- •Contents
- •Preface
- •1. Classification and physicochemical properties of surface-active substances
- •1.1 Synthetic detergent production
- •1.2 Classification of surface-active substances
- •1.3 Detergents and surfactants
- •1.4 Synthetic surfactant or soap
- •What's the difference?
- •1.5 Soaps and detergents
- •Cleansing action of soap
- •1.7 Synthetic detergents
- •1.8 Advantages and disadvantages of synthetic detergents with respect to soaps
- •Washing powders
- •1.9 Structure and properties of surface-active substances
- •Critical concentration of cluster formation
- •Control questions
- •1.10 Surface tension
- •1.11 Physical and chemical action of washing substances and detergent solutions
- •Control questions
- •1.12 Solubilization
- •1.13 Washing action
- •Control questions
- •2. Synthetic detergents composition
- •2.1 Inorganic compounds in synthetic detergent compositions
- •Alkaline salts of inorganic acids
- •Purposes of alkaline electrolytes
- •Control questions
- •2.2 Organic components used in synthetic detergents structure
- •Main components of synthetic detergents’ compositions
- •Hydrotropic substances.
- •Control questions
- •2.4 Production of enzyme-based detergents
- •2.5 Enzyme stabilization
- •2.6 Applications of enzyme-based detergents
- •3. Synthetic detergents production
- •3.1 Reception, storage and preparation of raw material for synthetic detergent manufacture
- •3.2 Technology of compositions preparation
- •Control questions
- •3.3 Classification of synthetic detergents. Kinds of pollutions.
- •Control questions
- •3.4 Technology of washing compositions drying
- •3.5 Spray drying technology
- •Control questions
- •3.6 Basic technological circuits of powdery synthetic detergent manufacture by periodic and continuous ways
- •Control questions
- •3.7 Capital equipment at granulated synthetic detergents manufacture
- •3.8 Technology of drying in fluidized layer
- •Control questions
- •3.9 Technology of granulated synthetic detergents by combined methods
- •3.10 Packaging of powders
- •Basic raw material
- •Auxiliary raw material
- •Control questions
- •4.3 Chemistry and technology of soap production
- •Control questions
- •4.4 Cake synthetic detergents
- •4.5 Production of cake synthetic detergents by forming method
- •4.6 Production of cake synthetic detergents by pressing method
- •Control questions
- •4.7 Manufacture of paste and liquid detergents
- •4.8 Compositions and production technology of paste-like synthetic detergents
- •Control questions
- •4.9 Compositions and technology of liquid synthetic detergents production
- •Control questions
- •5. Chemical means of hygiene and cosmetics
- •5.1 Shampoos
- •Jump of quality
- •Electrostatics laws in operation
- •To expect, to prevent
- •Laziness -- the engine of progress
- •Content and form
- •5.2 Teeth care means
- •Literature list:
Critical concentration of cluster formation
Concentration of a SAS solution at which sharp change of its properties caused by cluster formation is observed refers to critical concentration of cluster formation.
Concentrations of detergent solutions used in practice are in the area of critical concentration of cluster formation:
Domestic washing of cotton fabrics concentration of active substance 2-3 g/l
Laundry, cotton fabrics 1-2 g/l
Wool, silk 0,7-2,5 g/l
Critical concentration of cluster formation is determined by the measurement of changing of one of properties of a solution: surface tension, viscosity, electrical conductivity, etc. The simplest and widespread way is based on the determination of change of solution’s color. In solution of SAS the corresponding paint is added which changes color of the solution at the achievement of critical concentration.
Critical concentration of cluster formation depends on length of a hydrocarbon chain:
CC = A – ВN
where A - a constant for the given temperature and homologous line;
B - an empirical constant, B = log 2;
N – a number of carbon atoms in a chain.
CC = K / (M - Mcr)3
where M - molecular weight of researched SAS;
Мcr – critical molecular weight (molecular weight of a homolog, not forming clusters in solution);
K – coefficient (for soap K = 1,8 · 106, for аlkylsulphates K = 5 · 105, for alkylsulphonates K = 7·105).
There are other formulas for calculation of critical concentration of cluster formation. Calculated data give good concurrence with experiment.
Control questions
What substance is a basic component of synthetic detergents?
Which substances refer to washing substances?
What is a surface-active substance?
What is a molecule structure of a surface-active substance?
Are SAS polar or not polar compounds?
Which radicals can be a hydrophilic part of a surface-active substance’s molecule?
Which radicals can be a hydrophilic part of a SAS molecule?
How can hydrophilic and hydrophilic parts be located in the molecule of SAS?
Which factors influence the solubility of SAS?
How does the solubility of SAS depend on temperature?
Classification of surface-active substance.
What is the hydrolysis?
Explain the mechanism of hydrolysis of soup molecules and molecules of synthetic detergents. What is the difference between them?
What are the clusters? Which kinds of clusters do you know?
What is the critical concentration of cluster formation?
Explain the structure of lamellar cluster.
How are molecules located in mixed clusters? Why does it happen?
Write the formula of sodium stearate. Where does this substance use?
Which compounds are the active washing substances in usual fatty soups?
Which compounds are the active washing substances in synthetic detergents?
What is the soup? Its properties and method of preparation.
Why does a water solution of soup have alkaline reaction? Write chemical reactions and explain