- Surface and interlayer base-characters in lepidocrocite titanate: The adsorption and intercalation of fatty acid
-
While layered double hydroxides (LDHs) with positively-charged sheets are well known as basic materials, layered metal oxides having negatively-charged sheets are not generally recognized so. In this article, the surface and interlayer base-characters of O2- sites in layered metal oxides have been demonstrated, taking lepidocrocite titanate K0.8Zn0.4Ti1.6O4 as an example. The low basicity (0.04 mmol CO2/g) and low desorption temperature (50-300 °C) shown by CO2- TPD suggests that O2- sites at the external surfaces is weakly basic, while those at the interlayer space are mostly inaccessible to CO2. The liquid-phase adsorption study, however, revealed the uptake as much as 37% by mass of the bulky palmitic acid (C16 acid). The accompanying expansion of the interlayer space by ~0.1 nm was detected by PXRD and TEM. In an opposite manner to the external surfaces, the interlayer O2- sites can deprotonate palmitic acid, forming the salt (i.e., potassium palmitate) occluded between the sheets. Two types of basic sites are proposed based on ultrafast 1H MAS NMR and FTIR results. The interlayer basic sites in lepidocrocite titanate leads to an application of this material as a selective and stable two-dimensional (2D) basic catalyst, as demonstrated by the ketonization of palmitic acid into palmitone (C31 ketone). Tuning of the catalytic activity by varying the type of metal (Zn, Mg, and Li) substituting at TiIV sites was also illustrated.
- Maluangnont, Tosapol,Arsa, Pornanan,Limsakul, Kanokporn,Juntarachairot, Songsit,Sangsan, Saithong,Gotoh, Kazuma,Sooknoi, Tawan
-
-
Read Online
- Fatty acid potassium had beneficial bactericidal effects and removed Staphylococcus aureus biofilms while exhibiting reduced cytotoxicity towards mouse fibroblasts and human keratinocytes
-
Wounds frequently become infected or contaminated with bacteria. Potassium oleate (C18:1K), a type of fatty acid potassium, caused >4 log colony-forming unit (CFU)/mL reductions in the numbers of Staphylococcus aureus and Escherichia coli within 10 min and a >2 log CFU/mL reduction in the number of Clostridium difficile within 1 min. C18:1K (proportion removed: 90.3%) was significantly more effective at removing Staphylococcus aureus biofilms than the synthetic surfactant detergents sodium lauryl ether sulfate (SLES) (74.8%, p 0.01) and sodium lauryl sulfate (SLS) (78.0%, p 0.05). In the WST (water-soluble tetrazolium) assay, mouse fibroblasts (BALB/3T3 clone A31) in C18:1K (relative viability vs. control: 102.8%) demonstrated a significantly higher viability than those in SLES (30.1%) or SLS (18.1%, p 0.05). In a lactate dehydrogenase (LDH) leakage assay, C18:1K (relative leakage vs. control: 108.9%) was found to be associated with a significantly lower LDH leakage from mouse fibroblasts than SLES or SLS (720.6% and 523.4%, respectively; p 0.05). Potassium oleate demonstrated bactericidal effects against various species including Staphylococcus aureus, Escherichia coli, Bacillus cereus, and Clostridium difficile; removed significantly greater amounts of Staphylococcus aureus biofilm material than SLES and SLS; and maintained fibroblast viability; therefore, it might be useful for wound cleaning and peri-wound skin.
- Kawahara, Takayoshi,Takita, Miki,Masunaga, Akihiro,Morita, Hayato,Tsukatani, Tadayuki,Nakazawa, Kohji,Go, Daisuke,Akita, Sadanori
-
-
- Iridium catalysts for acceptorless dehydrogenation of alcohols to carboxylic acids: Scope and mechanism
-
We introduce iridium-based conditions for the conversion of primary alcohols to potassium carboxylates (or carboxylic acids) in the presence of potassium hydroxide and either [Ir(2-PyCH2(C4H5N2))(COD)]OTf (1) or [Ir(2-PyCH2PBu2t)(COD)]OTf (2). The method provides both aliphatic and benzylic carboxylates in high yield and with outstanding functional group tolerance. We illustrate the application of this method to a diverse variety of primary alcohols, including those involving heterocycles and even free amines. Complex 2 reacts with alcohols to form the crystallographically characterized catalytic intermediates [IrH(η1,η3-C8H12)(2-PyCH2PtBu2)] (2a) and [Ir2H3(CO)(2-PyCH2PtBu2){μ-(C5H3N)CH2PtBu2}] (2c). The unexpected similarities in reactivities of 1 and 2 in this reaction, along with synthetic studies on several of our iridium intermediates, enable us to form a general proposal of the mechanisms of catalyst activation that govern the disparate reactivities of 1 and 2, respectively, in glycerol and formic acid dehydrogenation. Moreover, careful analysis of the organic intermediates in the oxidation sequence enable new insights into the role of Tishchenko and Cannizzaro reactions in the overall oxidation.
- Cherepakhin, Valeriy,Williams, Travis J.
-
p. 3754 - 3763
(2018/05/23)
-
- METHOD FOR PRODUCING SUCROSE FATTY ACID ESTER
-
PROBLEM TO BE SOLVED: To provide a method for producing a sucrose fatty acid ester having high monoester selectivity. SOLUTION: The method for producing a sucrose fatty acid ester comprises: a step of preparing an aqueous solution containing sucrose and a basic catalyst; and a step of producing a sucrose fatty acid ester by mixing the aqueous solution obtained in the preparation step, a fatty acid alkali metal salt and a melted fatty acid ester (excluding palmitic acid ester and stearic acid ester), and heating the mixture while stirring under reduced pressure. The step of producing a sucrose fatty acid ester has an earlier step of removing water from the mixture, and a subsequent step of performing transesterification after the earlier step. In the subsequent step, heating is performed through microwave irradiation such that the temperature of the mixture is below the sucrose decomposition temperature. SELECTED DRAWING: None COPYRIGHT: (C)2018,JPO&INPIT
- -
-
Paragraph 0041
(2018/01/02)
-
- Production of sucrose fatty acid ester
-
PROBLEM TO BE SOLVED: monoester of selection of higher fatty acid ester. SOLUTION: the method of manufacturing the fatty acid ester, and sugar and basic catalyst and a process for preparing an aqueous solution containing, in the process and the resultant aqueous solution, and an alkali metal salt of a fatty acid, and other fatty acid ester is melted under a reduced pressure by mixing with the heated to generate a fatty acid ester and process, is provided, the process of generating a fatty acid ester, a mixture of water and a front-stage process, the process of step of performing, after having poststage and, in the process of poststage, by irradiation of microwaves, and less than the decomposition temperature of the mixture is heated so that the sugar. Selected drawing: no
- -
-
Paragraph 0042
(2017/05/06)
-
- SUCROSE FATTY ACID ESTER WITH LOW DEGREE OF SUBSTITUTION AND PROCESS FOR PRODUCING THE SAME
-
The invention provides a process for producing a low-substitution-degree sucrose fatty acid ester characterized by lowering a degree of substitution of a raw sucrose fatty acid ester, which eliminates the troublesome removal of solvents and a problem concerning viscosity increase in a liquid reaction mixture in processes heretofore in use. By the process, a sucrose fatty acid ester having a low average degree of substitution, which is suitable for use as an emulsifying agent for foods, etc., can be yielded with a high quality. This process for producing a sucrose fatty acid ester having a low degree of substitution is characterized by reacting a raw sucrose fatty acid ester with an activated sucrose in the presence of a solvent having a dielectric constant at 20°C of 35.0 or lower and having no hydroxyl group.
- -
-
Page/Page column 10-11
(2010/11/28)
-