Detergents foam performance

The LAS/AS and LAS/AS/AES combinations used in some U.S. spray-dried laundry powders for more than 30 years have provided good detergency with moderate to high foaming performance [39]. A typical example of a low-density, spray-dried, high-foaming laundry powder is shown below ... 

Uses Detergent, foaming agenL foaming detergent for pharmaceuticals, cosmetics, bubble baths, high performance light-duty liquid formulations... 

Quahty control testing of siUcones utilizes a combination of physical and chemical measurements to ensure satisfactory product performance and processibihty. Eor example, in addition to the usual physical properties of cured elastomers, the plasticity of heat-cured mbber and the extmsion rate of TVR elastomers under standard conditions are important to the customer. Where the siUcone appHcation involves surface activity, a use test is frequently the only rehable indicator of performance. Eor example, the performance of an antifoaming agent can be tested by measuring the foam reduction when the sihcone emulsion is added to an agitated standard detergent solution. The product data sheets and technical bulletins from commercial siUcone producers can be consulted for more information. 

If one compares several commercial LAS samples for foam stability, detergency performance, critical micelle concentration (CMC), hardness sensitivity, or... 

The DATs present in LAB will readily sulfonate to form dialkyltetralin-sulfonate or DATS. The foam and detergency performance properties of individual C DATS homologs are very similar to that of the corresponding C j LAS homologs [21]. Thus, even at a level of 10% DATS in the LAB, no decrease in foam or detergency performance is observed. In some liquid formulations, the presence of DATS can provide a beneficial hydrotropic effect to LAS [22]. Figure 8 illustrates that DATS are indeed surfactants, as evidenced by their surface tension vs. concentration plot. 

Monoamidotriphosphate compounds have been evaluated for their combined detergent-sequestrant action [65,66]. Good surfactant properties are also attributed to organoaminodialkylenephosphonic acids. Typical compounds of this kind are the tetra- and trialkali salts of decyl-, dodecyl-, and tetradecylaminodi (methylphosphonate). Values of surface tension and detergency are given in Refs. 118 and 216-219. Wash test results, foam behavior, wetting performance, and surface tensions of aqueous solutions of phosphate esters have been tabulated [12,17,18,33,37,50,52,56,90,220]. 

Due to their distinctive physico-chemical properties, non-ionic surfactants are applied in the fields of industry, processing technology and science, wherever their interfacial effects of detergency, (de)foaming, (de)emulsification, dispersion or solubilisation can enhance product or process performance. The characteristics of non-ionic surfactants that make them beneficial for detergents include their relatively low ionic sensitivity and their sorptive behaviour [17]. 

The continued use of ABS in some small markets, for example the South East Asia region, despite the advantages offered by LAS in terms of performance characteristics such as foam generation and detergency [75,76], seems to be linked to political situations (oleochemical producer pressure) rather than to any other economical justification. 

Some chemical additives such as corrosion inhibitors, wax crystal modifiers, detergents, and demulsifiers provide performance which is difficult to duplicate through refining without adversely affecting some other fuel property. Other additives such as metal chelators, fuel sweeteners, biocides, lubricity improvers, foam control agents and combustion enhancers can also be used to solve fuel performance problems. 

Because the sarcosinates have the ability to raise the cloud point of nonionic surfactants, this feature can be used to advantage in the formulation of dishwasher rinse aids. At the cloud point and up to 15C above it, foam generation is reduced and detergency is enhanced. By adjusting the cloud point of the formula to the use temperature, one can take full advantage of this performance feature. 

Good foam breakability of SAE having a lower carbon range may lead to excellent performance in detergent formulations which other surfactants have never shown. 

The adsorption mechanisms of surfactant at interfaces have been extensively studied in order to understand their performance in many processes such as dispersion, coating, emulsification, foaming and detergency. These interfaces are liquid-gas (foaming), liquid-liquid (emulsification) and liquid-solid (dispersion, coating and detergency). 

Applications. At present there are very few known applications, although the surfactants have significant potential due to their unique properties. Sulphonated fatty acids are used in some hard-surface cleaning formulations where their low foam is a benefit and in emulsion polymerisation, where they perform similarly to LAS but with greatly reduced tendency to foam. Future applications for these products may include machine dishwash, extended use in detergent products and industrial applications such as pigment dispersants. For these to be realised, further process development will be required to give a more consistent and better defined product. 

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