Hand soap

The wax glycol distearate is added to make shampoos opaque and pearlescent. It has tiny flakes that mix well with surfactants, and stay in solution. They also add shear-thinning qualities, making liquid hand soaps pump out of the bottle more easily. 

Near the surfactant region the crystalline or lamellar phase is found. This is the region one finds in hand soaps. The ordinary hand soap is mainly the salt of fatty acid (coconut oil fatty acids or mixtures [85%] plus water [15%] and some salts. X-ray analyses have shown that the crystalline structure consists of a layer of soap separated by a water layer (with salts). The hand soap is produced by extruding under high pressure. This process aligns the lamellar crystalline structure lengthwise. If the degree of expansion versus temperature is measured, the expansion will be found... 

A compound that has two immiscible hydrophilic and hydrophobic parts within the same molecule is called an amphiphilic molecule (as mentioned earlier). Many amphiphilic molecules show lyotropic liquid-crystalline phase sequences, depending on the volume balances between the hydrophilic part and the hydrophobic part. These structures are formed through the microphase segregation of two incompatible components on a nanometer scale. Hand soap is an everyday example of a lyotropic liquid crystal (80% soap + 20% water). 

These structures are extensively described in the current literature (Fanum, 2008 Friberg, 1976 Birdi, 2002 Holmberg, 2004 Somasundaran, 2006). Even within the same phases, their self-assembled structures are tunable by the concentration for example, in lamellar phases, the layer distances increase with the solvent volume. Lamellar structures are found in systems such as the common hand soap, which consists of ca. 0% soap + 20% water. The layers of soap molecules are separated by a region of water (including, salts etc.) as a kind of sandwich. The x-ray diffraction analysis shows this structure very clearly. Since lyotropic liquid crystals rely on a subtle balance of intermolecular interactions, it is more difficult to analyze their structures and properties than those of thermotropic liquid crystals. Similar phases and characteristics can be observed in immiscible diblock copolymers. 

Synthetic musks are important ingredients for the fragrance industry. They are heavily used in laundry detergents, fabric softeners, cleaning products, air fresheners, and so on, and in cosmetic and personal hygiene products such as hand soap, shampoo, and perfume. Nitro, polycyclic, macrocyclic, and the newest dass, alicydic musks constitute the four major classes. The OSPAR (Oslo-Paris) Commission summarized information on their environmental behavior that was relevant to its charge, namely protection of the northeast Atlantic marine environment [37]. Most of the identified uses of synthetic musks are expected to lead to their release to... 

Surfactants and Detergents Uses. Perhaps tire largest use of sulfonic acids is the manufacture of surfactants and surfactant formulations. In almost till cases, the parent sulfonic acid is an intermediate which is converted to a sulfonate prior to use. The largest volume uses for sulfonic acid intermediates arc the manufacture of heavy-duty liquid and powder detergents, light-duty liquid detergents, hand soaps (see Soaps), and shampoos. 

Many anionic surfactants can react with a cationic dye such as methylene blue to form strong ion pairs that can be extracted by a suitable organic solvent and can be determined using colorimetric techniques. The anionic surfactants that respond to the methylene blue test are primarily the sulfonate (RS03 Na+) and the sulfate ester (R0S03 Na+) type substances. On the other hand, soaps and the alkali salts of fatty acids (C-10 to C-20) used in certain detergents do not respond to the above test. The various anionic surfactants and their characteristic structural features are presented in Figure 2.32.1. 

In personal care, washing involving the body, hair and teeth is the fundamental application of surfactants and there are also important roles played by surfactants as emulsifiers in skin care products. In the late 1970s the hand soap market was revolutionised by the introduction of liquid soaps based on synthetic surfactants as opposed to the bar soaps based on natural... 

One of the most widely used antimicrobial products today is 2,4,4 -trichloro-2 -hydroxydiphenyl ether, known more commonly as triclosan (Fig. 15. Id). Triclosan finds extensive use in mouthwashes, toothpastes, liquid hand soaps, deodorant products, and the like. Although it is effective against most bacteria, it has poor antifungal properties. Triclosan is also important as a textile finish, but since its water solubility is very low, aqueous application requires use of dispersing agents and binders. 

In the daily care of contact lenses, wearers are instructed to clean their hands with soap and to dry hands their hands with lint-free towels prior to handling their lenses. Selection of the specific soap product is important. In addition, to cleaning the hands thoroughly, it should be rinsing and should not cause ocular irritation even if residual amounts are transferred to the lens. With these considerations in mind, some hand soaps have, therefore, been designed specifically for contact lens users. 

What is the approximate concentration of hydroxide ions in a solution of hand soap ... 

Assessment of safety for use The materials at issue here are the full range of products for which dermal exposure will occur in the normal course of use. These range from cosmetics and hand soaps to bleaches, laundry detergents, and paint removers. No manufacturer desires to put a product on the market, which cannot be safely used and will lead to extensive liability if placed in the marketplace. Accordingly, the desire here is to accurately predict the potential hazards in humans that is, to have neither false positives nor false negatives. 

Amphosol [Stepan]. (cocamidopropyl betaine) TM for chemical used in shampoos, liquid hand soap, bubble bath, thickeners, and foam enhancers. 

Brown and Kaplan made use of the buffering property of oils in phenol solutions. Their formulation contained up to 95% phenol combined with oils. A patch test behind the ear had to be carried out before the facial peel. If there was skin necrosis, they reduced the strength of the phenol by gradually adding oil in small quantities until the right dose was found for the patient s skin. To increase the strength of the mixture, on the other hand, soap (saponified cresol) was added or the concentration of phenol was increased. 

New liquid hand soap products introduced to the market in the last decade continue to focus on superior cleaning plus antibacterial and skin moisturizing benefits. Triclosan is the universal choice of antimicrobial agent for these products. 

Hand soap concentrate, use solution, and method for modifying a hand soap concentrate... 

Examples of time sweep test results at 2 Hz for an antibacterial hand soap are shown in Figure 4.11 and Figure 4.12. Figure 4.11 summarizes the complex modulus components, G andG", and the complex viscosity, n, while Figure4.12 shows the experimental variables of phase angle and amplitude obtained at 23 to 24°C. 

FIG. 4.11 Measurement results for an antibacterial hand soap determined at 2 Hz using the T2SR rheometer at room temperature. 

Antibacterial LDLD compositions are regulated by the FDA in the U.S. The reason is because they are positioned as antibacterial liquid hand soaps. ... 

Figure 11.1 and Figure 11.2 show some representative commercial liquid hand soap and liquid body wash/shower gel products from around the world. 

FIG. 11.1 Commercial liquid hand soap products from around the world. 

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