Polymer-thickened foams

A foam that, in addition to the stabilizing surfactants, contains polymer and a cross-linking agent. The foam is first generated as a polymer-thickened foam, and after a delay period, gels. See also Stiff Foam. 

When the vapours to be controlled are flammable, many of these foams are quite similar to that of the protein, fluoroprotein and aqueous film-forming foams used in firefighting [99,103,107] (see also Section 12.10). When long-term odour and toxicity control are more important, many of these are polymer-thickened foams and gelling foams [101-103]. Other applications of foam blankets are discussed in Sections 10.5 and 13.9. 

Polymer thickened foams to which time-delayed cross-linking agents have been added, gelling foams, can be used to improve the efficiency of... 

Polymer-Thickened Foam. A foam which, in addition to the stabilizing surfactants, contains polymer. Polymer-thickened foams are formulated to produce increased stability and viscosity. See also Gel Foam, Stiff Foam. 

This class of materials includes inhibited greases produced by impregnation of a polymer thickener into liquid oils foamed by the inhibitor vapors. The polymer forms a skeleton that, under high loads, imparts the properties of a solid to the lubricant p < 0.1 — 2.0 kPa). Thanks to the high viscosity of the foamed oil, it localizes in the polymer skeleton cells so that the system becomes quasi-compatible. It can be roughly referred to as a plastic, although showing the properties of both solid and liquid polymer materials. 

Many shale gas service companies use groundwater pumped directly from the formation or treated water for their fracturing jobs. In some well stimulations, proppants are not needed to prop fractures open, so simple water or slightly thickened water can be a cost-effective substitute for an expensive polymer of foam-based fracturing fluid with proppant (Ely, 1994). Hydraulic fracturing performance is not exceptional with plain water, but, in some cases, the production rates achieved are adequate. Plain water has a lower viscosity than gelled water, which reduces proppant transport capacity. 

Here you find the pastes. Hazelnut paste is a dispersion of particles in a thick emulsion of two liquids, as is peanut butter. Jam is thickened by natural polymers. Soft cheese, butter and margarine are in the refrigerator these are complicated structures of fat crystals, oil, water and many other components. All these pastes have a yield stress that is low enough to let them be spread by a knife, but not so low that they run off bread. Users do find the cold butter a bit stiff and the jam a bit thin. As a developer you might want to improve these things. Bread - a solid foam - is a surprising structure when looked at it closely. Fresh bread is often too soft to cut easily. 

Furniture fabrics are back-coated with non-slip finishes, often with polymer-based ones. The formulation may include thickeners and flame retardants. Back-coating is mostly achieved by nip-padding or using a doctor (squeegee) or by foam application or spray techniques (for a lower add-on). Another one-side application is rotary printing (screens with regular perforation). 

To enhance the rate of penetration, y y has to be made as high as possible, 0 as low as possible, and p as low as possible. For the dispersion of powders into Hquids, surfactants should be used that lower 0 but do not reduce too much the viscosity of the liquid should also be kept at a minimum. Thickening agents (such as polymers) should not be added during the dispersion process. It is also necessary to avoid foam formation during the dispersion process. For a packed bed of particles, r may be replaced by K, which contains the effective radius of the bed and a tortuosity factor, which takes into account the complex path formed by the channels between the particles, that is ... 

Improvements in chemical research and development have increased the stability of foams by improving gellants and stabilizers. Thickening of the continuous phase increases the difficulty for gas bubbles to coalesce. Although relatively high qualities are required to achieve stability, qualities of less than 52% can maintain dispersion of the gas phase. Further improvements in foam stability can be accomplished by cross-linking the polymers in the aqueous phase. To date, foams have been established with qualities less than 40% (5). The use of low-quality foams is advantageous if viscosity or fluid loss control is a primary concern. If the formation sensitivity or fluid flow-back is important, low-quality foams are not desirable because of the reduced gas volume and increased fluid volume. 

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