Well‐defined PEO‐b‐PMMA was prepared, initiated by macroinitiator PEO‐Br, by means of ATRP, where esterification of the terminal hydroxyl group of PEO with 2‐bromoisobutyryl bromide yielded a macroinitiator PEO‐Br. Highly ordered microporous films (hexagonal pattern) were constructed by emulsion micelles of such amphiphilic diblock copolymer formed from a solution with CHCl3/H2O/THF = 100:5:10 (v/v). We also constructed the microporous films using diblock copolymer by the current water‐assisted method.
Poly(2‐alkyl‐2‐oxazoline)s can be regarded as pseudo‐peptides or bioinspired polymers, which are available through living/controlled cationic polymerization and polymer (“click”) modification procedures. Materials and solution properties may be adjusted via the nature of the side chain (hydrophilic‐hydrophobic, chiral, bio‐functional, etc.), opening the way to stimulus‐responsive materials and complex colloidal structures in aqueous environments. Herein, we give an overview over the macromolecular engineering of polyoxazolines, including the synthesis of biohybrids, and the “smart”/bioinspired aggregation behavior in solution.
A series of π‐conjugated polymers linked by benzocarborane (1,2‐(buta‐1′,3′‐diene‐1′,4′‐diyl)‐1,2‐dicarbadodecaborane) were synthesized via Sonogashira–Hagihara polycondensation reaction. The opened molecular structure of diiodo monomer containing benzocarborane resulted in fast polymerization and high molecular weights. The obtained polymers were fully characterized by 1H, 13C, and 11B NMR spectroscopies. UV‐vis absorption and photoluminescence studies revealed the acceptor‐profile of benzocarborane. Unlike the polymers linked by o‐carborane, these polymers exhibited strong luminescence in the solution state, presumably because the inductive effect of carborane is dominant, rather than cage‐π interactions.
A direct access to photochromic polymeric vesicles was demonstrated via polymerization‐induced self‐assembly and reorganization (PISR). The resulting vesicles displayed interesting photochromic behaviors different from that of their free polymer chains in DMF, and the vesicles exhibited stronger fluorescence and excellent photostability due to confinement of conformational flexibility of the polymer chains in aggregates.
Summary: We demonstrate a novel approach for constructing photoactive multilayer films in which the aggregation of fluorescing molecules is effectively eliminated. In the films formed via a layer‐by‐layer electrostatic self‐assembly technique, the core‐shell amphiphilic copolymer, poly[(sodium 4‐styrenesulfonate)‐block‐vinylnaphthalene], was deposited. The isolated cores served as nanosized host sites for photoactive guest molecules (pyrene, perylene). The efficient energy transfer between polymeric chromophores and perylene molecules was observed.
AFM image of a nanostructured polymeric film prepared via a layer‐by‐layer technique and containing photoactive block copolymer poly[(sodium 4‐styrenesulfonate)‐block‐vinylnaphthalene]. Below is the representative height profile taken along the drawn line. 相似文献
Summary: The vapor‐based synthesis and characterization of a reactive polymer, poly[(4‐formyl‐p‐xylylene)‐co‐(p‐xylylene)] ( 1 ), have been reported. The reactive polymer coating enables the immobilization of oligosaccharides via the chemoselective aldehyde‐hydrazide coupling reaction.
Summary: Amphiphilic cylindrical brush‐coil block copolymers consisting of a polystyrene coil and a cylindrical brush block with poly(acrylic acid) side chains are prepared by ATRP of t‐butylacrylate from a block comacroinitiator. Upon acidolysis of the poly(t‐butylacrylate), water‐soluble polymers were obtained that were observed to form micelles consisting of 4–5 block copolymers on average in aqueous solution. The star‐like nature of such micelles was clearly visualized by scanning force microscopy.
Schematic of coil‐cylindrical brush block copolymer PS‐b‐(PiBEMA‐g‐PAA), its AFM image clearly showing the main chain and the PAA corona of the cylindrical brush block. 相似文献
The conformational behavior of a single AB block copolymer is studied by Monte Carlo simulation. The A‐A and A‐B interactions have the character of excluded volume interactions while the B units attract each other; the attractive B blocks can move along the chain. The collapse transition of the chain with increasing attraction between the B units is analyzed. Intrachain separation of the A and B units takes place in the course of the chain collapse with the formation of “globule with a tail” conformations. The globule is formed by the attractive moving B blocks while the tail consists of the swollen A segments. The model of AB block copolymer with moving B blocks can describe the behavior of interpolymer complexes between a long macromolecule and shorter polymer chains.
π‐Conjugated microporous networks have been prepared from the tetraarylated diketopyrrolo[3,4‐c]pyrrole unit as a tetrafunctional building block. The reactions are carried out using microwave‐assisted Yamamoto or Sonogashira cross‐coupling. Red insoluble powders are obtained, showing intense fluorescence. The polymer networks exhibit a high gas storage capability, with BET surface areas up to about 500 m2 · g−1.
We have developed a novel strategy for the preparation of ion‐bonded supramolecular star polymers by RAFT polymerization. An ion‐bonded star supramolecule with six functional groups was prepared from a triphenylene derivative containing tertiary amino groups and trithiocarbonate carboxylic acid, and used as the RAFT agent in polymerizations of tert‐butyl acrylate (tBA) and styrene (St). Molecular weights and structures of the polymers were characterized by 1H NMR and GPC. The results show that the polymerization possesses the character of living free‐radical polymerization and the ion‐bonded supramolecular star polymers PSt, PtBA, and PSt‐b‐PtBA, with six well‐defined arms, were successfully synthesized.
Summary: A water‐soluble gold nanoparticle aggregate 2 was prepared by chloroauric acid and a polypseudorotaxane 1 of mono‐6‐thio‐β‐cyclodextrin with poly(propylene glycol) bis(2‐aminopropyl ether) ( ≈ 2 000) in the presence of sodium borohydride in N,N‐dimethylformamide (DMF) solution. The investigative results indicated that the gold nanoparticle aggregate 2 might act as an efficient DNA‐cleavage reagent.
A typical TEM image of gold nanoparticle aggregate 2 . 相似文献
