Emulsification condensation

As water vapor in the air cools and reaches its dew point, it begins to condense and fall from the air. Condensation of water vapor on the inside of fuel storage and transportation equipment can lead to unexpected water-related problems such as emulsification and bacterial growth. Fuel system condensate water accumulation... 

It is most often prepared by acid hydrolysis of sodium silicate followed by emulsification in an alcohol water mixture and subsequent condensation to give solid silica gel. This is then washed and dried for use as HPLC column packing. The exact conditions under which these procedures are carried out (e.g. pH, catalysts, temperature) will affect the properties of the resulting material. The most important qualities with regard to the chromatographic performance of the gel are the average particle size, the particle shape, the specific surface area and the pore size. Other factors which are also important are the pH of the gel surface, the number of active silanol groups and the presence of metal ions. 

In the new process, other separation zones are added after the normal first separation zone. The heavy phase from the first zone is sent to a suipper and the vaporized solvent, steam, and fine mist particles are withdrawn from the top and are conveyed to the second separation zone. In the second separation zone, the stream consisting of solvent, steam, and mist particles flow through a circuitous path where it is contacted couniercurrently with a sU eam of light oil which scrubs the asphaltene and resin mist from the solvent. A portion of the light phase oil containing asphaltenes and resins is recycled to the second separation zone or it can be recycled to the first separation zone. The solvent and steam mixture leaving the second zone is conveyed to a solvent condenser and water separation zone. No emulsification problems are exp>erienced because the mist particles have been removed in the first separation zone. 

Lyophobic emulsions are generally obtained by dispersion (emulsification) of one liquid in another in the presence of surfactants. Surfactants used in this application are referred to as emulsifiers these are typically the surfactants belonging to the third and fourth groups (see Chapter II). Only a few types of usually dilute emulsions can be formed by condensation. These include an oil emulsions formed in steam engines. 

First, 100 parts of m-dinitrobenzene is added to 1,000 parts of water at 90 C contained in a reducer fitted with a reflux condenser and a propeller-type stirrer. Upon emulsification, 245 parts of sodium sulfide (9HaO), dissolved in a minimum of water, is gradually run in. The dinitro compound is gradually reduced to m-nitroaniline, the end point being determined by the formation of a definite black streak when ferrous sulfate solution is added to filter paper spotted with some of the reducer liquor. 

In this paper, an accurate method for determining the concentration of manganese and other metals in gasoline and diesel fuel by ICP without the use of chilled spray chamber, direct injection nebulizer, ultrasonic nebulizer with micro-porous membrane desolvator, thermostated condenser, or emulsification is discussed. 

The process has been extensively explored by Barbe and coworkers in Australia (where the same scientists established the spin-off company Ceramisphere), and can be viewed as an emulsification of a sol-gel solution in which gelation takes place concomitantly. Depending on the order of addition of the different chemicals, furthermore, the porous microparticles prepared from interfacial hydrolysis and condensation of TEOS in W/0 emulsion will be full porous matrix particles or core-shell capsules. Normally, if the emulsification of the sol-gel solution takes place concomitantly with gelation, full microparticles are formed with the dopant molecules homogeneously distributed within the inner huge porosity of the particles (Figure 18.3). 

Another common approach to water-based coating formulations is post-emulsification of a polymer in water. Several condensation polymers, e.g. alkyds, i.e. fatty-acid-modified polyesters, polyurethanes and epoxy resins, have been made into dispersions by the use of a suitable emulsifier and application of high shear. For instance, long oil alkyd resins of the type used in white-spirit-based formulations have been successfully emulsified by using nonionic surfactants such as fatty alcohol ethoxylates, alkylphenol ethoxylates or fatty acid monoethanolamide ethoxylates. Neutralization of alkyd carboxylic groups helps in producing small emulsion droplets and with the proper choice of surfactant, droplet diameters of less than 1 pm can be obtained. Such dispersions are sufficiently stable for most applications. 

Finally, under well-defined conditions, it is possible to polymerize performed emulsion droplets. This is especially true for emulsions prepared by condensation methods where the conditions can be controlled in such a way that both secondary nucleation can be avoided and droplet or particle stability can be maintained during the entire polymerization. In the case of emulsions prepared by comminution techniques, suspension polymerization is a good example of a system where the (conditions) properties of emulsions can be converted into the corresponding properties of sols/suspensions. For smaller drop sizes, the solubility of the monomer in water is crucial, but unfortunately, very hydrophobic monomers are technically unimportant, at least nowadays. The addition of hydrophobic molecules needs tailored emulsification procedures regarding and DSD, and a certain maturation time to result in stable emulsions. Miniemulsion polymerization is a promising way, although the question as to what extent a 1 1 copy of an emulsion is possible is still waiting for an answer. 

Metallic sulfonates, such as sodium sulfonate, are often used as emulsifiers in both water-in-oil and oil-in-water emulsions. Other emulsifiers used include ethylene oxide condensation products and derivatives of polyhydroxy alcohols such as sorbitol and sulfosuccinates for water-in-oil emulsions. For oil-in-water emulsions, soaps of fatty acids, rosins, or naphthenic acids are often used as emulsifiers. In either application, the role of emulsifiers is to change the interfacial tension at the water and oil interface. In cases where emulsification with water is undesirable, demulsifiers are used. Frequently, the demulsifiers are heavy metal soaps, such as alkaline earth sulfonates. These surfactants function by lowering emulsion stability. 

Surface pressure measurements at the air-water interface showed that the lipid molecules begin to associate at low monoglyceride monomer concentration (typically 10 mol dm for mono-olein), forming a cubic structure. Monoglycerides of saturated fatty acids associate to form lamellar liquid crystalline phases at low concentrations. These condensed layers form at the oil-water interface at and above the critical temperature which is the temperature used for emulsification. These liquid crystalline phases play a major role in emulsion stabilisation (see Chapter 6). As discussed before, lamellar liquid crystalline phases form at the O/W interface, providing a barrier against coalescence. These multilayers signifi-... 

Either plant steam or steam from a portable steam generator can be used. If a steam lance is used, the detergent solution may enter the steam gun by venturi action and mix with the steam. Steam removes oil, greases, and soaps by first thinning them with the heat. Dispersion and emulsification of the oils then occurs, followed by dilution with the condensed steam. The system should provide control over the steam, water, and detergent flows so that the full effects of the detergent s chemical action, the heat of the steam, and the abrasive action of the pressure jet are attained for maximum cleaning efficiency. 

The subject of dispersion polymerisation in organic media has been comprehensively reviewed (Do This reference should be consulted for a detailed treatment of the theory of particle stabilisation and the kinetics and mechanism of free radical dispersion polymerisation in organic mediae In this paper, emphasis is placed on the more practical aspects of preparing polymer latexes and on useful empirical rules for newcomers to the field wishing to make their own latexeSc Processes for the preparation of latexes by addition and condensation polymerisation and by inverse emulsification of aqueous monomer solutions in organic liquids are reviewedo... 

Resin-water emulsions can be produced by the post-reaction emulsification of a condensation or addition polymer, by the use of surfactants or emulsifiers to form an oil-in-water emulsion of the polymer in the aqueous phase. This is simply a method of obtaining a polymer in an aqueous medium. This type of emulsion is different from a tme emulsion polymer made by the process of emulsion polymerisation. 

Chem. Descrip. Pre-neutralized emulsifable amidoamine condensate Uses Softener base imparting a dry, soft hand to cotton and other fabrics Properties Disp. in hot water DM-1722-A [Octel Perf. Chem. Thornley]... 

CONDENSATION OR LOW-ENERGY EMULSIFICATION METHODS RELATION BETWEEN PHASE BEHAVIOR AND NANO-EMULSION PROPERTIES... 

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