Colloidal

Colloidal describes a state of matter where tiny, insoluble particles of one substance are dispersed evenly throughout another substance. These particles are larger than molecules but small enough to remain suspended, creating a mixture that appears homogeneous to the naked eye, even though it's heterogeneous at a microscopic level. The dispersed particles do not settle out readily due to factors like Brownian motion and surface charges. This state is crucial in various applications from food science to pharmaceuticals and materials science. The stability of a colloidal system can be affected by temperature, pH, and the addition of electrolytes.

Colloidal meaning with examples

• 1. Milk is a common example; fat droplets are dispersed throughout the water-based liquid. These fat particles are larger than individual molecules but remain suspended. This makes milk appear uniform, but if left to sit for long periods, the fat may separate, demonstrating colloidal instability.
• 2. Many paints and inks are colloidal systems, where pigment particles are suspended in a liquid. This allows for a consistent colour distribution and easy application. The addition of certain substances helps keep the pigment from clumping or settling at the bottom.
• 3. Certain blood products like blood plasma are colloidal dispersions, and the presence of specific molecules suspended helps to maintain the blood's viscosity and osmotic pressure. These molecules are essential for various biochemical processes.
• 4. Gelatin desserts often feature a colloidal structure. Gelatin molecules are dispersed in water and undergo a phase change upon cooling, trapping water within a semi-rigid network. The consistency is a direct result of this process.
• 5. Some pharmaceuticals are formulated as colloidal suspensions to improve drug delivery or enhance stability. These suspensions can help the drug bypass some barriers within the body.