Synergism binary mixtures

Mutual synergism of binary mixtures containing fine particles can be quantified in terms of the departure of the 0-x2 curve from a linear tie line, which signifies absence of synergism, joining 7 and 2 for the respective components, as shown in Fig. 54. A convenient measure of this departure is the shaded area lying between the -x2-curve and the linear tie line. This can be derived analytically in terms of what will be called the Synergism number Sy, normalized with respect to 07+0, of both the coarse and the fine particles ... 

Synergism of antioxidants was reviewed in the monographs [1-9]. The classification of binary mixtures of inhibitors is based on the mechanisms of action of particular inhibitors [10,11], One of the classification schemes is given in Ref. [11], If one takes into account the... 

For binary mixtures, a straight line (isobole) is produced joining Di and D2 and passing through di, d-2). The interaction index (Cl) is 1, <1, or >1 when the combinations show zero interaction, synergism, or antagonism using dose addition, respectively. 

Molecular Interaction and Synergism in Binary Mixtures of Surfactants... 

During the past few years, the determination of the interfacial properties of binary mixtures of surfactants has been an area in which there has been considerable activity on the part of a number of investigators, both in industry and in academia. The Interest in this area stems from the fact that mixtures of two different types of surfactants often have interfacial properties that are better than those of the individual surfactants by themselves. For example, mixtures of two different surface-active components sometimes reduce the interfacial tension at the hydrocarbon/water interface to values far lower than that obtained with the individual surfactants, and certain mixtures of surfactants are better foaming agents than the individual components. For the purpose of this discussion we define synergism as existing in a system when a given property of the mixture can reach a more desirable value than that attainable by either surface-active component of the mixture by itself. 

Synergism in surface tension reduction efficiency. The efficiency of surface tension reduction by a surfactant is defined (9) as the solution phase concentration required to produce a given surface tension (reduction). Synergism in this respect is present in a binary mixture of surfactants when a given surface tension (reduction) can be attained at a total mixed surfactant concentration lower than that required of either surfactant by itself. This is illustrated in Figure 2. 

We were able to test the analog synergism in another setting where the analogs could be produced in sufficient quantity by synthesis. The wild pepper, Piper tuberculatum, was the most active of 16 pepper plants from Costa Rica assessed in our study (Bernard et al., 1995). Four insecticidal piperamides from P tuberculatum were produced by synthesis (Scott et al., 2002) and the lethal concentrations of the compounds were assessed alone and in binary, tertiary and quaternary mixtures. Although binary mixtures were no more toxic than individual compounds, toxicity increased with three and four compounds in the mixture, while keeping the total... 

The list in Table 10.1 contains numerous lipophiles and hydrophiles. A vast number of mixture combinations are possible. Though most mixtures have not been studied, one possible binary mixture from this list—hexane and methyl ethyl ketone (MEK)—has a known synergism. 

The values for the binary mixtures of the above-cited molecular solvents and ILs under study are very similar. In all cases, the values exhibit positive deviation from ideal behaviour. However, in the mixtures with AN, a slight synergetic effect appears at high IL mole fraction, and in mixtures with MeOH, this effect is clearly noticeable at all compositions. The prominence of the synergetic effect in mixtures with MeOH could be related to the fact that the E values of both pure solvent components of the mixture are nearly equal. Also, synergism on E values was reported for the [bmim][PFg] + ethanol solvent mixtures. 

Rosen MJ, Gao T, Nakatsuji Y, Masuyama A. Synergism in binary mixtures of surfactants. 12. Mixtures containing surfactants with two hydrophilic and two or three hydrophobic groups. Colloids Surfaces A Physicochem Eng Aspects 1994 88 1-11. 

Rosen, M. J. Gao, T Nakasiyi, Y Masuyama, A. Synergism in Binary Mixtures of Surfactants. 12. Mixtures Containing Surfactants with Two Hydrophilic and Two or Three Hydrophobic Groups. Colloids Surf. A 1994, 88,1-11. 

Synergism is observed when binary mixtures of some phenols and aromatic amines are introduced into hydrocarbon. It is related to the interaction of inhibitors and radicals formed from them. For the combined introduction of phenyl-N-P-naph-thylamine and 2,6-di-fert-butylphenol into oxidized ethylbenzene (v, = const, 343 K), phenol is consumed first, and amine begins to consume only after its disappearance, although RO 2 reacts with amine more rapidly (A31 = 1.3T0 l/(mol s), 333 K) than... 

Figure 54. Measure of synergism for binary particle mixtures. (Kwauk, 1984, 1986.)...

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