What’s the Difference Between Solutions, Suspensions and Colloids?

Posted by Tal Shechter on Sep 26, 2019 9:00:00 AM

Thoughtful businessman looking at three arrows drawn on chalkboard-474958-editedMany industries use homogenizers as part of their manufacturing processes. Companies (cosmetic, food, chemical and pharmaceutical, to name but a few) need homogenizers to mix together the elements of their products. Effective mixtures not only have a better viscosity, consistency, texture, flavor and/or appearance (depending on the end product’s use), they create a stability within the product that extends shelf life, as well as increases bioavailability and efficacy (when applicable). This ultimately saves businesses of all types both time and money. In order to understand how homogenizers can facilitate all these advantages, however, it’s first necessary to learn about “mixtures.” Contrary to what might seem apparent, the word “mixture” can mean a lot of different things. Read on for a simple explanation of the difference between solutions, suspensions and colloids — all of which can be accurately classified as mixtures!


Mixtures Are Either Homogeneous or Heterogenous      

Chemically, all matter is either a pure substance (an element or compound) or a mixture of two or more elements and/or compounds. Furthermore, mixtures can either be homogeneous or heterogenous. A homogeneous mixture is uniform in its composition, meaning that no matter how you divide it, it will always display the same properties. For example, air is homogeneous mixture of several separate gases (N2, O2, H2O, and CO2); any volume of air will always contain the same ratios of its component gases.

All homogeneous mixtures can also be called solutions, composed of the solvent (the component of the substance that exists in the greatest amount) and one or more solutes (those components that exist in smaller volumes). In essence, solutes are “dissolved” in the solvent, making it impossible to identify either. And while water is the most evident solvent, other gases, liquids and even solids can be solvents, too.

A heterogenous mixture, on the other hand, is not uniform in composition; it’s a combination of two or more substances, like sand. Sand, when viewed under a microscope, will display an uneven distribution of particles, meaning no one handful will contain the same ratio of individual parts.


Heterogeneous Mixtures Can Be Further Separated Into…

All homogeneous mixtures are solutions, but heterogenous mixtures can be split into two separate categories: suspensions and colloids.

Suspensions are heterogenous mixtures where the individual components of the substance can be physically observed (when left to settle). Think about how many oil-based salad dressings separate into two layers in a bottle. Or how a bit of dirt in a glass of water eventually falls in a layer of silt at the bottom. These are all examples of suspensions.

Colloids are also heterogenous mixtures of particles, but the particles in colloids are significantly smaller than those found in suspensions — only 1 to 1,000 nanometers in diameter. Although these particles are very tiny, they remain larger than those found in homogeneous solutions and generate a tell-tell opaque appearance when light is applied to them. Indeed, colloids are often differentiated from solutions via the Tyndall Effect, the scattering of light that occurs when a light beam encounters the particles within a heterogenous mixture. If a beam cannot pass through a substance but rather bounces off it, you know that there are individual particles suspended in that substance reflecting the light, thus making it either a colloid or a suspension. Some examples of colloids include milk, mayonnaise and butter.


BEE International: The Clear Choice for High-Pressure Homogenizers

The effective mixing of components determines the value of many different types of products. Homogenizers, especially quality high pressure homogenizers (HPHs), create stable solutions, suspensions and colloids that can be used for a variety of purposes. If you would like to learn more about homogenizers and the specific benefits of a BEE International high pressure homogenizer, please contact us today!

You are also welcome to download our free eBook, “How to Achieve Efficient & Consistent Particle Size Reduction,” for additional insight on the benefits of consistent particle size reduction.


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