Time-resolved fluorescence and light scattering studies of water-soluble block-copolymer micelles with polyelectrolyte shells

1992 ◽  
Vol 58 (1) ◽  
pp. 201-207 ◽  
Author(s):  
K. Procházka ◽  
D. Kiserow ◽  
C. Ramireddy ◽  
S. E. Webber ◽  
P. Munk ◽  
...  
Keyword(s):  
Light Scattering ◽  
Block Copolymer ◽  
Water Soluble ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
Block Copolymer Micelles ◽  
Copolymer Micelles

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.

Block copolymer micelles in solutions of a homopolymer: Dynamic light scattering and viscosity studies

Polymer ◽  
1996 ◽  
Vol 37 (16) ◽  
pp. 3531-3535 ◽  
Author(s):  
JoséR. Quintana ◽  
María D. Jáñez ◽  
Issa Katime
Keyword(s):  
Light Scattering ◽  
Block Copolymer ◽  
Dynamic Light Scattering ◽  
Block Copolymer Micelles ◽  
Copolymer Micelles

Light scattering evidence of selective protein fouling on biocompatible block copolymer micelles

Nanoscale ◽  
2012 ◽  
Vol 4 (15) ◽  
pp. 4504 ◽  
Author(s):  
Fernando C. Giacomelli ◽  
Petr Stepánek ◽  
Vanessa Schmidt ◽  
Eliézer Jäger ◽  
Alessandro Jäger ◽  
...  
Keyword(s):  
Light Scattering ◽  
Block Copolymer ◽  
Protein Fouling ◽  
Block Copolymer Micelles ◽  
Copolymer Micelles

Light scattering and fluorescence studies of block copolymer micelles of polystyrene-block-poly(hydrogenated isoprene) in the selective solvent 1,4-dioxane-n-heptane

Polymer ◽  
1993 ◽  
Vol 34 (1) ◽  
pp. 103-110 ◽  
Author(s):  
Karel Procházka ◽  
Bo Medhage ◽  
Emad Mukhtar ◽  
Mats Almgren ◽  
Petr Svoboda ◽  
...  
Keyword(s):  
Light Scattering ◽  
Block Copolymer ◽  
Selective Solvent ◽  
Fluorescence Studies ◽  
Block Copolymer Micelles ◽  
Copolymer Micelles

scholarly journals Structure of PEP–PEO block copolymer micelles: exploiting the complementarity of small-angle X-ray scattering and static light scattering

2011 ◽  
Vol 44 (3) ◽  
pp. 473-482 ◽  
Author(s):  
Grethe Vestergaard Jensen ◽  
Qing Shi ◽  
María J. Hernansanz ◽  
Cristiano L. P. Oliveira ◽  
G. Roshan Deen ◽  
...  
Keyword(s):  
Light Scattering ◽  
Block Copolymer ◽  
Small Angle ◽  
Static Light Scattering ◽  
Length Scales ◽  
X Ray ◽  
X Ray Scattering ◽  
Block Copolymer Micelles ◽  
Copolymer Micelles ◽  
Poly Ethylene

The structure of large block copolymer micelles is traditionally determined by small-angle neutron scattering (SANS), covering a large range of scattering vectors and employing contrast variation to determine the overall micelle morphology as well as the internal structure on shorter length scales. The present work shows that the same information can be obtained by combining static light scattering (SLS) and small-angle X-ray scattering (SAXS), which provide information on, respectively, large and short length scales. Micelles of a series of block copolymers of poly(ethylene propylene)-b-poly(ethylene oxide) (PEP–PEO) in a 70% ethanol solution are investigated. The polymers have identical PEP blocks of 5.0 kDa and varying PEO blocks of 2.8–49 kDa. The SLS contrasts of PEP and PEO are similar, providing a homogeneous contrast, making SLS ideal for determining the overall micelle morphology. The SAXS contrasts of the two components are very different, allowing for resolution of the internal micelle structure. A core–shell model with a PEP core and PEO corona is fitted simultaneously to the SAXS and SLS data using the different contrasts of the two blocks for each technique. With increasing PEO molecular weight, a transition from cylindrical to spherical micelles is observed. This transition cannot be identified from the SAXS data alone, but only from the SLS data.

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