Oily Soil

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. 

Roll-up. The principal means by which oily soil is removed is probably roU-up. The appHcable theory is simply the theory of wetting. In briefest outline, a droplet of oily soil attached to the substrate forms at equiUbrium a definite contact angle at the oil-sohd-air boundary line. This contact angle (Fig. 4) is the result of the interaction of interfacial forces in the three phase boundaries of the system. These interfacial forces, expressed in mN/m(= dyn/cm), or interfacial free energy values expressed in mj/m (erg/cm s) are conveniently designated 1SA iSlj subscripts relate to the Hquid-air,... 

The phenomena at the liquid/liquid interface are of outstanding importance for the removal of oily soil from the surface. The interfacial tension is one of the decisive parameters in the rolling-up process. This parameter vary considerably, de-... 

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

General Remarks. In the use of products containing alkyl ether sulfates, oily soil removal as well as dispersion plays an important role. The driving force responsible for the separation of oily soil from a substrate (Fig. 10) is the wetting tension j defined by equation (1) ... 

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. 

There are several features to note about Figure 4.7. While water will bead on a surface prepared with PTFE or an FA, it will wet a nylon-6,6 surface. For the case of hexadecane, botlr PTFE and FA surfaces will show appreciable contact angles, while a nylon-6,6 surface will be wetted completely (0 = 0). This is the reason that oily soils are relatively difficult to remove from materials made from nylon-6,6. The surface of a material prepared with a FA using perfluoroalkyl chains often has a lower surface tension than PTFE. For comparison, the surface tensions of nylon-6,6, PTFE " and FAs are estimated to be about 46, 24, and 10-20 mN/m, respectively. 

The surface tensions of materials prepared with are some of the lowest attainable with the reagents commonly available, which is why many carpet and textile repellents are based on the chemistry of perfluoroalkyl chains. For example, a nylon-6,6 carpet would be wetted by oily soils, which, according to Eq. (4), would be difficult to remove. The presence of a FA coating on die fiber lowers its surface tension and repels the oil contaminant. In general, a liquid dial has a high surface tension will not wet a solid with low surface tension (e.g., water on PTFE). The converse is also true. A low-surface-tension liquid will wet a high surface tension solid (e.g., hexadecane on nylon-6,6). 

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. 

The preparation of cellulose copolymers with vinyl monomers, which have functional groups that are hydrophilic in nature, has given textile products with improved soil release properties. For example, as shown in Figure 5, crosslinked cellulose-poly (methacrylic acid) copolymer fabrics exhibited both increased oily and aqueous soil release during washing compared with the crosslinked control fabrics. However, for oily soil, when softeners were added to the wash water, this improvement in soil release decreased. Crosslinked cellulose-poly (hydroxyethyl methacrylate) copolymer fabrics exhibited no improvement in oily soil release and only slight improvement in aqueous soil release compared... 

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. 

Transformer storage lot—oily soil (3 samples), clayey soil (3 samples), and gravel (3 samples). 

Disposal pit—sandy soil, clayey soil, oily soil, industrial sludge, and gravel we will collect a minimum of 3 samples from each of them. 

The removal of liquid oily soils from surfaces is generally understood in terms of three basic mechanisms the roll - back of droplets of oily soil, the surfaces of which are modified by the presence of an adsorbed layer of surfactant direct emulsification of macroscopic droplets of soil and the direct solubilization of the oily soil into surfactant micelles or other interfacial phases formed (1-3). 

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. 

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