The effect of β-cyclodextrin (β-CD) on the aggregation behavior of a nonionic surfactant, Triton X-114 ((1,1,3,3-tetramethylbutyl)phenyl-polyethylene glycol), in aqueous solutions has been studied as a function of temperature by means of turbidity, dynamic light scattering (DLS), transmission electron microscopy (TEM), and rheo-small angle light scattering (rheo-SALS). The Triton X-114 (TX-114) solutions possess unique structural variations and display special aggregate transitions upon β-CD addition. In contrast to the reported aggregate disruption effect of β-CD for dilute nonionic surfactant solutions, aggregate growth is found in the aqueous TX-114 solutions of 93 mM upon β-CD addition. The micelle to vesicle transition induced by β-CD addition, which can greatly influence the turbidity and the viscosity of the solutions, is quantified by the characteristic length and aspect ratio of the aggregates. The characteristic length and aspect ratio of the aggregates change significantly after β-CD addition. It shows that aggregate growth may occur in nonionic surfactant–CD systems, as well as the reported ionic surfactant–CD systems. It is proposed that the CD–CD H-bonds create intermicelle interactions and promote aggregation of the CD/surfactant complexes, resulting in the formation of micrometer-scale phase-separated droplets.
Nonionic surfactant solution is often used to separate and purify biomaterials, and the viscosity of nonionic surfactant solution plays an essential role in the design of separation process. In this study, the viscosity data are obtained for aqueous Triton X-114 ((1,1,3,3-tetramethylbutyl)phenyl−polyethylene glycol) solutions of three mass fractions of 0.01, 0.02, and 0.05 at temperatures from 293.15 to 313.15 K, and an empirical correlation describing the effect of temperature on the viscosity is derived. The predicted values by the correlation are in good agreement with the experimental data.
A cloud point extraction (CPE) method was used as a pre-concentration strategy prior to the determination of trace levels of silver in water by flame atomic absorption spectrometry (FAAS) The pre-concentration is based on the clouding phenomena of non-ionic surfactant, triton X-114, with Ag (I)/diethyldithiocarbamate (DDTC) complexes in which the latter is soluble in a micellar phase composed by the former. When the temperature increases above its cloud point, the Ag (I)/DDTC complexes are extracted into the surfactant-rich phase. The factors affecting the extraction efficiency including pH of the aqueous solution, concentration of the DDTC, amount of the surfactant, incubation temperature and time were investigated and optimized. Under the optimal experimental conditions, no interference was observed for the determination of 100 ng·mL −1 Ag + in the presence of various cations below their maximum concentrations allowed in this method, for instance, 50 μg·mL −1 for both Zn 2+ and Cu 2+ , 80 μg·mL −1 for Pb 2+ , 1000 μg·mL −1 for Mn 2+ , and 100 μg·mL −1 for both Cd 2+ and Ni 2+ . The calibration curve was linear in the range of 1–500 ng·mL −1 with a limit of detection (LOD) at 0.3 ng·mL −1 . The developed method was successfully applied for the determination of trace levels of silver in water samples such as river water and tap water.
Zijun Sun,Meiying Song,Weiling Zou,Zhengquan Su,Yan Bai
In the weakly citric acid-Na 2 HPO 4 buffer solution, chito-oligosaccharides (COS) interacted with acid blue 119 to form an ion-association complex of COS-acid blue 119, which increased the resonance Rayleigh scattering (RRS) intensities at 349 nm. Moreover, with the addition of Triton X-114 (TX114), the RRS intensities of the system increased and the changes of the intensities were linear to the concentration of COS in the range of 0.125–3.00 µg/mL with the limit of detection (LOD) of 37 ng/mL. The regression equation was Δ I = 1348.6c + 6.1063 with the correlation coefficient of 0.9984. The experimental conditions were optimized, the effects of the coexisting substances were evaluated and excellent selectivity was exhibited. The reaction mechanism and causes of the RRS intensity enhancement were also discussed. At the same time, the method was demonstrated with the determination of COS in health products with satisfactory results. Therefore, the proposed method was proved as a simple, low cost, high sensitive and selective method.
危险品化学品经营许可证（带存储）