The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
The continuous demand for novel hybrid materials in specific technological applications inspires people to develop new synthetic strategies in a modular and efficient way. In the recent years, extensive efforts have been devoted to using polyhedral oligomeric silsesquioxane (POSS) to construct multifunctional nanohybrids and nanocomposites with tunable hierarchical structures and unparalleled properties...
Hierarchical assembly of macromolecules has been central in creating complex nanostructures. In this work, polystyrene-block-poly (perfluorooctylethyl acrylates) (PS-b-PFOA) diblock copolymers were synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization and shown to assemble into hierarchical structures in bulk with the interplay of nanophase separation and crystallization...
Multiblock copolymers of poly(arylene ether sulfones) (PAESs) and poly(1,4-cyclohexylenedimethylene terephthalate) (PCT) were synthesized via melt-phase polymerization. PAES oligomers (Mn = 2000 g/mol) were synthesized with hydroxyethoxyl end groups, and then reacted with dimethyl terephthalate (DMT) and 1,4-cyclohexanedimethanol (CHDM) to obtain segmented copolymers with the goal of introducing semi-crystallinity...
Based on our recent understanding and development of functionalized molecular nanoparticles (MNPs) as building blocks for constructing various giant molecules, we report our efforts on design and synthesis of an asymmetric giant amphiphile, diBPOSS–C 60 , composed of one [60]fullerene (C 60 ) covalently linked with two isobutyl-functionalized polyhedral oligomeric silsesquioxane (BPOSS)...
A series of efficient and spectrally stable blue light-emitting polyfluorene derivatives containing 3,7-dibenzothiophene-S,S-dioxide (SO) unit in main chain and oxadiazole (OXD) moiety in the side chain were synthesized via Suzuki copolymerization. It was realized that the glass transition temperatures of the resulted copolymers PFSO-OXD increased gradually with the content of OXD, while the UV-vis...
Incorporation of 4,4′-dihydroxy-p-terphenyl (DHTP) and a new bisphenol comonomer, 4,4′-[trans-1,4-cyclohexanediylbis(methylene)] bisphenol (CMB), into a dichlorodiphenyl sulfone (DCDPS) based poly(ether sulfone) resulted in a synergistic effect with an order of magnitude increase observed in the strain at break when compared to the structural analogs. Polysulfones with the CMB monomer and other bisphenol...
We report the design and synthesis of a thermally-responsive dumbbell-shaped polymer based on one β-cyclodextrin (β-CD)-terminated polyethylene glycol (PEG) segment and several poly(N-isopropylacrylamide) (PNIPAM) segments through combining click reaction with atom transfer radical polymerization. Thermally-triggered self-assembly and molecular inclusion behaviors of the polymer were investigated...
Large complex micelles based on H-shaped terpolymers (poly(ethylene glycol))(poly(N,N-dimethylaminoethyl methacrylate))-polytetrahydrofuran-(poly(N,N-dimethylaminoethyl methacrylate)) (poly(ethylene glycol)) ((PEG)(PDMA)-PTHF-(PDMA)(PEG)), with proper block ratio, are obtained through ultrasonic vibration. However, similar micellar morphology is not found using other traditional methods, such as evaporation...
The adhesion between two immiscible polymers stitched together via mobile chains is studied with large scale molecular simulations employing a coarse-grained bead-spring model. An adhesion model is presented that incorporates both connector molecular slipping out viscously and bulk dissipation in two dissimilar glassy polymers, in which one is dense melt and another is loose. The contributions to...
Two water soluble conjugated polymers, poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) and ammonium ion stabilized poly(phenylene vinylene) (P2), are found to be able to reduce noble metal ions to zero-valent metals via a direct chemical deposition technique. Au nanoparticle clusters can be obtained through reduction of Au 3+ ions by PEDOT:PSS and the electronic coupling...
Green light-emitting polyfluorenes were synthesized by Suzuki polycondensation via introducing dibenzothiophene-S,S-dioxide-(di-)tri-phenylamine (G 1 and G 2 ) moieties and dibenzothiophene-S,S-dioxide (SO) unit into the polyfluorene backbone, respectively. PF–SO–G copolymers show a high thermal stability and a moderate photoluminescence quantum yield in the range of 20–40%. The lowest...
The effects of melt structure and shear flow on the polymorphic nature of β-cylindrites were investigated by means of wide angle X-ray diffraction (WAXD), small angle X-ray scattering (SAXS), polarized light microscopy (PLM), differential scanning calorimeter (DSC), and Scanning Electron Microscope (SEM). The temperature-resolved SAXS/WAXD experiments indicate that the NMP (near melting point) melting...
For the first time, the scope of Fisher esterification has been extended to fullerene derivatives to improve the synthesis of alkyne-functionalized fullerenes (fullerynes) using 1-chloronaphthalene as a solvent and a specially-designed, home-made reactor to promote high yield. The design allows for higher solubility of fullerene derivatives and a continuous azeotropic distillation for the removal...
Conformational behaviors of syndiotactic polystyrene (sPS) in chloroform were investigated by detecting its concentration dependence of intrinsic fluorescence in the range from 25 to −62 °C. For the dimer emission, the coexistence of T-shaped configuration with sandwich configuration was observed and the contribution of sandwich configuration increases with increasing sPS concentration in the system...
Reduced graphene oxide (RGO)-polymer composites were prepared via π–π stacking interactions of RGO with the perylene bisimide-containing poly(glyceryl acrylate) (PBIPGA). PBIPGA was synthesized via atom transfer radical polymerization (ATRP) of solketal acrylate (SA), using bifunctional N,N′-bis{2-[2-[(2-bromo-2-methylpropanoyl)oxy]ethoxy]ethyl}perylene-3,4,9,10-tetracarboxylic acid bisimide (PBI-Br)...
Formation of β-cylindrites of isotactic polypropylene under various wall shear stress (σ w ), supercooled temperature of melt (T e ) and crystallization temperature (T c ) has been investigated by polarized light microscopy (PLM), wide angle X-ray diffraction (WAXD), and differential scanning calorimeter (DSC). To have better control over the thermomechanical history, instead...
Graphene nanosheets were prepared by complete oxidation of pristine graphite followed by thermal exfoliation and reduction. Polyethylene terephthalate (PET)/graphene nanocomposites were prepared by melt compounding. Transmission electron microscopy observation indicated that graphene nanosheets exhibited a uniform dispersion in PET matrix. The incorporation of graphene greatly improved the electrical...
We report here the preparation of nanostructured polypyrroles (PPys) with different morphologies (nanospherical or nanofibrillar) through a surfactant-assisted oxidative polymerization route. Nanofibrillar PPy has a higher redox current, presumably due to a higher surface area accessible to the electrolytes and a lower charge transfer resistance compared to that of the spherical PPy. The impedance...
Using hydrophobic acrylic acid-2-ethylhexyl ester (AAEHE) as a comonomer of methacrylic acid (MAA), a series of hydrophobically modified (HM) poly(methacrylic acid) (PMAA) (HMPMAA) hydrogels were prepared by UV solution copolymerization and studied as controlled-release matrices. The result indicates that swelling degree of the HMPMAA hydrogels can sensitively respond to change in pH. However, the...
Cylindrical brushes with a macromolecular backbone and well-defined side chains of different length (4=<P nsc =<38) were synthesized by polymerization of macromonomers. The effect of side chain length on the intermolecular order has been investigated by means of X-ray scattering on the melt-extruded samples. The increase of the side chain molar mass results in an increase of...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.