Surfactants and polymers in aqueous solution pdf

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    Clouding is a Characteristic Feature of. Polyoxyethylene-Based Surfactants and Polymers. vi. Surfactants and Polymers in Aqueous Solution. Many industrial formulations such as detergents, paints, foodstuff and cosmetics contain both surfactants and polymers and their interaction. SurfACtAntS. AnD PoLyMerS. In AqueouS. SoLutIon november 16–20, solutions, surfactant and polymer adsorption and . from each PDF-file.

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    Surfactants And Polymers In Aqueous Solution Pdf

    Surfactants and Polymers in Aqueous Solution. Based on the book. Surface Chemistry of Surfactants and Polymers. September , in Malmö, Sweden. Request PDF on ResearchGate | Surfactants And Polymers in Aqueous Solution | Polymer Properties are Governed by the Choice of MonomersThe Molecular. Request PDF on ResearchGate | On Jan 1, , K. Holmberg and others published Surfactants and Polymers in Aqueous Solution.

    This article has been cited by other articles in PMC. Abstract In this paper, the use of surfactants for solubilization of hydrophobic organic dyes mainly solvent and disperse dyes has been reviewed. The effect of parameters such as the chemical structures of the surfactant and the dye, addition of salt and of polyelectrolytes, pH, and temperature on dye solubilization has been discussed. Surfactant self-assemble into micelles in aqueous solution and below the concentration where this occurs—the critical micelle concentration CMC —there is no solubilization. Above the CMC, the amount of solubilized dye increases linearly with the increase in surfactant concentration. It is demonstrated that different surfactants work best for different dyes. In general, nonionic surfactants have higher solubilization power than anionic and cationic surfactants. It is likely that the reason for the good performance of nonionic surfactants is that they allow dyes to be accommodated not only in the inner, hydrocarbon part of the micelle but also in the headgroup shell. It is demonstrated that the location of a dye in a surfactant micelle can be assessed from the absorption spectrum of the dye-containing micellar solution. Keywords: dye, water insoluble, hydrophobic, surfactant, solubilization, micelle 1. Introduction The use of surfactants for solubilization of dyes dates back to the s [ 1 , 2 , 3 , 4 , 5 , 6 ]. For the majority of applications an aqueous medium is used and the choice of surfactant is decisive of the adsorption and fixation of the dye at the substrate e. Moreover, the surfactant is essential for removing poorly bound dye from the substrate by a solubilization mechanism in an after-treatment washing procedure. This paper reviews the use of surfactants for solubilization of hydrophobic dyes. Surfactants are also used to create suspensions and emulsions of dyes.

    Rheological measurements. References 1. Landoll, L. Evani, S. Polym Mater. Glass, J. McCormick, C.

    In Encyclopedia of Polymer Science and Engineering, 2nd ed. Bock, J. Ezzell, S. Wang, K. Magny, B. Lundberg, D. Ma, Z. Coatings , 21, Mast, A.

    Colloids Polym. Alahapperuna, K.

    Polymer Micelles

    Reynolds, P. Coatings , 20, Trends Polym. Seng, W. Colloids Surf. Tam, K. Tirtaatmadja, V. Islam, M. Khan, Z.

    Li, Y. Elliott, P. Ma, J. English, R. Bokias, G. Smith, G. Xin, X. Bastiat, G. Gouveia, L. Ali, S. Methemitis, C. Panmai, S. Biggs, S. Grassl, B. Zhong, C.

    Tan, H. Dai, S. Kujawa, P. Part B, Polym. It is assumed that the concentration of surfactant on the phase separation surface and properties of the absorption layer depend on the number and kind of polar groups as well as the structure and length of the carbohydrate chains [ 21 ]. An approximate value of the optimal amount of stabilizer can be calculated with reference to the size of the phase separation surface, thickness of the layer, and critical concentration of surfactant molecules in the system.

    The stabilizing influence of the surfactant involves not only decreasing the surface tension at the interface, but also forming a structural barrier within the volume which will ensure dispersion stability [ 22 , 23 ]. An aqueous dispersion of a pigment is an unstable system, because.

    Surfactants and Polymers in Aqueous Solution | Wiley Online Books

    In order to prepare a stable dispersion, a definite stabilizer is needed. Four kinds of stabilizing additives can be distinguished. The least effective ones are simple, non-organic electrolytes. The fourth kind includes fine grain insoluble powders. The powder particles form a mono-layer rim stabilizing the system. The pigment particles stabilized in water by a nonionic surfactant or water-soluble polymers usually have a slight negative charge due to an excessive adsorption of anions from the water phase.

    The value of electrokinetic potential, as one of the factors determining aggregation stability of the pigment particles, has been neither explicitly explained nor justified so far [ 24 , 25 , 26 ]. Nowadays, it is impossible to characterize the stability of the disperse system by means of one simple method.

    The instability is the result of collision of particles caused by Brownian motion and convection leading to contact and agglomeration. Thus, the influence of surfactant structure on the dispersion stability is a crucial issue depending of three factors: a geometric barrier involving the preservation of the minimal distance between molecules of the stabilizer during the phases and a definite ratio between the polar and non-polar groups, an energy barrier defining the minimal deformation strength of the adsorption layer and a concentration barrier conditioning the presence of a saturated adsorption layer on the particle surface [ 9 , 27 , 28 , 29 ].

    It is often said that the presence of a electrical double layer is the factor determining the stability of dispersion molecules. However, this approach needs to be questioned as there is neither qualitative nor quantitative correlation with the disperse system properties. The electrical double layer determines only the adsorption layer thickness and partly the diffusion layer thickness and it apparently increases the size of dispersed particles [ 8 ].

    High-molecular stabilizers should be classified into a separate group. This is caused by the fact that their structure on the surface is different from the one for low-molecular compounds. The amount of low-molecular surfactant necessary for stabilization of a unit surface are of dispersed particles is significantly higher than the amount of high-molecular stabilizer [ 17 , 22 ]. The possibility of cooperation between surfactant molecules and the remaining components should also be accounted for.

    The choice of a given surfactant should depend on the kind of disperse system which defines the structure and interaction of the surfactant with the phases.

    SURFACTANTS AND POLYMERS IN AQUEOUS SOLUTION

    So far there has been no satisfying, theoretical description of the considered phenomena. Therefore, taking into account all the factors affecting the persistence of the dispersed system, it is necessary to take into consideration the results of experimental tests while choosing the surfactant [ 17 , 18 , 21 ]. Sedimentary tests play a very important role in the research on dispersed systems properties. Undoubtedly, defining the relationship between the dispersed system structure with regard to intermolecular interactions is an especially difficult task.

    The kind of internal structure formed is determined by the type of contacts occurring between particles of the dispersed phase. Research on the operation mechanisms of surfactants is of key importance for direct contacts of particles between each other and has a large influence on all kinds of stability effects.

    They affect the formation kinetics of the network and its rheological properties. Despite efforts of many researchers, a theoretical description and analysis of the phenomena occurring during the formation of the disperse system, its behavior during a long-term storage or definition of the destabilization mechanism is still to very clear.

    The above mentioned fact was an inspiration for the authors to take up research on the considered issue. The subject of sedimentary tests are aqueous dispersions of pigments stabilized by different surfactants and concentrators.

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