504-53-0Relevant articles and documents
Preparation and Characterization of Glycerol-Based Cleavable Surfactantsand Derived Vesicles
Jaeger, David A.,Jamrozik, Janusz,Golich, Timothy G.,Clennan, Malgorzata Wegrzyn,Mohebalian, Jamshid
, p. 3001 - 3006 (1989)
Four cleavable double-chain surfactants were synthesized: trimethylammonium methanesulfonate 1a, the analogous bromide 1b, dimethyl(3-sulfopropyl)ammonium hydroxide inner salt 1c, and sodium 3--1-propanesulfonate 1d.Vesicles of 1a, 1b, and 1d prepared by sonication were characterized by 1H NMR line width narrowing, dynamic laser light scattering, differential scanning calorimetry, and dye entrapment and leakage studies.In vesicular form, the hydrolytic lability of 1d was greater than that of 1a/1b, due to a combination of electrostatic effects resulting from the different subtituents on the dioxolane ring.Neutral organic compounds can be readily isolated from vesicular solutions of 1d after its hydrolysis.Thus 1d is appropriate for the applicaton of vesicular media to preparative chemistry.
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Hoffmann,Ralston,Ziegler
, p. 301,302 (1939)
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Impact of the oxygen defects and the hydrogen concentration on the surface of tetragonal and monoclinic ZrO2 on the reduction rates of stearic acid on Ni/ZrO2
Foraita, Sebastian,Fulton, John L.,Chase, Zizwe A.,Vjunov, Aleksei,Xu, Pinghong,Barth, Eszter,Camaioni, Donald M.,Zhao, Chen,Lercher, Johannes A.
, p. 2423 - 2434 (2015/02/05)
The role of the specific physicochemical properties of ZrO2 phases on Ni/ZrO2 has been explored with respect to the reduction of stearic acid. Conversion on pure m-ZrO2 is 1.3 times more active than on t-ZrO2, whereas Ni/m-ZrO2 is three times more active than Ni/t-ZrO2. Although the hydrodeoxygenation of stearic acid can be catalyzed solely by Ni, the synergistic interaction between Ni and the ZrO2 support causes the variations in the reaction rates. Adsorption of the carboxylic acid group on an oxygen vacancy of ZrO2 and the abstraction of the a-hydrogen atom with the elimination of the oxygen atom to produce a ketene is the key to enhance the overall rate. The hydrogenated intermediate 1-octadecanol is in turn decarbonylated to heptadecane with identical rates on all catalysts. Decarbonylation of 1-octadecanol is concluded to be limited by the competitive adsorption of reactants and intermediate. The substantially higher adsorption of propionic acid demonstrated by IR spectroscopy and the higher reactivity to O2 exchange reactions with the more active catalyst indicate that the higher concentration of active oxygen defects on m-ZrO2 compared to t-ZrO2 causes the higher activity of Ni/m-ZrO2.
Super water-repellent surfaces resulting from fractal structure
Shibuichi, Satoshi,Onda, Tomohiro,Satoh, Naoki,Tsujii, Kaoru
, p. 19512 - 19517 (2007/10/03)
Super water-repellent surfaces showing a contact angle of 174° for water droplets have been made of alkylketene dimer (AKD). Water droplets roll around without attachment on the super water-repellent surfaces when tilted slightly. The AKD is a kind of wax and forms spontaneously a fractal structure in its surfaces by solidification from the melt. The fractal surfaces of AKD repel a water droplet completely and show a contact angle larger than 170° without any fluorination treatments. Theoretical prediction of the wettability of the fractal surfaces has been given in the previous paper.3 The relationship between the contact angle of the flat surface θ and that of the fractal surface θf is expressed by the equation cos θf = (L/l)D-2 cos θ where (L/l)D-2 is the surface area magnification factor. The fractal dimension of the solid AKD surface was determined to be D ≈ 2.3 applying the box-counting method to the SEM images of the AKD cross section. L and l, which are the largest and the smallest size limits of the fractal behavior of the surface, are also estimated from the box-counting method. The contact angles of some water/1,4-dioxane mixtures on the fractal and the flat AKD surfaces were determined, and the values of cos θf were plotted against cos θ. The plot of cos θf against cos θ agrees well with the theoretical prediction. It has been demonstrated by this work that the fractal concept is a powerful tool to develop some novel functional materials.
