https://nathan.instras.com/documentDB/paper-311.pdf

Poly(ethylene oxide)-poly(propylene oxide )-poly (ethylene oxide) block copolymer surfactants in aqueous solutions and at interfaces: thermodynamics, structure, dynamics, and modeling

Pluronic® block copolymers as novel polymer therapeutics for drug and gene delivery

Nano-engineering block copolymer aggregates for drug delivery

Polymeric micelles - a new generation of colloidal drug carriers.

Crew-cut micelle-like aggregates of various morphologies prepared from polystyrene-b-poly(acrylic acid), PS-b-PAA, diblock copolymers under near-equilibrium conditions, were studied by transmission electron microscopy (TEM). The insoluble block (PS) contents in the copolymers ranged from 80 to 98 wt %. In spherical micelles, the micelle cores, formed by aggregation of the PS blocks, were generally monodisperse. A comparison between star and crew-cut micelles showed that the latter are distinguished by a low density of corona chains on the core surface and a low degree of stretching of the PS blocks in the cores. As the PAA content in block copolymer decreased, the morphology of the aggregates changed progressively from spheres to cylinders, to bilayers (both vesicles and lamellae), and eventually to compound micelles consisting of an assembly of inverted micelles surrounded by a hydrophilic surface. The compound micelles are believed to be a new morphology for block copolymers. The addition of homopolysty...

Multiple Morphologies and Characteristics of “Crew-Cut” Micelle-like Aggregates of Polystyrene-b-poly(acrylic acid) Diblock Copolymers in Aqueous Solutions

L'etude en fonction de la concentration du copolymere de la variation des proprietes spectroscopiques du pyrene provoquee par son partage entre les phases micellaires et aqueuses permet de determiner les concentrations critiques micellaires et les coefficients de partage

Poly(styrene-ethylene oxide) block copolymer micelle formation in water: a fluorescence probe study

Poly(butyl methacrylate) latex labeled with either phenanthrene or anthracene is prepared by semicontinuous radical emulsion polymerization. The latex film formation process is studied by analysis of the non radiative energy transfer. The results show that interdiffusion of polymer chains across particle boundaries occurs. The time and temperature dependance of the diffusion coefficient is studied

Molecular aspects of latex film formation: an energy-transfer study

The diffusion of polymer molecules across an interface is an important topic in polymer physics. Measuring this diffusion process requires a labeling experiment so that the mixing of otherwise identical molecules can be followed. Here we examine the use of nonradiative energy transfer to follow the interdiffusion of polymer molecules during the annealing of latex films. Those films are prepared from a mixture of phenanthrene (Phe, the donor)‐ and anthracene(An, the acceptor)‐labeled poly(butyl methacrylate) (PBMA) latex particles. We examine in some detail the kinetics of direct energy transfer (DET) at an interface and the evolution of the DET kinetics as the components mix. Time resolved and steady state measurement approaches are compared, and the former is employed to examine molecular diffusion in a series PBMA latex films. Various diffusion models are considered. Diffusion coefficients are calculated by treating the data in terms of a Fickian spherical diffusion model. A film from one set of samples is similar in molecular weight to that studied by small angle neutron scattering (SANS) [K. Hahn, G. Ley, H. Schuller, and R. Oberthur, Colloid Polym. Sci. 264, 1029 (1986)]. Diffusion coefficients calculated from both sets of experiments using similar Fickian diffusion models are very similar in magnitude.

Molecular diffusion and latex film formation: An analysis of direct nonradiative energy transfer experiments

Latex films represent a high-surface area analogue of the polymer welding phenomenon. In both instances, the growth in strength of the joint is coupled to the diffusion of polymer molecules across a polymer-polymer interface. In order to observe this diffusion, one needs contrast. Here the contrast is provided by labeling half of the poly(butyl methacrylate) microspheres with a donor group (phenanthrene) and the other half with an acceptor (anthracene). Polymer interdiffusion leads to a growth in the extent of direct nonradiative energy transfer observed when the phenanthrenes are selectively excited with UV light

Yongcai Wang

Papers

Poly(styrene-ethylene oxide) block copolymer micelle formation in water: a fluorescence probe study

Molecular aspects of latex film formation: an energy-transfer study

Molecular diffusion and latex film formation: An analysis of direct nonradiative energy transfer experiments

Polymer diffusion across interfaces in latex films

Freeze-fracture studies of latex films formed in the absence and presence of surfactant