共查询到20条相似文献,搜索用时 31 毫秒
1.
Atsushi Kimoto Jun‐Sang Cho Kiyoshi Ito Daigo Aoki Tohru Miyake Kimihisa Yamamoto 《Macromolecular rapid communications》2005,26(8):597-601
Summary: The photo‐crosslinking of carbazole dendrimers was analyzed by UV and IR spectroscopic methods. Photoirradiation results in the formation of a film that is insoluble in toluene and benzene. Time‐of‐flight mass spectrometry studies revealed that the photoirradiation lead to an oligomerization of the dendrimer through crosslinking. The resulting insoluble dendrimer film could be applied as a hole‐transport layer in efficient polymer electroluminescence devices (PLEDs).
2.
Kaushik Mallick Mike J. Witcomb Andy Dinsmore Mike S. Scurrell 《Macromolecular rapid communications》2005,26(4):232-235
Summary: We report a new method for the preparation of polyaniline nanoballs by using HAuCl4 as an oxidizing agent. During the reaction, aniline is oxidized and forms polyaniline whilst the hydrogen tetrachloroaurate is reduced and forms gold nanoparticles. These gold nanoparticles are found to decorate the nanoballs.
3.
Summary: A novel method combining RAFT polymerization with pulsed‐laser initiation for determining chain‐length dependent termination rate coefficients, kt, is presented. Degenerative chain‐transfer in RAFT enables single‐pulse pulsed‐laser polymerization (SP‐PLP) traces to be measured on systems with a narrow radical distribution that remains essentially unchanged during the experiment. SP‐PLP‐RAFT experiments at different polymerization times allow for determining kt as a function of chain length via classical kinetics assuming chain‐length independent kt.
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5.
Mihee Heo Jonggi Kim Jin Young Kim Changduk Yang 《Macromolecular rapid communications》2010,31(23):2047-2052
A rod‐coil block copolymer consisting of poly(3‐hexylthiophene) (P3HT) and poly(N‐vinylcarbazole) (PVK) ( P3HT‐ b ‐PVK ) in a single molecular architecture is prepared as the first example for WOLEDs. By obtaining the phase separated domains in thin film of the resulting block copolymer, it is possible to suppress energy transfer from PVK as wide bandgap units to P3HT as low bandgap blocks, yielding dual emissions for white electroluminescence with CIE coordination of (0.34, 0.33).
6.
Xue Li Petra Gring Eckhard Pippel Martin Steinhart Dong Ha Kim Wolfgang Knoll 《Macromolecular rapid communications》2005,26(14):1173-1178
Summary: A simple route to an ordered array of metal/semiconductor oxide composite nanodots is presented. Micellar monolayer films of polystyrene‐block‐poly(2‐vinyl pyridine) (PS‐b‐P2VP) loaded with HAuCl4 in the P2VP nanodomains are used as templates. TiO2 is generated selectively within the polar P2VP domains of PS‐b‐P2VP/HAuCl4 films by chemical vapor deposition of TiCl4. Subsequent removal of the organic matrix by oxygen plasma or UV light leads to an array of Au/TiO2 composite nanoparticles on the substrate surface.
7.
Weipeng Lv Shuoqi Liu Xiaobin Fan Shulan Wang Guoliang Zhang Fengbao Zhang 《Macromolecular rapid communications》2010,31(5):454-458
A dextran‐based dual‐sensitive polymer is employed to endow gold nanoparticles with stability and pH‐ and temperature‐sensitivity. The dual‐sensitive polymer is prepared by RAFT polymerization of N‐isopropylacrylamide from trithiocarbonate groups linked to dextran and succinoylation of dextran after polymerization. The functionalized nanoparticles show excellent stability under various conditions and can be stored in powder‐form. UV and DLS measurements confirm that the temperature‐induced optical changes and aggregation behaviors of the particles are strongly dependent on pH.
8.
Boualem Hammouda 《Macromolecular theory and simulations》2012,21(6):372-381
The single‐polymer form factor is determined for branched polymers using a scaling argument in order to recover the low‐Q Porod exponent characteristic of the overall structure. The high‐Q Porod exponent characterizes the local branching structure. An alternative approach based on a high‐Q expansion contains information about functionality, branch length and branch content. The specific case of a starburst dendrimer for which the form factor is known is discussed. The model predictions are compared to small‐angle neutron scattering data from a dilute solution of dendrimer in D2O.
9.
Jong Hyeok Park Yong Taik Lim O Ok Park Young Chul Kim 《Macromolecular rapid communications》2003,24(4):331-334
A dramatic increase in the photostability of a blue‐light‐emitting polymer, poly(9,9‐dioctylfluorene), was achieved by the addition of 5–10 nm gold nanoparticles. The optical absorption band of the gold nanoparticles was tuned to resonate the triplet exciton ground state bandgap energy of the polymer. Photo‐oxidation rate of poly(9,9‐dioctylfluorene) was effectively reduced by doping the polymer with very small amounts (≈10−6–10−5 volume fraction) of the gold nanoparticles.
10.
Antoni Snchez‐Ferrer Alexey Merekalov Heino Finkelmann 《Macromolecular rapid communications》2011,32(8):671-678
The mechanical behaviour of monodomain nematic side‐chain liquid‐crystalline elastomers containing azoderivatives as pendant groups or crosslinkers has been studied under UV irradiation and in the darkness at different temperatures. From the evaluation of the opto‐mechanical experiments, the mechanical efficiency, kinetic rates, activation energies and the isomerization mechanism of the azocompounds in the liquid‐crystalline matrix could be determined, as well as the effect of the chemical constitution of the azobenzene derivatives and their role in the elastomeric network.
11.
Yong Yan Jin Fang Yajie Zhang Huili Fan Zhixiang Wei 《Macromolecular rapid communications》2011,32(20):1640-1644
Self‐assembly of two‐dimensional (2D) structures from functional molecules is of great scientific importance. Herein, using a typical linear conducting polymer, polyaniline as building blocks, 2D single crystalline microplates are successively produced. The structure of 2D microplates is clearly defined by selected area electron diffraction, X‐ray diffraction, and Raman spectroscopy. Owing to the anisotropic arrangement of linear conjugated PANI molecules, the microplate shows a typical anisotropic electrical transport property.
12.
An atomic force microscope in the compression mode was used to probe the nanomechanical response of single dendrimeric molecules, as well as dendrimer aggregates adsorbed on silicon surface. The force‐compression behaviour of individual, generation 5 poly(amido amine) (PAMAM) dendrimers was described by a Hertzian model for the deformation of elastic bodies. The modulus values obtained ranged between 700 MPa (single dendrimers) and 150 MPa (dendrimer aggregates).
13.
Meizhen Yin Yong Ye Mengmeng Sun Naiwen Kang Wantai Yang 《Macromolecular rapid communications》2013,34(7):616-620
A polyvinylpyrrolidone (PVP)‐based fluorescent film with stable optical properties is successfully prepared in one pot without any additive. The reaction mechanism of ring‐opening and self‐crosslinking of linear PVP is proposed and demonstrated. The morphologies and the nanostructures of the fluorescent film as well as the unmodified film are investigated. The dye is incorporated into the film networks via covalent linkages, thus leading to the highly stable optical properties. The facile and effective synthesis approach opens a new way for the design of other multi‐functional composite materials based on linear PVP.
14.
Guillaume Gody Paul Boullanger Catherine Ladavire Marie‐Thrse Charreyre Thierry Delair 《Macromolecular rapid communications》2008,29(6):511-519
Biotinylated gradient glycopolymers have been synthesized via RAFT copolymerization of an acrylamide derivative of galactose with N‐acryloylmorpholine in the presence of a biotin CTA. The polymerization was controlled with a linear increase in molecular weights up to 80% conversion. Copolymer chains have a gradient microstructure with an increasing proportion of galactose units towards the ω chain end. The presence of the biotin ligand at the α end of the chains was confirmed by 1H NMR and MALDI‐ToF MS. This strategy based on the use of a biotin‐CTA instead of a post‐polymerization labelling of the chains resulted in a high percentage of α‐functionalized chains (92–95%). Such α‐end‐functionalized glycopolymer chains may interact with streptavidin‐modified surfaces.
15.
Wai‐Yeung Wong Chun‐Kin Wong Suk‐Yue Poon Albert W.‐M. Lee Tian Mo Xin Wei 《Macromolecular rapid communications》2005,26(5):376-380
Summary: The synthesis and thermal, redox and photoluminescence properties of a soluble donor‐acceptor polyplatinayne with the electron‐accepting silole ring and its model compound are described. The polymer has an optical band gap of 2.10 eV which is much lower than that of thienyl‐ or silyl‐bridged congeners. The incorporation of electron‐accepting silole unit in the metallopolymer main chain creates a new π‐conjugated system that features unique donor‐acceptor characteristics.
16.
TriPEGylated functionalized dendritic poly(ethylene imines) were synthesized and their transportation properties for rose Bengal (up to 50 guests per dendrimer) were evaluated. A critical aggregation concentration was observed, demonstrating the formation of aggregates among the dendrimers. The structure‐activity relationships show that their encapsulation capacities were dependent linearly on the density of the PEG shell, either as PEG length or degree of functionality, which confirmed that the PEG chains play a predominant role in the encapsulation process. It further gives some insights that the guest molecules appeared to be predominantly located in the PEG shell rather than in the core.
17.
Summary: It has been shown that stable aqueous dispersions of nanoparticles of the rigid‐rod ladder‐type polymer poly(benzo‐bisimidazobenzo‐phenanthroline) (BBL) can be prepared in order to facilitate BBL processing. The obtained dispersions have a controllable particle size in the range between 50 and 150 nm and, consequently, the deposition of layers by spin‐coating or drop‐casting is realized. The resultant films exhibit a particulate structure and their morphology has been characterized by means of SEM and AFM. Upon investigation of the BBL dispersions in organic field‐effect transistors an ambipolar charge carrier transport has been observed, which presumably is related to the presence of mobile ions.
18.
Xiuli Zhao Xiaobin Ding Zhenghua Deng Zhaohui Zheng Yuxing Peng Xinping Long 《Macromolecular rapid communications》2005,26(22):1784-1787
Summary: A well‐dispersed gold nanoparticle/poly(N‐isopropylacrylamide) (PNIPAm) hydrogel nanocomposite with thermoswitchable electrical properties is prepared by the copolymerization of functional Au nanoparticles with N‐isopropylacrylamide. It is found that the electrical conductivity of the nanocomposite changes by two orders of magnitude at moderate temperature (Ttran) upon temperature stimuli. The change of electrical properties is reversible during a heating and cooling cycle.
19.
Summary: A new calix[4]arene‐based periodic mesoporous organosilica has been synthesized using tetraethoxysilane (TEOS) and a calix[4]arene‐based silane monomer as the precursors and cetyltrimethylammonium bromide (CTAB) surfactant as the structure‐directing template, and is shown to be capable of visual detection and entrapment of NO2.
20.
Alexander Kamyshny Matti Ben‐Moshe Shai Aviezer Shlomo Magdassi 《Macromolecular rapid communications》2005,26(4):281-288
Summary: Two types of ink‐jet inks are presented: ink containing an aqueous dispersion of silver nanoparticles and an oil‐in‐water microemulsion‐based ink. The metallic ink contains nanoparticles of silver, which are formed in the presence of an ionic polymeric stabilizer. Sintering of the printed image obtained with the use of such silver‐based inks at temperatures as low as 300 °C results in formation of patterns possessing noticeable conductivity. The microemulsion inks are based on a thermodynamically stable microemulsion, in which the dispersed oil phase is a volatile solvent containing a water‐insoluble colorant. After contact of the jetted ink droplets with a substrate, nanodroplets of the microemulsion are converted into nanoparticles of the solubilized colorant. In some cases, it was found that the evaporation of microemulsion ink droplets leads to formation of rings composed of ordered nanoparticles.