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The telomerization of butadiene with alcohols is an elegant way to synthesize ethers with minimal environmental impact since this reaction is 100% atom efficient. Besides telomerization of butadiene with methanol and water that is industrially developed, the modification of polyols is still under development. Recently, a series of new substrates has been involved in this reaction, including diols, pure or crude glycerol, protected or unprotected monosaccharides, as well as polysaccharides. This opens up the formation of new products having specific physicochemical properties. We will describe recent advances in this field, focusing on the reaction of renewable products and more specifically on saccharides. The efficient catalytic systems as well as the optimized reaction conditions will be described and some physicochemical properties of the products will be reported. [ABSTRACT FROM AUTHOR]

Discontinuous growth process of the Multilamellar vesicle (so called Onion) driven by shear quench was investigated by viscometry and microscopy in detail. Discontinuous Onion growth was observed when the final shear rate corresponded to the intermediate shear rate domain where the shear-thickening and shear-thinning viscosity appeared. In this process, large Onion transformed back into the lamellae and then formed large Onion. Small Onion to lamellae degradation process might be achieved by two modes, first the disruption of the configurational order of densely packed Onions followed by the rupture of Onion as second process. The second process would be characterized by the shear-banding flow pattern composed of the Onion-Lα coexisting state. We suggest that the appearance of the shear-band structure and the Onion reformation developed from the shear-band might be scaled by considering the mechanical energy balance with the bending elastic energy of bilayers. [ABSTRACT FROM AUTHOR]

Lyotropic liquid crystals (LLCs) are amphiphilic molecules that have the ability to self-organize into highly ordered yet fluid, phase-segregated assemblies in the presence of an added polar liquid such as water. The resulting ordered assemblies, called LLC phases, have specific nanometer-scale geometries with periodic hydrophilic and hydrophobic features ranging in structure from bilayer lamellae to extended and interconnected channel systems. Because of their highly uniform, porous nanoscale structures, LLC phases and LLC-based materials have been proposed for use in a number of materials applications. However, only during the last two decades have LLC materials with functional properties and demonstrated applications of LLC systems been realized. This work provides an overview of functional LLC materials and the areas of application where they have made an impact. As new functional properties and capabilities are realized in LLC materials, it is almost certain that they will play more prevalent roles in nanoscience and nanotechnology in the near future. [ABSTRACT FROM AUTHOR]

Natural gas hydrates can be formed and stored at much more moderate thermodynamic conditions compared to conventional gas storage media that make it as a new means of transportation and storage for natural gas. In this work, an experimental investigation of natural gas hydrate formation has been conducted in a high-pressure water-spraying reactor, which is cooled by the circulation water through an external cooling jacket. The process of hydrate formation can be observed visually through a pair of glass windows and recorded by a digital video. The characteristics of gas hydrate formation by water spraying under different conditions were determined by the development of pressure combined with temperature. The results showed that the induction time of hydrate formation can be greatly shortened by water spraying. Solution with appropriate surfactant SDS was found to increase the formation rate obviously and the mechanism was discussed. [ABSTRACT FROM AUTHOR]

A series of aliphatic (2E)-alkenals and alkanals from C5 to C13 were tested for their antibacterial activity against Salmonella choleraesuis ssp choleraesuis ATCC 35640. The activity against this food-borne bacterium is correlated with the hydrophobic alkyl chain length from the hydrophilic aldehyde group. (2E)- Dodecenal (C12) was most effective against S. choleraesuis with the minimum bactericidal concentration (MBC) of 6.25 μg/mL (34 mM), followed by (2E)-undecenal (C11) with an MBC of 12.5 μg/mL (77 μM). The time kill curve study showed that (2E)-dodecenal was bactericidal against S. choleraesuis at any of its growing stages. The antibacterial action of medium-chain aldehydes comes in part from their ability to function as nonionic surfactants. Based on the above head and tail concept, a series of antioxidative alkyl gallates (3,4,5-trihydroxybenzoates), was synthesized and tested for their antibacterial activity against S. choleraesuis. Nonyl (C9) and octyl (C8) gallates were noted to be the most effective against this food borne bacterium with MBCs of 12.5 μg/mL, followed by decyl (C10) gallate with an MBC of 25 μg/mL. Dodecyl (C12) gallate still exhibited the activity against S. choleraesuis with an MBC of 50 μg/mL. Propyl (C3) gallate showed no activity against S. choleraesuis up to 3200 μg/mL. The length of the alkyl group plays a role in eliciting the activity to a large extent. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic hydrocarbons (PAHs) in soils can be mobilized by surfactants and other mobilizing agents such as dissolved organic matter (DOM). DOM from Fructus Gleditsia sinensis contains a large amount of natural non-ionic surfactant triterpenoid saponins and thus can be considered as a natural complex of general DOM and natural non-ionic surfactants. In this study we use crude water extract of Fructus Gleditsiae Sinensis Lam. (CWE-FGS) as a removal agent with no purification procedure to investigate the possibility of developing a more green and more cost effective remediation agent that may compete for the chemically synthesized ˵manmade″ surfactants or purified or partially purified natural biosurfactants. Results showed that the removal rates of phenanthrene and pyrene from contaminated soils by 5% of CWE-FGS were 59% and 52%, respectively. The removal capacities of Tween 80 and rhamnolipids for PAHs from contaminated soils were also studied for comparison. The removal capacity of CWE-FGS for PAHs from contaminated soils was lower than that of Tween 80, but higher than that of rhamnolipids. Thus, it can be safely conclude that CWE-FGS can be a potential natural remediation agent for PAHs from contaminated soils. [ABSTRACT FROM AUTHOR]