Foam properties related

Foam properties related to salt. The addition of sodium chloride to soybean protein suspensions caused them to form high-capacity, low-stability foams (13). It was suggested that foam capacity increased because salt improved protein solubility at the interface of the colloidal suspension during foam formation, but retarded the partial denaturation of the surface polypeptides of proteins that are necessary for protein-protein interaction and stability. 

Foam properties related to heat. Peanut kernels were moist heated in a temperature-controlled retort at 50, 75, and lOQOC for 15-min intervals ranging from 15 to 90 min (30). Quantities of water-extractable proteins decreased as heating time increased from 15 to 90 min at all three temperatures (Figure... 

Foam properties related to seed type. Soybean flour suspensions produced thick egg white-type foams at all pH levels tested except at 4.0 (Figure 14 47). Although the increase in capacity of suspensions at pH values 6.5 and 4.0 was identical, a medium thick foam was produced by the latter. At pH 4.0, the level of soluble protein in the suspension was significantly lower than at the higher pH values the latter three percentages of protein were similar. A decline in foaming capacity at pH... 

The use of AOS and other surfactants as steam-foaming agents has been studied by several oil companies in laboratories and in the field [55-62]. In the next section we will view olefinsulfonate structure-property relations [40] that have helped design optimum surfactants for enhanced oil recovery applications. 

The responses chosen all relate to important foam properties. We believed that yi, the emulsion droplet size, determines y2, the cell size in the resultant foam, and we wished to determine whether this is true over this range of formulations. The foam pore size ys should determine the wetting rate y7, so these responses could be correlated, and yg, the BET surface area, should be related to these as well. The density y and density uniformity ys are critical to target performance as described above, and ys, the compressive modulus, is an important measure of the mechanical properties of the foam. 

Table 4.6 relates to examples only and cannot be generalized data cannot be used for design purposes. See also Table 4.5 for foam properties. 

The mechanical properties at low strain rates, dynamic mechanical properties, creep-recovery behaviour, thermal expansion and thermal conductivity of foams manufactured from blends of LDPE with an EVA and with an isoprene-styrene block copolymer were studied as a function of the LDPE content in the blends. The experimental results demonstrated important aspects related to the modification of the foam properties by blending. 16 refs. 

Figure 2. Foam properties and content of soluble constituents related to pH and percentage of glandless cottonseed flour in aqueous suspensions...

In the present case, the foam density relates perfectly with the previously observed rheological properties, as a transition in the flow behavior was detected at approximately 20 wt% of PPE (Fig. 13). In the viscoelastic case (below the percolation limit), the PPE content neither significantly influences the foamability nor the blend rheology. At elevated contents (beyond percolation), however, the PPE content strongly affects the rheological response of the blend and, subsequently, degrades the foaming behavior, which is verified by a reduced expandability. 

Other methods of determining foam stability include monitoring physical properties related to the foam. For example, several researchers discuss the use of NMR spectroscopic or MRI imaging monitoring of foam stability [109,124]. 

Oilseed Protein Properties Related to Functionality in Emulsions and Foams... 

Lin et al. (15) showed that sunflower meal was superior to soybean and sunflower concentrates or isolates In emulsion capacity. McWatters and Cherry (9) compared select functional properties of defatted soybean, peanut, field pea, and pecan flours and showed that major seed storage proteins were important in emulsifying and foaming properties. Protein solubility was related to the quality of the emulsions and foams. Behavioral characteristics contributed by nonprotein components that occur naturally In the seeds, especially carbohydrates, were Implicated. 

Foam films are usually used as a model in the study of various physicochemical processes, such as thinning, expansion and contraction of films, formation of black spots, film rupture, molecular interactions in films. Thus, it is possible to model not only the properties of a foam but also the processes undergoing in it. These studies allow to clarify the mechanism of these processes and to derive quantitative dependences for foams, O/W type emulsions and foamed emulsions, which in fact are closely related by properties to foams. Furthermore, a number of theoretical and practical problems of colloid chemistry, molecular physics, biophysics and biochemistry can also be solved. Several physico-technical parameters, such as pressure drop, volumetric flow rate (foam rotameter) and rate of gas diffusion through the film, are based on the measurement of some of the foam film parameters. For instance, Dewar [1] has used foam films in acoustic measurements. The study of the shape and tension of foam bubble films, in particular of bubbles floating at a liquid surface, provides information that is used in designing pneumatic constructions [2], Given bellow are the most important foam properties that determine their practical application. The processes of foam flotation of suspensions, ion flotation, foam accumulation and foam separation of soluble surfactants as well as the treatment of waste waters polluted by various substances (soluble and insoluble), are based on the difference in the compositions of the initial foaming solution and the liquid phase in the foam. Due ro this difference it is possible to accelerate some reactions (foam catalysis) and to shift the chemical equilibrium of some reactions in the foam. The low heat... 

Surfactant foaming properties are related to surfactant chemical structure parameters such as hydrophobe size, ethylene oxide chain length, and hydrophile functional group. 

Surfactant foaming properties are related to oil phase composition. The composition of the residual oil will change in the course of a COj EOR project. The optimum COj mobility control agent may thus change during the course of the project. 

Correlation equations relating surfactant chemical structure to performance characteristics and physical properties have been established. One atmosphere foaming properties of alcohol ethoxyl-ates and alcohol ethoxylate derivatives have been related to surfactant hydrophobe carbon chain length, ethylene oxide content, aqueous phase salinity, and temperature. Similar correlations have been established for critical micelle concentration, surfactant cloud point, and surfactant adsorption. 

Foam exhibits higher apparent viscosity and lower mobility within permeable media than do its separate constituents.(1-3) This lower mobility can be attained by the presence of less than 0.1% surfactant in the aqueous fluid being injected.(4) The foaming properties of surfactants and other properties relevant to surfactant performance in enhanced oil recovery (EOR) processes are dependent upon surfactant chemical structure. Alcohol ethoxylates and alcohol ethoxylate derivatives were chosen to study techniques of relating surfactant performance parameters to chemical structure. These classes of surfactants have been evaluated as mobility control agents in laboratory studies (see references 5 and 6 and references therein). One member of this class of surfactants has been used in three field trials.(7-9) These particular surfactants have well defined structures and chemical structure variables can be assigned numerical values. Commercial products can be manufactured in relatively high purity. 

Foaming properties can be quantitatively related to surfactant chemical structure, surfactant physical properties, and test conditions using the technique of multiple correlation analysis.(11) The current studies were restricted to linear correlation equations to permit the analyses to be performed on a small microcomputer. While non-linear equations having higher correlation coefficients than obtained herein can be developed, theoretical insights are often limited due to the complexity of the various terms of such equations. The quality of the correlations were assessed using the correlation coefficient (r ) criteria of Jaffe (12)... 

Foaming properties of alcohol ethoxylates and alcohol ethoxylate derivatives are related to chemical structure features such as hydrophobe size and linearity, ethylene oxide chain length, and the terminating group at the end of the ethylene oxide chain. Foaming properties may be mathematically related to chemical structure parameters using multiple correlation analysis. ... 

Minissieux, L., "Oil Displacement by Foams in Relation to Their Physical Properties in Porous Media", J. Petr. Tech., January 1974, pp 100-108. 

This survey deals with the fundamental morphological parameters of foamed polymers including size, shape and number of cells, closeness of cells, cellular structure anisotropy, cell size distribution, surface area etc. The methods of measurement and calculation of these parameters are discussed. Attempts are made to evaluate the effect and the contribution of each of these parameters to the main physical properties of foamed polymers namely apparent density, strength and thermoconductivity. The cellular structure of foamed polymers is considered as a particular case of porous statistical systems. Future trends and tasks in the study of the morphology and cellular structure-properties relations are discussed. 

Chapter 10 on test methods is an expansion of the listings of standard test methods presented in Chapter 11. The first section of this chapter lists, in alphabetic order, 130 properties of cellular plastics and elastomers and tabulates the standard test methods used for each. Only number designations are given. The second section is a somewhat detailed discussion, also in alphabetical order, of 22 foam properties tested by standard test methods. The third section is a brief invited presentation of several non-standardized test methods currently in use. Chapter 11 on standardization documents lists published specifications, test methods and other related standards used in the U.S., in addition to British standards and ISO International Standards. A total of 361 standards are covered. A glossary of 221 terms is included. 

Zhu, H., and Damodaran, S. (1994). Heat-induced conformational changes in whey protein isolate and its relation to foaming properties. /. Agric. Food Chem. 42, 846-855. 

Consumers evaluate several different properties related to foam. The amount of foam formed when the water and product are first introduced into the wash basin or sink is referred to as the flash foam or the initial foam volume. The persistence of the foam in the presence of food soils is also judged. This is referred to as foam stability in the presence of soils. Foam must be present until the end of the dishwashing process. This performance measure is referred to as foam mileage or longevity. For some consumers, the quality of foam might also be important. This is particularly true for those consumers that use LDLDs to wash their hands. The quality or hand feel of the foam should be rich and thick however, the foam must rinse quickly from the dishes. 

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