Oily soil detergency

BIO-SOF N-300 Calsoft T-60 detergent, oily soils Hydromax 300 detergent, ointments... 

In detergency, for separation of an oily soil O from a solid fabric S just to occur in an aqueous surfactant solution W, the desired condition is 730 = 7wo+7sw. Use simple empirical surface tension relationships to infer whether the above condition might be met if (a) 73 = 7w. (6) 70 = 7W, or (c) 73 = 70. 

Oil-wet reservoirs, 73 614 Oily-soil detergency, 3 433-437 Ointments, ophthalmic, 73 716 Oka/Merck varicella-zoster virus, 25 496-497... 

Solubilisation is important in the formulation of pharmaceutical drugs containing water insoluble ingredients, in detergency (removal of oily soil), in emulsion polymerisation and in micellar catalysis. 

We also describe the spreading of a thin surfactant laden aqueous film on a hydrophilic solid, i.e., one in which the dynamic contact angle is small. In such a case, the osmotic pressure gradient generated by the nonuniform distribution of surfactant micelles in the liquid film can drive fhe spreading process. The mofivation for this study comes from the need to understand the detergent action involved in the removal of an oily soil from a soiled surface. This paper presents an overview of our recent work. 

Alkaline cleaners are available which allow the separation of excess oily soil from the cleaner. These formulations involve the use of surfactants that are good detergents but poor emulsifiers. Agitation of the bath during the work shift causes a temporary emulsification, which keeps the soil in suspension. After a prolonged period of inactivity (usually overnight), the oily soils float to the surface where they are skimmed off. This method is quite effective with mineral oil-type soils but is less so with fatty oils. 

Notes Use of detergent quaternary greatly improves performance oily soils Formula L-102... 

Each component has a specific function. The Metasilicate will increase paint stripping efficiency provided sufficient alkalinity is present. The Gluconate or Glucoheptonate provide the derusting. Burco TME and Burco ADS-100 provide removal and dispersion of particulate soils while the Dodecylbenzenesulfonate adds wetting and oily soil detergency. Each component can be adjusted according to the improvement needed. 

Solubilisation is of practical importance in the formulation of pharmaceutical and other products containing water-insoluble ingredients51, detergency, where it plays a major role in the removal of oily soil (pages 166-176), emulsion polymerisation (page 17) and micellar catalysis of organic reactions52. 

Solid soils are commonly encountered in hard surface cleaning and continue to become more important in home laundry conditions as wash temperatures decrease. The detergency process is complicated in the case of solid oily soils by the nature of the interfacial interactions of the surfactant solution and the solid soil. An initial soil softening or "liquefaction", due to penetration of surfactant and water molecules was proposed, based on gravimetric data (4). In our initial reports of the application of FT-IR to the study of solid soil detergency, we also found evidence of rapid surfactant penetration, which was correlated with successful detergency (5). In this chapter, we examine the detergency performance of several nonionic surfactants as a function of temperature and type of hydrocarbon "model soil". Performance characteristics are related to the interfacial phase behavior of the ternary surfactant -hydrocarbon - water system. 

Figure 3.12 Two liquids A (detergent) and B (oily soil) on a solid surface (a) separated and (b) in contact, yA and yB = wetting tensions, yAB = interfacial tension, R = interfacial wetting tension [3].

The presence of surfactants also influences the overall efficiency of other active ingredients of detergents, e.g. bleach and enzymes. Afirst requirement for the efficacy of these ingredients is a wetting of the textile substrate and hydrophobic or oily soils by the washing liquor. Besides this wetting function, all the other effects of soil removal of surfactants which have been... 

Figure 3.32 Build-up and breakdown of the foam of different high-foaming light-duty detergents in presence of an oily soil (reproduced with permission [9]).

Of these mechanisms, solubilisation and emulsification of soils are controlled by detergent composition, hydrodynamic flow is controlled by washing machine design and fibre flexing is controlled by fabric construction. The textile chemist can only influence the mechanisms that involve the fibre surface, i.e. rollup of oily soil, penetration of soil-fibre interface, surface abrasion and finish swelling. Finishes have been developed that provide soil release performance by taking advantage of all of these mechanisms. 

When a surfactant-water or surfactant-brine mixture is carefully contacted with oil in the absence of flow, bulk diffusion and, in some cases, adsorption-desorption or phase transformation kinetics dictate the way in which the equilibrium state is approached and the time required to reach it. Nonequilibrium behavior in such systems is of interest in connection with certain enhanced oil recovery processes where surfactant-brine mixtures are injected into underground formations to diplace globules of oil trapped in the porous rock structure. Indications exist that recovery efficiency can be affected by the extent of equilibration between phases and by the type of nonequilibrium phenomena which occur (J ). In detergency also, the rate and manner of oily soil removal by solubilization and "complexing" or "emulsification" mechanisms are controlled by diffusion and phase transformation kinetics (2-2). 

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