The video below shows several different long chained oils, each progressively more viscous. Viscosity can be defined as the measurement of a liquids resistance to flow, also referred to as a liquids internal friction. Glycerol, CH 2OHCHOHCH 2OH, is viscous partly because of the length of the chain but also because of the extensive possibilities for hydrogen bonding between the molecules. Fuel oil, lubricating grease, and other long-chain alkane molecules are quite viscous for this reason. This is because the molecular chains get tangled up in each other like spaghetti-in order for the liquid to flow, the molecules must first unravel. Itcorresponds roughly to the intuitive notion of a fluids thickness. For liquids, it corresponds to the informal concept of thickness. The viscosity of a liquid is a proportion of its protection from deforming at a given rate. The viscosity of a fluid is a measure of its resistance to deformation at a given rate. Shear stress is the force per unit area required to. Viscosity is the propensity of a liquid to oppose any adjustment in its shape or movement. The result is typically expressed in centipoise (cP), which is the equivalent of 1 mPa s (millipascal second). Many factors may influence the quality and stability of foods, and viscosity is definitely one of the aspects receiving more attention during the manufacturing process. The formula for measuring viscosity is fairly simple: viscosity shear stress / shear rate. Uses of viscometry in the food and beverage industry. Liquids containing long molecules are invariably very viscous. Viscosityis a material property which describes the resistance of a fluid to shearing flows. Viscosity is the measure of a substance's resistance to motion under an applied force. Honey, mostly glucose and fructose (see image below) is a good example of a liquid which owes its viscosity to hydrogen bonding. For many fluids the tangential, or shearing, stress that causes flow is directly proportional to the rate. It controls the liquid flow in such processes as spraying, injection molding, and surface coating. Liquids whose molecules are polar or can form hydrogen bonds are usually more viscous than similar nonpolar substances. Viscosity is a major factor in determining the forces that must be overcome when fluids are used in lubrication and transported in pipelines. Viscosity is governed by the strength of intermolecular forces and especially by the shapes of the molecules of a liquid. Those like ether or gasoline which flow very readily have low viscosities. Liquids which flow very slowly, like glycerin or honey, have high viscosities. The resistance to such flow is called the viscosity. \)īecause its molecules can slide around each other, a liquid has the ability to flow.
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