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Four oil dispersants of interest for practical use in the Baltic Sea were tested as regards toxicity to animals from the littoral zone of the same area. The dispersants tested were Corexit 7664, Berol TL-188, Berol TL-198, all water-base dispersants, and BP 1100-X, an oil-base dispersant. Two species of fish, two species of bivalves and two species of crustaceans were tested. Significant differences in toxicity were found between the water-base dispersants at concentrations above 1700 ppm. Below this concentration there were no significant differences. The dispersants contain similar surfactants in similar concentrations, but differ with respect to types and amount of solvent. The observed differences at high concentrations are, therefore, argued to be connected chiefly to differences between these solvents. Differences in toxicity to different animal types were found between the water-base dispersants and the oil-base dispersants. The toxicity of Corexit 7664 was (96h LC50 approximate values): fish, 1000 ppm; bivalves, 2000 ppm; crustaceans, 10,000 ppm. The toxicity order was strikingly reversed for BP 1100-X: crustanceans, 150 ppm; bivalves, 2000 ppm; fish, 10,000 ppm. This difference in toxicity for different animal types is suggested to be connected mainly to differences in the chemical character of the outer layer of the body surface of the animals.

The occurrence of emulsions and froths in flotation and SX circuits is a hydrometallurgical problem that may reoccur in many plants, resulting in down time and considerable expense. The mechanics of their occurrence is more clearly understood by microscopic study and application of surface chemistry.Deleterious froths and emulsions may be attributed to a number of causes, the most common of which are colloidally dispersed solids (or hydrosols) that concentrate along interfaces between oil and water. The structure of an emulsion or froth may be studied microscopically to determine the internal and external phases and to identify the emulsifying agent. After establishing the cause, ways of elimination and future prevention can be suggested. Effective ways of prevention may include (1) change in pH, (2) addition of flocculating agent to remove emulsifier, (3) addition of dispersing agent to disperse emulsifying agent, (4) change in plant practice to avoid formation of surface active materials, etc.S...

The toxic effects of crude oil, the dispersant, Corexit 7664, and mixtures of these on the respiration and mortality of two species of bivalve have been examined. A light Arabian crude is most toxic to one, Corexit is most toxic to the other. The susceptibility to oil of the mussel Brachidontes is also reflected in a significant depression of respiration rate at sub-lethal concentrations.

Crawling and respiration rates of the snail Littorina littorea are increased in the presence of Bunker C oil and decreased with brief exposure to a low toxicity dispersant (Corexit 8666) in sea water at 20 C. The addition of the dispersant to an oil:seawater mixture also decreases both crawling and respiration. Behavioral traits, such as crawling, and physiological indices, such as respiration, may be sensitive measures of sublethal effects of pollutants on organisms.

Lactose, the principal solid component of whey, is a potentially inexpensive and abundantly available raw material. Its chemical structure is well suited to serve as the hydrophilic portion of a nonionic surfactant molecule. Accordingly, a series of esters of lactose was prepared by reaction of fatty acid chlorides with anhydrous lactose in N-methyl-2-pyrrolidinone. Monoesters of lauric, myristic, palmitic, stearic, oleic, and tallow fatty acids were obtained in this manner. Other methods of synthesis of the products were investigated but were unsuccessful. The lactose esters and their oxyethylated products were evaluated for detergency behavior, emulsification time, and lime soap dispersant requirement. The results indicate that their surfactant properties are comparable to those exhibited by analogous sucrose derivatives.

Corn starch was depolymerized by gamma irradiation (cobalt 60, approximately 1.25 Mrads/h) to prepare reduced viscosity products for surface-sizing paper. The general effects of irradiation were determined on the extent of starch degradation, as well as dispersion variables. Low levels of irradiation, 0.02 to 0.5 Mrad, had a profound influence on granule swelling and disruption at a pasting temperature of about 90°C as determined in a recording viscometer. Product properties are affected considerably by carbonyl and carboxyl groups even when introduced at levels below 1 mmol/100 g. Carbonyl groups impart alkali sensitivity that produces significant degradation during dissolution in stoichiometric quantities of alkali. Carboxyl groups in starch paper sizes are detrimental because they act as dispersants for fines and fillers in repulped paper. Apparently dispersion in alkali is the most effective way to utilize irradiated starches as surface-sizing agents. Corn starch irradiated to 2 Mrads and dispersed in alkali improved paper properties as well as a high quality commercial product.

The toxicities to marine animals of nine oil dispersants, three oil emulsions with Corexit and of a dispersion of Oman crude oil, have been studied in continuous flow aquarium systems at 96-h exposures followed by a recovery period in clean sea-water. New types of dispersants were found to be less toxic than older types and oil emulsions more toxic than dispersants alone or crude oil alone. Fishes and bivalves were found most sensitive. Crustaceans were the most resistant to dispersants but very susceptible to oil emulsions. The tolerance of different species was found to be related to their mode of life, more active species being more susceptible. Delayed mortality of bivalves increased their susceptibility if the recovery period was included. Effects on locomotory behaviour of fishes and crustaceans, breathing rate of fish, valve-closure of bivalves and byssal thread formation of common mussels have been demonstrated for both dispersants and oil emulsions. The general sequence of such effects was: increased activity; successively impaired activity; immobilization; and death. Recovery is good for fish and crustaceans but poor for bivalves due to the delayed effects. Ecological consequences of dispersants and oil pollution in the marine environment are discussed.

A series of sodium methyl N-alkylsulfosuccinamates was prepared by the reaction of methyl N-alkylmaleamates with sodium bisulfite in aqueous ethanol. The surface-active properties and detergency of these derivatives were compared with those of a series of disodium N-alkylsulfosuccinamates prepared by the reaction of sodium sulfite with N-alkylmaleamic acid in water. The ester derivatives generally showed good lime soap dispersing requirement and washing ability in combination with soap, where-as the disodium salts were somewhat deficient in these properties and exhibited good washing ability only at 0.2% concentration with the surfactant as the sole component.

α-Sulfo fatty alkanolamides were prepared by sodium methylate catalyzed reactions of methyl α-sulfo fatty esters with alkanolamines, such as ethanolamine, N-methyl-2-hydroxyethylamine, diethanolamine, 3-hydroxypropylamine, 2-hydroxypropylamine, and diglycolamine. Pure compounds, such as α-sulfo palmitamides and stearamides, as well as the α-sulfo tallow amides, were prepared and evaluated as surface-active agents. The α-sulfo fatty alkanolamides were found to have excellent stability to alkali. Their stability to acid ranged from excellent in the case of α-sulfo diglycolamides to poor in the case of α-sulfo diethanolamides. Poor stability to acid was related to ease of conversion to ester-amines. Washing tests on standard soil cloths showed that the compounds were good detergents by themselves and were also effective in combination with soap and silicates. Their lime soap dispersant requirements ranged from 7–10.

1. Conditions for carrying out the two stages in the preparation of succinimide additives have been established. 2. The physicochemical properties of the synthesized samples of additives have been studied. The nitrogen content of the final additive and its alkalinity increase as the amine and imine group content of the polyethylene-polyamine used for the synthesis increases. 3. The additive prepared from tetraethylenepentamine has better dispersive and wetting properties than the additive prepared from a polyethylenepolyamine fraction.

The following seven compounds were prepared, R-N=C-NH-_??_+SO3Na R : n-pentyl (1) : n-heptyl (2); n-nonyl (3); n-undecyl (4); n-tridecyl (5); n-pentadecyl (6); n-heptadecyl (7), and their physico-chemical properties in aqueous solutions were studied.The results obtained were as follows.1) Surface-active abilities such as reduction of surface tension, emulsification of liquid paraffin, solubilization of Orange OT, deflocculation of calcium carbonate and wet-through to the cotton cloth were observed in the aqueous solutions of sample (3), (4), (5), (6) and (7).2) Sample (6) and (7) appear to be excellent dispersants for various dyes and pigments.

As environmentalists, we must constantly be aware of, and recognize the potential pollution problems that might result from an oil spill cleanup approach or system. Based on biodegradability and ultimate oxygen demand data developed by the Edison Water Quality Laboratory as well as others, it would appear that more than knowledge of toxicity and emulsion efficiency should guide our decisions regarding the use of chemical dispersants for oil spill cleanup.

本資料は, 最近使用されている数多くのセメント分散剤 (コンクリート減水剤) について下記のような考察を行なったものである.(1) それぞれの主成分から分類した場合およびASTMの分類を参考にして現況を説明した.(2) 使用結果からみて, それぞれの銘柄による相違およびコンクリートの凝結および初期硬化速度に及ぼす効果の相違をそれぞれ“種類”および“型”による相違と表現し, セメント分散剤の種類および型について説明した.(3) AE剤と異なって, セメント分散剤は, それぞれの特性に非常に大きな相違があるため, 単位水量の減少効果, 圧縮強度に及ぼす影響, および初期硬化速度に関する実験結果を示し, 結果から種類, 型による相違点を示し, 正しいセメント分散剤の使用方法について説明した.

Direct infrared spectrophotometric evidence of interactions between lubricating oil dispersants and a zinc dialkylphosphorodithioate (ZDP) is presented. Increasing the concentration of the dispersants polyamino monoalkenylsuccinimide, barium thiophosphonate, and basic barium dinonylbenzene sulfonate in a mineral oil containing 1.2% by weight of a ZDP decreased the intensity of the phosphorus-oxygen-carbon and phosphorus-sulfur infrared bands, and caused the appearance of a new band at 668 cm−1. The dispersants barium dinonylnaphthalene sulfonate, calcium petroleum sulfonate, and alkaline petroleum sulfonate decreased the intensity of the phosphorus-sulfur bands only after the solutions had aged, and independently of dispersant concentration. It is speculated that chemical reactions cause these interactions between the ZDP and the dispersants, and that ionic metal phosphorodithioates are formed. The possibility of association, isomeric, and complexation effects is also explored. Regardless of the exact mec...

The objective of this study was to gain a better understanding of the mechanisms responsible for rheological dilatancy in an aqueous pigment suspension. Of particular interest was the relationship between the extent of dilatancy and colloidal stability. This relationship was studied using iron oxide suspensions which were dispersed by addition of sodium polymethacrylate having a molecular weight of 4000. The level of colloidal stability was varied by changing the degree of dissociation of the carboxyl groups on the polymer. Measurements of the extent of adsorption of the dispersant were made and the adsorbed charge was found to correlate very well with low‐shear viscosity measurements. Additional experiments were made to determine the effect of pigment volume concentration on dilatancy over the range of 40–47%. A cup‐and‐bob viscometer was used to measure the shear stress over a shear rate range of 100–4000 sec−1. The extent of rheological dilatancy was found to increase with (a) decreasing colloidal stab...

Butadiene, urea, and sulfuric acid react to form a new sulfated polymer. The sodium salt of the polymer, called BUS, is a good detergent and dispersant; it is practically nontoxic and nonirritating. BUS-soap blends are good detergents for use in hard water. BUS can be precipitated from waste water by heavy metal salts and can be removed by percolation through soil.

Blends of soap with small amounts of lime soap dispersing agents are efficient detergents in hard water and require little or no tripolyphosphate builder. Lime soap dispersing agents examined include sulfated ethoxylated fatty alcohols, sulfated N-(2-hydroxyethyl) fatty amides, methyl esters of α-sulfo fatty acids, 2-sulfoethyl fatty acid esters and N-methyl-N-(2-sulfoethyl) fatty amides as well as nonionics derived from tallow alcohols. Detergency evaluations were carried out with three commercial soiled cotton cloths as well as by a laboratory multi-wash technique. Formulations containing 80% soap, 10% lime soap dispersing agent and 10% builder gave optimum detergency values. Builder effectiveness was rated tripolyphosphate>silicate (1:1.6)> metasilicate = citrate = oxydiacetate = nitrilotriacetate>carbonate≫sulfate. The detergency of soap-lime soap dispersed combinations compared favorably with a standard brand household heavy duty granular detergent in 50, 150 and 300 ppm hardness water on three soiled cloths.

The authors made experiments to see the influense of higher aliphatic amines (lauryl amine, stearyl amine, their acetates, stearyl trimethyl ammonium chloride) used for vulcanisation of natural rubber on the vulcanization reaction, physical properties and aging of the vulcanisates. Higher aliphatic amines, when added as vulcanization acceleator, accelerate vulcanization remarkably and raise both tensile strength and hardness. This accelerating effect rises in the following order : lauryl amine acetate, stearyl amine acetate lauryl amine, stearyl amine, stearyl trimethyl ammonium chloride. Higher aliphatic amine can be used by itself as vulcanization accelerator, but has a tendency to over-vulcanize quickly, making the vulcanization time shorter. Aging is also accelerated, probably the later part of vulcanization being a factor of the ageing, as can be supposed from reactivity of_higher aliphatic amine. Higher aliphatic amine can be used effectively as dispersing agent or releasing agent. It is considered possible to use these amines with good result in the form of their derivatives and, when compounded as should be, chemical for rubber industry.

Clay contents of soils, containing varying amounts of allophane, have been calculated from measurements of surface areas of separated fractions using adsorption of nitrogen, acetic acid, and water-vapour as methods of measurement. The clay contents obtained in this way were greater than the amount of clay which could be extracted from the soil at either pH 3 or pH 9, and generally much greater than the amounts of clay given by a standard method of mechanical analysis using sodium hexametaphosphate as dispersing agent. Acetic acid adsorption, although giving greater surface areas than nitrogen adsorption, gave rather similar figures for clay content, but water-vapour adsorption, which gave still greater surface area values, led to clay contents in rather poorer agreement with those obtained from the nitrogen surface areas. Because the presence of organic matter affects both nitrogen and acetic acid surface area values, these are best determined on a separated clay fraction, and on the residual sil...

Polyisobutenyl (PIB) succinimides are widely used as low/medium temperature detergent/dispersant additives in lubricants. To elucidate their mechanism of action, soluibility, micelle formation, adsorption, zeta potential, sedimentation and detergency studies have been carried out on a range of PIB succinimides in non-aqueous media. The results showed that the performance of PIB succinimides in various tests was dependent both on the molecular weight of the PIB and on the chemical structures of the amine used to make the succinimide. It was also concluded that these additives function by a steric stabilization mechanism and not by either electrostatic repulsion or micellar solubilization.

The free-radical polymerization of several monomers in an aqueous suspension containing chemically opened chrysotile asbestos fibrils was investigated with the intention of promoting complete encapsulation of the individual colloidal fibrils. The degree of polymer deposition on the colloidal substrate is dependent upon several factors including monomer and polymer solubility, initiator type, ionic comonomers, and degree of interfacial wetting. Successful encapsulation was achieved by the addition of novel unsaturated polyelectrolytes which served a dual role as dispersing agent and comonomer. Such methods are useful for the preparation of reinforced composites with controlled interfacial properties. In one example, it is shown that asbestos fibrils surrounded by a rubbery layer can impart greater toughness to a reinforced composite, compared to a composite in which the rubbery phase is dispersed at random or isolated from the interface. The technique can be extended to other types of fillers. The various methods of chemically “opening” asbestos are summarized.

The effect of chemical bonding between phases of a glass matrix-metal composite on strength and fracture behavior was investigated. When no chemical bonding occurs, strengthening can be achieved through the mechanical formation of an interface between the dispersant and matrix. Even greater strengthening can be obtained by the formation of a chemical bond. Strengthening occurs by the limitation of the Griffith flaw size and is controlled by micromechanical stress concentrations developed on loading. Internal stresses developed on cooling from the fabrication temperature control the path of fracture. A chemical bond counteracts the micromechanical stress concentration and therefore increases the strength.

In order to explain the relation between the mode of solubilization by non-ionic surface active agent and the chemical structure of the disperse dyes, visible light absorption spectra of the aqueous dispersions of several aminoanthraquinone dyes were measured for varied contents of the non-ionic surface active agent added as dispersing agent. In further experiment polyoxyethylene glycol, the chemical structure and the properties of which were just the same as those of the hydrophilic group of the non-ionic surface active agent, was used as dispersing agent in place of the latter, and absorption spectrum obtained for each dye was investigated for comparison as well as that of the n-hexan or the benzene solution of the same dye, respectively. The experimental results suggested the following:(1) While 1, 4, 5, 8-tetraamino-, 1, 4-diamino-and 1-amino-4-hydroxy-anthraquinone were solubilized into the hydrophilic region of the micelle, 1-amino-2-methyl- and 1-methylamino-derivative get in the inner hydrophobic, when the content of the non-ionic dispersing agent is increased above CMC, and the micelle is formed in the solution.(2) 1, 4-bismethylaminoanthraquinone, however, may be solubilized into the region between the hydrophilic and the hydrophobic of the micelle.

It is shown that the dispersing agents added to disperse dyebaths stabilise the dye suspension and act as restraining and retarding agents. With some dyes, especially at low temperatures, the normal retarding effect is reversed, probably owing to an increase in the rate of dissolution of crystalline particles of dye in presence of dispersing agent.

Fibre saturation values have been determined at 60° and 80°c, in presence of a dispersing agent, for 15 disperse dyes on secondary cellulose acetate. In most cases the results agree with those obtained by calculation from aqueous solubilities and partition coefficients in the absence of dispersing agent. With the more hydrophilic disperse dyes, however, e. g. those containing two N–β–hydroxyethyl groups, low values are obtained in presence of dispersing agent. This is attributed to adsorption of dispersing agent rendering the fibre more hydrophobic. When a fibre saturation value is determined by means of a single dyeing carried out in presence of a large amount of commercial dye, the result may be much too high owing to (a) the presence of coloured impurities and shading components and (b) the absence of sufficient dispersing agent to stabilise the concentrated dispersion and so prevent surface adsorption of dye by the fibre.

Synthetic wax particles containing sulfaethylthiadiazole (SETD) dispersed throughout and on the surface were made by a method of aqueous dispersion using various concentrations of polysorbate 80 USP and sorbitan monooleate each alone and in combination as dispersants. The in vitro release of SETD from 50–70 mesh wax particles was investigated with a rotating bottle dissolution apparatus, using simulated gastric and intestinal fluids. The dispersant factor was found to affect both the release rate and the proportion of total drug apparently constituting the prolonged-release fraction.

It can be conclusively proved that the individual particle in latex of Hevea brasiliensis after the evaporation of the dispersing agent is surrounded by an adsorbed layer, probably of protein and resin. In the dispersed condition, the particle shows a difficulty penetrable and not deformable surface. After puncture a highly viscous mass flows out from the interior, and at the moment it comes in contact with the dispersing agent it stiffens to a plastic jelly, while the remaining shell exhibits remarkably elastic properties. After the evaporation of the dispersing agent, there occurs a progressive gelation and transformation into an elastic substance. The same result is obtained when the rubber phase is coagulated by acids or electrolytes. The establishment of this fact is important in connection with the usual preparation of raw rubber. It was proved that the consistency of the particles and the thickness of the elastic shell are dependent on the age of the trees. We are dealing not with a definite membrane, but with a variable enveloping shell whose strength seems dependent on the degree of polymerization of the hydrocarbon. In general the results of the present work prove the latest concepts of the structure of rubber, i. e., the existence of various degrees of polymerization, which can be traced back to the structure of the latex particles.

Heating montmorillonites to their dehydroxylation temperatures destroyed their ability to form an aerogel. The breakdown of the aerogel structure coincided with the loss of hydroxyl water from the montmorillonite. Apparently, this loss of water was accompanied by a loss of the layer charge. Particle size and aerogel-forming ability appear to be inversely related properties for at least some montmorillonites. The kaolinite investigated did not form an aerogel in any size fraction. The formation of montmorillonite aerogels from various concentrations of clay was investigated. The texture and physical appearance of these aerogels was examined and presented herein. Thawed clay suspensions exhibited a variety of behaviors. The Volclay bentonite, which appar- ently formed a true sol was unaffected by freezing. In all other clays at least some of the fine clay particles agglomerated on freezing and large clumps were observed dropping out of the melting ice. After stirring the thawed suspensions less clay was dispersed than in the unfrozen suspension counter- parts. Addition of a dispersing agent to these suspensions caused more clay to remain dispersed following freezing-thawing-stirring.

An examination has been made of the influence of different chemicals on certain natural Swedish clays. It was found that, besides the mineral salts, dispersing agents play an especially important role in the mechanical properties of a clay. An attempt was made to isolate dispersing agents from clays, and it was found that in the cases Investigated the quick clay contained a mixture of sodium-magnesium carbonate, and that these salts together have a strong dispersing effect on certain actual clays. Note added in proof: After the writing of this report further work has given additonal results. Thus it is possible to isolate a peptizing agent from a natural mud desposit by treating it with diluted sodium hydroxide solution. Such a dispersing agent was found in a clay situated below a mud desposit. It was also possible to convert non-peptizable clays in peptizable. A non-peptizable clay was dispersed in MgCl2, CaCl2 or FeCl3, the solution filtered off and the resulting clay tested the resultant prope...

The influence of suspended particles on the rheological properties of residual fuel oil was investigated by using a rotational viscometer. It was found that a small amount of suspended particles of irregular shape remakably affected the viscosity and that the viscosity increased with the increase of particle size at a definite concentration, which caused practically trouble-some clogging of strainer and incomplete combustion. An evaluation method of sludge dispersant for fuel oil was also proposed based on the above conclusion.

Oil—soluble surface-active copolymers have been prepared by copolymerizing C8-C18α-olefins with polar monomers. Polyacetates, polyalcohols, and a polynitrile with 1 to 5 polar groups per hydrocarbon chain and with molecular weights from 10,000 to 40,000 were obtained. Sedimentation, diffusion, and viscosity measurements showed the polymers to be most expanded in polar organic solvents and to contract and form aggregates of 10 or more molecules in hydrocarbon solutions. Studies with adsorbed and insoluble monolayers showed that these polymers adsorb onto water, glass, or carbon surfaces as thin monolayers with nearly all the polar groups attached. These polymers are unusually effective dispersants for solids in oil.

Each rigid urethane foam formulation must be carefully designed to meet the key requirements of its specific end use. For example, refrigerator insulation is an application which requires low thermal conductivity, low density, and excellent resistance to humid aging. The present investigation was carried out to determine variations in foam properties caused by changes in catalyst concentration, isocyanate/hydroxyl ratio in the quasi-prepolymer, quasi-prepolymer cooking time, dispersing agent concentration, and isocyanate/hydroxyl ratio in the total foam. The basic foam formulation contained sorbitol polyether (Hydroxyl Number 490), toluene diisocyanate, trichlorofluoromethane blowing agent, catalyst, and dispersing agent. The results showed that the tensile strength decreased as the isocyanate/hydroxyl ratio in the total foam increased. Shear strength was affected strongly by catalyst concentration, and by isocyanate/hydroxyl ratio in the prepolymer and in the total foam. Cure time (at room temperature) was strongly affected by catalyst concentration and technique of prepolymer preparation. The only factors having a significant effect on humid aging resistance were isocyanate/hydroxyl ratio in the prepolymer and in the total foam. The effects on thermal conductivity were complex, and included an interaction between dispersing agent concentration and catalyst concentration, and also between prepolymer preparation technique and isocyanate/hydroxyl ratio in the prepolymer. The compressive strength increased with catalyst concentration, and was strongly affected by prepolymer preparation techniques. Key effects and interactions were plotted in graphical form.

Most of the conventional mineral processing separation methods are not effective on mineral mixtures that contain a large percentage of slimes. Selective flocculation is a potentially attractive process for treating such mixtures. The process relies on achieving conditions under which the polymer flocculant adsorbs onto the surface of one mineral and not on the others. In a practical system this selective adsorption would have to be achieved under conditions of fluctuating water quality and mineral composition. Partially hydrolysed polyacrylamides with a molecular weight of around 3 × 106 have been used in the selective flocculation separation of a synthetic finely-divided mixture of haematite and a silicate (100% < 20 μm). It was possible to flocculate selectively from the mixture either the haematite or the silicate by using polyacrylamides of differing anionic character. It was usually necessary to employ a 1:1 electrolyte and a dispersant, in addition to the flocculant, to achieve good selectivity in this system.

The effects of dispersants and CMC on the salt contaminated bentonite mud are described in this paper.

This paper deals mainly with those agents which affect the properties of the solid/liquid interface. In the case of dispersions of solid particles the action is usually one of flocculation or de-flocculation. The two photomicrographs (Figs. 1 and 2) illustrate the two conditions in the case of an aqueous suspension of lead chromate. Figure 1 shows the flocculated system and Fig. 2 the same system after the addition of a dispersing agent.

A series of new phenolic amino sulfonates has been prepared from mono- and dialkylphenols, formaldehyde, and N-methyltaurine by the Mannich condensation. From monoalkylphenols either mixtures of mono-and disubstituted products or completely disubstituted materials were obtained. Surface-active properties, of which lime soap dispersant activity is notable, were summarized for these products.

Toxicity tests using a wide variety of shore animals reveal that the latest generation of dispersants have very low toxicity and no long-term effects.

EDWARDS AND BREMNER'S (1967) TECHNIQUE OF DISPERSING SOILS BY SONIFICATION TO FORM STABLE SUSPENSIONS FOR PARTICLE-SIZE ANALYSIS WITHOUT THE ADDITION OF DISPERSANT HAS BEEN TESTED ON A RANGE OF SOILS AND CHALK. CARBONATE SOILS OR ACID SOILS, CONTAINING A SUITE OF MINERALS WHICH NORMALY FORM FLOCCULATED SUSPENSIONS IN WATER, YIELDED STABLE SUSPENSIONS IN WATER IF THE SOIL ORGANIC MATTER CONTENT WAS SUFFICIENTLY HIGH. WITH SIMILAR SOILS, LOW IN ORGANIC MATTER, DISPERSANT HAD TO BE ADDED TO STOP PARTIAL FLOCCULATION OF THE TEST SUSPENSIONS. ANY GYPSUM PRESENT IN SOILS HAS TO BE REMOVED TO PREVENT FLOCCULATION. FOR SOILS VERY STRONGLY AGGREGATED BY ORGANIC MATTER, ALL THE PARTICLES SMALLER THAN 2 MICRONS PRESENT CAN BE RELEASED ONLY BY SONIC VIBRATION IN DISPERSANT RATHER THAN WATER. ON FOUR SOILS STUDIED IN DETAIL, THE MAXIMUM AMOUNTS OF SMALLER-THAN-2 MICRON PARTICLES OBTAINED BY SONIC VIBRATION, VIGOROUS SHAKING, AND THE I. S. S. S. METHOD HAVE BEEN COMPARED. ON THREE OF THE FOUR SOILS, THE VALUES WERE IN CLOSE AGREEMENT. /TRRL/A/

Equilibrium isotherms have been obtained at 80dc. with acetate rayon and five disperse dyes. Two azo dyes showed a linear relationship up to saturation between dye on the fibre and dye in the aqueous phase. Non-linear curves were obtained with three anthraquinonoid dyes, but a straight line was obtained when a solubilisate of 1-methylamino-4-anilinoanthraquinone was used in place of a dispersion. With purified Dispersol Fast Scarlet B the slope of the isotherm was found to be independent of liquor: yarn ratio, and inversely proportional to the concentration of dispersing agent over a limited range. The adsorption by acetate rayon of purified Lissapols C and LS has been studied at 80δc. Both detergents hydrolyse gradually in hot aqueous solution.

The part played by the polar dispersant in the gelation of hydrocarbons by montmorillonite-organic complexes is considered on the basis of data collected from various sources. A mechanism, based on ionic double-layer theory, is proposed which is consistent with these data. The fact that various organic cations will undergo exchange in organic media for dimethylbenzyllaurylammonium (DMBL) cation already electrostatically bonded to the surface of montmorillonite provides strong support for the mechanism. Regardless of the validity of this mechanism, it is concluded that electrostatic effects must be considered in any discussion of the role of the dispersant in these hydrocarbon grease systems.

Usinga queous solutions of polyethylene oxides of various degrees of polymerisation as dispersing agent, paper making by means of Japanese tradional hand-process was studied.Concerningthe dispersibility, some properties of the solution of polyethylene oxide were also investigated.Results obtained are summarized as follows.1) Water soluble polyethylene oxide can be used as the dispersing agent in the paper making, and the dispersibility is generally proportional to degree of polymerization of the polymer. The paper making properties of the solution, however, differ from those of Tororo-aoi mucilage.2) Block copolymer of propylene oxide and ethylene oxide has not the dispersibility, but the mixture of the block copolymer and polyethylene oxide indicates good dispersibility.3) The dispersibility of polyethylene oxide is improved by adding sodium alginate or CNIC, but the paper making properties of the solution differ appreciably from those of Tororo-aoi mucilage.4) Addition of phosphates has no influence upon the dispersibility of polyethylene oxide.5) Paper made up by use of polyethylene oxide as the dispersing agent has somewhat worse texture but rather better toughness than that made up by using Tororo-aoi mucilage.6) Viscosity and filterability of the solution of polyethylene oxide and sedimentation velocity of pulp fibers in the solution have not direct relation to the dispersibility of the solution.

A theoretical analysis of curves expressing the rate of fading of dyes in different physical forms is given, illustrated by typical examples of the fading of dyes in transparent films, measured spectrophotometrically. Molecularly dispersed dye fades according to an approximate first-order law (exponential decrease of rate), and dye in large particles according to an approximate zero-order law (constant rate). In aggregated particles fading probably occurs only at the surface. First-order fading occurs with some water-insoluble dyes in “solid solution” in a hydrophobic substrate (collodion), and some surface-active dyes in a hydrophilic substrate (methylethylcellulose) appear to exist mainly as molecular dispersions, since they also give first-order fades. In contrast, entirely aggregated dyes, e.g. water-insoluble dyes prepared in substance and incorporated in hydrophilic films, show zero-order fades. The form of the fading-rate curves of most water-soluble dyes, however, suggests that the dyes are present in both forms, i.e. as a heterogeneous mixture of single molecules and aggregated material, the proportion of each varying according to the physical properties of the dye. The heat generated during irradiation causes some of the larger aggregates to break up. This may lead to a slight initial rise in depth of colour or, in special cases, to a fading rate which increases with time. The forms of the appropriate fading-rate curves show that a disaggregating agent (phenol) and a cationic surface-active dispersing agent, when mixed with acid dyes in films, decrease the amount of dye aggregate present. The fading rates of the Procion (ICI) reactive dyes in cellulose film are of the same form as those of most water-soluble dyes, and appear to demonstrate that most of the dye is in some form of aggregated state or is enmeshed in crystalline regions of the fibre. The results explain why the light-fastness grading of dyed fabrics may differ with the extent to which fading has progressed when the assessment is made.

Chemical dispersants have a role in the cleanup of oil spills. However, neither dispersion nor any other current technique is a panacea for this purpose. There are situations where dispersants can be used for the benefit of our natural resources; but there are also instances where they should not be used. Similarly, there are conditions under which they are effective, as well as limits where they become ineffective. These aspects of the subject, as well as the mechanism of and basis for dispersing oil slicks, will be discussed. An understanding of the mechanism of dispersency is of prime importance in order to appreciate the behavior and variation in effectiveness of various generic types of surface active agents in promoting oil-in-water dispersions. In this regard, the presence of naturally occurring surfactants in crude oil and their properties are discussed. Even for the same chemical agent, its efficiency can vary due to the influence of many factors such as method of application, degree of mixing, type of oil, temperature of water, amount of circulation in the body of water, etc. Some chemicals can be more sensitive to a specific factor than others. Therefore, an appreciation of mechanism and the effect of environmental and application factors is necessary in order to assess the appropriate scope of application for dispersants as a tool for the handling of oil spills.

For better understanding on the physical properties of lignosulfonate and its peracetic acid-degradation product as a dispersing agent, the dispersing effect of both lignin preparations to ZnO was investigated. The water-soluble part of dioxane lignin degraded with peracetic acid was also used as a lignin dispersant.These three lignin preparations were fractionated to the smaller fractions, respectively, which ware different in the molecular weight and the content of the dissociating groups, such as sulfonyl and carboxyl groups. The dispersing effect of the fractions thus obtained was compared by measuring the sedimentation volume and the viscosity of a ZnO slurry. The adsorption amount of each fraction on a ZnO particle was also determined.From the results, it was indicated that the molecular weight of some fractions of each lignin preparation which have a best dispersing effect for ZnO slurry, is in the range from 8×103 to 2×104. But, the higher or lower polymer diminished the effect. The amount of lignin absorped on ZnO particle increased with increasing the molecular weight. It was also found that the main fraction of lignosulfonate has better dispersing effect for ZnO than it of the other two lignin preparations.Although a dissociating group, such as sulfonyl or carboxyl group is necessary for making a lignin dispersant, the dispersing ability of a lignin preparation did not correlate so much with the content. So this relationship seems to be a secondary effect for dispersing ZnO.