Colloid
Colloid is a heterogeneous mixture of two or more substances in which
particles of a substance measuring between 1 and 1000 nm are dispersed
(dispersed) evenly in the medium of another substance. Substances
dispersed as particles are called dispersed phases, whereas the substance into
the medium disperses the particles called the dispersing medium.
Colloid is a dispersion system whose particle size is larger than the solution, but smaller than the suspension (crude mixture) (Retnowati, 2008: 141). The colloids consist of two forms, the dispersed phase (dispersed agent) and the dispersing medium (the medium used for dispersing) (Kamaludin, 2010: 422).
Macroscopically, the colloid looks like a solution, in which a homogeneous mixture of solutes and solvents is formed. However, microscopically, it looks like a suspension, a heterogeneous mixture in which each of the mixed components tends to separate each other. The color in the paint comes from the color of the pigment that is not soluble in water or any other solvent medium. However, the paint looks like a homogeneous mixture like a salt solution and not a heterogeneous mixture like a mixture of sand with water. This happens as paint is a colloidal system with dispersed pigments in water or other paint solvent medium.
Colloid is a dispersion system whose particle size is larger than the solution, but smaller than the suspension (crude mixture) (Retnowati, 2008: 141). The colloids consist of two forms, the dispersed phase (dispersed agent) and the dispersing medium (the medium used for dispersing) (Kamaludin, 2010: 422).
Macroscopically, the colloid looks like a solution, in which a homogeneous mixture of solutes and solvents is formed. However, microscopically, it looks like a suspension, a heterogeneous mixture in which each of the mixed components tends to separate each other. The color in the paint comes from the color of the pigment that is not soluble in water or any other solvent medium. However, the paint looks like a homogeneous mixture like a salt solution and not a heterogeneous mixture like a mixture of sand with water. This happens as paint is a colloidal system with dispersed pigments in water or other paint solvent medium.
A.
Various kinds
of colloids
Colloids have various forms, depending on the phase of the dispersant and the dispersed agent. Some colloid types:
Colloids have various forms, depending on the phase of the dispersant and the dispersed agent. Some colloid types:
1.
Aerosols that
have a dispersant of a gas. Aerosols that have a liquid dispersed substance are
called liquid aerosols (eg fog and clouds) whereas those with solid dispersed
substances are called solid aerosols (eg, airborne smoke and dust).
2.
Sol Colloidal
system of solid particles dispersed in liquids. (Examples: River water, soap
sole, detergent sole, paint and ink).
3.
Emulsion The
colloidal system of liquids is dispersed in other liquids, but the two liquids
do not dissolve. (Example: coconut milk, milk, mayonnaise, and fish oil).
4.
Scalding
Colloidal System from a gas dispersed in a liquid. (Example: on metal ore
processing, fire extinguishers, some cosmetics, and others). There is also a
solid froth which is a gas dispersed in solid (Example: Styrofoam, pumice, sponge,
marshmallow).
5.
Gel colloidal
system rigid or semi-solid and semi-liquid. (Example: Jelly,
glue).
B. Properties of Colloid
1. Tyndall Effect
The Tyndall effect is a symptom of scattering of light beam (light) by colloidal particles. This is because the size of the colloidal molecule is quite large. This Tyndall effect was discovered by John Tyndall (1820-1893), a British physicist. Therefore it is called the Tyndall effect.
The Tyndall effect is the effect that occurs when a solution is exposed to light. When the true solution is irradiated with light, the solution will not scatter light, whereas in the colloidal system light will be dissipated. This happens because colloidal particles have relatively large particles to scatter them. In contrast, in the true solution, the particles are relatively small so that the scattering occurs only slightly and is very difficult to observe.
The Tyndall effect is a symptom of scattering of light beam (light) by colloidal particles. This is because the size of the colloidal molecule is quite large. This Tyndall effect was discovered by John Tyndall (1820-1893), a British physicist. Therefore it is called the Tyndall effect.
The Tyndall effect is the effect that occurs when a solution is exposed to light. When the true solution is irradiated with light, the solution will not scatter light, whereas in the colloidal system light will be dissipated. This happens because colloidal particles have relatively large particles to scatter them. In contrast, in the true solution, the particles are relatively small so that the scattering occurs only slightly and is very difficult to observe.
2. Brownian
motion
Brownian motion is the movement of colloidal particles that always move straight but erratic (random motion / irregular). If the colloid is observed under an ultra microscope, then we will see that the particles will move to form a zigzag. This zigzag movement is called Brownian motion.
The particles of a substance are constantly moving. The movement can be random as in liquids and gases (called Brownian motion), whereas in solids only oscillate in place (excluding Brownian motion). For colloids with a liquid or gas dispersing medium, the movement of particles will result in collisions with the colloidal particles themselves. The collision took place from all directions. Because the particle size is small enough, the collisions that occur tend to be unbalanced. So there is a resultant collision that causes changes in the direction of motion of particles resulting in the motion of zigzag or Brownian motion.
The smaller the size of colloidal particles, the faster Brown's motion takes place. Similarly, the larger the size of colloidal particles, the slower the Brownian motion occurs. This explains why Brownian motion is difficult to observe in solution and is not found in the heterogeneous mixture of liquids with solids (suspension).
Brownian motion is also affected by temperature. The higher the temperature of the colloidal system, the greater the kinetic energy the particles of the dispersing medium are. As a result, Brown's motion of the dispersed phase particles is accelerating. Similarly, the lower the temperature of the colloidal system, the slower the Brownian motion.
Brownian motion is the movement of colloidal particles that always move straight but erratic (random motion / irregular). If the colloid is observed under an ultra microscope, then we will see that the particles will move to form a zigzag. This zigzag movement is called Brownian motion.
The particles of a substance are constantly moving. The movement can be random as in liquids and gases (called Brownian motion), whereas in solids only oscillate in place (excluding Brownian motion). For colloids with a liquid or gas dispersing medium, the movement of particles will result in collisions with the colloidal particles themselves. The collision took place from all directions. Because the particle size is small enough, the collisions that occur tend to be unbalanced. So there is a resultant collision that causes changes in the direction of motion of particles resulting in the motion of zigzag or Brownian motion.
The smaller the size of colloidal particles, the faster Brown's motion takes place. Similarly, the larger the size of colloidal particles, the slower the Brownian motion occurs. This explains why Brownian motion is difficult to observe in solution and is not found in the heterogeneous mixture of liquids with solids (suspension).
Brownian motion is also affected by temperature. The higher the temperature of the colloidal system, the greater the kinetic energy the particles of the dispersing medium are. As a result, Brown's motion of the dispersed phase particles is accelerating. Similarly, the lower the temperature of the colloidal system, the slower the Brownian motion.
3. Adsorption
Adsorption is the absorption of particles or ions or other compounds on the surface of colloidal particles caused by the surface area of the particles. Adsorption must be distinguished by absorption, which means absorption occurring within a particle.
Example:
Adsorption is the absorption of particles or ions or other compounds on the surface of colloidal particles caused by the surface area of the particles. Adsorption must be distinguished by absorption, which means absorption occurring within a particle.
Example:
(I) Fe (OH) 3 Colloid is positively charged because its
surface absorbs H + ions.
(Ii) As2S3 Colloid is negatively charged because its surface absorbs S2 ions.
(Ii) As2S3 Colloid is negatively charged because its surface absorbs S2 ions.
4. Colloidal load
Known two kinds of colloids, the colloids are positively charged and negatively charged colloids.
Known two kinds of colloids, the colloids are positively charged and negatively charged colloids.
5. Colloid coagulation
Coagulation is a clumping of colloidal particles and forming a precipitate. With the occurrence of coagulation, means dispersed substances no longer form colloids.
Coagulation may occur physically such as heating, cooling and stirring or chemically such as the addition of electrolytes, mixing different colloidal loads.
Coagulation is a clumping of colloidal particles and forming a precipitate. With the occurrence of coagulation, means dispersed substances no longer form colloids.
Coagulation may occur physically such as heating, cooling and stirring or chemically such as the addition of electrolytes, mixing different colloidal loads.
6. Protective colloids
Protective colloid is a colloid that has properties to protect other colloids from the coagulation process.
Protective colloid is a colloid that has properties to protect other colloids from the coagulation process.
7. Dialysis
Dialysis is the separation of colloids from disruptive ions by passing liquids mixed with colloids through semipermeable membranes that act as filters. This semipermeable membrane can be passed through a liquid but can not be crossed by colloids, so colloids and liquids will split.
Dialysis is the separation of colloids from disruptive ions by passing liquids mixed with colloids through semipermeable membranes that act as filters. This semipermeable membrane can be passed through a liquid but can not be crossed by colloids, so colloids and liquids will split.
8. Electrophoresis
Electroferesis is the event of separation of charged colloid particles by using electric current.
Electroferesis is the event of separation of charged colloid particles by using electric current.
Here is my video link about of colloid:
https://www.youtube.com/watch?v=sKgnPaLYIP4
What are the benefits of colloids in the health field, explain?
BalasHapusHelps patients with kidney failure
HapusThe process of dialysis to separate the colloidal particles and solutes is the basis for the development of dialysis. Application in health is a blood-washing machine for people with kidney failure. The small ions and molecules can pass through the semipermiabel membrane thus at the end of the process in the sac only remaining colloid alone. By performing dialysis that utilizes the principle of colloid dialysis, toxic compounds such as urea and keratin in the blood of patients with kidney failure can be excluded. The cleaned blood is then put back into the patient's body.
For food and medicine
There are substances that are not soluble in water so it must be packed in colloid form so easy to drink. Examples of drugs in capsule form.
What are the properties of colloids?
BalasHapusTyndall effect, Brownian motion, Electrophoresis, Absorption, Coagulation, Colloid Lycophore and Lycopholus Colloid, Dialysis, Colloid Protector
Hapuscan you explain example colloid in daily life and chemistry?
BalasHapusExamples of adsorption events are
HapusHealing stomach pain caused by pathogenic bacteria using norit
The process of purifying water using alum
The process of digesting sugar cane water when making sugar
Examples of tyndal effects in everyday life ie:
Light car or flashlight when fired into foggy air
The appearance of orange and blue when the afternoon arrived
Visible light of sun entering through the leaf slit.
What is function colloid?
BalasHapusColloid is widely used in everyday life, in the life of everyday life. This is indeed an important colloidal property, which can be used to mix substances that can not be mutually homogeneous and stable to each other for large-scale production.
Hapusplease give a example of tyndall effect
BalasHapusExamples of tyndal effects in everyday life ie:
HapusLight car or flashlight when fired into foggy air
The appearance of orange and blue when the afternoon arrived
Visible light of sun entering through the leaf slit.
Explain about colloidal features
BalasHapusDirectors are differentiated by colloid size, colloid making can be done in two ways, namely:
Hapus1. Dispersion
Dispersion is done by reducing the particle size.
A) Mechanical way
Minimizes coarse grains into fine grains.
Example: sulfur sol can be made by grinding sulfur powder with sugar until smooth and then mixed with water.
B) Peptitasi
Adding a chemical to break the coarse particles into colloidal particles.
Example: agar is peppered by water.
C) Bredig arc
Colloid making by using high-voltage electric current causing spark jumps at both ends.
Example: making metal soles.
2. Condensation
Making colloids by altering small particles (solution) into colloidal particles.
A) Hydrolysis reaction
Example:
Making Fe Fe (OH) ₃ by heating the FeCl lar solution.
B) Redox reaction
Creation of sulfur soles by flowing H₂S gas into SOO solution.
C) Double Decomposition Reaction
Preparation of AgCl solvent from AgNO lar solution with dilute NaCl solution.
D) Solvent Substitution Reaction
The gel preparation of a mixture of saturated calcium acetate solution with alcohol.
explai about Protective colloids?
BalasHapusColloid hydrophil which can stabilize colloid hydrophob is called protective colloid or protective colloid. Protective colloids act to protect the charge of colloidal particles by coating them to avoid coagulation. Casein protein acts as a protective colloid in breast milk. Gelatin is used as a protective colloid in ice cream to keep from forming ice cubes.
Hapuswhat it is Tyndall Effect and brownian motion? please explain !
BalasHapusThe Tyndall effect is a symptom of scattering of light beam (light) by colloidal particles. This is because the size of the colloidal molecule is quite large.
HapusBrownian motion is the movement of colloidal particles that always move straight but erratic (random motion / irregular).
Why colloids are between homogeneous and heterogeneous phases?
BalasHapusBecause of the homogeneous and heterogeneous mixture there is a colloidal mixing system, or it can also be called a homogeneous (phase) switching form to become heterogeneous. The homogeneous mixture is a mixture having the same properties on each part of the mixture, for example sugar and rain solution. While the heterogeneous mixture itself is a mixture of unequal properties on each part of the mixture, for example water and oil, then sand and cement.
Hapus