Glycerol viscosity

Glycerol. Glycerol is a viscous Newtonian fluid (99.9% glycerol is about 1.6 Pa s at room temperature). It is extremely hygroscopic (it absorbs water from the atmosphere), so any free surfaces must be protected from the moist atmosphere to maintain the viscosity. Glycerol is even more transparent than glucose syrup and is good for transitional and laminar flow Newtonian LDA work. 

Physical Properties. All colourless liquids, completely miscible with water, except benzyl alcohol and cyclohexanol, which are slightly soluble. Pure glycol and glycerol have high viscosity, which falls as the hygroscopic liquids absorb water from the air. 

Weight glycerol Grams per liter Relative density 25725°C Viscosity, mN s m 2... 

Properties. Antimony pentafluoride [7783-70-2], SbF, is a colorless, hygroscopic, very viscous liquid that fumes ia air. Its viscosity at 20°C is 460 mPa-s(=cP) which is very close to the value for glycerol. The polymerization of high purity SbF at ambient temperature can be prevented by addition of 1% anhydrous hydrogen fluoride, which can be removed by distillation prior to the use of SbF. The pure product melts at 7°C (11), boils at 142.7°C,... 

The newer HFC refrigerants are not soluble in or miscible with mineral oils or alkylbenzenes. The leading candidates for use with HFC refrigerants are polyol ester lubricants. These lubricants are derived from a reaction between an alcohol and a normal or branched carboxyflc acid. The most common alcohols used are pentaerythritol, trimethylolpropane, neopentjlglycol, and glycerol. The acids are usually selected to give the correct viscosity and fluidity at low temperatures. 

Cosmetics. Castor od and its derivatives are utilized in cosmetic and personal care products. The low pour point and high viscosity produce lubricity and wetting properties desired in Hpsticks. Basic Hpstick contains 20—44 wt % castor od, which also acts as an ideal dispersant for pigments (116). One Hpstick formula contains 38 wt % castor od and 9.5% glycerol monoricinoleate (117). 

The resultant yellow sodium cellulose xanthate is dispersed in an aqueous caustic soda solution, where some hydrolysis occurs. This process is referred to as ripening and the solution as viscose . When the hydrolysis has proceeded sufficiently the solution it transferred to a hopper from which it emerges through a small slit on to a roller immersed in a tank of 10-15% sulphuric acid and 10-20% sodium sulphate at 35-40°C. The viscose is coagulated and by completion of the hydrolysis the cellulose is regenerated. The foil is subsequently washed, bleached, plasticised with ethylene glycol or glycerol and then dried. 

The strong interactions between the water molecules also become obvious from NMR measurements by Tsujii et al..57) 13C-NMR experiments were used for determining the microviscosity of water in reversed micelles of dodecylammonium-propionate with 13C glycine cosolubilized. It was found that the apparent viscosity of the water-pool corresponds to the viscosity of a 78 % aqueous glycerol solution, obviously as a consequence of the extended network formation by strong hydrogen bonding. 

Miura (Y3) have studied the effect of the addition of glycerol to water on the reaction rate constant. The reaction in the liquid phase is second order. Their values for k" at 28°C, which indicate a slight increase with increasing viscosity, are given in Table I. 

Water (density 1000 kg/m3, viscosity 1 mN s/m2) is pumped through a 50 mm diameter pipeline at 4 kg/s and the pressure drop is I MN/m2. What will be the pressure drop for a solution of glycerol in water (density 1050 kg/m3. viscosity 10 mN s/m2) when pumped at the same rate Assume the pipe to be smooth. 

Glycerol is well known for its strong hydrogen bonding in the liquid phase and its high viscosity. To study its wetting properties, we deposited glycerol on mica by condensation from its vapor in standard laboratory air [9]. 

Recently, an electrorheological effect, i.e., an increase in the viscosity and dynamic shear moduli of lecithin/n-decane solutions in the presence of small amounts of polar additives (water or glycerol) when an external electric field is applied to the system, has been observed [65]. 

Finite amounts of glycerol (its viscosity is 945 cP at 25°C) can be dispersed in AOT/heptane or in CTAB/heptane + chloroform systems. The resulting solutions consist of thermodynamically stable, spherical droplets of glycerol stabilized by the surfactant [33,235]. The presence of glycerol within the micellar core results in a reduction of the surfactant mobility [137]. 

The extremely violent reaction was put down to the alcohol s high viscosity, which limited the dissipation of gas produced by the reaction. Refer to alcohols and glycerol. 

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