This work is focused on the synthesis and self-assembly of novel dendritic star polymers with a dendritic polyamidoamine core and many linear polystyrene arms. The polymers can synchronously form unimolecular micelles (ca. 10 nm) and large multimolecular micelles (ca. 100 nm) in selected solvents (tetrahydrofuran/methanol) at room temperature. Atomic force microscopy, scanning electron microscopy, and dynamic light scattering measurements have provided direct evidence that the large micelles are a kind of multimicelle aggregate with the basic building units of unimolecular micelles. Accordingly, a possible self-assembly process is put forward, and a new aggregate model, termed multimicelle aggregate, is suggested to explain the formation of the large micelles. In the multimicelle aggregate model, the large micelles are the aggregates of small micelles associated by intermicellar interactions such as hydrogen bonds and p–p stacking interactions. It is the first demonstration of the self-assembly mechanism for the large multimolecular micelles generated from the solution self-assembly of dendritic star polymers. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
The hydrophilic homopolymer brushes of poly(acrylamide) (PAAM) and poly(2-hydroxyethyl methacrylate) (PHEMA) were prepared by means of atom transfer radical polymerization (ATRP) on the modified silicon gel by the initiator that was prepared by vapor method. The block copolymer brushes consisting of PAAM and PHEMA blocks were obtained by using the homopolymer brush as the macroinitiator for the second ATRP polymerization of another monomer. The structures of the homopolymer brushes and the block copolymer brushes were characterized by IR and X-ray photoelectron spectroscopy (XPS). XPS revealed that the first polymer layer of the surface was partly covered with the second polymer layer after being block-copolymerized with the second monomer. SEM showed that the silicon gel particles with polymer brushes were made up of the silicon gel particles as the core and the polymer as the shell. Under appropriate conditions, the copper or cadmium ion was introduced into the silicon gel with the homopolymer brushes and the block copolymer brushes to form the inorganic–organic hybrid material. TGA analysis showed that the inorganic–organic hybrid material is more stable. The results of ESR indicated that the inorganic–organic hybrid material with the polymer metal complex basing on the silicon gel particle possessed well paramagnetism. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Amphiphilic diblock copolymer polycaprolactone-block-poly(glycidyl methacrylate) (PCL-b-PGMA) was synthesized via enzymatic ring-opening polymerization (eROP) and atom transfer radical polymerization (ATRP). Methanol first initiated eROP of ϵ-caprolactone (ϵ-CL) in the presence of biocatalyst Novozyme-435 under anhydrous conditions. The resulting monohydroxyl-terminated polycaprolactone (PCL–OH) was subsequently converted to a bromine-ended macroinitiator (PCL–Br) for ATRP by esterification with α-bromopropionyl bromide. PCL-b-PGMA diblock copolymers were synthesized in a subsequent ATRP of glycidyl methacrylate (GMA). A kinetic analysis of ATRP indicated a living/controlled radical process. The macromolecular structures were characterized for PCL–OH, PCL–Br, and the block copolymers by means of nuclear magnetic resonance, gel permeation chromatography, and infrared spectroscopy. Differential scanning calorimetry and wide-angle X-ray diffraction analyses indicated that the copolymer composition (ϵ-CL/GMA) had a great influence on the thermal properties. The well-defined, amphiphilic diblock copolymer PCL-b-PGMA self-assembled into nanoscale micelles in aqueous solutions, as investigated by dynamic light scattering and transmission electron microscopy. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5037–5049, 2007
![Poly[imino[(1S)-1-(carboxymethyl)-2-oxo-1,2-ethanediyl]]](http://img.cochemist.com/ccimg/26100/26063-13-8.png)
![Poly[imino[(1S)-1-(carboxymethyl)-2-oxo-1,2-ethanediyl]]](http://img.cochemist.com/ccimg/26100/26063-13-8_b.png)
