کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
594760 | 1453992 | 2011 | 9 صفحه PDF | دانلود رایگان |

The interactions between an anionic dye and cationic surfactants were investigated using surface tension measurements, spectroscopy, conductometry, and pulsed field gradient NMR (PFG-NMR). Spectroscopic and surface property characterization of the solution as a function of surfactant concentration in the presence of the dye revealed formation of three species: a dye–surfactant ion pair, small mixed aggregates of the dye and surfactant (below the critical micelle concentration (CMC) of these surfactants), and micelles composed of the cationic surfactant. Above the CMC, the dye reverted to its monomeric state or bound to the surface of the micelle. Chemometric resolution analysis confirmed the formation of three species. The hydrodynamic radii of the micelles were determined by self-diffusion coefficient measurements. The average size of the micelles was larger in the presence than in the absence of the dye. Regular solution theory was used to describe the synergistically enhanced ability to form mixed aggregates of dyes and surfactants.
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► The interactions between dye and surfactant molecules with opposite charges were discussed in detail.
► The results demonstrated that the interactions between surfactants and dyes may be divided into three processes: (1) Formation of hydrophobic and hydrophilic dye–surfactant ion pairs or complexes (Regions I and II). (2) Dye and surfactant aggregate formation over a size range of 0.73–0.86 nm (Region III). (3) Surfactant micelle formation (Region IV).
► These processes were observed as a function of surfactant concentration. The use of multivariate resolution methods was appropriate for studying and interpreting these processes.
Journal: Colloids and Surfaces A: Physicochemical and Engineering Aspects - Volume 380, Issues 1–3, 5 May 2011, Pages 119–127