with the aid of the theory of the intermediate stages. According to the theory, the catalyst (K) makes up for the first time in one of the last speeches of the interval.
Features of the catalytic activity of enzymes
Enzymes are called natural catalysts that speed up biochemical reactions in creatures and plants, as well as humans. As a rule, stinks wash squirrels
The second important feature of enzymes as catalysts of non-protein nature is high specificity, that is. vibrkovist dії
Distinguish between substrate and group specificity. In different substrate specificities, enzymes exhibit catalytic activity
Designation of disperse systems
Systems, in which one speech, which is found in a dispersed (finished or fragmented) state, are evenly divided into the same speech, are called dispersed.
The degree of dispersity is the value that shows how the number of particles can be placed on a vdrіzku dozhina in 1 m
Understanding the transverse dimension can be clearly expressed for spherical particles (as well as the diameter of these particles) and for particles that form the shape of a cube (as well as the long edges of a cube). For
In colloid-dispersed systems, particles of the dispersed phase are composed of impersonal atoms, molecules or ions
The number of these structural units in one particle can be col-
For the dispersion of solid bodies vicorist mechanical, ultrasonic, chemical methods, vibration.
These processes are widely zastosovuyt in the people's state: in the production of cement, pomelo grain and other products, refinement of coal in energy, in the preparation of farb, refills, etc. Svitiv
Dispersion of rіdin
For dispersing the rіdin and otrimannya droplets in aerosols and emulsions of vicorous, it is important to use mechanical methods: crushing, shvidka mixing, which is accompanied by cavitational changes.
Gas dispersion
For the extraction of gas bulbs in the countryside, there should be a sprinkling of dispersion options: 1) bubbling - the passage of a gas jet through the countryside
Condensation methods
These methods make it possible to capture dispersed particles with any size, including 10-8 - 10-9 m. Therefore, stinks are widely used in nanotechnologies, chemistry. Separate
Methods of physical condensation
Condensation of vapors of various speeches near the gaseous medium is eliminated by aerosols. In natural minds, fog, gloom are settled by such a rank. Spiral condensation
Methods of chemical condensation
In these methods, a new phase is established during the passage of homogeneous chemical reactions, which leads to the establishment of indistinct speeches in the middle. Can you react
Purification of sols
Otrimani chi in another way columnar differences (especially for the additional method of chemical condensation), it is practical to avenge a small number of low molecular weight pollutants from looking zastosuvannya.
Compensatory dialysis and visualization
For the purification of biological rіdins, which are used by colonic systems, a compensatory dialysis should be established, in which the physiologist will replace the pure retailer.
MOLECULAR-KINETIC POWER OF SOLES
At the cob stage, the development of the coloid chemistry was hardened, as to disperse systems, on the basis of true differences, not so much molecular-kinetic power, like the thermal movement of particles
Brownivsky Rukh
The most important factor that contributes to the molecular kinetic power of the sols is the Brownian movement of the particles of the dispersed phase. It is named after the English botanist Robert Brough.
Diffusion
Under the influx of thermal and Brownian rush, there is a miraculous process of vibrating the concentration of particles over the entire volume of the column. This process is also called diffusion. Dі
Sedimentation in sols
Koloidni particles in the ashes are constantly known under the influx of two oppositely straightening forces: the forces of gravity, for the fluff, it seems to be the step of speech, the forces of diffusion, pіd
Osmotic vice in sols
Koloidnі razchiny, like and right, osmotic vice, wanting to have a lot less size. Why is it explained that at the same and the same concentration of
ultramicroscope
Koloidni particles behind their size are smaller, lower dozhina filled with visible light, and that cannot be matched by a great optical microscope. In 1903 p. Austrian Christians R. Zigmond and G. Z
Let's take a look at the mechanism of the establishment of the DES of the colloidal part by the adsorption path
As an example, we take the sol, omitting the additional method of chemical aggregation as a result of mixing the true differences of two speeches: nitrate and potassium iodide Ag
Electronetic power of the sols
The proof that many particles in sols are composed of two differently charged particles that move one at a time one can be taken, as if they were added to a dispersed
See the persistence of sols
As it was shown earlier, hydrophobic colloid-dispersed systems, in porovnyann with true differences, exude thermodynamic instability and scaling to a mimic change
Theory of coagulation Deryagin-Landau-Verwey-Overbeck
With the coagulation of the sols, there were a lot of theories, for the help of which they tried to explain all the regularities that are guarded by the acidic and the calciferous equalities. So, in 1908 p. G. Freindl
Injection of electrolytes on the stability of the sols. Threshold of coagulation. Schultz-Hardi rule
A factor that leads to coagulation, may be a cold effect, which destroys the aggregate stability of the system. Krіm chіmіni temіni yogo rіlі may have a mechanical inflow
Charguvannya coagulation zones
When you add to the column of electroplating, you can store ions in your warehouse with advanced coagulative building (large organic anions, tri- or chotivalent ions of metals) m
Coagulation of sols with sums of electrolytes
The coagulative effect of the sum of electrolytic substances manifests itself in a different way, in the fallow nature of ions, which indicates coagulation. If electricity is close to their power (for example, NaCl and KCl), then
Speed of coagulation
The process of coagulation is often characterized by the rapidity of coagulation. The speed of coagulation, similar to the speed of chemical reactions, is determined by the change (change) in the number of coagulated particles into one
Koloidny Zakhist
It is not uncommon to expect an increase in the stability of lyophobic sols to a coagulative effect of electrolytes with the addition of active speeches. Such speeches are called zahisnym, and they are stabilizing on
Design of high-molecular spoluks
Krіm so-called lyophobic sols (reportedly reviewed by us more), colloidal chemistry developing and other highly dispersed systems - the distribution of polymers: proteins, polysaccharides, rubbers, etc. Prich
Parts of the dispersed phase in them are not micelles (like in lyophobic sols), but rather macromolecules (for their dimensions, they can be compared with micelles)
At zv'yazku z tsim for razvedenih rozchinіv Naval Forces the term "lyophilic sol" is fundamentally wrong. Ale zі zbіlshennyam kontsії polimer аbo z zіrshennyam rozchinnї zdatnostі
Significant characteristic of high-molecular spoluks
High-molecular structures (HMCs) or polymers are called folds of speech, the molecules of which are composed of a large number of repeating groupings of atoms, which may be the same.
Swelling and rozchinennya Navy
The separation of high molecular weight speeches is a collapsible process that works on the separation of low molecular weight speeches. So, with the difference between the remaining ones, mutually zmishuvannya roslin
Thermodynamic aspects of the swelling process
Thermodynamically mimic swelling and expansion of high-molecular polymers are constantly accompanied by changes in the free Gibbs energy (∆G = ∆H – T∆S< 0).
Vice swelling
Even if the polymer swells up, if there is any way to change the swell of it, then in a new way it is the name of the swollen vice. It's equivalent to a wicked vise
Osmotic vice of IUD designs
As if it were a highly dispersed system, the particles of such shills are up to thermal fluctuations, the IUDs can create an osmotic pressure. It depends on the concentration of the polymer, but in practice it can
Oncotic blood pressure
Osmotic pressure in biological homelands: blood, lymph, internal and intercellular homelands - not only in place of their various low molecular weight speeches, but also nayavnistyu distinguished
Viscosity of different polymers
Due to the viscosity of the differences in high-molecular compounds, they sharply differ in the differences in low-molecular-weight speeches and sols. At the same and the same concentration of viscosity, the viscosity of the polymers is significantly
Vіlna that zv'yazana water in roses
In polymers, as a part of the retailer, it appears mitically bound to macromolecules after the solvation processes occur, and at the same time, they take the fate of Brownian Rus. Insha
Polyelectrolyte
A lot of natural and synthetic polymers can be found in the warehouse of elementary lanes of their macromolecules of various onogenic functional groups, building dissociation in water sources.
Officials who add to the stability of polymer development. Vysolennya
The right varieties of polymers, as well as the varieties of low molecular masses, are aggregatively stable and, on the basis of sols, can last a long time without the addition of stabilizers. Porush
Designing electrolytics as conductors of a different kind. electrical conductivity of electrical supplies
Fallow in the building conduct an electric stream, all speeches are divided into 3 main types: conductors, conductors and dielectrics. Speech of the first type can be about
Equivalent electrical conductivity of different
Equivalent electrical conductivity is used for electrical conductivity of electrical conductivity with a thickness of 1 m, which is between the same electrodes with such an area, so that the volume is equal to
This jealousy is called the law of independent circulation or the law of Kohlrausch
The values of λk and λа are also called the rupture of cations and anions. Stink, apparently, dovnyuyut λк = F Ψ
Practically zastosuvannya electrical conductivity
Knowing the equivalent electrical conductivity of the difference, it is possible to unravel the step (a) and the dissociation constant (K) of the difference in the new weak electrolyte: de λV -
metal electrode
When the metal plate is lowered near the water, a negative electric charge is released on the surface. The mechanism of yoga appeared the axis of chomu. At the knots of crystal graters, metals are found
The reduction of electrode potentials
The absolute value of the electrode potential cannot be directly determined. It is possible to reduce the difference of potentials, which is the fault between two electrodes, which makes a closed electric circuit.
Oxide-watering electrodes
Іsnuyut razchiny, scho to keep two words in one's warehouse, in some atoms of the same element, they change at a different degree of oxidation. Such differences are called otherwise oxidize
Diffusion and membrane potential
Diffusion potentials vindicate between the two differences. Moreover, they can be like a variety of different speeches, so it is possible to distinguish one and the same speeches, only in
The middle of ion-selective electrodes is widened by the widening of the glass electrode, which can be used for the determination of pH values
The central part of the glass electrode (Fig. 91) is a bag, prepared from a special streak-guided hydrated glass. Vіn zapovneniya water HCl іz vіdomoyu concentration
The chemical core of an electric struma, or the galvanic elements transform the energy, which is seen when the oxidation-oxidation reactions are overrun, into an electric energy
Potentiometry
Potentiometry is the name of a group of methods of calciferous analysis, based on the most recent occurrence of an equally important potential of the electrode, omitted in the range, type of activity (concentration
Distinguish between direct and indirect potentiometry or potentiometric titration
Direct potentiometry (ionometry) is a ce-potentiometric method, for which an indicator electrode has an ion-selective electrode. Ionometriya - easy, simple, express
Coagulation is a complex of chemical and physical infusions between negatively charged colloidal particles and cations, tobto. positively charged chemical reagents. There is a victorious difference in strength and weight, which will ensure the stability or, at the same time, the stability of the colloidal suspension, and itself:
Forces of electrostatic winding;
Brownivsky Rukh;
Van der Waals gravity forces;
The power of all-world gravity.
Coagulation destabilizes the column suspension for the help of two different mechanisms: charge neutralization and chemical bonding.
Charge neutralization
Positively charged coagulants neutralize the negative charge, which leaves the columns. If the charge is close to the skin part of the neutralizations, the stinks step by step approach, changing their effective radius, becoming, zreshtoy, unstable and can stick together one by one. When zіtknennі chastki z'єdnuyutsya one z one for rahunok vodnevyh zv'yazkіv or, for example, the forces of van der Waals, utvoryuyuchi great masi, or plastіvtsі.
The energy of mixing, which stagnates in the purification process, increases the frequency of these particles, increasing the agglomeration of solid speech and adhering to the plastics.
Chemical bonding
Utvennyu plastіvtsіv priyaє polimerny nature of coagulants. Long-term molecular lances spit agglomerated particles, fill spots on the same surface to the outside, ringing together around the large plastic masses, which are easy to see.
There are two mechanisms that take part in the process of coagulation, charge neutralization play a significantly important role, lower chemical connection.
Adsorption of the polymer on particles of the solid phase should not be carried out before flocculation. Necessary mental rest is the adsorption of one macromolecule or associate of macromolecules on decal particles and plastic particles that are composed of particles bound by polymeric places.
Based on these findings, the theory of flocculation of neutral particles was developed by La Mer. Zgіdno z La Merome, during flocculation on the cob, primary adsorption occurs and the skin macromolecule attaches itself in segments up to one column. Adsorbed molecules occupy a part of the surface of the particles (more precisely, active centers, on which adsorption is possible), and the surface grid (1 - θ) is filled with villous. Then, in the process of secondary adsorption, free segments of adsorbed molecules are fixed on the surface of other particles, binding them with polymeric sites.
Assessing the possibility of adsorption of already fixed macromolecules on the free surface of other particles, it is necessary to protect the following factors: 1) spacing of the area of the free surface of the particles and the surface occupied by macromolecules; 2) competition of macromolecules, which are located in different segments of macromolecules, which are already adsorbed on the same parts; 3) steric folds, which move along the path of particles with adsorbed macromolecules to the free surface of other particles.
Theoretically, the flocculation of La Mera should be taken to respect only sp_v_dnoshnennia free and occupied by macromolecules on the surface of the particles.
The speed of flocculation is deposited in the number of important particles, in the presence, on the vine, the particles will approach in order to allow adsorption, the spheres of attraction forces and the flexibility of the movement of particles, as signifying the immovability of such a closeness.
Approximation of particles to the air, sufficient for the manifestation of attraction forces, can be observed in the wake of the Brownian movement, the movement of particles with micro-volutes, which settles with mechanical mixing (microturbulence in the flow of water), unequal swidness ruhu of particles during sedimentation or filtration, as well as wrapping that ruhu vilnyh.
In the development of La Mer's manifestation of the improvement of the electric charge of the columnar particles and macroions and the nature of adsorption forces, by analogy with coagulation, the degree of flocculation can be expressed equally
u f = dn / dt = – Up to f R f φ f θ(1 - θ) n 2 ,
de K f - Coefficient that characterizes the mind of the particles;
R f - the sphere of attraction forces - stand between the centers of the particles, at which flocculation occurs, R f \u003d 0.5 (d 1 + d 2)? (Figure II.6, a);
φ f - coefficient, which is the total influence of van der Waals and Coulomb forces between particles and macromolecules;
θ(1 - θ) - a factor that indicates the possibility that the surface of one particle is free to be displaced by macromolecules adsorbed on the surface of the other part;
n is the largest concentration of suspended particles.
The flocculation of particles, the expansion of which is great, is seen under the influx, which is blamed on the sweat, which collapses and moves with a different swirl of micro-obstruction in the middle.
Two possible mechanisms of coagulation and flocculation of particles in sweat that collapse are described. One of them flows in the minds of turbulence, in the flow, de є a wide range of turbulent pulsations.
The value of the change in the structure of plastics, their value and thickness, which depends on the hour of mixing. Tsya zmina vіdbuvaєtsya from the onset of causes:
a) through more equal distribution of the polymer, which after dosing is carried over in excess in okremi masses of the suspension, and adsorption of skin molecules on the daedal and a greater number of solid particles; due to the increase in the intensity of the mixing, the polymer was remixed;
b) after the adsorption of large segments of macromolecules on the same solid particles and the short life of polymeric sites;
c) through the collapsing of aggregates with shortened places on the other and their interrelationships between themselves, further adsorption of macromolecules on the free surface of the broken aggregates.
Ruining of aggregates is important in the periods of clotting of cololic particles between themselves, shards of Van der Waals force, which act between particles, smaller mites, lower forces, which induce the adsorption of macromolecules to the polymer.
The presence of the optimal doses of the polymer during flocculation can be established by different methods: by changing the calamity of the columnar size or suspension after adding the flocculant (changing the calamity in coarse dispersions), suspension transparency after sedimentation flocculated through a porous partition with a sealed ball of cake (maximum fluidity the adoption of the largest plastics), for the fineness of the filtrate and for an hour of filtering entanglement from the granular material.
The limitless input to the flocculation process is due to the expansion of macromolecules (molecular weight of the polymer): the greater the expansion of macromolecules, the greater the number of segments in the adsorbed macromolecules, the greater the number of segments in the adsorbed macromolecules, the greater the number of segments in adsorbed macromolecules, the greater the number of adsorbed macromolecules before adsorption on other parts. A large macromolecule can bind more solid particles, thus making more plastics.
At the same time, in the world of growing expansion of macromolecules, steric manifestations begin to appear and it becomes difficult for particles to adsorb adsorbed macromolecules to the surface of other particles.
Spіlna diya both factors lead to the fact that the most effective flocculation and the maximum expansion of plastics due to posterigatisya with a single expansion of macromolecules, more precisely - a singing expansion between the expansion of columnar particles and macromolecules of a polymer.
Wash the stosuvannya flocculants for water purificationOn the basis of all the consistency of the revealed regularities, it is necessary to indicate that polyacrylamide flocculants without and in combination with mineral coagulants can successfully vicorate for the purification of natural and waste waters in terms of importance and colo їdno-dispersed speeches. Optimization of the process of water purification is not an exact algorithm and should be deposited with various factors. The characteristics of the flocculant (nature, chemical warehouse, molecular weight, conformation of macromolecules and concentration of the flocculant) and coagulant (nature and concentration), technological factors (method and moment of dosing of the flocculant and coagulant, efficiency of mixing, trivality) zmіshuvannya that іn). so is the quality of the liquid water (chemical and dispersive warehouse, pH value and temperature). Undoubtedly, with the improvement of these factors, it is possible to intensify the purification and decontamination of natural tasting waters, as well as to improve the process of ceramic water purification with the method of removing purified water to the norms of drinking water I could take it easy.
Change of steel system
Koloidnі system mayut vysokorozvinenu surface division and, hence, the great superfluous free surface energy. Therefore, these systems are thermodynamically unstable. As if by virtue of the minds the ash myceliums come near the tightness between themselves, the stinks come from the great aggregates.
coagulation- the whole process of scaling the koloid particles in the sols, which are blown under the swell of the splendid swells.
Sedimentation- The process of sedimentation of enlarged particles of the solid phase and the sol.
The process of coagulation of the coatings from the change in the degree of dispersity and aggregation of the aggregative instability of the colonic systems.
There are 2 stages in coagulation:
1) prihovanu coagulation - if neonatal gas is still not possible to watch for the presence of a new change in the ash.
2) obvious coagulation, if the process of aggregation of particles of the dispersed phase can be easily visualized.
Coagulation can be caused by changes in temperature, trivial dialysis, supplementation of electricity, various kinds of mechanical infusions (mixing, strushuvannya, zbovtuvannya), strong cold, ultracentrifugation, concentration, electric struming , die on the sol with another sol.
Shards of the head mental change in the stability of the columns are the loss of an electric charge, the main methods of their coagulation are the methods of removing charges.
Coagulation of hydrophobic sols with electrolytes
In order to develop the coagulation process, it is necessary to have a minimum concentration of electrolyte in the ash.
Coagulation threshold- Lowest concentration mmol/l of electrolyte, which leads to coagulation (turbidity, change of contamination).
Schulze-Hardi rule- They are coagulators with a high charge, they cause coagulation at lower concentrations, they are lower charge.
The Schulze-Hard rule may have a similar character, because Coagulyucha diya elektrolitu deposit not only in the charge of iogo ions. Active organic singly charged ions may be more strongly adsorbed.
For the magnitude of the coagulative property, the ions of puddle metals can be placed in a series of ions of these metals - lyotropic rows.
Cs + >Rb + >NH 4 + >K + >Na + >Li +
Coagulation of hydrophobic sols can be called for with the help of a sum of electrolytes. Whenever possible, 3 falls:
1) Coagulative effect of the mixing of electrolytes is suspected.
2) Coagulation of the amount of electrolytic substances is less, lower in different pure electrolytic substances. Tse apparition ring antagonism ioniv. It is tamanly sumishey ioniv, mum rіznu valency.
3) In a number of moods, there is a mutually stronger coagulation of the ions that are shy. This phenomenon is called synergy ioniv.
Coagulation of hydrophobic kololidіv can but viklikana zmіshuvannyam sevny kіlkіsnyh spіvіdnoshnyah z іnshim hydrophobic sol, granules of which may be a sign. This manifestation is called mutual coagulation. Mutual coagulation occurs when there is a change in sea and river water. At the same time, the ions of salts of sea water are adsorbed on the charged particles of river water, after which coagulation occurs. For reasons of reason, a large number of mules are steadily accumulating on the days, a lot of millions and islands are being settled.
At the same time: ink was used with kolod rozchinas of different barnniks. Moreover, in different ink columns, the particles are charged in different ways. The axis of why, when changing different inks, may be mutually coagulated.
Mechanism of electrolytic coagulation
The granule becomes electrically neutral in that case, like the opposites of the diffuse ball, negatively charged, move into the adsorption ball. The higher the concentration of electrolyte, the more the diffuse ball decreases, the less the potential becomes, the more the coagulation process begins. For the first concentration of electrolyte, practically all the protons pass into the adsorbing sphere, the charge of the granule decreases to zero and coagulation occurs with maximum fluidity.
The coagulative effect of electrolytes is formed to squeezing the diffuse ball and the vibratory adsorption on the column particles of quiet ions of electrolytes, thus forming the proliferating charge of the granule. The greater the charge of the ion, the more intensively the wines are adsorbed. The accumulation of ions in the adsorbed sphere is accompanied by a change in the potential of the diffuse sphere.
Visnovok: coagulative effect of electrolytic fields in the change of forces between the columnar particles through the reduction of the potential and the change of the electric ball and the embossment of the diffuse part, the addition of the electr role - a coagulant, pulling behind it the lowering of the rozklinuvalnaya dії hydrated membranes.
When adding to the ashes of electrolytic ions with richly charged ions, the charge of some of the charge behind the sign of the charge of the columnar particles, may not coagulate, but stabilize the sol and change the potential. This phenomenon is called rechargejennya zoliv.
One of the most widely used methods in practice is to reduce the amount of suspension in water and sedimentation under gravity forces. However, the houses, which dazzle with the calamity and color of natural waters, are permeated with small rosemaries, in the wake of which the sedimentation seems to be right on the edge, the shards of the diffusion force prevail over the forces of gravity. On the other side, the presence of houses of a colloid character is even more complicating the process of sedimentation. To speed up the processes of settling, filtering, flotation and improving their efficiency, water houses are coagulated.
Coagulation of small houses is called the process of enlargement of large and important particles of the dispersed system, which is due to their interaction and association in the aggregate. Coagulation is a complex of chemical and physical interactions between negatively charged columnar particles and cations, tobto. positively charged chemical reagents. Vaughn vikoristovuє raznі vіdshtovhuvannya that tyazhіnnya, yakі zabezpechayut stіykіst аbo, navpaki, not stіykіstі koloїdnoїsuspensії, and itself:
Forces of electrostatic winding;
Brownivsky Rukh;
Van der Waals gravity forces;
The power of all-world gravity.
Coagulation destabilizes the column suspension for the help of two different mechanisms:
- charge neutralization
The energy of mixing, which stagnates in the purification process, increases the frequency of these particles, increasing the agglomeration of solid speech and the adhesion of plastics.
- chemical bonding
There are two mechanisms that take part in the process of coagulation, charge neutralization play a significantly important role, lower chemical connection. The cycle of the process of aggregation of particles, which have stuck, in a rare phase, is being completed.
The word "coagulation" is similar to the Latin "coagulare", which means "to take together." Coagulation plays an important role in the processes of water purification for removing the callous particles, which can give drinking water an unacceptable relish, color, smell or calamity. Tse shy way to add to the crude water of special chemical reagents (coagulants). Under the influence of coagulants, even small, supralingually dispersed colloidal particles are united at once in a large mass (plastic), so that it is possible to see by such methods under the solid and rare phases, as sedimentation, flotation and filtration.
The main officials, yakі vplyvayut process coagulation domіshok water obsyagom (convective coagulation), є: temperature and luzhnіst water; concentration of water ions and anion water storage; the correct choice of the dose of coagulant, the consistency of its fluctuation and the uniformity of the dose under the water; instead of water, natural suspensions; wash the process of plasticity (orthokinetic phase of the coagulation process).
The correct choice of coagulant dose may be of primary importance for coagulation of water houses. Under the dose of the coagulant, it is necessary to take into account the mass amount of the reagent, so that it is added to one volume of water, which is processed. The dose of the coagulant is controlled by mg / l, g / m 3.
On the face of it, the injection of a dose of coagulant into the process of clarification and the snebaring of the water gives a coagulation curve. Її can be divided into three zones. In zone I, at low doses of the coagulant, the effect of clarification and lightening of the water in the presence or filtration is insignificant. In zone II, an increase in the dose of coagulant is sharply indicated for the effect of clarification and the effect of water pollution. The cordon between zones I and II is called the threshold of coagulation. In zone III, an increase in the dose of coagulant does not give a noticeable improvement in the effect of clarification and water reduction. The curve is practically parallel to the abscissa axis. The cordon between zones II and III bears the name of the optimal dose.
When coagulating the house, water the necessary liquid and equal distribution of reagents in the її obsyaz for ensuring maximum contact of the particles of the house with the intermediate products to the hydrolysis of the coagulant (as a result of a short interval for an hour), chips of the hydrolysis process, polymerization ії and adsorption proceed for 1 second.
For an even and fluid mixing of reagents with water, they should be introduced at the zones of the greatest turbulence in the flow at some points along the way. In order to mix the reagent with water, it is necessary to transfer the reagent underlays (I will add the introduction of the reagents), which will ensure that they are swept evenly in the channels or the pipelines that supply, and the mixture, deviate away from the intensive mixing of the introduced reagents with broken water. Reagent underlays are recommended to be used with perforated tubular systems or inserts for pipelines that are mechanical supports. The loss of pressure in the pipeline when the designation of the outbuildings is installed is usually 0.1 ... 0.2 and 0.2 ... 0.3 m.
Perikinetic (molecular-kinetic) coagulation stops, if the particles reach a size of 1 ... 10 microns, it is practically possible to avoid the coagulant in the treated water with a period of dry distribution of the coagulant. It is not effective to mix up the coagulant and the small amount of agglomeration of water houses at the same dose of the reagent. Then, it is necessary to create an optimal mode of robotic mixing, when the coagulant enters into the dot with the maximum number of particles of the house, before the reaction of hydrolysis and polymerization ends.
Stagnation of polymeric flocculants after destabilization of the suspension of the colonic coagulants allows to increase the efficiency of the purification process. Plants of their own great molecular mass of polymeric flocculants superbly effectively dissolve the spaces between microlayers, which vinicles during coagulation, creating more macro-splashes. Following the coagulation of even small amounts of flocculants (0.01 - 0.5 mg / l), maximizing the capture of particles, speeding up the establishment of plastics and making plastics more thin and dry. Vykoristannya flocculants for the purpose of meti allows the intervening dosing of coagulants to the minimum quantity necessary for the destabilization of the columnar suspension, shards for which the superfluous quantity of coa is not required a goulant for making suspension, building a siege.
The result of the process of coagulation is the removal of sludge, like an indistinct sedimentation of flotation sludge.
Rules for coagulation with electrolytes. Threshold of coagulation. Schulze Hardy's rule. See coagulation: concentration and neutralization. Coagulation with sums of electrolytes. Yavische "wrong rows". Mechanism and kinetics of coagulation
Coagulation is the process of sticking particles out of the creations of great aggregates. As a result of coagulation, the system loses its sedimentation stability, so that the particles become too large and cannot take the fate of Brownian Rus.
Coagulation is a fleeting process, it will not lead to a change in the interfacial surface and, therefore, a change in the free surface energy.
There are two stages of coagulation.
Stage 1 - coagulation is attached. At this stage, they often grow larger, but still do not use up their sedimentary stability.
Stage 2 - obvious coagulation. At this stage, they often use up their sedimentary stability. As the thickness of the particles is greater than the thickness of the dispersion medium, a siege is established.
Causes of coagulation are different. Chi іsnuє sovnishnіy infusion, which at sufficient intensity does not mean bicoagulation.
Coagulation rules:
1. Use strong electricity, add to the sol at a sufficient amount, call for yogo coagulation.
The minimum concentration of electrolyte, if coagulation starts, is called the coagulation threshold C k .
Another change in the threshold of coagulation is the value of VK, as it is called coagulative building. Tse obsyag sol, which coagulates under the action of 1 mole of electrolyte:
tobto. the lower the coagulation threshold, the more the coagulating building fit into the electrolyte.
2. Not all electrolyte can coagulate, but only that ion, the charge of which follows the sign of the protion charge of the mycelium of the lyophobic sol. Zei ion is called coagulant ion.
3. The coagulation capacity of the ion-coagulant is greater, the greater the charge of the ion.
Kіlkіsno tsya regularity is described by the empirical rule of Schulze - Gardi:
or .
where a is a constant value for this system;
Z is the charge of the ion to the coagulant;
Threshold of coagulation of single-charged, double-charged, triple-charged ion-coagulant.
The rule is established, that the coagulative forces of the ion are greater, that the yogic valence is greater. It has been experimentally established that they with the highest valence may have lower coagulation threshold values, lower ones with lower ones. Also, for coagulation, it is better to take ions with a higher degree of oxidation. Although the valency of ions is the same, the coagulative building is to be deposited in the same degree of hydration of ions. The greater the radius of the ion, the greater the coagulation. Following this rule, lyotropic rows are folded. Organic ions-coagulants, sound, coagulate hydrosols more quickly, lower inorganic ones, tk. stinks are easily polarized and adsorbed. From the look of a suspended electric ball (DES) it is important that coagulation is possible at times, if the z-potential is > 30 mV.
The coagulation property of the ion with the same charge is greater, the greater the yogic crystal radius. The reason is from one side, in the great polarization of ions with the largest radius, then, in their building, they are attracted to the surface, which is formed from ions and polar molecules. On the other side, the greater the radius of the ion, then less, for one and the same size of the charge, the hydration of the ion. Hydrate shell changes the electrical interaction. The coagulation property of organic ions is greater than that of inorganic ions.
For singly charged inorganic cations, the coagulative property changes in the following order:
Lyotropic series.
With an increase in the concentration of the ion-coagulant z, the potential of the sol mycelium changes after the absolute value. Coagulation can start even if the z-potential drops to 0.025 - 0.040 (and not to zero).
When coagulating the sol with electrolytes, concentration and neutralization coagulation are distinguished.
Concentration coagulation may occur, if there is a change in the influence of an indifferent electrolyte due to the compression of the diffuse ball of protions and the change in the absolute value of the z-potential.
Let's take a look at the concentration coagulation of the sol of sribl chloride, stabilized by sebyl nitrate, when potassium nitrate is introduced into the force.
Mycelium formula may look like:
On fig. 3.1.2.1 indications of the schedule for changing the potential in DES mycelium chloride. Curve 1 is brought up to the exit mycele, curve 2 - after the addition of KNO 3 to the quantity, which indicates coagulation. With the addition of KNO 3, the diffuse ball of protions is squeezed, the formula of the mycelium looks like:
On fig. 3.1.2.2 Presentation of potency curves that characterize the interaction of particles in this ash. The z-potential of the outer colloidal particle is positive, creating a potential barrier of coagulation ∆U = 0 (curve 2 in Fig. 3.1.2.2). That is why nothing matters to the small particles to get close to such a place, to overcome the forces of gravity - coagulation occurs. Scattered in this way, the cause of coagulation is an increase in the concentration of protions, it is called concentration coagulation.
For which way the theory gives the formula
de g – coagulation threshold;
Z - constant, slightly deposited in the asymmetry of electrolyte, tobto. changing the number of charges for a cation and anion;
A is a constant;
e is the electron charge;
e - dielectric penetration;
Z is the charge of the coagulating ion;
T is temperature.
It is clear that the value of coagulation thresholds for one-, two-, three-, two-charged ions due to spivvіdnostis 1 to (1/2) 6 to (1/3) 6 to (1/4) 6 etc. ., tobto. be grounded earlier on the empirical rule of Schulze - Hardy.
Neutralization coagulation occurs when a non-indifferent electrolyte is added to the sol. At the same potential, they are connected in a small-scale way, which leads to a change in the absolute values of the thermodynamic potential, and also, to the z-potential right up to zero.
If you take the sol to chloride chloride as if you were taking it out, then in order to neutralize the potential-determining Ag + ions, it is necessary to introduce, for example, potassium chloride into the sol. After the addition of the singing quantity of the non-indifferent electrolyte mycel matima looked:
There will be no ions in the system, which will adsorb on the surface of the AgCl particles, and the surface will become electrically neutral. When such particles are closed, coagulation occurs.
Oskilki cause coagulation in times of neutralization of potential-determining ions, such coagulation is called neutralization coagulation.
It is necessary to note that for a complete neutralization of coagulation, a non-indifferent electrolyte is to be blamed for additions to a strictly equivalent quantity.
When coagulating a sum of electrolytics, two types of processes are distinguished:
homocoagulation
heterocoagulation
Homocoagulation - enlargement of similar particles in a larger unit of the siege. Moreover, in the process of growing, the small parts are different, and the great ones are bigger for their rahunok. On whom is founded the manifestation of activation and recrystallization. This process is described by Kelvin-Thomson:
,
de C ? - Razchinnist macro-parts;
C - variability of microparticles;
V m – molar volume;
R - universal constant gas;
T is temperature;
r is the particle radius.
From equal to high, scho concentration is about a small radius greater, so diffusion goes from a greater concentration to a lesser one.
In another type, there are aggravation of various particles, or the adhesion of particles of a dispersed system on foreign bodies, or on surfaces that are introduced into the system.
Heterocoagulation - mutual coagulation of various dispersed systems.
The coagulation of a sum of electrolytic substances can be of great practical importance, so as to add one electrocoagulant to the sol, in fact, coagulation is taken under the injection of two electrolytic ones, so that in the system there is an electric t-stabilizer. In addition, the technology for coagulation often has a sum of two electrolytes. Understanding the patterns of mutual interaction of electrolytes is also important in case of continued influx of biologically active ions on the organs and tissues of a living organism.
When coagulating the sol, two more and more electrolytes can lead to three falls (Fig. 3.1.2.3). On the abscissa axis, the concentration of the first electrolyte C 1 is shown, and C k1 is the first coagulation threshold. Similarly, along the y-axis, the concentration of another electrolyte C 2 is added, and C k2 is the second coagulation threshold.
1. Additive electric current (line 1 in Fig. 3.1.2.3). Electrolytes develop independently one type of one, their total effect is formed from the influx of skin electrolytes. Although z 1 '-concentration of the first electrolyte, then for the coagulation of the sol, the concentration of the other electrolyte is due to but equal to 2 '. Additivity is observed when there is a similarity of coagulative properties of both electrolytes.
2. Synergism diy (line 2 Fig. 3.1.2.3). Electrolytes are like bi spriyat one to one - for coagulation they need less, lower is needed for the rule of additivity (from 2″< c 2 ′). Условия, при которых наблюдается синергизм, сформулировать трудно.
3. Antagonism of diy (line 3 of Fig. 3.1.2.3). Electrolytes like bi oppose one to one and for coagulation of their next, add more, lower required for the rule of additivity. Antagonism is feared at a great difference in the coagulative division of electrolytes.
Іsnuє k_lka theories, how to explain the phenomenon of antagonism. For one reason, there may be a chemical interaction between ions.
For example, for the AgCl sol, stabilized with potassium chloride, coagulant to form cations. For example, a great coagulant building can be a thorium-charged ion Th 4+. However, if you take Th(NO 3) 4 and K 2 SO 4 sums for coagulation, then the coagulative density of Th (NO 3) 4 is significantly less than that of the taken Th (NO 3) 4 . It is due to the fact that as a result of the chemical reaction the complex is established:
and instead of chotyrically charged ions Th 4+, the ash will contain singly charged cations K + , coagulating which are significantly weaker (the Schulze-Hard rule).
Heteroadagulation - adhesion of particles of the dispersed phase to a foreign surface, which is introduced into the system.
One of the reasons for this is the adsorption of the stabilizer on this surface. For example: the placement of cobbled particles on the fibers during fermentation and crushing.
For hydrophobic sols, as an IUD, sound vicorous proteins, carbohydrates, pectin; for non-aqueous sols - rubbers.
With the introduction of electrolytes into the column, which avenge the high-valent ions with the opposite charge of the particles, the appearance of "wrong rows" is guarded. Vono believes in the fact that when adding up to okremih portions of the sol, the daedal and the increasing amount of electrolyte sol are filled with stable, then coagulation occurs at the singing concentration interval; let the sol become stable again and, nareshti, at the time of the increase in the concentration of electrolyte, the coagulation is already residual. Similar phenomena can call forth great organic ions. It is explained by the fact that with small quantities of ions introduced to the electrolyte, it is not enough to coagulate the sol, so that the value of the x-potential is overwhelmed by the minimum (Fig. 3.1.2.4). With large quantities of electrolyte yoga, they can coagulate. This interval of concentration varies according to the x potential of the particles from the x critical first sign to the x critical second sign.
At even higher concentrations of rich valent ions, they recharge the colloidal particle and the sol is again stable. In this zone, the x-potential is again higher than the critical value, but the turns are beyond the sign of the particles of the free sol. Nareshti, with a high capacity of the output electrolyte of a rich valent iodine, they again reduce the value of the x-potential to a lower value beyond the critical one and the residual coagulation is again restored.
The advancement of the aggregative stability of the sol by way of introduction into the new high-molecular structure (IUD) is called the kolodny zahist. It is necessary to make a solution of smelting on the surface of the ash (hydrate or Navy), so that the interaction between the particles of the electrolyte is changed.
As a kіlkіsnu characteristic of coagulation Zіgmondі zaproponuvav vykoristovuvat shvidkіstі coagulation.
The speed of coagulation is the cost of changing the concentration of columnar particles in one hour with a constant obsession of the system.
de n is the concentration of particles;
The sign "-" is indicative of the fact that the concentration of particles changes over time, and the speed is always positive.
Coagulation steps a:
de Z - the total number of particles in one hour; Z ef - the number of effective zіtknen (tobto zіtknen, scho lead to coagulation) in one hour.
Even though a = 0, there is no coagulation, the colony is aggregatively stable.
If a = 1, then coagulation is expected, so. skin zіtknennya particles lead to їх zlipannya.
Yakscho 0< a < 1, наблюдается медленная коагуляция, т.е. только некоторые столкновения частиц приводят к их слипанию.
In order for the particles to stick together, and not to scatter like springy clumps, the potential barrier of coagulation ΔU k is to blame. єyu, sufficient for the hem of this bar'єru. To improve the level of coagulation, it is necessary to reduce the potential barrier. It is possible to reach the addition of an electrolyte sol - a coagulant.
Fig. 1 shows the density of coagulation fluidity in terms of electrolyte concentration. 3.1.2.5.
The graph shows three plots:
I. 
.
Also, kinetic energy kT<< ΔU к, (k – постоянная Больцмана) – лиофобный золь агрегативно устойчив.
ІІ. 
, then. the potential barrier of coagulation is greater, but it can be equalized with the kinetic energy of the column particles, moreover, with an increase in the concentration of electrolyte - the coagulant of the veins changes, and the speed of coagulation increases . 3 km - threshold of total coagulation, 3 kb - threshold of normal coagulation. Tsya plot of crooked bending fallow:
There is a lot of coagulation on this dilyance.
Skin zіtknennya to cause particles to stick - go shvidka coagulation.
The theory of swedish coagulation, developed by M. Smolukhovsky in 1916, is based on advancing positions.
1. The system is monodisperse, the particle radius is r.
2., tobto. mustache is effective.
3. Less than the first particles are seen.
4. The kinetics of coagulation is similar to the kinetics of a bimolecular reaction:
,
de k - Coagulation density constant.
Integrate the cost, dividing the changes:
,
de u 0 - Concentration of particles of the sol at the cob hour;
u t - The concentration of particles in the sol at the time t.
To characterize the swedish coagulation, the period of coagulation (period of half coagulation) q.
The period of coagulation (q) is an hour, after which the concentration of large particles changes twice.
Depending on the theory of swedish coagulation, the coagulation constant lies in the diffusion coefficient and can be charged for equal
To put the value of the diffusion coefficient on the target, we take:
In this way, knowing the viscosity of the dispersion medium and the temperature, one can calculate the constant of the density of the dispersion coagulation. Smolukhovsky's theory was repeatedly verified experimentally, and it took away the brilliance of confirmation, without respect for the author's admission.
Povіlna coagulation due to inconsistent efficiency due to the foundation of the energy barrier. The simple introduction of the magnitude of the coagulation step and the formula of Smoluchowsky's theory did not lead to a valid theory. N. Fuchs elaborated the theory of total coagulation more thoroughly. Він ввів at the kinetic equal coagulation multiplier, which is the healthy energy bar of coagulation ΔU up to:
,
de k KM - The constant of fluidity of total coagulation;
k CB - constant of fluidity of fluid coagulation;
P - steric chinnik;
ΔU to - potential barrier of coagulation;
k - Postiyna Boltzmann.
In this way, for rozrahunku constant coagulation rate it is necessary to know the potential coagulation bar, the value of which lies ahead of the z-potential.
The stability factor, or the increase factor W, shows how many times the consistency constant of normal coagulation is less than the consistency constant of normal coagulation.
,
Next, designate five officials of stability, the middle two of the first ones play the main role.
1. Electrostatic resistance factor.
Vіn obumovleniya nayavnіstyu DES and x-potential on the surface of the particles of the dispersed phase.
2. Adsorption - solvation stability factor.
Vіn obumovleniya to reduce the surface tension due to the interaction of the dispersed medium with a frequent dispersed phase. This factor plays a significant role, if columns of PAR are vicarious as a stabilizer.
3. Structural - mechanical chinnik of durability.
It is due to the fact that on the surface of the particles of the dispersed phase, smelting is established, which will lead to springiness and mechanical strength, which will require an hour and energy to ruminate. This stability factor is realized in quiet depressions, if high molecular weights (IUDs) are vicarious as stabilisers.
4. Entropy factor of stability.
Coagulation lead to a change in the number of particles in the system, also, to a change in entropy (ΔS<0), а это приводит к увеличению свободной энергии системы ΔG>0. For this reason, the system is mimicry pragne partly one in one, and evenly (chaotically) rozpodiliti behind the obsyag of the system. Tsim obumovleniy entropy factor of stability. However, the number of particles in the colloid variety is equal to the true variety of the same mass concentration is less, so the role of the entropy factor is small. However, even though the particles are stabilized by speeches, which may have long lamb lances (Navy) and therefore may have a rich conformation, then when such particles are brought closer together, they enter into interaction. It is necessary to change the number of possible conformations to change the number of possible conformations, hence the change in entropy. Therefore, the system pragne vіdshtovhnuti often one in one.
5. Hydrodynamic stability factor.
Iomu spryaє zbіlshennya schіlnostі and dynamic viscosity of the dispersion medium.
In real systems, there is a sound of a factor of stamina. The skin factor needs a specific method of its neutralization. Tse complicate the creation of the wild theory of stability. So far, only private theories are being developed.
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