Colloidal chemistry, geometry

Surfactant molecules can be considered as building blocks for certain forms of geometry in colloidal chemistry. Various forms of association molecules can be obtained as the concentration of surfactant in water is increased and/or physicochemical conditions are changed (e.g. CMC, Craft-point, etc.). Figure 2 schematically shows the most likely structural configurations and assemblages of surfactants association in an aqueous system (26). Upon addition of oil and a short-chain alcohol, for example, one can convert the oil-in-water micelles into water-in-oil microemulsions. It is therefore possible to induce a transition from one structure to another by changing the physicochemical conditions such as temperature, pH and addition of mono or di-valent cations to the surfactant solution. It should be also noted that the sur-... 

As already noted in Section 8, it is practically impossible to measure the shape and size of each cell individually therefore, on uses statistical geometry methods for the calculation of the morphological parameters. Originally, these methods had been developed and used in crystallography, petrography and colloid chemistry for analyzing the macrostructures of crystals, metal alloys, minerals, suspensions, etc. 

Some alchemists even considered gold as condensed sunbeams [1] and used to represent it by the symbol of a circle, the hallmark of mathematical perfection. Let us recall in this respect, e.g., the Golden Section in geometry, the concept of a gold number in colloidal chemistry after R. A. Zsigmondy (Z. Anal. Chem. XL, 697 (1901)) and J. B. Richter and M. Faraday (Phil. Trans. CXLVII, 145 (1857), and the Golden Rule in quantum theory. 

Vitruvius Pollio Marcus 100 BC) It. arch., authority on architecture for centuries, studied hydraulics, clocks, mensuration, geometry, mech. engineering Void Marjorie Jean (1913—1969) US chem., colloid chemistry, theory of DTA Vopenka Petr ( 935-) Czech math, and phil., inventor of the alternative theory of sets, books on same and various philosophy aspects... 

The word gold has been used in many different fields, mostly to evoke perfection, like for example the famous gold section in geometry. In chemistry, the concept of a gold number is used to represent the protective action of colloid (Ref. [10], p. 738). This concept was... 

Atomic force microscopy (AFM) [20] has recently been used to image interfacial aggregates directly, in situ and at nanometer resolution [21, 22], The key to this application lies in an unusual contrast mechanism, namely a pre-contact repulsive force ( colloidal stabilization force ) between the adsorbed surfactant layers on the tip and sample. In contrast to previous adsorbate models of flat monolayers and bilayers, AFM images have shown a striking variety of interfacial aggregates - spheres, cylinders, half-cylinders and bilayers - depending on the surface chemistry and surfactant geometry. I review the AFM evidence for these structures and discuss the possible inter-molecular and molecule-surface interactions involved. 

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