Viscosity antifoaming agents

Typical Functions or Types of Additives Available For Fracturing Fluid Systems Antifoaming agents Bacteria control agents Breakers for reducing viscosity Buffers... 

The improvements have come by way of petroleum oils with viscosity index improvers, or synthetics with naturally high viscosity index. The problem of packing deterioration, or rusting, is chiefly a chemical matter. Hydraulic fluids for the various applications include those made from petroleum, synthetic oils, and aqueous solutions containing antifreeze and rust inhibitors. Antifoam agents are necessary in some hydraulic fluids. 

Other silicone antifoaming agents can be based on oligomethylsiloxanes of various viscosity and are prepared similarly. Instead of OS-2 solution, some emulsion brands use the Solvar solution or solutions of emulsifiers OP-7 and OP-10. 

Dimethicones of various viscosities are widely used in cosmetic and pharmaceutical formulations. In topical oil-in-water emulsions dimethicone is added to the oil phase as an antifoaming agent. Dimethicone is hydrophobic and is also widely used in topical barrier preparations. Therapeutically, dimethicone may be used with simethicone in oral pharmaceutical formulations used in the treatment of flatulence. Dimethicone is also used to form a water-repellent film on glass containers. See Table I. 

Administration) and/or kosher requirements. High molecular weight antifoam agents, when used in the low-viscosity broth, typically reduce the gas-liquid mass transfer coefficient. 

During Escherichia coli cultivation on casein peptone, yeast and meat extract as medium components and in presence of an antifoam agent, the surface tension (36mNm ) and surface viscosity (1.9 cP) were constant and did not depend on the cultivation time. 

Antifoam agents destroy the surface elasticity and sinface viscosity of the foaming system. The antifoam agent must have, therefore, low surface tension to spread on the foam lamellae. To be active at low concentrations, they must also be insoluble in the foaming mediiun [38]. 

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