A highly viscous fluid tends to be thick, like honey or cold maple syrup. Compared to a relatively nonviscous fluid, such as water, highly viscous liquids flow much more slowly. Of course, when you add energy, in the form of heat, the molecules making up these liquids become less densely packed and are better able to slide past one another.
Generally speaking, larger molecules, such as the large chains of carbohydrates in syrup, slide past one another with greater difficulty than the minuscule molecules of water. The ungainly shapes of constituent molecules create greater friction as they slide past one another. Thus, particle shape contributes to viscosity. Understanding the viscosity of a given liquid is important when processing liquids, as viscosity is a property that will affect flow through your production system, not to mention ultimate issues such as packaging decisions.
Most fluids are classified as either Newtonian or non-Newtonian. Water is a simple example. You can shake a container of water for hours, but it will still flow at the same rate. Ketchup, however, is a non-Newtonian fluid. Technically and scientifically, the term syrup is also employed to denote viscous, generally residual, liquids, containing substances other than sugars in solution. Artificial maple syrup is made with water and an extremely large amount of dissolved sugar.
The solution is heated so more sugar can be put in than normally possible. The solution becomes super-saturated. The syrup employed as a base for medicinal purposes consists of a concentrated or saturated solution of refined sugar in distilled water. The "simple syrup" of the British Pharmacopoeia is prepared by adding 1 kg of refined sugar to mL of boiling distilled water, heating until it is dissolved and subsequently adding boiling distilled water until the weight of the whole is 1.
The specific gravity of the syrup should be 1. Flavoured syrups are made by adding flavouring matter to a simple syrup. For instance, syrupus aromaticus is prepared by adding certain quantities of orange flavouring and cinnamon water to simple syrup.
Water and sugar are both made up of molecules with tiny charges, which act like magnets around oppositely charged atoms. However, water is made of tiny H20 molecules, which slide past each other as they transfer from one surface to another. Meanwhile, sugar's molecules are much larger, and lock together into a solid when they're at room temperature. But Javadi and his colleagues found that for extremely viscous fluids, like honey, the speed at which the fluid falls under gravity outstrips the speed with which the waves within the fluid grow.
This means honey can form into long thin strings before the waves are large enough to break the strands. The team then confirmed their mathematical predictions through experiments using silicone oils with a range of viscosities.
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