93 research outputs found
Environmental effects on electron spin relaxation in N@C60
We examine environmental effects of surrounding nuclear spins on the electron
spin relaxation of the N@C60 molecule (which consists of a nitrogen atom at the
centre of a fullerene cage). Using dilute solutions of N@C60 in regular and
deuterated toluene, we observe and model the effect of translational diffusion
of nuclear spins of the solvent molecules on the N@C60 electron spin relaxation
times. We also study spin relaxation in frozen solutions of N@C60 in CS2, to
which small quantities of a glassing agent, S2Cl2 are added. At low
temperatures, spin relaxation is caused by spectral diffusion of surrounding
nuclear 35Cl and 37Cl spins in the S2Cl2, but nevertheless, at 20 K, T2 times
as long as 0.23 ms are observed.Comment: 7 pages, 6 figure
Sucrose Monoester Micelles Size Determined by Fluorescence Correlation Spectroscopy (FCS)
One of the several uses of sucrose detergents, as well as other micelle forming detergents, is the solubilization of different membrane proteins. Accurate knowledge of the micelle properties, including size and shape, are needed to optimize the surfactant conditions for protein purification and membrane characterization. We synthesized sucrose esters having different numbers of methylene subunits on the substituent to correlate the number of methylene groups with the size of the corresponding micelles. We used Fluorescence Correlation Spectroscopy (FCS) and two photon excitation to determine the translational D of the micelles and calculate their corresponding hydrodynamic radius, Rh. As a fluorescent probe we used LAURDAN (6-dodecanoyl-2-dimethylaminonaphthalene), a dye highly fluorescent when integrated in the micelle and non-fluorescent in aqueous media. We found a linear correlation between the size of the tail and the hydrodynamic radius of the micelle for the series of detergents measured
Polymerization-Induced Self-Assembly of Block Copolymer Nano-objects via RAFT Aqueous Dispersion Polymerization
In this Perspective, we discuss the recent development of polymerization-induced self-assembly mediated by reversible additionâfragmentation chain transfer (RAFT) aqueous dispersion polymerization. This approach has quickly become a powerful and versatile technique for the synthesis of a wide range of bespoke organic diblock copolymer nano-objects of controllable size, morphology, and surface functionality. Given its potential scalability, such environmentally-friendly formulations are expected to offer many potential applications, such as novel Pickering emulsifiers, efficient microencapsulation vehicles, and sterilizable thermo-responsive hydrogels for the cost-effective long-term storage of mammalian cells
Alcohols Effect on Critic Micelle Concentration of Polysorbate 20 and Cetyl Trimethyl Ammonium Bromine Mixed Solutions
Ionic Surfactant Aggregates in Saline Solutions: Sodium Dodecyl Sulfate (SDS) in the Presence of Excess Sodium Chloride (NaCl) or Calcium Chloride (CaCl 2
Enhanced oil recovery by nonionic surfactants considering micellization, surface, and foaming properties
Fluorescence Study of the Aggregation Behavior of Different Surfactants in Aqueous Solutions in the Presence and in the Absence of Gas
Reply to âComment on âEffect of Pressure on Colloidal Behavior in Hydrothermal Waterâ â: Role of p K
Micelle Aggregation Numbers of Surfactants in Aqueous Solutions:Â A Comparison between the Results from Steady-State and Time-Resolved Fluorescence Quenching
Role of Oscillatory Structural Forces for Interactions in Thin Emulsion Films Containing Micelles
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