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Hydrophobically modified hydroxyethyl cellulose and the interaction of the surface active agent , and its co- stable emulsion

Author: WeiYunPing
Tutor: SunDeJun
School: Shandong University
Course: Colloid and Interface Chemistry
Keywords: Hydrophobically associating polymers Surfactant Cationic Gemini surfactant Emulsion Stability
CLC: O648.23
Type: Master's thesis
Year: 2009
Downloads: 231
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Abstract

Recent years, macromolecular surfactant as an emulsifier and stabilizer has attracted extensive attention, including a special class of macromolecular surfactant - hydrophobically associating polymers, has become one of the hot. Such polymer is a hydrophilic backbone polymer with a small amount of a hydrophobic group, thus having amphiphilic, and can reduce the system table, and interfacial tension, although this ability than traditional small molecule surfactants small 's. However, due to its larger molecular structure and the molecular main chain hydrophobic group Guo.Association, the thickening ability of the aqueous solution is much stronger than the thickening ability of the small molecule surfactant. In practical applications, it is often the surfactant complex with such polymers and small molecules, complex system may produce many new different from the nature of the single polymer or a surfactant. Add surfactant occurs through hydrophobic interactions with the polymer interaction, so that the thickening ability of the mixed system, have been improved foaming and emulsifying ability; while the presence of the polymer will also affect the physical and chemical properties of the surfactant solution so that The physical parameters of the surface tension of the solution, the critical micelle concentration and aggregation number, interfacial adsorption behavior are significant changes. Hydrophobically modified hydroxyethyl cellulose (HMHEC) in this paper as the main object of study, the study of the HMHEC the traditional single-chain anionic and cationic surfactants (SDS, CTAB) system, the complex system of novel Gemini surfactant solution The nature of its impact on the stability of the emulsion, summarizes the variation of the stability of the emulsion, the emulsion stability mechanism, theoretical and practical significance for the study of the stability of emulsions such polymer and surfactant co . The main contents of this paper include the following two parts: 1.HMHEC with the traditional single-chain surfactants with stable emulsion through a variety of means of experimental research HMHEC with SDS and CTAB interaction in aqueous solution and preparation stable emulsion by HMHEC / SDS and HMHEC / CTAB composite system, examines the impact of various factors on the stability of the emulsion. Between HMHEC with surfactant in the aqueous solution will occur a strong hydrophobic Guo.Association. With the increase in the concentration of surfactant, HMHEC / surfactant mixed aqueous solution viscosity first increases gradually decreased after a maximum, in line with the classic model hydrophobically associating polymers interact with traditional surfactant. HMHEC / mixed aqueous solution of the surfactant with the oil phase is mixed in the aqueous solution the HMHEC and surface active agent adsorbed on the oil / water interface and thus have a stronger ability to reduce the oil / water interfacial tension such that the emulsification process easier, HMHEC / surfactant mixed aqueous solution prepared in emulsion stability is increased with increasing surfactant concentration, the particle size of the emulsion droplets decreases. HMHEC with the anionic surfactant SDS, the interaction is stronger than the cationic surfactant CTAB, low surfactant concentrations, the stability of the emulsion prepared by the HMHEC / SDS mixed system higher than the emulsion prepared as a mixed system of HMHEC / CTAB Stability of liquid. 2.HMHEC with this part of the novel Gemini surfactant complex with a stable emulsion by means of table, interfacial tension, steady-state fluorescence, viscosity experiments investigated the separate Gemini surfactant 12-2-12 aqueous solution with HMHEC/12-- 2-12 mixed aqueous nature of the system, and successfully prepared by both the complex system stable emulsion. Significantly higher than the the Gemini surfactant special molecular structure - molecular structure contains two hydrophilic head group and two hydrophobic chain, reduce the capacity of the table, the interfacial tension of DTAB. 12-2-12 solution HMHEC join both interact the HMHEC added to the surfactant solution to provide a smaller polarity hydrophobic environment, the lower table, interfacial tension and mixed system capacity than separate surface active agent. Due 12-2-12 unique morphology of the aggregates in solution, HMHEC/12-2-12 mixed viscosity of the system features HMHEC / conventional surface active agent is first increased and then decreased with the change in the concentration of the surface active agent is different from, but show three stages, linear micelles ,12-2-12 is formed in the high surfactant concentration. Stratification stability of the emulsion prepared in by HMHEC/12-2-12 mixed system is improved with increasing concentration of the surface active agent in the low surfactant concentrations the HMHEC added to play a significant role to improve the stability of the emulsion. The main innovation of this dissertation: 1. Study the the HMHEC SDS, CTAB interaction of aqueous systems and both complex system of emulsion stability, and contrast HMHEC / SDS with HMHEC / of CTAB two The nature of the system. HMHEC / surfactant synergistic mechanism of stable emulsions. With the preparation of emulsions of the HMHEC with the surfactant complex system can greatly reduce the amount of surface active agent having a low toxicity and environmental advantages. . Cationic Gemini surfactant 12-2-12 with the HMHEC the interaction, and investigated the nature of the emulsion prepared both complex system. Enrich the interaction between hydrophobically associating polymers Gemini surfactant emulsion application content.

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CLC: > Mathematical sciences and chemical > Chemistry > Physical Chemistry ( theoretical chemistry ),chemical physics > Colloid chemistry ( physical and chemical dispersion system ) > Crude dispersion system > Emulsion
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