Properties of Suspensions and Colloids

Types of Suspensions

• Coarse suspensions: Particles are visible to the naked eye and settle quickly.
• Fine suspensions: Particles are smaller and take longer to settle.
• Deflocculated suspensions: Particles are highly dispersed and do not settle quickly.

Properties of Colloids

• Heterogeneous: Colloids consist of two or more phases (solid, liquid, or gas).
• Stable: Colloids do not settle or separate over time.
• Tyndall effect: Colloids scatter light, making them appear cloudy or opaque.
• Brownian motion: Colloidal particles exhibit random motion due to collisions with surrounding molecules.

Characteristics of Colloidal Particles

• Size: Colloidal particles range from 1-100 nm in diameter.
• Shape: Colloidal particles can be spherical, irregular, or fibrous.
• Surface area: Colloidal particles have a high surface area-to-volume ratio.
• Electrical charge: Colloidal particles can be positively or negatively charged, influencing their behavior and interactions.

Types of Suspensions

• Coarse suspensions have particles visible to the naked eye that settle quickly.
• Fine suspensions have smaller particles that take longer to settle.
• Deflocculated suspensions have highly dispersed particles that do not settle quickly.

Properties of Colloids

• Colloids are heterogeneous, consisting of two or more phases (solid, liquid, or gas).
• Colloids are stable and do not settle or separate over time.
• Colloids exhibit the Tyndall effect, scattering light and appearing cloudy or opaque.
• Colloids display Brownian motion, with particles moving randomly due to molecular collisions.

Characteristics of Colloidal Particles

• Colloidal particles range in diameter from 1-100 nm.
• Particles can be spherical, irregular, or fibrous in shape.
• Colloidal particles have a high surface area-to-volume ratio.
• Particles can carry an electrical charge, influencing behavior and interactions, with possible positive or negative charges.

Mixtures

Suspensions

• Coarse suspensions consist of large particles that settle quickly, often visible to the naked eye, such as sand in water or mud in water.
• Fine suspensions are composed of smaller particles that settle slowly, may require a centrifuge to separate, such as clay in water or flour in water.

Colloids

Properties

• Colloidal particles exhibit the Tyndall Effect, scattering light and making its path visible.
• Brownian Motion is a characteristic of colloidal particles, which exhibit random, zigzag motion due to collisions with surrounding fluid molecules.
• Colloidal particles often possess an electric charge, affecting their behavior and interactions.
• The stability of colloids is due to the balance of attractive and repulsive forces between particles.
• Colloids can exhibit unique optical properties, such as opacity or transparency, due to the size and distribution of particles.
• Colloids can affect the surface tension of a liquid, leading to changes in its behavior and properties.