CONCENTRATION MICELLAIRE CRITIQUE PDF

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NaCl dehydrates hydrophilic group nonionic surfactants. Therefore, CMC decreases. The length of the hydrophobic block polymer micelles is not reduced. All these substances are poorly soluble in water and therefore soy lecithin does not have CMC in an aqueous solution, The lecithin phospholipids can form. Nous supposerons que dans la phase aqueuse, la concentration de ces molécules est* égale à leur concentration micellaire critique (CMC). Considérons un.

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Conservation Science in the United Kingdomed. Upon introduction of surfactants or any surface active materials into the system, they will initially partition into the interfacereducing the system free energy by:. Department of Commerce, National Bureau of Standards.

The CMC generally depends on the method of measuring the samples, since a and b depend on the properties of the solution such as conductance and photochemical characteristics.

Color measurements on the cleaned samples were made as previously described, and these were aged in crotique light box fitted with Philips PL-L 36W compact fluorescent lamps color 84, lumen, color temperature K Daniels and McIntyre An initial study of detergents and washing recipes for use in the conservation of textile objects.

Journal of Applied Biosciences

Washing is a nonreversible, interventive treatment and should be carried out with maximum efficiency to deter the need for repetition.

The value of the critical micellization concentration can depend, to a certain extent, on the property under consideration and on the method chosen to measure this property. The washing followed cooncentration regime described in table 2.

The aim of the present study was to find one or more suitable alternatives to Synperonic N, principally by studying their cleaning properties on artificially soiled textiles.

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Phase 2 was to investigate whether artificially aged samples of surfactant-cleaned cotton and wool textile produced cirtique effect that would cause a change in color or pH or reduce the tensile strength.

Critical micelle concentration – Wikipedia

An apparatus for studying conservation light bleaching. For example, if we take a solution of a surfactant above CMC and start introducing air bubbles at the bottom of the solution, these bubbles, as they rise to the surface, pull out the surfactants from the bulk to the top of the solution creating a foam column thus bringing down the concentration in bulk to below CMC.

The combined list critiqeu seven surfactants for further testing: Surfactants by their very nature are harmful to living things, as they alter the properties of membranes surrounding cells. Residues may be directly observed using scanning electron microscopy or measured quantitatively using time-of-flight secondary ion mass spectrometry Howell and Carr The need to replace Synperonic N is immediate due to the phasing out of its use in The variation in color measurements for wool was minimal.

JAIC , Volume 43, Number 1, Article 5 (pp. 55 to 73)

Concentrayion using this site, you agree to the Terms of Use and Privacy Policy. A second set of samples was prepared in exactly the same manner, but these samples were not aged.

Critical micelle concentrations of aqueous surfactant systems. Synperonic N, previously known as Lissapol, has been widely used in conservation since its recommendation in Plenderleith’s book on the conservation of antiquities and works of art Plenderleith These graphs were useful, as they gave a direct indication of the cleaning ability of each surfactant, with the gray columns representing the soil liberation from the presoiled areas. All values lay within one standard deviation of the mean figs.

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A collection of writing tools micellairw cover the foncentration facets of English and French grammar, style and usage. The CMC is an important characteristic of a surfactant.

This technique allows for some of the surfactant micelles to be used up during the washing process without reducing the cleaning efficiency. Fit functions for properties such as electrical conductivity, surface tension, NMR chemical shifts, absorption, self-diffusion coefficients, fluorescence intensity and mean translational diffusion coefficient of fluorescent dyes in surfactant solutions have been presented.

Critical micelle concentration

For the purpose of this experiment, the surfactants were tested in a solution at five times their CMC. The maximum load was measured. The present selection has been based mainly on cleaning ability of the pure surfactant in distilled water solution acting on standard soiled textiles. The conductivity behavior of solution samples obtained during the cleaning of the model textiles was similar whether wool or cotton was being washed.

Along with its availability and expense, the other main factors that should be considered include efficiency of cleaning and residue Hofenk de Graff ; Timar-Balazsy and Eastop Photograph of fabric samples after washing wool on the left, cotton on the right.

The white column on figures 5 and 6 represents soil redeposition to the clean area, but this finding was only confirmed by reviewing the original data.