Asymmetric epoxidation of unfunctionalized olefins accelerated by thermoresponsive self-assemblies in aqueous systems

2016 ◽  
Vol 6 (2) ◽  
pp. 488-496 ◽  
Author(s):  
Yaoyao Zhang ◽  
Rong Tan ◽  
Guangwu Zhao ◽  
Xuanfeng Luo ◽  
Donghong Yin
Keyword(s):  
Organic Solvents ◽  
Pure Water ◽  
Asymmetric Epoxidation ◽  
Aqueous Systems ◽  
Complex Core ◽  
Self Assembled

A thermoresponsive self-assembled nanoreactor, comprising a hydrophilic PNIPAAm shell and a hydrophobic chiral salen MnIII complex core, exhibits unprecedented efficiency and facile reusability in asymmetric epoxidation of unfunctionalized olefins in pure water without using any organic solvents.

Measurement and Modeling of Latent Heat Release During Freezing of Aqueous Solutions in a Small Container

2000 ◽  
Author(s):  
Ramachandra V. Devireddy ◽  
John C. Bischof ◽  
Perry H. Leo ◽  
John S. Lowengrub
Keyword(s):  
Mass Transport ◽  
Heat Release ◽  
Latent Heat ◽  
Pure Water ◽  
Heat Of Fusion ◽  
Freezing Process ◽  
Latent Heat Release ◽  
Aqueous Systems ◽  
Heat And Mass Transport ◽  
Latent Heat Of Fusion

Abstract The latent heat of fusion, ΔHf of a cryobiological medium (a solute laden aqueous solution) is a crucial parameter in the cryopreservation process. The latent heat has often been approximated by that of pure water (∼ 335 mJ/mg). However, recent calorimetric (DSC - Pyris 1) measurements suggest that the actual magnitude of latent heat of fusion during freezing of solute laden aqueous systems is far less. Fourteen different pre-nucleated solute laden aqueous systems (NaCl-H2O, Phosphate Buffered Saline or PBS, serum free RPMI, cell culture medium, glycerol and Anti Freeze Protein solutions) were found to have significantly lower ΔHf than that of pure water (Devireddy and Bischof, 1998). In the present study additional calorimetric experiments are performed at 1, 5 and 20 °C/min in five representative cryobiological media (isotonic or 1× NaCl-H2O, 10× NaCl-H2O, 1× PBS, 5× PBS and 10× PBS) to determine the kinetics of ice crystallization. The temperature (T) and time (t) dependence of the latent heat release is measured. The experimental data shows that at a fixed temperature, the fraction of heat released at higher cooling rates (5 and 20 °C/min) is lower than at 1 °C/min for all the solutions studied. We then sought a simple model that could predict the experimentally measured behavior and examined the full set of heat and mass transport equations during the freezing process in a DSC sample pan. The model neglects the interaction between the growing ice crystals and is most appropriate during the early stages of the freezing process. An examination of the coefficients in the heat and mass transport equations shows that heat transport occurs much more rapidly than solute transport. Hence, the full model reduces to one in which the temperature profile is constant in space while the solute concentration profile obeys the full time and space dependent diffusion equation. The model reveals the important physical parameters controlling the mass transport at the freezing interface and further elucidates the experimental results, i.e. the temperature and time dependence of the latent heat release.

Self-Assembled Nanostructures of a Cholesterol-Saccharide Conjugate which Acts as an Amphiphilic Gelator of Organic Solvents

2009 ◽  
Vol 5 (2) ◽  
pp. 245-251 ◽  
Author(s):  
Qian Jiang ◽  
Yinsong Wang ◽  
Jian Weng ◽  
Lingrong Liu ◽  
Zhimin Zhou ◽  
...  
Keyword(s):  
Organic Solvents ◽  
Self Assembled

Self-Assembled Enzymatic Nanowires with a “Dry and Wet” Interface Improve the Catalytic Performance of Januvia Transaminase in Organic Solvents

ACS Catalysis ◽  
2021 ◽  
pp. 372-382
Author(s):  
Cuihua Wei ◽  
Juan Zhou ◽  
Tiangang Liu ◽  
Wanqi Zhao ◽  
Xian-En Zhang ◽  
...  
Keyword(s):  
Organic Solvents ◽  
Catalytic Performance ◽  
Self Assembled

Self-assembled Gels of Amphiphilic Sequential Peptide in Water and Organic Solvents

2011 ◽  
Vol 40 (6) ◽  
pp. 617-619 ◽  
Author(s):  
Rong Cai ◽  
Ying Zhao ◽  
Kempei Ogura ◽  
Masayoshi Tanaka ◽  
Takatoshi Kinoshita ◽  
...  
Keyword(s):  
Organic Solvents ◽  
Self Assembled

Self-Assembled Nanotubes in Organic Solvents

2006 ◽  
Vol 241 (1) ◽  
pp. 68-74 ◽  
Author(s):  
Nancy Diáz ◽  
François-Xavier Simon ◽  
Marc Schmutz ◽  
Philippe Mésini
Keyword(s):  
Organic Solvents ◽  
Self Assembled

Self-Assembled Diamide Nanotubes in Organic Solvents

2005 ◽  
Vol 117 (21) ◽  
pp. 3324-3328 ◽  
Author(s):  
Nancy Díaz ◽  
François-Xavier Simon ◽  
Marc Schmutz ◽  
Michel Rawiso ◽  
Gero Decher ◽  
...  
Keyword(s):  
Organic Solvents ◽  
Self Assembled

Self-assembled structures of CuO primary crystals synthesized from Cu(CH3COO)2–NaOH aqueous systems

CrystEngComm ◽  
2012 ◽  
Vol 14 (16) ◽  
pp. 5289 ◽  
Author(s):  
Xiaoxue Xu ◽  
Hong Yang ◽  
Yinong Liu
Keyword(s):  
Aqueous Systems ◽  
Self Assembled ◽  
Primary Crystals

Self-Assembled Diamide Nanotubes in Organic Solvents

2005 ◽  
Vol 44 (21) ◽  
pp. 3260-3264 ◽  
Author(s):  
Nancy Díaz ◽  
François-Xavier Simon ◽  
Marc Schmutz ◽  
Michel Rawiso ◽  
Gero Decher ◽  
...  
Keyword(s):  
Organic Solvents ◽  
Self Assembled
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