Ionic dispersing agent

The basic dyes are applied from a liquor the pH of which is 5-5 for pale to medium and 4-5 for heavy shades. For the medium shades 1 g/1 of acetic acid (80 per cent) wiU give the desired pH for heavy shades 1 g 1 of acetic acid (80 per cent) and 1 g/ of sodium acetate wUl be required. It is also ad isable to add 1 gjl of a non-ionic dispersing agent. In most cases there is very little adsorption of the dye below 75°C (167°F) and the critical range is from 80 to 100°C as shown in the graph in Fig. 23.12. It is therefore advisable to raise the temperature to 75°C quite rapidly (20 minutes) and then allow one hour for it to reach 100°C. 

Dispersing agents for polar or ionic solids in hydrocarbon media generally have polarizable lyophobic groups and long alkyl chains that can extend into the solvent. They can be monomeric or polymeric. 

Three different ways have been developed to produce nanoparticle of PE-surfs. The most simple one is the mixing of polyelectrolytes and surfactants in non-stoichiometric quantities. An example for this is the complexation of poly(ethylene imine) with dodecanoic acid (PEI-C12). It forms a solid-state complex that is water-insoluble when the number of complexable amino functions is equal to the number of carboxylic acid groups [128]. Its structure is smectic A-like. The same complex forms nanoparticles when the polymer is used in an excess of 50% [129]. The particles exhibit hydrodynamic diameters in the range of 80-150 nm, which depend on the preparation conditions, i.e., the particle formation is kinetically controlled. Each particle consists of a relatively compact core surrounded by a diffuse corona. PEI-C12 forms the core, while non-complexed PEI acts as a cationic-active dispersing agent. It was found that the nanoparticles show high zeta potentials (approximate to +40 mV) and are stable in NaCl solutions at concentrations of up to 0.3 mol l-1. The stabilization of the nanoparticles results from a combination of ionic and steric contributions. A variation of the pH value was used to activate the dissolution of the particles. 

Leveling/dispersing agent for acid dyeing of nylon--non-ionic. DYLEV NC ... 

Altun A, Ozbay G. Effects of ionic versus non-ionic contrast agents on dispersion of ventricular repolarization. Turk Kardiyol Dernegi Ars 1998 26 362-7. 

Sorbitan monoesters are partial esters of sorbitol with fatty acids (monolaurate in this case). They have a molecular weight of between 346 and 964. Sorbitan monolaurate is widely used in cosmetics, the food industry and pharmaceutical preparations. Sorbitan monoesters are non-ionic surfactants, dissolving and dispersing agents. One of the problems of using sorbitan monoesters is that in the presence of strong acids (like TCA) they tend to form soaps that have no power to attack the skin. This is partly why TCA adjuvanted with sorbitan monolaurate is less aggressive for the skin. 

Non-ionic brightening agent can also be taken up by the fibre from suspensions. The fibre material is treated with a solution containing disperse type brighteners and 2% formic acid (85%) (pH 3 to 4) at 100°C for 30 to 40 min. Exhaustion can be accelerated by raising the temperature of the bath to 110 C. 

Examples of commonly used dispersing agents containing multiple ionic groups and aromatic hydrophobic groups are p-naphthalene-sulfonic acid-formaldehyde condensates and ligninsulfonates (Chapter 1, Section IA2). 

The PIB macroinitiators can also initiate living anionic polymerization of a wide variety of functional monomers, such as vinyl pyridine, N,N-dimethylacryl-amide, and a variety of protected monomers, such as silylated 2-hydroxyethyl methacrylate. Polymerization studies with these monomers are in progress. The resulting products are potential new thermoplastic elastomers, dispersing agents, blending compounds, emulsifiers, non-ionic surfactants, biomaterials etc. 

Phospholipids are ionic amphiphiles, and due to the amphiphilic character they function well as emulsifying and dispersing agents. ... 

White base paint + pigment paste based on universal dispersing agent + ionic liquid as third component (so-called post addition)-efficiency of procedure (A) is higher than (C), but the negative point of it is that it requires higher quantities of the iraiic liquid... 

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