How to Read a Ternary Phase Diagram

Countercurrent Chromatography

Alain Berthod , ... Suzana G. Leitão , in Comprehensive Analytical Chemical science, 2002

two.2.1 Basic properties of ternary stage diagrams

Ternary phase diagrams are used to represent all possible mixtures of three solvents [ 1]; they are described in Affiliate three. Here, we shall indicate how they should be used to minimize the solvent consumption. Figure 2.one (top) shows the methanol–chloroform–water ternary phase diagram with the tie-lines in the biphasic domain. V particular compositions are shown in the diagram: Table 2.i lists their respective compositions, and they all belong on the same tie-line. And so, by definition, they separate into two liquid phases that take exactly the aforementioned compositions. The only difference is the stage volume ratio. Whatsoever liquid composition belonging to the tie-line is prepared, the aqueous phase is Composition ane and the organic stage is Composition v, both on the binodal curve on both ends of the tie-line. Information technology is very important to realize that a CCC separation performed with the 5:9:7, v/v/v, chloroform–methanol–water arrangement [2] volition give exactly the same results equally i done with the 13:vii:four, 5/5/v, system [3]. The two systems belonging to the same necktie-line split up into 2 phases that take exactly the same composition. The difference is that Composition 2 (rich in methanol and water) separates in 77% of the light aqueous phase and only 23% of the heavy chloroform-rich organic phase (left tube in Fig. 2.1). The chloroform-rich 13:7:4 system (Composition iii) separates in the 35% aqueous phase and 65% heavy organic phase (Tabular array 2.one, and correct tube in Fig. 2.ane). The amount of phases is dissimilar, but their compositions are identical. Since the book of mobile phase used for a separation is larger than the volume of stationary stage, Composition 2 will be prepared if the selected mobile phase is the aqueous phase. In contrast, Limerick 4 is appropriate if the mobile phase is the organic lower phase. Compositions one and 5 will be prepared, in both cases and respectively, if the separation needs more mobile stage than the amount initially prepared.

Fig. two.1. Ternary phase diagrams. Height: system CHCl₃–MeOH–H_twoO; the verbal solvent proportions of the v compositions indicated are listed in Table 2.1. Bottom: organisation heptane–MeOH–H₂O; the upper phase of any of the mixtures in this arrangement is pure heptane.

Tabular array 2.1. Composition of the chloroform–methanol–water liquid systems belonging to the tie-line shown in Fig. ii.one.

Mixture	Limerick (CHClthree–MeOH–H2O v/v/five)				Upper phase volume (mixture 1)	Lower stage volume (mixture 5)
	Integer ratio	v%	v%	v%
1	Aqueous phase	7.5	l.1	42.iv	100%	0%
2	5:nine:7	23.eight	43	33.ii	77.iv%	22.half-dozen%
three	4:four:3	36.iv	36.4	27.2	60.1%	39.9%
iv	13 : 7 : 4	54.2	29.ii	sixteen.6	35.four%	64.half dozen%
5	Organic phase	79.viii	17.half dozen	2.half dozen	0%	100%

The heptane–methanol–water ternary system should be mentioned because it is extremely convenient for apply in CCC [4,5]. Equally shown in Fig. 2.1 (bottom), all its tie-lines converge toward the heptane noon. This means that whatever proportions of heptane–methanol–water are mixed, the upper phase is always pure heptane (lesser correct tube in Fig. 2.ane). Furthermore, if the water-to-methanol volume pct ratio is higher than 20%, information technology can be considered that there is practically no heptane in the lower phase (Fig. 2.1). In practice, if the separation can be carried out with the heptane–methanol–water i:one:1, v/v/v, system, it is possible to prepare ane phase by just mixing equal amounts of methanol and water; the other phase is pure heptane. With this system, when heptane is the mobile phase, pure heptane can be used without pre-equilibrating information technology with the methanol–water stationary phase. If heptane is the stationary phase, a slope with increasing amounts of methanol, up to eighty% five/v methanol, tin be run without affecting the stationary phase [half dozen].

Read total affiliate

URL:

https://www.sciencedirect.com/science/article/pii/S0166526X02800058

Introduction to Supercritical Fluids

Richard Smith , ... Cor Peters , in Supercritical Fluid Science and Applied science, 2013

Ternary Phase Diagrams

A ternary phase diagram shows possible phases and their equilibrium according to the composition of a mixture of 3 components at constant temperature and pressure. Effigy 4.23 shows a schematic of a ternary phase diagram. Single-phase regions are areas that originate from the vertex of the triangle and that are not enclosed past blackness curves. Two-phase regions are areas enclosed by black curves and for the 2-phase regions shown, some necktie-lines are shown by bluish dashed-lines. Tie-lines show the equilibrium two phases and can be experimentally determined or calculated from theory.

Figure iv.23. Schematic ternary stage diagram for a mixture of A, B and C. Black lines announce stage boundaries. Regions enclosed by the black lines show similar types of phase behavior. Dashed-blueish lines give the composition of phases in equilibium. A point on the diagram represents a composition that is specified in terms of mole fraction or weight fraction. The point, (0.3, 0.4, 0.three) is at the center of the small triangle in the diagram and is located by following the ruby-red diagonal 60° line at red 0.iii and the horizontal line at bluish 0.four or whatever combination of two of the coordinates (A, B, C).

In Figure 4.23 , a single three-phase region exists and is given past the triangle in the center of the diagram. There are no tie lines for the iii-stage region since compositions are given by the vertices of the small triangle in the center of the diagram. In other words, compositions of each of the 3-phases in equilibrium are invariant and do non depend on the overall composition.

A point having composition (A, B, C) on Figure four.23 tin exist located anywhere on the ternary diagram and such a bespeak represents the overall limerick of the phase, regardless of the number of phases. The compositions on a ternary diagram must sum to unity if in mole or weight fractions, or to 100 if in percent. Knowledge of any two of the compositions allows the 3rd composition to be obtained past subtraction. So, fundamentally, the method used for locating and plotting points on the ternary stage diagram of Figure four.23 is the same every bit that for the ternary diagram, Figure four.22 introduced at the outset of this section.

The ternary phase diagram becomes more interesting when the phases of A, B and C at the given temperature and pressure are assigned [TPD1]. Then, the phases that are in equilibrium tin can be determined and many analyses tin be made. In this text, a simplified set of steps is given for determining the phases for cases of a small-scale number of amass phases. Schreinemakers' rule gives an additional method for assigning phase behavior to regions on a phase diagram [TPD2].

Tip Box#4

Steps for assigning phases on ternary diagrams

(i)

Assign each substance or compound a unique designation such as L₁ , Fifty₂ or V for a supercritical phase or a vapor phase.

(ii)

Start from each vertex, characterization areas of the triangle that extend upwardly to any of the boundaries equally L₁ , L_two or V every bit appropriate. These are unmarried-stage homogeneous phases.

(iii)

For each region remaining, annotation the adjacent homogeneous phases. The region provides the equilibrium between the adjacent homogeneous phases such as L₁ –Five, L_one –L_two and so on. Continue until all regions are labeled.

Example 4.ii

Assignment of phases in a ternary diagram

For the ternary phase diagram shown in Effigy 4.23 , suppose that A and B, are in liquid states and C is in its supercritical state. Label the phases and regions of phase equilibria.

Solution. Follow Tip Box #4 : (i) use Fifty_i for a phase rich in component A, Fifty₂ for a stage rich in component B and V for the supercritical stage that is rich in component C, (two) label single-stage homogeneous regions and (iii) label regions co-ordinate to side by side homogeneous phases.

In the initial stride, L_ane , Fifty₂ and V are labeled. Then, regions are labeled according to the side by side single-phase homogeneous regions every bit shown by blue arrows. Finally, the central triangle is labeled according to the adjacent phases as shown past cherry-red double-line arrows.

Comment: Tie-lines are not shown to reduce clutter. The steps shown can be used for whatsoever phase diagram. The intersection of three ii-phase regions gives a three-stage region.

The ternary stage diagram contains a lot of data on the phase behavior of the mixture of three components. However, information technology too contains considerable data on the phase behavior on the three binary mixtures, A–B, B–C and A–C that is implied past examining the edges of the diagram and the intersecting regions of phase equilibria.

Instance 4.iii

Binary component stage beliefs from a ternary phase diagram

Determine the phase beliefs of the binary components of the ternary stage shown in Effigy iv.23 assuming that A and B, are in liquid states of Fifty_ane and L_two , respectively, and C is in its supercritical state that is labeled as V.

Solution. Utilize the analysis of Instance 4.ii and examine each edge (A–B, A–C, B–C) of the ternary diagram to see whether it is intersected by any type of region.

Edge A–B shows one stage region adjoining it over the range x _A  >   0.two and ten _A  <   0.65 so that A and B are partially miscible as liquids. If A is gradually added to B, A will dissolve into B equally a homogeneous solution. Yet, when the fraction of A exceeds x _A  =   0.2, then the solution will split into 2 liquid phases, 50₁ and 50_two , with L₁ being rich in A and L₂ being rich in B. If more than A is added to the liquid–liquid mixture, and so the amount of the L₁ stage will increase and then finally, the L₂ phase will dissolve into the 50_i phase and the solution will be homogeneous at 10 _A  >   0.65.

Edge A–C has an L₁ –V region from x _C  >   0.22 and x _C <   0.82. Therefore, if C is added to A, the solution will be homogeneous upwardly to 10 _C  =   0.22. So, if more C is added the mixture will phase split into a vapor–liquid mixture. The mixture will remain as 50_i –V until the C exceeds ten _C  =   0.82 and then it will be a homogeneous vapor phase.

Border B–C shows an 50₂ –V region over the range of compositions, x _C >   0.23 and x _C <   0.65. Therefore, the discussion of this edge is similar to that for edge A–C.

Comment: Information technology is important to remember that a ternary diagram is at abiding temperature and pressure. If no regions intersect a given edge, then this ways that the binary pair is completely miscible in all proportions (i.e. homogeneous) at the given T and P.

Example 4.4

Determination of the phases nowadays with a ternary phase diagram

Determine the phases nowadays for compositions given every bit (A, B, C) using the ternary phase shown in Figure iv.23 : (0.1, 0.8, 0.1), (0.6, 0.1, 0.3), and (0.35,   0.iv, 0.25).

Solution. For each set of compositions, whatever two coordinates are sufficient to specify the location of the point in Figure 4.23 . Then the number of phases and their blazon tin be found by the region for which the point falls:

(0.05, 0.9, 0.05)	A mixture of A, B, and C that is in the unmarried phase region
(0.half dozen, 0.1, 0.iii)	A mixture of A, B, and C that is in the Fiftyone–Five two phase region
(0.35, 0.4, 0.25)	A mixture of A, B, and C that is in the Lone–Fifty2–Five 3 phase region

Comment: The specification of a point on a ternary diagram allows ane to know the phases of the organisation.

Read full chapter

URL:

https://www.sciencedirect.com/science/article/pii/B9780444522153000040

Label of Porous Solids Vii

Supriyo Bhattacharya , ... Keith E. Gubbins , in Studies in Surface Science and Catalysis, 2007

iv.1 Lattice Monte Carlo Simulation Of Surfactant-Oil-Water-Silica Systems

The ternary phase diagram for the H _iiiT₅H_three-oil-h2o system is shown in Fig. 3a. Spherical micelles are observed at low oil and surfactant concentrations. Elongated micelles and hexagonal arrangements of cylindrical micelles are observed at medium surfactant concentrations, near the surfactant-water side of the phase diagram. Starting from the hexagonal phase on the surfactant-water side, nosotros detect the emergence of a lamellar phase as we move towards high oil concentrations. In our simulations, bicontinuous structures appeared just in 1 signal on the phase diagram, although we believe that boosted points would be found by doing extensive simulations in this zone of the phase diagram. It must be noted that the transitions between the different structures are not first order in nature. Phase separation is observed on the surfactant-oil side between a dilute surfactant solution and a surfactant rich phase. The characteristics of the stage diagram are highly dependent on the interactions of the oil with the other components in the system.

Fig. 3. (a) Surfactant-oil-water phase diagram; (b) Surfactant-silica-water phase diagram; simulation points are shown as follows: (▴) spherical micelles, (Δ) elongated micelles, (○) cylindrical micelles, (•) bicontinuous phase, (□) lamellar phase. Phase boundary lines are provided as a guide to the eye.

The surfactant-water-silica stage diagram is shown in Fig. 3b. Due to the stronger caput-silica allure as compared to the water-caput attraction, we detect phase separation betwixt the surfactant-rich, silica-rich and water-rich phases. Ordered phases that are observed at different regions of the stage diagram depend on the component concentrations; spherical micelles are found at low to medium surfactant concentrations, bicontinuous structures are observed at high surfactant and intermediate silica concentrations, whereas cylindrical structures are seen at loftier surfactant and high water concentrations.

We now investigate the self-associates behavior by introducing oil to the surfactant-h2o-silica solution. The effect of oil on the surfactant-silica liquid crystal stage has been highlighted in the literature [6]. We mimicked the experimental pathway past starting from cipher oil concentration on the surfactant-water-silica phase diagram. We selected this initial signal in the region of the hexagonal phase because it has been reported that the silica structure is hexagonal in absenteeism of oil [half dozen]. The oil concentration is now raised in pocket-sized increments, keeping the proportion of the other components constant. In Fig. 4, we show simulation snapshots of iii dissimilar structures with increasing oil concentration. This too shows the nature of the pore structure after removal of the surfactants and solvents. At low oil concentrations, the construction is cylindrical (similar to SBA-15) and becomes lamellar every bit the oil level is increased. As the oil concentration is increased further, the lamellar construction transforms into spherical mesocells resembling the MCF structure, with a pore diameter almost 2.5 times that of the cylinders and the lamellae. Fig. v shows the experimental results from Lettow et al. [6]. In both the simulations and the experiments, cylindrical structures are observed at low oil levels and these structures transform into mesocellular foams once the oil concentration is increased. However, the transition from cylinders to mesocells follows separate pathways in the simulations and the experiments. Every bit proposed past Lettow et al. [6], undulations occur on the surface of the cylinders prior to the formation of the mesocells. In our simulations, nosotros were unable to notice any such construction. Moreover, lamellar structures were not establish in the experiments. This behavior suggests that there may be other structure-directing forces in the medium oil concentration regime, which are not being considered in the simulations. It is too possible that the lamellar structures occurred within a very small region in the experimental stage diagram and were thus undetected.

Fig. 4. Simulation: Modify in pore construction with increasing oil concentration (by volume). (a) 2%, (b) 9%, (c) 23%. In Fig. 4c, ii periodic images are shown aslope for amend visualization. All three snapshots are of the same calibration. For clarity, but the silica particles are shown.

Fig. five. Experiment [6]: Change in pore structure with increasing oil / surfactant mass ratios. (a). 0.00, (b) 0.21, (c) 0.50.

Read full affiliate

URL:

https://world wide web.sciencedirect.com/science/article/pii/S0167299107800681

Volume III

Jian-Feng Nie , in Physical Metallurgy (Fifth Edition), 2014

20.4.1.6.three Mg–Nd–Ag Alloys

The ternary phase diagram of the Mg–Nd–Ag system is rather incomplete ( Berger and Weiss, 1988), and therefore the equilibrium solid solubility of Ag in Mg and the equilibrium intermetallic phases in the Mg-rich terminate of the Mg–Nd–Ag system are both unclear. Co-ordinate to the Mg–Ag binary phase diagram, the maximum equilibrium solid solubility of Ag in Mg is ∼fifteen   wt% at the eutectic temperature of 472   °C, and it falls to approximately ii   wt% at room temperature, and the intermetallic stage at the Mg-rich side of the phase diagram is Mg_threeAg (space grouping P6₃/mmc, a  =   0.488   nm, c  =   0.779   nm). More 50 years ago, Payne and Bailey (1959–sixty) constitute that the relatively low tensile strength of Mg–Nd alloys could be considerably increased by Ag additions. This discovery subsequently led to the development of a commercial alloy designated QE22, Mg–second–two.5Ag–0.7Zr (wt%). The alloy QE22 is age hardenable, and its aging curves at 150–300   °C are shown in Figure 65. Within the temperature and time selected, a maximum hardness value of ∼85 VHN is obtainable when the blend is anile at 150   °C. After the height hardness is obtained at each temperature, the prolonged aging leads to only a slight reduction in hardness.

Figure 65. Age hardening response of Mg–2.1wt%Nd–two.5wt%Ag–0.7wt%Zr alloy (QE22) alloy at 100–300   °C (Kallisch, 1998). (For color version of this effigy, the reader is referred to the online version of this book.)

In the temperature range 200–300   °C, the decomposition of the supersaturated solid solution phase of α-Mg in QE22 alloy was reported (Gradwell, 1972; Lorimer, 1987) to occur via two independent atmospheric precipitation sequences. 1 sequence involves the formation of GP zones, in the form of [0001]_α rods, metastable γ phase that also forms as [0001]_α rods, and the equilibrium stage (Mg₁₂Nd₂Ag) that has a lath morphology and a nonetheless to exist adamant hexagonal structure. The other sequence has the germination of GP zones of an ellipsoid shape, the metastable β phase of an equiaxed morphology, and the equilibrium stage Mg₁₂Nd_twoAg. Gradwell (1972) proposed that both types of GP zones formed simultaneously during aging at temperatures up to 250   °C. Without providing the transformation mechanisms, he further proposed that the rod-similar GP zones transformed into the rod-shaped γ phase, while that the ellipsoidal GP zones transformed into the equiaxed β phase.

The metastable γ phase reportedly has a hexagonal structure (a  =   0.963   nm, c  =   1.024   nm), but the OR between γ and the magnesium matrix phase has not been reported. The metastable β phase likewise has a hexagonal structure (a  =   0.556   nm, c  =   0.521   nm), and its OR with α-Mg stage is such that (0001)_β//(0001)_α and ${\left[\mathrm{x}\overline{\mathrm{one}}0\right]}_{\text{β}}//{\left[11\overline{2}0\right]}_{\mathrm{\alpha }}$ . The equilibrium phase Mg₁₂Nd₂Ag was originally reported to have a complex hexagonal structure (Gradwell, 1972; Lorimer, 1987). But in two separate studies of alloy QE22 (Kiehn et al., 1997; Barucca et al., 2009), this equilibrium phase was inferred, without any potent supportive evidence, to be (Mg,Ag)₁₂Nd that has a tetragonal structure (a  =   1.03   nm and c  =   0.59   nm), that is isomorphous to that of Mg₁₂Nd. To unambiguously establish the structures of all precipitate phases, including that of the equilibrium precipitate phase, in the alloy QE22, it seems necessary to apply mod facilities such equally atomic resolution HAADF-Stem and electron microdiffraction in any efforts to be made in future studies.

Gradwell (1972) studied the precipitation hardening mechanism in QE22 by examining foils taken from specimens which had been strained ii% in tension after aging for various times at 200   °C. He concluded that height hardness coincided with the transition from precipitate cut to Orowan looping, and that maximum age hardening was associated with the presence of the γ and β precipitates. The alloy QE22 in the meridian-aged status has superior tensile backdrop and creep resistance over many other magnesium alloys. QE22 in its summit-aged condition exhibits a 0.2% proof strength of 205   MPa at room temperature, 195   MPa at 100   °C, and 165   MPa at 200   °C. The pitter-patter strength, the stress required to produce 0.2% creep strain in 500   h, of this alloy is 135   MPa at 150   °C and 65   MPa at 200   °C. Nevertheless, this blend is relatively expensive and thus has express applications just in the aircraft and aerospace industries.

Read full affiliate

URL:

https://www.sciencedirect.com/science/commodity/pii/B9780444537706000204

DTA AND Estrus-FLUX DSC MEASUREMENTS OF ALLOY MELTING AND FREEZING

William J. Boettinger , ... John H. Perepezko , in Methods for Phase Diagram Determination, 2007

APPENDIX B RECOMMENDED READING

Monographs on ternary stage diagrams:

•

F.North. Rhines, Stage Diagrams in Metallurgy, McGraw-Loma Book Comp., 1956.

•

G. Massing and B.A. Rodgers, Ternary Systems, Dover Publications, NY, 1960.

•

A. Prince, Alloy Phase Equilibria, Elsevier, Amsterdam, 1966.

•

D.R.F. W, Ternary Equilibrium Diagrams, second edn, Chapman & Hall, London, UK, 1982.

•

D.R.F. West and N. Saunders, Ternary Phase Diagrams in Materials Science, Maney-Institute of Materials, London, United kingdom of great britain and northern ireland, 2002.

A classic in the field, full general focus on a wide range of materials, not specific to alloys:

•

P.D. Garn, Thermoanalytical Methods of Investigation, Academic Press, NY, 1965.

A concise summary of techniques and estimation:

•

Thousand.E. Brown, Introduction to Thermal Assay; Techniques and Applications, Chapman & Hall, NY, Chapter 4 , 1988.

A full general handling of solidification:

•

Principles of solidification, Vol. 15; Casting, Metals Handbook, 9th edn, ASM, Metals Park, OH, 1988.

•

H. Biloni and Due west.J. Boettinger, Solidification, in P. Haasen and R.West. Cahn (eds.), Physical Metallurgy, 4th edn, N Holland, Amsterdam, 1996, p. 669.

An fantabulous summary of the DTA response to the solidification of ternary alloys under equilibrium (lever police) melting and solidification:

•

T. Gödecke, Z. Metallk., 92 (2001) 966 [In German language].

A general guide to skilful technique for phase diagram determination:

•

R. Ferro, Yard. Cacciamani and G. Borzone, Intermetallics, eleven (2003) 1081.

A review, focused on Al alloys, on DTA techniques with a major focus on solid state reactions and with some melting work. Effect of prior sample history made articulate:

•

M.J. Starink, Inter. Mater. Rev., 49 (2004) 191.

Read full chapter

URL:

https://world wide web.sciencedirect.com/scientific discipline/commodity/pii/B9780080446295500057

Alloys with Nickel

Nikolay A. Belov , ... Andrey A. Aksenov , in Multicomponent Phase Diagrams, 2005

7.five Al–Mn–Ni PHASE DIAGRAM

Consideration of this ternary phase diagram is necessary because of the presence of manganese in some Ni-containing commercial alloys (usually equally an impurity) ( Tables seven.1 and 7.2). Moreover, this phase diagram is the ground for promising casting heat-resistant alloys considered elsewhere (Belov et al., 1993b, c; Belov, 1994, 1996; Belov et al., 1994; Belov and Zolotorevskii, 2003; Lin et al., 2004).

Scarce data on the Al–Mn–Ni system suggest that a ternary compound with the formula Al_sixteenMn_threeNi can be in equilibrium with (Al) in add-on to the binary aluminides Al₃Ni and Al₆Mn (Mondolfo, 1976). This chemical compound contains 23–26% Mn and v.six–9.5% Ni and has an orthorhombic structure (infinite group Bbmm, Bbm2, or Bbtwom, ~160 atoms per unit cell) with lattice parameters a = 2.38 nm, b = 1.25 nm, c = 0.755 nm; and density, iii.62 g/cm³.

The projection of liquidus surface and the distribution of phase fields at 627°C are shown in Effigy 7.5. Two invariant reactions (eutectic and peritectic) may proceed in Al–rich alloys (Table 7.10). Tabular array 7.11 shows monovariant reaction occurring in the Al corner of the system. The solubility of nickel in solid aluminum is very small. The solubility of manganese in (Al) decreases in the presence of nickel from 1% at 627°C in a binary alloy to near 0.8% in a ternary blend with nickel. Less than 0.05% Ni dissolves in the Al₆Mn stage. The Al_threeNi compound dissolves a maximum of 0.26% Mn (Mondolfo, 1976).

Figure seven.5. Stage diagram of Al–Mn–Ni system: projection of the solidification surface and distribution of phase regions in the solid country at 627°C.

Tabular array vii.10. Invariant reactions in ternary alloys of Al–Mn–Ni organisation (Mondolfo, 1976; Drits et al., 1977)

Reaction	Point in Figure 7.five	T, °C	Concentrations in liquid phase
			Mn, %	Ni, %
L + Al6Mn ⇒ (Al) + Al16MnthreeNi	P	645	1.7	iv.5
L ⇒ (Al) + Al3Ni + Al16Mn3Ni	E	637	ane.iii	5.3

Table 7.eleven. Monovariant reactions in ternary alloys of Al–Mn–Ni system

Reaction	Line in Effigy seven.5	T, °C
L ⇒ (Al) + AlsixMn	ei−P	658–645
L ⇒ (Al) + All6Mn3Ni	P–E	645–637
L ⇒ (Al) + AlthreeNi	e2−Eastward	640–637

In the as–cast country, the solubility of manganese in (Al) tin be significantly higher than in the equilibrium ane: according to our data upward to 1.5% Mn can deliquesce in (Al) in an Al–4% Ni–2% Mn alloy. As the cooling charge per unit increases, so does the solubility; too, the region of principal solidification of (Al) extends, mainly towards the increase in the Mn concentration.

Read total affiliate

URL:

https://www.sciencedirect.com/science/commodity/pii/B978008044537350007X

Proceedings of the International Conference on Colloid and Surface Scientific discipline

Hideki Sakai , ... Masahiko Abe , in Studies in Surface Scientific discipline and Catalysis, 2001

three RESULTS AND DISCUSSION

Effigy one shows the ternary phase diagram of aqueous mixtures of trans - AZTMA and SDBS at 25   °C. Mixed micellar phases (Thousand) existed on the binary surfactant-water axes in Fig. 1. Precipitates (P) were formed forth the equimolar line. Spontaneously formed vesicles (V) were observed in a relatively wide range of mixing compositions on both cation-rich and anion-rich sides (V   +   50 and V   +   L   +   P regions). Freeze replica TEM observation and glucose dialysis experiments likewise confirmed vesicle germination.

Fig. 1. Ternary stage diagram for AZTMA/SDBS / H2O at 25   °C. Micelle region is M. Precipitate is P. Two-stage region is vesicles and lameller stage (V   +   L). 3-phase region is vesicles, lameller phase and precipitate (V   +   Fifty   +   P).

The result of low-cal irradiation with Hg-Xe lamp (San-ei Supercure-203S) on the aggregation state of cation-rich aqueous mixtures of trans - AZTMA and SDBS (total concentration; 0.05 %, AZTMA: SDBS =   six: 4   wt%, betoken A in Fig.1) was studied. UV/vis absorption spectra showed that the spectroscopic characteristics of AZTMA in aqueous mixtures with SDBS were almost the same as those of AZTMA alone in its aqueous solutions equally reported ²⁾ and ΑΖTΜΑ constituting vesicles underwent reversible trans - cis isomerization upon alternating UV and visible light irradiation.

The effect of low-cal irradiation on the assemblage state was then directly observed using a transmission electron microscope via freeze replica technique. The samples were frozen in liquid nitrogen and fractured at -120   °C using a freeze fracture device (Hitachi, FR-7000A). The fractured surfaces were immediately replicated by evaporating platinum at an angle of 45°, followed by carbon film at normal incidence, to increase the mechanical stability of replica. The replicas thus prepared were examined on an electron microscope JEOL TEM1200EX). In a micrograph of the equally-prepared solution (trans form, Fig. 2(a)), spherical vesicles with an average size of 50-100   nm were observed. Later on 2   h UV-light irradiation (Fig. ii(b)), spherical vesicles disappeared and large elongated molecular aggregates were observed, though the nature of these big molecular aggregates has not yet been identified except that this solution is highly turbid. Furthermore, subsequent visible light irradiation resulted in reformation of vesicles with an average size of ca. 50   nm. These results clearly demonstrate that vesicle formation and disruption tin be reversibly controlled with photoirradiation in the present catanionic AZTMA/SDBS system.

Fig. 2. Freeze-replica TEM micrographs of AZTMA/SDBS (=   6/4   wt%) mixed aqueous solutions

(a) as prepared, (b) later UV irradiation

The effect of photoirradiation on the trapping efficiency of AZTMA/SDBS vesicles was investigated with the glucose dialysis technique ^five) . Figure iii represents the trapping efficiency of ΑΖTΜΑ / SDBS mixed solutions (total surfactant concentration; ane   wt%) every bit a part of their composition. The trapping efficiency of as-prepared (trans form) solutions was loftier (2-4% against total glucose amount) at the compositions where vesicles are formed (AZTMA compositions are 0. 30-0.50 and 0.60 0.75), whereas it was most zero at the equimolar composition (the AZTMA ratio is 0.547). Later on cis form formation induced past UV-light irradiation for 12   hours, the trapping efficiency decreased drastically. For case, it decreased from 3.1   % to 0.3   % by UV-low-cal irradiation for the AZTMA/SDBS =   6/four   wt% solution. Furthermore, the following visible light irradiation for 12   h (in advance of dialysis) caused re-increment in the trapping efficiency to iii.two %. These results confirm the disruption and reformation of vesicles induced by the UV and visible light irradiation, and besides advise that the release of aqueous compounds encapsulated in the vesicles tin can be controlled past the photochemical reaction of AZTMA.

Fig. 3. Glucose amount uptaken by AZTMA/SDBS mixture (Total surfactant concentration 1.00   wt%)

The allowed packing of surfactant molecules is governed by the "surfactant number ⁶⁾ v/a₀l_c, where five is the volume of the hydrophobic portion of the surfactant, l_c is the length of the hydrophobic group, and a₀ is the head grouping surface area of the surfactant molecule. In terms of the surfactant mixtures of interest here, the dynamic ion pairing of ionic single-tailed surfactants apparently brings about a pseudo double-tailed zwitterionic surfactant, which results in a smaller head grouping and a larger hydrophobic region than those in the individual surfactants. This ion pairing was confirmed by Kaler et. al ⁷⁾ with surface tension and conductivity measurements. The dynamic pairing of trans-AZTMA and SDBS should roughly double the surfactant number, leading to a transition from spherical micelles in the pure component systems to vesicles in the mixed surfactant systems.

On the other paw, the germination of cis-course by UV-calorie-free irradiation causes an increase in the critical micelle concentration (cmc) ²⁾ . Thus, the cmc of trans-AZTMA corresponds to that of alkyltrimethylammonium bromide with carbon chain length of 16, while the cmc of cis-AZTMA corresponds to that of alkyltrimethylammonium bromide with carbon chain length of 14. Furthermore, the volume of the hydrophobic portion (5) increases and the length of the hydrophobic group (l_c) decreases through cis-form germination. This would produce an increase in the surfactant number of AZTMA, thereby causing transformation from vesicles to a planer lamellar structure.

Read full chapter

URL:

https://world wide web.sciencedirect.com/scientific discipline/commodity/pii/S0167299101821406

13th International Symposium on Process Systems Engineering (PSE 2018)

Hirokazu Sugiyama , ... Menghe Xu , in Computer Aided Chemical Engineering, 2018

three.1 Generation of procedure alternatives

Effigy 2 (a) shows the ternary stage diagram of the THF/water/methanol organisation that was calculated using the UNIQUAC holding estimation method in Aspen Plus®. The point "inlet" represents the concentration of the waste matter solvent mixture (64.3%, 35.v%, 0.ii%). The constraint lines I and II indicate the required concentration of THF in the initial and extended design bug, respectively; the line III indicates the required methanol concentration, which is common to both problems. The target area of the initial design trouble is almost on the vertex of THF; the target area of the extended pattern problem contains that of the initial problem and is stretched on the top left side of the triangle. For overcoming the distillation purlieus, the alternatives of zeolite membrane, pressure swing, azeotropic distillation, and entrainer processes using ethylene glycol or glycerol were generated, and modelled using Aspen Plus®. The master paths of the get-go three processes are indicated in Figure ii (a).

Effigy 2. (a) ternary stage diagram of THF/water/methanol (b) pressure swing process

Read full affiliate

URL:

https://world wide web.sciencedirect.com/science/article/pii/B9780444642417503487

Small-Angle Scattering Studies of Block Copolymer Micelles, Micellar Mesophases and Networks

Kell Mortensen , in Amphiphilic Block Copolymers, 2000

10 Bi-continuous phases

While bi-continuous microemulsions often appear in ternary stage diagrams of oil, h2o and low-molecular surfactants, at that place has merely recently been observations of such phases in binary systems of block copolymers and solvent. The showtime ascertainment was fabricated in an aqueous solution of the depression PEO-content PEO-PPO-PEO tri-cake copolymer, EO₆PO₃₆EO₆ previously mentioned [35]. In Fig. 21 are shown handful functions of 30% EO₆PO₃₆EO₆ solutions in the lamellar L_α -phase described above, and in the bi-continuous 50 ₃ sponge-phase with the characteristic handful function as described by Teubner and Strey [60].

More recently, the microemulsion sponge phases have been observed in systems of ABA tri-cake copolymers dissolved in A-homopolymers [61] and in a ternary systems of AB-diblock copolymer and A- and B-homopolymers [62]

Read full chapter

URL:

https://www.sciencedirect.com/science/article/pii/B9780444824417500104

Atomistic Simulations of Properties and Phenomena at Loftier Temperatures

Rita Khanna , Veena Sahajwalla , in Treatise on Procedure Metallurgy: Process Fundamentals, 2014

2.iii.five.5.3 Fe–C–S System

Ohtani and Nishizawa calculated the Fe–C–South ternary phase diagram on the basis of the thermodynamic analysis of Iron–C and Iron–Southward and Fe–C–S ternary melts [ 203]. The Gibbs free energy of individual phases was approximated by the interstitial solution model, assuming both C and S to be interstitial atoms. Calculated results indicated that re-melting reactions occurred during the cooling of Fe–C–S alloy, a effect subsequently confirmed through SEM investigations on Fe–C–Southward (0.02   wt%) alloy.

Sahajwalla and Khanna carried out a MC simulation written report of the effect of sulfur on the solubility of graphite in iron melts in the temperature range 1400–1600   °C based on the atomistic model of Fe–C system developed in their group [204]. Atoms in the ternary Fe–C–S organisation were arranged on a graphitic hexagonal lattice and pair-wise interactions between them were assumed to be short-ranged. Information technology is well-known that C and S atoms are strongly repulsive in the Fe–C–Southward organization and S atoms too repel each other [205]. The attractive bond between Atomic number 26 and S is very stiff and is more than or less ionic in nature. This strong Fe–South bond is capable of distorting the electron distribution effectually the Fe cantlet and affecting other bonds fabricated by information technology [206]. In the outcome of such a distortion taking place, the resulting bail energy volition exist a fraction (one   − ɛ) of the energy of the bond made in the absence of a Iron–S bond, with ɛ ranging between 0 and 1.

Representing atoms as magnetic spins (Due south  =   +   1 for carbon, S  =   −   one for iron and S  =   0 for sulfur), the Hamiltonian H of the arrangement in the spin −   ane Ising model can be written equally

(2.three.69) $H=-{\displaystyle \sum _{i\ne j}^{\mathit{nn}}\left[J_1\left(\alpha -\beta \right)S_i^{\alpha }{S}_j^{\beta }+{\mathrm{Grand}}_{\mathit{ij}}{R}_{\mathrm{one}}\left(\alpha -\beta \right)\right]}-{\displaystyle \sum _{i\ne j}^{\mathit{nnn}}\left[J_2\left(\alpha -\beta \right){\mathrm{South}}_i^{\alpha }{S}_j^{\beta }+{\mathrm{Chiliad}}_{\mathit{ij}}{R}_2\left(\alpha -\beta \right)\right]}-H{\displaystyle \sum _i{\mathrm{Southward}}_i}$

where spin S ^α _i represents the blazon of atom (α) occupying the site i while values of J are the various interaction parameters of the Fe–C system. The constant K_ij has a value of 1 if either one or both sites i and j are occupied by S and is zero otherwise. Values of R correspond diverse interactions of S with other atoms. The coefficient Js and Rsouth accept units of energy. H is the magnetic field.

Allow J correspond the magnitude of the nearest-neighbor C–C interaction forcefulness. Various interaction parameters have been represented in units of J. Simulations were carried out using the post-obit prepare of interaction parameters: J ₁(C–C)   = J; J ₂(C–C)   = γJ; J ₁(Fe–Atomic number 26)   = J ₂(Iron–Iron)   =   − J; J _ane(Fe–C)   = J ₂(Fe–C)   =   0.fiveJ and 0.sixJ; R ₁(S–S)   = R ₂(S–Southward)   =   −(0.ane–0.v)J; R ₁(S–C)   = R ₂(S–C)   =   −(0.i–0.5)J; R _i(Fe–South)   = R _two(Fe–S)   =   (0.2–1)J. The bonds made by Fe atoms which have at to the lowest degree one bail with a sulfur atom were modulated past a factor (one   − ɛ) where ɛ takes on three values: 0.0, 0.5, and ane. Two values of γ (0.02 and 0.2) were used in these simulations. Detailed simulations on the system showed that the strength of the Iron–C interaction (J ₁(Atomic number 26–C)   =   0.vJ or 0.6J) did not announced to accept much effect on the linear trend of the subtract in graphite solubility with sulfur. It besides does not seem to affect the magnitude of the slope to a neat extent.

Every bit C and S atoms tended to readapt each other to regions of high and depression concentrations, it was causeless that this deportation was mediated past an Iron atom [207]. Treating both C and South atoms on an equal basis and assuming electronic distortions around Fe play a significant role in this deportation process, two new parameters (δ'south) were defined. δ(Fe–C) represents the modification in the Fe–C interaction parameter, when the Atomic number 26 cantlet has an boosted bond with S. Similarly δ(Fe–S) represents modification in the Iron–S interaction parameter, when the Fe atom has an additional bond with C. These parameters were varied over a big range in simulations on the Fe–C–Due south system. δ(Fe–S) ranged from −   0.v to 1.0 with δ(Iron−C)   =   ane.0. Information technology was expected that a locally repulsive Fe–S interaction may lead to a displacement of S from C's neighborhood. Simulations results on a homogenous Fe–C–South arrangement showed that the liquid separates into ii immiscible regions just for δ(Atomic number 26−Due south)   =   1.0. This indicates that baloney around Fe does not significantly affect Iron–South interaction strength and may be neglected. This separation was, nevertheless, most pronounced for δ(Fe−C)   =   1.5. A new issue, emerging from these simulations, was the simultaneous displacement of fe from regions of loftier carbon concentration to regions of high sulfur concentration.

Stage diagram simulations on carbon solubility also led to similar conclusions. Modest values of δ(Fe–S) (−   0.v and 0.0), which were plant unsuitable in miscibility studies, also showed negligible effect of sulfur on carbon solubility. The parameter, δ(Fe−C)   =   0.5, was constitute to be completely unsuitable as it led to a slight increase in solubility rather than a subtract. Optimum parameters for this system, which simultaneously simulate the well-known backdrop of Iron–C–South system are: ɛ(Fe−Atomic number 26)   =   1.0, δ(Fe−S)   =   1.0, δ(Fe−C)   =   1.0 and 1.five. These simulation results on the Fe–C–S system clearly show that distortions around Fe due to a strong Fe–Due south bond exercise non play a meaning part in the molten state. Even though a slight increase in Fe–C repulsion locally gives optimum results, this diminutive model with null distortions, with all local modification parameters equal to unity, likewise brings out key features of the Fe–C–S system.

Read full affiliate

URL:

https://world wide web.sciencedirect.com/science/article/pii/B9780080969862000096

kirkhopefintioned.blogspot.com

Source: https://www.sciencedirect.com/topics/chemistry/ternary-phase-diagram

Share :