Nonaqueous Polar Solvents in Reverse Micelle Systems

Abstract

CONTENTS 1. Introduction 4569 2. Background 4569 2.1. Aqueous Reverse Micelles 4569 2.2. Definition of Aqueous and Nonaqueous Reverse Micelles 4572 3. Characterization of Reverse Micelles 4573 3.1. Methods Demonstrating the Presence of Reverse Micelles 4573 3.2. Surfactant Packing at the Reverse Micelle Interface 4574 4. Reverse Micelles Encapsulating Nonaqueous Polar Organic Solvents 4578 4.1. Reverse Micelles Containing Glycerol 4578 4.2. Reverse Micelles Containing Other Polyols 4580 4.3. Reverse Micelles Containing Formamide 4582 4.4. Reverse Micelles Containing Other Amides: DMF and DMA 4584 4.5. Other Polar Solvents 4585 5. Requirements for Effective Reverse Micelle Formation 4586 5.1. Polar Solvent Properties 4586 5.2. Problem Systems: Methanol and Acetonitrile 4587 6. Room Temperature Ionic Liquids in Reverse Micelles 4589 7. Nonaqueous Reverse Micelles as Nanoreactors 4593 8. Future Directions and Cautions 4596 Author Information 4597 Corresponding Author 4597 Notes 4597 Biographies 4597 Acknowledgments 4598 References 4598

From the sap's perspective: The nature of vessel surfaces in angiosperm xylem

“…Lipids lining hydrophobic surfaces, with their hydrophilic head groups facing the sap, would probably be detached from those surfaces during dehydration. Lipid micelles are likely to be altered and reversed, causing the hydrophilic head groups to face inward and fatty acids to face outward (Correa et al, 2012). Dehydration therefore would explain the broken-up nature of the lipid layer along surfaces under TEM, which suggest that microscope techniques that preserve hydration are better tools for studying the ultrastructure FIGURE 3.…”

The effect of water on the microstructure and properties of benzene/[bmim][AOT]/[bmim][BF4] microemulsions

“…15 To date, almost all research on the self-assembly of surfactants in ILs has exclusively focused on using nonionic surfactants, like Triton X-100, Tween 20 and Brij 30. 26 44,45 We noted that the phase behavior of both microemulsions has many features in common with the corresponding aqueous systems. Different from the Triton X-100 system, their microemulsion size falls into the normal range, i.e.…”

“…15,[20][21][22] Several reviews on the actual state of the art of ILs and microemulsions have also been published. [23][24][25][26] Gao et al were the first to discover that [bmim] [BF 4 ] assembles in polar nanosized droplets when dispersed in cyclohexane as solvent. 11 Recently, Han and his co-workers discovered that the 1,1,3,3-tetramethylguanidinium type of ILs can be dissolved in supercritical CO 2 reverse micelles.…”

Spectral features of 4,4-diaminodiphenyl sulfone in anionic and cationic inverted micelles

“…As the emission of Dapsone in dilute hydrochloric acid-water mixture does not indicate any change of position of ICT emission we may rule out the possibility of protonation of probe molecule on encapsulation by reverse micelle (environment of lower pH value than the bulk solution) [26]. The plot of emission maximum with W values (Inset of Figure 2b) suggests the probe is not in the organic solvent; rather it is in the interfacial region [32]. The emission maximum remains unchanged with the increment of the pool size.…”

“…The emission maximum remains unchanged with the increment of the pool size. The decrement in emission intensity could be due to more and more deactivation via internal conversion (IC), as a result of formation of hydrogen bond between the either of the acceptor groups NH 2 and head group of AOT reverse micelle and also with water molecule [32][33][34][35].…”