2915-57-3Relevant articles and documents
Dynamics in the interior of AOT lamellae investigated with two-dimensional infrared spectroscopy
Kumar, S. K. Karthick,Tamimi,Fayer, Michael D.
, p. 5118 - 5126 (2013)
The dynamics inside the organic regions of aerosol-OT (AOT)/water mixtures in the lamellar mesophase, bicontinuous cubic (BC) phase, and in an analogous molecule without the charged sulfonate headgroup are investigated by observing spectral diffusion, orientational relaxation and population relaxation using ultrafast two-dimensional infrared (2D IR) vibrational echo spectroscopy and IR pump-probe experiments on the asymmetric CO stretch of a vibrational probe, tungsten hexacarbonyl (W(CO)6). The water layer thickness between the bilayer planes in the lamellar phase was varied. For comparison, the dynamics of W(CO)6 in the normal liquid bis(2-ethylhexyl) succinate (EHS), which is analogous to AOT but has no charged sulfonate headgroup, were also studied. The 2D IR experiments measure spectral diffusion, which results from the structural evolution of the system. Spectral diffusion is quantified by the frequency-frequency correlation function (FFCF). In addition to a homogeneous component, the FFCFs are biexponential decays with fast and slow time components of ～12.5 and ～150 ps in the lamellar phase. Both components of the FFCF are independent of the number of water molecules per headgroup for the lamellae, but they slow somewhat in the BC phase. The dynamics in the ordered phases are in sharp contrast to the dynamics in EHS, which displays fast and slow components of the FFCF of 5 and 80 ps, respectively. As the hydration level of AOT increases, vibrational lifetime decreases, suggesting some change in the local environment of W(CO)6 with water content.
Diacidic ionic liquid supported on magnetic-silica nanocomposite: a novel, stable, and reusable catalyst for selective diester production
Fareghi-Alamdari, Reza,Nadiri Niri, Mehri,Hazarkhani, Hassan,Zekri, Negar
, p. 2615 - 2629 (2018/09/13)
Abstract: Supported diacidic ionic liquid on magnetic silica nanoparticles (SDAIL@magnetic nanoSiO2) was successfully prepared through a multi-step approach. 2,2- bis ((3- methylimidazolidin-1-yl) methyl) propane- 1,3- diol bromide salt was immobilized onto the surface of magnetic silica nanoparticles via covalent bonding to prepare a novel powerful acidic catalyst. The synthesized catalyst was characterized by FT-IR, SEM, TGA, VSM, N2 adsorption–desorption measurements and acid-base titration. The catalytic activity of the prepared SDAIL@magnetic nanoSiO2 was investigated for the selective diesterification of alcohols by phthalic anhydride to afford corresponding dialkyl plasticizers under solvent-free conditions. The nature of two acidic counter anions as well as the presence of Lewis acidic species (Fe3O4) on the magnetic nanosilica and high surface area of the nanosilica influenced the behavior of the catalyst. Surperisingly, the high acidic character of the catalyst facilitates the reaction with a short reaction time. Furthermore, TG analysis strongly demonstrates that major content of IL is still stable on the support up to 290?°C, so catalyst has a good thermal stability. Under the optimized conditions, the conversion of phthalic anhydride was 100% and diester plasticizers were obtained with excellent yields (80–100%). The SDAIL@magnetic nanoSiO2 catalyst showed a good reusability and could be easily separated from the reaction mixture using an external magnet thanks to its superparamagnetic behavior and reused for several runs without significant activity loss. An important advantage of the SDAIL@magnetic nanoSiO2 was its high-hydrophilicity resulted in excellent selectivity towards the formation of only diesters which are commonly used plasticizers in different industries. Graphical abstract [Figure not available: see fulltext.].
OILY INGREDIENT FOR COSMETIC PREPARATION AND COSMETIC PREPARATION
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Page/Page column 9, (2008/06/13)
The present invention provides oils for cosmetics comprising a dibasic acid diester represented by general formula (I) (wherein R1, R2, R3 and R4, which are the same or different, each represent lower alkyl) and excellent in solubility of a long-wave ultraviolet light absorber or the like, and so forth.
