Nonionic gels, preparation

Nonionic surfactants, including EO-PO block copolymers, may be readily separated from anionic surfactants by a simple batch ion exchange method [21] analytical separation of EO-PO copolymers from other nonionic surfactants is possible by thin-layer chromatography (TLC) [22,23] and paper chromatography [24], and EO-PO copolymers may themselves be separated into narrow molecular weight fractions on a preparative scale by gel permeation chromatography (GPC) [25]. 

The photoelastic behavior of nonionized PAAm network and ionized P(AAm/MNa) network prepared by the copolymerization of AAm with MNa ( MNa = 0.05) was investigated in water-acetone mixtures [31]. For a pure PAAm network, the dependences of all photoelastic functions (see Eqs. (15) and (16)), i.e. modulus G, strain-optical function A and stress-optical coefficient C, on the acetone concentration in the mixtures are continuous (Fig. 17). At ac = 54 vol %, the ionized network undergoes a transition which gives rise to jumpwise change in G, A and C also the refractive index of the gel n8 changes discontinuously. While in the collapsed state the optical functions A and C are negative, in the expanded state they are positive. 

Early oxidation hair dyes were used in solution form these have been replaced by cream- or gel-based formulas. The oil-in-water emulsions commonly used can be supplemented with auxiliary ingredients, such as polymers to improve combing ability, as well as other conditioning additives. Extensive patent literature is available on this point [35], Gel formulations may be based on alcoholic solutions of nonionic surfactants or fatty acid alkanolamide solutions, which form a gel when mixed with the oxidant. The type (emulsion or gel) and the basic composition of the preparation strongly influence dyeing [47], Different base formulations with the same dye content yield varying color depths and shading due to the distribution of the dye between the different phases of the product, interaction with surfactants, and diffusion from the product into the hair. 

Stable o/w creams prepared with ionic or nonionic emulsifying waxes are composed of (at least) four phases (Fig. 7.20) (f) dispersed oil phase, (2) crystalline gel phase, (3) crystalline hydrate phase, and (4) bulk aqueous phase containing a dilute solution of surfactant. The interaction of the surfactant and fatty alcohol components of emulsifying mixtures to form these stmctures (body) is critical. It is also time-dependent, giving the name self-bodying to these emulsions. The overall stability of a cream is dependent on the stability of the crystalline gel phase. 

The mesoporous aluminas synthesized using a nonionic templating method are thermally stable not only to template removal, but also to prolonged heating at elevated temperature. Therefore, these aluminas would be able to maintain their unique structural features in fairly demanding catalyst preparations and catalytic applications. Unlike sol-gel-derived aluminas, the synthesis temperature used for the hydrolysis and condensation of the aluminum alkoxide did not affect the resulting thermal evolution from the aluminum hydroxide to transitional alumina and the subsequent thermal stability of the transitional alumina. The only observed effect of synthesis temperature was the impact on median pore diameter and pore volume.[231]... 

Traditionally, anionic surfactants have offered better detergency then nonionics, but were not compatible in acid systems. This formulation uses Avanel S-70, an anionic molecule which performs even at very low pH s and aids in the removal of surface oils and deposits. Unlike nonionics, Avanel S-70 will dissolve readily into the formulation without forming gel particles thus eliminating the need for excessive agitation. This formulation can be used for over-the-road aluminum trailers, wire wheels on automobiles or in the preparation of aluminum for anodizing and cleaning. 

The order of component addition is important. The mixing of concentrated anionic and nonionic surfactants must be avoided because it produces gels that dissolve very slowly. Typically, a master batch of nonionic surfactant, initiator, and LMA was prepared for use with all the solutions of a series of experiments. This approach ensures that the small concentration components are all at the same concentration. To a portion of this well-mixed master batch was added more nonionic surfactant if necessary, propanamide (if used), water to about 80 g, anionic surfactant, mercaptoethanol, and water to 100 g, with stirring as appropriate. 

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