Transmission and Confocal Fluorescence Microscopy and Time-Resolved Fluorescence Spectroscopy Combined with a Laser Trap:  Investigation of Optically Trapped Block Copolymer Micelles

1998 ◽  
Vol 102 (43) ◽  
pp. 8440-8451 ◽  
Author(s):  
Thomas Gensch ◽  
Johan Hofkens ◽  
Jan van Stam ◽  
Herman Faes ◽  
Serge Creutz ◽  
...  
Keyword(s):  
Block Copolymer ◽  
Fluorescence Microscopy ◽  
Fluorescence Spectroscopy ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
Laser Trap ◽  
Confocal Fluorescence ◽  
Block Copolymer Micelles ◽  
Copolymer Micelles ◽  
Optically Trapped

Kinetic Pathway of the Cylinder-to-Sphere Transition in Block Copolymer Micelles Observed in Situ by Time-Resolved Neutron and Synchrotron Scattering

2013 ◽  
Vol 2 (12) ◽  
pp. 1082-1087 ◽  
Author(s):  
Reidar Lund ◽  
Lutz Willner ◽  
Dieter Richter ◽  
Peter Lindner ◽  
Theyencheri Narayanan
Keyword(s):  
Block Copolymer ◽  
Time Resolved ◽  
Block Copolymer Micelles ◽  
Copolymer Micelles

scholarly journals Close-packed block copolymer micelles induced by temperature quenching

2018 ◽  
Vol 115 (28) ◽  
pp. 7218-7223 ◽  
Author(s):  
Liwen Chen ◽  
Han Seung Lee ◽  
Sangwoo Lee
Keyword(s):  
Block Copolymer ◽  
Spherical Particles ◽  
Face Centered Cubic ◽  
Time Resolved ◽  
Hexagonal Close Packed ◽  
Block Copolymer Micelles ◽  
Copolymer Micelles ◽  
Crystal Grains ◽  
Self Assembled ◽  
Face Centered

Close-packed structures of uniformly sized spheres are ubiquitous across diverse material systems including elements, micelles, and colloidal assemblies. However, the controlled access to a specific symmetry of self-assembled close-packed spherical particles has not been well established. We investigated the ordering of spherical block copolymer micelles in aqueous solutions that was induced by rapid temperature changes referred to as quenching. As a function of quench depth, the quenched self-assembled block copolymer micelles formed three different close-packed structures: face-centered cubic (fcc), random stacking of hexagonal-close-packed layers (rhcp), and hexagonal-close-packed (hcp). The induced hcp and rhcp structures were stable for at least a few weeks when maintained at their quench temperatures, but heating or cooling these hcp and rhcp structures transformed both structures to fcc crystallites with coarsening of the crystal grains, which suggests that these noncubic close-packed structures are intermediate states. Time-resolved scattering experiments prove that the micellar rhcp structures do not originate from the rapid growth of competing close-packed structures. We speculate that the long-lived metastable hcp and rhcp structures originate from the small size of crystal grains, which introduces a nonnegligible Laplace pressure to the crystal domains. The reported transitions from the less stable hcp to the more stable rhcp and fcc are experimental observations of Ostwald’s rule manifesting the transition order of the key close-packed structures in the crystallization of close-packed uniform spheres.

Time-resolved SANS for the determination of unimer exchange kinetics in block copolymer micelles

2001 ◽  
Vol 55 (5) ◽  
pp. 667-673 ◽  
Author(s):  
L Willner ◽  
A Poppe ◽  
J Allgaier ◽  
M Monkenbusch ◽  
D Richter
Keyword(s):  
Block Copolymer ◽  
Time Resolved ◽  
Block Copolymer Micelles ◽  
Exchange Kinetics ◽  
Copolymer Micelles

AGGREGATION-ENHANCED EMISSION OF DIBLOCK COPOLYMER CONTAINING TETRAPHENYLTHIOPHENE-QUINOLINE PENDANT FLUORPHORES BY SELECTIVE SOLVENT PAIRS

2013 ◽  
Vol 01 (03) ◽  
pp. 1340003 ◽  
Author(s):  
CHIH-MIN YANG ◽  
CHUNG-TIN LAI ◽  
TAI-LIN CHEN ◽  
WEI-LUN CHIEN ◽  
JIN-LONG HONG
Keyword(s):  
Fluorescence Spectroscopy ◽  
Diblock Copolymer ◽  
Morphological Difference ◽  
Time Resolved Fluorescence ◽  
Selective Solvent ◽  
Time Resolved ◽  
Hexane Content ◽  
Copolymer Micelles

PSQu-PBS in THF/hexane increase with the increasing hexane content. Copolymer micelles formed in THF/hexane mixtures are supposed to have higher extent of aggregation, leading to more pronounced AEE effect than micelles formed in THF/ H 2 O . Time-resolved fluorescence spectroscopy was conducted on PSQu-PBS and PSQu solutions to evaluate the respective lifetimes involved in the excited monomer and aggregated species and to compare the extent of aggregation in all sample solutions. Solid PSQu-PBS samples prepared from 80 vol.%- H 2 O and –hexane solutions of PSQu-PBS were then inspected by TEM to reveal their morphological difference and its influence on the extent of aggregation leading to the AIE effect.

β-lactam Functionalized Poly(isoprene-b-ethylene oxide) Amphiphilic Block Copolymer Micelles as a New Nanocarrier System for Curcumin

2010 ◽  
Vol 6 (3) ◽  
pp. 277-284 ◽  
Author(s):  
Konstantinos Gardikis ◽  
Konstantinos Dimas ◽  
Aristidis Georgopoulos ◽  
Eleni Kaditi ◽  
Stergios Pispas ◽  
...  
Keyword(s):  
Block Copolymer ◽  
Ethylene Oxide ◽  
Amphiphilic Block Copolymer ◽  
Block Copolymer Micelles ◽  
Copolymer Micelles

Donnan Equilibria in Polymeric Micellar Systems with Weak Polyelectrolyte Shells: The Lowering of the pH Value

1997 ◽  
Vol 62 (11) ◽  
pp. 1730-1736 ◽  
Author(s):  
Petr Munk ◽  
Zdeněk Tuzar ◽  
Karel Procházka
Keyword(s):  
Ionic Strength ◽  
Block Copolymer ◽  
Ph Value ◽  
Electrolyte Solutions ◽  
Hydrogen Ions ◽  
Micellar Systems ◽  
Weak Electrolytes ◽  
Block Copolymer Micelles ◽  
Copolymer Micelles ◽  
Polyelectrolyte Solutions

When two electrolyte solutions are separated and only some of the ions can cross the boundary, the concentrations of these ions are different on both sides of the boundary. This is the well-known Donnan effect. When weak electrolytes are involved, the imbalance includes also hydrogen ions: there is a difference of pH across the boundary and the dissociation of nondiffusible weak electrolytes is suppressed. The effect is very pronounced when the concentration of the weak electrolyte is high and ionic strength is low. The significance of this phenomenon is discussed for polyelectrolyte solutions, and particularly for block copolymer micelles with weak polyelectrolyte shells. The effect is quite dramatic in the latter case.

Sign in / Sign up

Export Citation Format

Share Document