Double-jet method

Crystallization of CaCOj with the Anionic PAMAM Dendrimers by the Double Jet Method... 

Monodisperse emulsions, prepared by the double-jet method, have a narrow range of grain sizes of uniform shape. The grains can be either cubic or octahedral, depending on the conditions of preparation. 

Surface image is formed predominantly in monodisperse, fine-grain emulsions prepared by the double-jet method. 

Of these methods, the double-jet method leads generally to a relative uniform ("monodisperse") crystal population with uniform morphology when material addition i ates, temperature, and pAg are closely controlled (Figure 2). For such systems, nucleation and subsequent growth have been studied in detail. The present review will concentrate on some recent developments in these areas. 

The influences of the sodium salt of poly(acryhc acid) (PAA) on the crystaUiza-tion of CaC03 to act as an inhibitor for crystal formation has been intensively investigated [80,95,96]. In the presence of PAA imder a feed ration of a repeating imit of acrylate to calcium ions of 0.62 using the double-jet method, httle... 

A delay addition of sodium salt of PAA for precipitation of CaCOs was carried out by the double-jet method [97]. After addition of the aqueous solutions of 0.1 M CaCl2 and 0.1 M (NH4)2C03 into an aqueous solution, an aqueous solution of sodium salt of PAA (Mw = 1200) was added to the reaction mixture after incubation at 30 °C for several minutes. The feed ratio of a repeating unit of PAA to calcium ions was 0.62. Little crystalline CaCOs was collected after incubation at 30 °C imder N2 for 1 day when the sodium salt of PAA (Mw = 1200) was added to the reaction mixture after incubation at 30 °C for 1 min. When the sodium salt of PAA (Mw = 1200) was added to the reaction mixtiue after incubation for 20 min, a small amoimt of vaterite was obtained. 

The anionic polyamidoamine (PAMAM) dendrimers act as effective protective agents for the most unstable vaterite crystal [47-49]. Delay addition of the anionic PAMAM dendrimers also gave vaterite particles by the double-jet method [102]. After the calcium reactants (0.1 M CaCU and 0.1 M (NH4)2C03) were injected via syringe into distilled water, an aqueous solution of the G1.5 PAMAM dendrimer was added to the reaction mixture after the start of precipitation for several minutes (1, 3, 20, or 60 min). The experimental conditions and results are summarized in Table 4. At the high... 

Double-jet crystal growth method, 19 179 Double-layer compression, 11 631 Double-layer forces, flocculation and,... 

The emulsions used in this work were composed of the suspension of AgBr grains in aqueous gelatin solution, and were prepared by the controlled double-jet precipitation method. The edge lengths... 

Turbidimetric Methods. Established turbidimetric methods (24—29) were used to measure the ripening rates of fine-grain AgBr-gelatin dispersions (Figure 8). The dispersion was prepared by controlled pAg (pBr 3 at 35°C), double-jet, constant-flow-rate addition of 0.1-0.2... 

Three basic methods have generally been employed in the precipitation of silver, glides single-jet, double-jet, and continuous (Figure 1). In the single-jet method, the silver... 

Figure 1. Schematic of basic AgX precipitation methods. Key single-jet, left double-jet, middle and continuous, right. (Reproduced, with permission, from Ref. 6. Copyright 1981, Marcel Dekker, Inc.)...

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