Co-reporter:Ben Dong, Baoyan Li, Yi Cao, Xinlei Meng, Han Yan, Shusheng Ge, Yun Lu
Tetrahedron Letters 2017 Volume 58(Issue 1) pp:35-42
Publication Date(Web):4 January 2017
DOI:10.1016/j.tetlet.2016.11.090
•The oligomers consisting of both thiophene and indole moieties were synthesized.•The conjugated oligomers show different bandgaps and absorption behaviors.•An electrochromic device based on oligomer (P3) displays a novel four-color changes.•The oligomer of P3 exhibits high sensitivity and selectivity for Zn2+ detection.Two series of thiophene oligomers and terthiophene oligomers consisting of both thiophene and indole moieties have been synthesized. They have same excitation-dependent photoluminescence characteristics, but different bandgaps and absorption behaviors, which relates to the number and denseness of indoles in the conjugated oligomers and the length of alkyl chains on indole moiety due to varied the π-π stacking interaction of conjugated structures in the as-prepared oligomers. A simple electrochromic device based on such a conjugated oligomer displays a novel four-color electrochromism from red to yellow, green and puce with the increased potential and possesses good environmental and redox stability. Such conjugated oligomer also exhibits high sensitivity and selectivity for Zn2+ detection.
Co-reporter:Han Yan;Xinlei Meng;Baoyan Li;Shusheng Ge
Journal of Materials Chemistry C 2017 vol. 5(Issue 40) pp:10589-10599
Publication Date(Web):2017/10/19
DOI:10.1039/C7TC03472E
On the basis of the molecular design of the donor–π–acceptor (D–π–A) pyrimidine-phthalimide derivatives, two new atypical AIE chromophores, 2-(4,6-dimethylpyrimidin-2-yl)isoindoline-1,3-dione (PB) and 2-(4,6-bis(4-(dimethylamino)styryl)pyrimidin-2-yl)isoindoline-1,3-dione (NPB), were synthesized and characterized by using IR, 1H NMR, 13C NMR and HRMS. Both PB and NPB exhibited obvious solid-state fluorescence emission due to their twisted geometries and positive solvatochromism due to their different molecular conformations in various solvents. Owing to the different push–pull electronic effects of substituents on the pyrimidine moiety, PB and NPB, acting as D–π–A compounds, showed different HOMO–LUMO gaps and a variable red-shifted emission in their solid state, substantiating the possibility to tune effectively the photophysical properties of these AIE chromophores by rational molecular design. In addition, PB and NPB could be easily and reversibly protonated at the site of the nitrogen atoms, causing dramatic color changes. This phenomenon opens up the potential avenues of developing novel colorimetric pH sensors and logic gates for specific applications.
Co-reporter:Han Yan, Xinlei Meng, Baoyan Li, Shusheng Ge, Yun Lu
Dyes and Pigments 2017 Volume 146(Volume 146) pp:
Publication Date(Web):1 November 2017
DOI:10.1016/j.dyepig.2017.07.046
On the basis of molecular design about the donor-acceptor (D-A) triphenylamine-coumarin (TPA-coumarin) dyad, two new bichromophores 7-butoxy-6-(4-(diphenylamino)phenyl)-4,8-dimethyl-2H-chromen-2-one (TC) and 7-butoxy-6-(4-(diphenylamino)phenyl)-8-methyl-4-(trifluoromethyl)-2H-chromen-2-one (TF), were synthesized and characterized by using IR, 1H NMR, 13C NMR and HRMS. Both TC and TF exhibited the expected solid-state fluorescence emission due to the aggregation induced emission effect and different degrees of positive solvatochromism due to their different molecular conformations in various solvents. Owing to the different push-pull electronic effects of substituents on the coumarin moiety, TC and TF, acting as the D-A compounds, showed different HOMO-LUMO gaps and a variable red-shifted emission in their solid-state, substantiating the possibility to effectively tune the photophysical properties of these bichromophores by rational molecular design.Download high-res image (269KB)Download full-size image
Co-reporter:Ben Dong, Mei Yang, Shusheng Ge, Yi Cao, Baoyan Li and Yun Lu
RSC Advances 2016 vol. 6(Issue 28) pp:23737-23745
Publication Date(Web):25 Feb 2016
DOI:10.1039/C6RA01468B
Polypyrrole (PPy) nanospheres with an average diameter of 20 nm were successfully synthesized by simply using 3-chloroperbenzoic acid in pure ethanol. As-prepared PPy nanospheres showed a moderate photoluminescence signal with a quantum yield (QY) of 2.2% and excitation-dependent photoluminescence characteristics. To carry out the PPy nanosphere surface functionalization, PEG2000, 4,7,10-trioxa-1,13-tridecanediamine and ethylenediamine severed respectively as surface passivating agents, and accordingly 5.5 nm, 4.5 nm and 3 nm sized nanodots were obtained, which exhibited enhanced fluorescence intensity with maximum QYs of 3.1%, 13% and 40% respectively and tunable band gaps in the range of 0.78–1.53 eV. These results were attributed to the increased electron density in PPy fluorescent nanospheres/dots. These resultant PPy fluorescent nanodots could be appropriately applied as cell-imaging agents, fluorescent inks and pH sensors owing to their outstanding characteristics of low cytotoxicity, good biocompatibility and high luminescence stability.
Co-reporter:Chen Shen, Jing Wang, Yi Cao and Yun Lu
Journal of Materials Chemistry A 2015 vol. 3(Issue 26) pp:6668-6675
Publication Date(Web):22 May 2015
DOI:10.1039/C5TC01156F
A green and facile hydrothermal approach for carbonizing boric acid and ethylenediamine into B-doped carbon dots (CDs) has been proposed, providing a new method to synthesize functional carbon dots on a large scale. The obtained B-doped CDs exhibit favorable aqueous solubility and strong fluorescence in both aqueous and solid states. Especially, the unique solid-state fluorescence properties of the B-doped CDs inspire new thoughts for other applications, accordingly a yellowish-green light emitting diode with the as-obtained CDs as light converters is demonstrated. Meanwhile, the as-prepared CDs also display intensely low toxicity and excellent multicolour fluorescence imaging ability in live cells.
Co-reporter:Tao Ni, Liang Xu, Yupeng Sun, Wei Yao, Tingyang Dai, and Yun Lu
ACS Sustainable Chemistry & Engineering 2015 Volume 3(Issue 5) pp:862
Publication Date(Web):April 3, 2015
DOI:10.1021/sc500828t
We report a facile method to fabricate reduced graphene oxide/polypyrrole hydrogels (rGO/PPy) simply by combining the self-assembly process at room temperature with oxidation polymerization at elevated temperature. The as-prepared composite hydrogels possess a cross-linked 3D hierarchical porous structure and show a compression-tolerant property and a high specific capacitance of 473 F g–1 at 1 A g–1. In particular, 82% of the capacitance value has been maintained after charge–discharge for 5000 cycles, suggesting the great potential applications of the rGO/PPy hydrogels in high-quality energy storage devices. This study provides a novel reference way for the self-assembly of other conducting polymer and graphene sheets for different applications.Keywords: Composite hydrogels; Compression capacity; Facile fabrication; Polypyrrole; Reduced graphene oxide; Specific capacitance;
Co-reporter:Liang Xu and Yun Lu
RSC Advances 2015 vol. 5(Issue 83) pp:67518-67523
Publication Date(Web):31 Jul 2015
DOI:10.1039/C5RA11711A
A simple, one-step approach has been developed to prepare a composite of cobalt sulfide/reduced graphene oxide (CoS/rGO) by using sodium thiosulfate as a sulfur source. The reduction of GO and the growth of CoS occurred simultaneously, forming a hybrid structure with CoS anchoring on the rGO surface. The prepared CoS/rGO composite was applied as an electrode material and found to exhibit a high specific capacitance and rate capability, such as 550 F g−1 and 400 F g−1 at a current density of 1 A g−1 and 40 A g−1 respectively as well as excellent cyclic stability for 5000 cycles of charge–discharge. The CoS/rGO composite could be a promising electrode material for a high performance supercapacitor.
Co-reporter:Yupeng Sun, Chen Shen, Jing Wang and Yun Lu
RSC Advances 2015 vol. 5(Issue 21) pp:16368-16375
Publication Date(Web):23 Jan 2015
DOI:10.1039/C4RA13820A
A facile, simple, effective and green method has been developed to synthesize nitrogen and sulfur co-doped carbon dots (N, S-CDs) from heparin sodium. The as-prepared N, S-CDs possess naked-eye observable blue-green luminescence, good biocompatibility, low toxicity and strong fluorescence in live cell imaging, indicating their great potential to serve as high quality optical imaging probes. Besides, the N, S-CDs can also be used as a competitive fluorescent sensing platform for the detection of Fe3+.
Co-reporter:Yupeng Sun, Chen Shen, Jing Wang and Yun Lu
RSC Advances 2015 vol. 5(Issue 27) pp:20691-20691
Publication Date(Web):20 Feb 2015
DOI:10.1039/C5RA90017D
Correction for ‘Facile synthesis of biocompatible N, S-doped carbon dots for cell imaging and ion detecting’ by Yupeng Sun et al., RSC Adv., 2015, 5, 16368–16375.
Co-reporter:Ting-yang Dai;Hong-juan Wang;Yi Cao 陆云
Chinese Journal of Polymer Science 2015 Volume 33( Issue 5) pp:732-742
Publication Date(Web):2015 May
DOI:10.1007/s10118-015-1628-9
Composites of polyaniline (PAn) and epoxide polysiloxane (EPSi) are reported for the first time. EPSi is designed, synthesized and N-grafted onto the PAn backbone through covalent bonds. As-prepared EPSi-g-PAn composites are soluble in organic solvents and the corresponding films can be easily produced via a simple solution-casting procedure. The composite films combine the mechanical characteristics of EPSi and the chemical properties of PAn, enabling the facile introduction of the noble metal particles. The successful fabrication of the composites is confirmed by the investigation of the molecular structure, crystalline structure and microstructure of the materials. The resulting composite films containing noble metal particles are employed as the catalysts for the hydrogenation of phenol to produce cyclohexanone, which exhibit the convenience and recyclability for usage as well as the high catalytic activities, including the conversion ratio of 97%–100% and the selectivity as high as 84%–98%. The present work not only provides a new method to improve the processability of the conducting polymers but also describes a kind of composite materials that may display outstanding preformances in industrial catalysis.
Co-reporter:Ting-yang Dai;Rong Tang;Xiao-xiao Yue;Liang Xu
Chinese Journal of Polymer Science 2015 Volume 33( Issue 7) pp:1018-1027
Publication Date(Web):2015 July
DOI:10.1007/s10118-015-1647-6
The capacitance performances of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT-PSS) supramolecular hydrogels have been investigated systematically. The materials show a specific capacitance of 67 F/g and display excellent rate capability at the scan rate as high as 5000 mV/s in the cyclic voltammogram measurements, accompanied by good cycle stability. On the basis of the measurements of the microscale morphologies, specific areas and electrical conductivities, the mechanisms for the improvement of the electrochemical properties are discussed and ascribed to the novel porous microstructures of the hydrogels and the synergetic effect of the rigid PEDOT and soft PSS components. Furthermore, polyaniline (PAn) is compounded with the PEDOT-PSS hydrogels through an interfacial polymerization process, endowing the hydrogel materials with a higher specific capacitance of 160 F/g at the scan rate of 5000 mV/s. The significance of this work lies in the demonstration of a novel method to solve the problems of conducting polymers in electrochemical applications.
Co-reporter:Jing Wang;Yi Cao
Journal of Nanoparticle Research 2015 Volume 17( Issue 5) pp:
Publication Date(Web):2015 May
DOI:10.1007/s11051-015-3046-x
The size-controllable polypyrrole (PPy) nanospheres are successfully synthesized by oxidative polymerization of pyrrole using N-methylene phosphonic chitosan (NMPC) as a structure-directing agent. By simply changing the amount of NMPC, the size of the PPy nanospheres can be adjusted from 190 to 50 nm in diameter. The spectrometric results suggest that the electrostatic interactions of phosphate groups in NMPC molecule with pyrrole ring might be a driving force for formation of the uniform and size-controllable PPy nanospheres. The PPy nanospheres with the diameter of 100 nm exhibit the largest capacity and a good cycling stability as electrode materials of supercapacitors. The as-prepared PPy nanospheres also can be combined with carbon dots to form composite nanospheres presenting enhanced fluorescence intensity, which show potential application in fluorescence detection.
Co-reporter:Jing Wang;Han Yan
Journal of Materials Science 2015 Volume 50( Issue 21) pp:6920-6925
Publication Date(Web):2015 November
DOI:10.1007/s10853-015-9242-3
A novel thiophene derivative (Fe–Th) with ferricyanide end group is successfully synthesized. The polythiophene derivative (Fe–PTh) is additionally obtained in aqueous solution by polymerization of Fe–Th, and shows a nanoparticle structure with a diameter from 10 to 100 nm. A simple solid-state electrochromic device is fabricated using the Fe–PTh as electrochromic material, and displays a novel three-color electrochromism from blue, green, and red with the increased potential.
Co-reporter:Chen Shen, Yupeng Sun, Jing Wang and Yun Lu
Nanoscale 2014 vol. 6(Issue 15) pp:9139-9147
Publication Date(Web):03 Jun 2014
DOI:10.1039/C4NR02154A
Carbon nanodots (CDs) of uniform size were prepared simply by the hydrothermal decomposition of folic acid (FA) precursor at various reaction temperatures. The CDs formed via dehydration of FA at 260 °C contributed the strongest photoluminescence (PL) signal and the highest quantum yield at about 68%, without assistance of any passivation agent. The effects of preparation conditions on PL behavior of CDs have been investigated in detail, and the quantum yield of the CDs was found to be associated strongly with sample crystallinity. Moreover, because the obtained CDs also exhibited high luminescence stability, abundant surface functional groups and good biocompatibility, there are many promising applications in printing ink, ion detection, pH sensors and cell imaging.
Co-reporter:Wei Yao, Tao Ni, Shujun Chen, Hao Li, Yun Lu
Composites Science and Technology 2014 Volume 99() pp:15-22
Publication Date(Web):30 July 2014
DOI:10.1016/j.compscitech.2014.05.007
Novel hybrid nanocomposites constructed via anchoring the Fe3O4@polypyrrole nanospheres with hierarchical porous structure on graphene nanosheets (graphene/Fe3O4@polypyrrole, GFP) have been prepared, and characterized by using TEM, XRD, XPS, FT-IR and TGA. The large saturation magnetization of 12.4 emu g−1 allows fast and economic separation of the GFP from solution. Due to the synergic effect between graphene and Fe3O4@polypyrrole, the GFP exhibits excellent adsorption capability of 348.4 mg g−1 for Cr(VI) removal, which is much higher than the previously reported values of other magnetic nanomaterials. Furthermore, the GFP is stable and recyclable, retaining about 72.2% of the removal efficiency after six adsorption–desorption cycles. The adsorption isotherms and kinetics could be well simulated by the Langmuir and pseudo-second-order models respectively. The GFP nanocomposites could be a good candidate for efficient Cr(VI) removal from the wastewater.
Co-reporter:Xutang Qing, Xiaoxiao Yue, Bing Wang, Yun Lu
Journal of Alloys and Compounds 2014 Volume 595() pp:131-137
Publication Date(Web):15 May 2014
DOI:10.1016/j.jallcom.2014.01.046
•Nanoporous Fe3O4 microspheres were synthesized by one-pot method.•No surfactants of additives were used.•Quasi-micropores, mesopores and macropores coexist.•Size of Fe3O4 microspheres could be easily tuned.•The electromagnetic wave absorption property was excellent.Multilevel nanoporous Fe3O4 microspheres were solvothermally synthesized using a functionalized ionic liquid [BMIM][FeCl4] as the iron source. Size of these microspheres could be easily tuned over the range of 26–411 nm by varying the volume ratio of alkali solution added. SEM, TEM and BET isotherm characterizations confirmed that Fe3O4 microspheres were formed by the assembly of nanoparticles with several nanometers in diameter and had a multilevel pore structure, including quasi-micropores, mesopores and macropores in/on each microsphere. The electromagnetic parameters of the Fe3O4 microspheres indicated that those nanopores contributed to the increase of dielectric loss and made an effective impedance match between dielectric loss and magnetic loss, thus enhancing the electromagnetic wave absorption of Fe3O4 microspheres. The minimum reflection loss of 80 wt% Fe3O4/epoxy resin composites showed excellent dual adsorptions at both low frequencies and high frequencies (−40.0 dB at 1.4 GHz with a sample thickness of 5.7 mm and −25.3 dB at 16.5 GHz with a sample thickness of 3 mm), which were related to the magnetic loss and dielectric loss offered by the porous Fe3O4 microspheres.
Co-reporter:Xutang Qing, Yi Cao, Jing Wang, Jingjie Chen and Yun Lu
RSC Advances 2014 vol. 4(Issue 99) pp:55971-55979
Publication Date(Web):21 Oct 2014
DOI:10.1039/C4RA06336H
Phosphorus, nitrogen and oxygen co-doped carbonaceous materials (PNODC) were facilely prepared by pyrolyzing phosphorus, nitrogen and oxygen-rich phytic acid doped polyanilines. ICP analysis and elemental analysis demonstrate that the maximum phosphorus content of the as-prepared PNODC reaches 6.02 wt% with the total heteroatom (phosphorus, nitrogen and oxygen) content up to 32.76 wt%. The symmetric supercapacitor built from PNODC could be operated at a very high working voltage of 1.9 V. A maximum energy density of 21.8 W h kg−1 is achieved at a power density of 238 W kg−1 and a voltage load of 1.9 V. The excellent electrochemical performance can be attributed to the high heteroatom content, the synergetic effect of phosphorus and nitrogen/oxygen co-doping and the protection of abundant heteroatom functionalities on the surface of the carbon electrodes.
Co-reporter:Hui Zhou, Tao Ni, Xutang Qing, Xiaoxiao Yue, Geng Li and Yun Lu
RSC Advances 2014 vol. 4(Issue 8) pp:4134-4139
Publication Date(Web):05 Dec 2013
DOI:10.1039/C3RA44647F
Graphene–polypyrrole (GPPy) composites with 3-dimensional macrostructure were prepared by a one-step self-assembly process, in which the continuous oxidation-reduction reaction of pyrrole monomers and graphite oxide in the existence of Cu2+ finally resulted in the formation of macroporous hydrogels. The as-prepared hydrogel exhibited a high specific capacitance of 498 and 295 F g−1 respectively at the scan rate of 5 mV s−1 and the discharge current density of 1 A g−1. Furthermore, a specific capacitance of 240 F g−1 could be achieved even if at a high current density of 10 A g−1, and maintained 80% of the capacitance value after charge–discharge for 5000 cycles. Such excellent capacitive properties in rate stability and cycling stability endow the GPPy hydrogels with great potential applications in high-performance energy storage devices. Besides, this study also provides new insights into the design and synthesis of graphene-based materials.
Co-reporter:Chen Shen, Yupeng Sun, Wei Yao, Yun Lu
Polymer 2014 Volume 55(Issue 12) pp:2817-2824
Publication Date(Web):6 June 2014
DOI:10.1016/j.polymer.2014.04.042
A facile method to prepare uniform polypyrrole (PPy) nanospheres is developed by using 3-chloroperbenzoic acid as oxidant, structure-induced reagent and dopant for polymerization of pyrrole without introducing extra acid, template and surfactant. The as-synthesized PPy nanospheres with an average diameter of 100–200 nm and conductivity about 10−2 S cm−1 are characterized by SEM, FTIR, UV–vis spectroscopy, XRD and elemental analysis in an effort to determine the identity of the nanospheres and the mechanism relevant to their formation and stabilization. Influences of experimental conditions on the morphology of the PPy nanospheres have been investigated. Via the high temperature pyrolyzation at 900 °C, the nitrogen-doped carbon nanospheres have been obtained from the PPy nanospheres precursors, which have a high conductivity of 10–100 S cm−1, showing a good potential as the electrode materials for high-performance supercapacitors due to their excellent electrochemical performance.
Co-reporter:Hui Zhou, Yupeng Sun, Geng Li, Shujun Chen, Yun Lu
Polymer 2014 Volume 55(Issue 17) pp:4459-4467
Publication Date(Web):18 August 2014
DOI:10.1016/j.polymer.2014.06.079
•Graphene/polyaniline hollow spheres were prepared via interfacial assembly process.•The difference of hydrophility played a key role in the formation of these spheres.•The electrochemial properties of the composite hollow spheres have been studied.A novel strategy has been developed to prepare hollow structured Nafion-modified-graphene/polyaniline (NGP) composites via interfacial assembly polymerization between an aqueous phase containing oxidant and an organic phase containing aniline monomers and Nafion-modified graphene. Fourier transform infrared (FTIR), Ultraviolet-visible (UV-vis) and X-ray diffraction (XRD) analyses confirmed the generation of polyaniline (PANI) on graphene during the interfacial polymerization. The morphological evolution of the product had been investigated by scanning electron microscopy (SEM) with respect to the reaction time, based on which a conceivable interpretation of the growth mechanism of the sphere architectures with composite component were given. The as-prepared hollow structured composites showed a good rate capability as electrode material for supercapacitor, and the as-designed interfacial assembly preparation strategy for such composites may provide a generic guideline in developing other graphene-base composite hollow spheres with different compositions.
Co-reporter:Hui Zhou, Wei Yao, Geng Li, Jing Wang, Yun Lu
Carbon 2013 Volume 59() pp:495-502
Publication Date(Web):August 2013
DOI:10.1016/j.carbon.2013.03.045
We report a novel and easy route to synthesize a mechanically strong hydrogel composed of graphene and poly (3,4-ethylenedioxythiophene) (PEDOT). 3,4-Ethylenedioxythiophene played the role of reducing agent to convert a highly oxidative graphite oxide (h-GO) to graphene and in situ polymerized itself synchronously on the active sites of the graphene to construct the hydrogel. The content of the carbonyl groups in h-GO was found to have a major impact on the generation of the hydrogel. Also the morphology and the quantity of PEDOT formed in the hydrogel were considered to be the key factors for improving the mechanical performance of the hydrogel. As-prepared enhanced graphene/PEDOT hydrogel displayed a compressive fracture stress as high as 29.6 MPa, a storage modulus about 2.1 MPa at 10 rad/s, a good electrical conductivity of 0.73 S/cm and a high specific capacitance of 174.4 F/g, which make it a potential candidate for a number of technologies such as electrochemical sensor and supercapacitor.
Co-reporter:Wei Yao, Hui Zhou, Yun Lu
Journal of Power Sources 2013 Volume 241() pp:359-366
Publication Date(Web):1 November 2013
DOI:10.1016/j.jpowsour.2013.04.142
•MnO2@PPy coaxial nanotubes are prepared without surfactant and additional oxidant.•The thickness of PPy outer layer deposited on MnO2 nanotubes can be adjusted.•A high specific capacitance of 380 F g−1 is obtained.•Excellent rate capability and good capacitance retention are achieved.Novel MnO2@polypyrrole (PPy) coaxial nanotubes have been prepared via a simple and green approach without any surfactant and additional oxidant. Under the acidic condition, MnO2 nanotubes act as both template and oxidant to initiate the polymerization of pyrrole monomers on its fresh-activated surface. Fourier transform infrared spectra (FT-IR), X-ray diffraction patterns (XRD), thermo-gravimetric analysis data (TG) and X-ray photoelectron spectra (XPS) suggest the formation of composite structure of MnO2@PPy. Also, FESEM and TEM images intuitively confirm that the PPy shell is coated uniformly on the surface of MnO2 nanotubes. Adjusting the concentrations of sulfuric acid or adding oxidant can modulate the morphology of the products accordingly. Due to the synergic effect between MnO2 core and PPy shell, the MnO2@PPy coaxial nanotubes possess better rate capability, larger specific capacitance of 380 F g−1, doubling the specific capacitance of MnO2 nanotubes, and good capacitance retention of 90% for its initial capacitance after 1000 cycles.
Co-reporter:Wei Yao, Chen Shen, Yun Lu
Composites Science and Technology 2013 Volume 87() pp:8-13
Publication Date(Web):18 October 2013
DOI:10.1016/j.compscitech.2013.07.023
Uniform core–shell Fe3O4@C@polyaniline (PANi) composite microspheres have been prepared via simple in situ polymerization in the absence of surfactants. In this case, the carbon intermediate layer plays an important role in the formation of trilaminar core–shell structure. By simply adjusting the molar ratio of aniline to Fe3O4, the thickness of the polymer shell can be tuned from about 27 to 62 nm. The obtained Fe3O4@C@PANi trilaminar core–shell composite microspheres are used as magnetic adsorbent for the removal of methyl orange (MO) dye from aqueous solution, exhibiting an excellent adsorption capability of 120.2 mg g−1 for MO and retaining about 81% of the removal efficiency after five adsorption–desorption cycles. The adsorption isotherms and kinetics are well described by the Langmuir and pseudo-second-order models respectively. The Fe3O4@C@PANi composite microspheres could be a good candidate in the waste water treatment for the removal of organic dyes.
Co-reporter:Hongjuan Wang, Tao Ni, Geng Li, Yun Lu
Synthetic Metals 2013 Volume 177() pp:52-59
Publication Date(Web):1 August 2013
DOI:10.1016/j.synthmet.2013.05.019
•We obtained comb-type polysiloxanes with carbonyl-functionalized side-chain.•We synthesized pseudo graft copolymers via hydrogen bonding interaction.•The sea urchin-like microspheres can be obtained.•The prepared films from DCAA displayed high conductivity of 20 S/cm.The comb-type polysiloxanes with carbonyl-functionalized side-chains, P(Si-g-MMA), were designed and prepared by direct hydrosilylation reaction between poly(methylhydrosiloxane) (PMHS) with active hydrogen atoms and methyl methacrylate (MMA) with unsaturated bond and carbonyl-function group. By further grafting polyaniline chains to P(Si-g-MMA) via hydrogen bonding interaction, the sea urchin-like P(Si-g-MMA)-PAn microspheres were obtained and characterized by GPC, FTIR, 1H NMR, TGA and SEM. The different morphology of the P(Si-g-MMA)-PAn microspheres can be modulated by simply adjusting the volume ratio of THF to H2O in the mixed solvent during the preparation. The as-prepared P(Si-g-MMA)-PAn can form self-supporting films by solution casting from dichloroacetic acid (DCAA) with conductivity as high as 20 S/cm and available mechanical properties, which would find many applications in various fields.
Co-reporter:Chen Shen;Wei Yao
Journal of Nanoparticle Research 2013 Volume 15( Issue 10) pp:
Publication Date(Web):2013 October
DOI:10.1007/s11051-013-2019-1
Highly functionalized carbon nanoparticles (F-CNPs) with average sizes of 5–30 nm were fabricated by hydrothermal carbonization of specific carbon sources at a mild temperature without usual strong acid treatment or surface modification. The morphology, structure, and fluorescent properties of the nanoparticles were characterized by transmission electron microscopy, dynamic light scattering, Fourier-transform infrared spectra, X-ray photoelectron spectroscopy, Raman spectra and fluorescent spectrophotometer. As a result, the abundant carboxylic, sulfonic, amine, or ethanamide groups were furnished on the surface of these carbon nanoparticles, offering the reaction sites for their possible further functionalization, and these functional groups also enhance the dispersion of carbon nanoparticles which are kept without precipitation for months. The hydrothermal treatment which is simple, green, and economical, also can endow the F-CNPs much more carboxyl groups, thus improving the quantum efficiency of as-prepared products. These functionalized carbon nanoparticles demonstrate the excitation wavelength-independent photoluminescence behavior, implying their potential applications in biological labeling, imaging, and chromatography.
Co-reporter:Hongjuan Wang, Yun Lu
Synthetic Metals 2012 Volume 162(15–16) pp:1369-1374
Publication Date(Web):September 2012
DOI:10.1016/j.synthmet.2012.05.024
By simply changing the concentration of aniline ([An]) and the molar ratio of dichloroacetic acid (DCA) to aniline ([DCA]/[An]), the polyaniline (PANI) nanostructures with different morphologies including 1D-nanotubes, 2D-nanoflakes, 3D-nanofiber networks and microspheres were obtained through a self-assembly process, respectively. It was found that morphological changes were closely related to DCA used as reaction media and [DCA]/[An], and also affected by the pH and temperature of reaction system. The strong hydrogen bonding effect of the two chlorine groups and one carboxyl group of DCA with the amine/imine groups of aniline/polyaniline might be a driving force for the self-assembling nanostructures. Spectral study indicated that phenazine-like units could be obtained in the early reaction state under different [DCA]/[An] ratios, which could be responsible for the formation of nanofiber networks and microspheres at an acidic medium of pH < 1.Graphical abstractPolyaniline nanostructures with different morphologies including 1D-nanotubes, 2D-nanoflakes, 3D-nanofiber networks and microspheres through a self-assembly process only using dichloroacetic acid.Highlights► We obtained four different polyaniline nanostructures through a self-assembly process only using dichloroacetic acid. ► Morphologies of polyaniline changed from 1D-nanotubes, to 2D-nanoflakes, to 3D-nanofiber networks and microspheres. ► In the strong acidic condition of pH < 1, we obtained the junctional nanofiber networks and the microspheres of polyaniline. ► The formation of these morphologies was considered to be the result of forming strong hydrogen bonding effect. ► Phenazine-like units could be responsible for the formation of nanofiber networks and microspheres.
Co-reporter:Zhiquan Shi, Hui Zhou, Yun Lu
Colloids and Surfaces A: Physicochemical and Engineering Aspects 2012 Volume 393() pp:153-159
Publication Date(Web):5 January 2012
DOI:10.1016/j.colsurfa.2011.11.016
The polyaniline/gold (PANI/Au) have been successfully deposited on the surface of the poly(tetrafluoroethylent) (PTFE) membrane by one step process via simple diffusing interfacial reaction. The concentration ratio of aniline monomer to doping agent affected the microstructure and electrical conductivity of the composite membrane. The morphology and structure of the as-prepared composite membrane were characterized by using SEM, XRD, GIXRD, ATR-FTIR, Raman and UV–vis spectroscopy, and a difference on the upside and bottom side surfaces of the membrane was detected. As a candidate of advanced catalytic systems, the catalytic function of the Au on the surface of composite membrane was investigated and showed integrated benefits such as good catalysis, pollution-free, easy separation, convenient operation and regeneration in practical applications.Graphical abstractHighlights► Poly(tetrafluoroethylene)@polyaniline/Au composite membranes made by one step process. ► Effect of concentration ratio of aniline monomer to doping agent on surface structure. ► Composite membrane with higher Au content in its upside surface. ► Good catalysis and other benefits of the composite membrane.
Co-reporter:Sunjie Ye, Yibo Liu, Shujun Chen, Shuang Liang, Ronan McHale, Negar Ghasdian, Yun Lu and Xiaosong Wang
Chemical Communications 2011 vol. 47(Issue 24) pp:6831-6833
Publication Date(Web):09 May 2011
DOI:10.1039/C1CC11424G
We fabricated PPy/PB core/shell nanoparticles via one-step miniemulsion polymerization using a metallosurfactant of EPE-Fe. The defined hollow structure endows PB nanoshells with an emission band at 612 nm. On incorporating PPy inside PB shells, a blue shift and enhanced fluorescence were observed due to charge transfer from PPy to PB.
Co-reporter:Sunjie Ye, Shujun Chen, Hongjuan Wang and Yun Lu
Physical Chemistry Chemical Physics 2011 vol. 13(Issue 10) pp:4668-4673
Publication Date(Web):31 Jan 2011
DOI:10.1039/C0CP02184A
We measure the emission spectra and quantum yields of Ag@PPy nanoparticles with different volume ratios of Ag core and PPy shell, and ascribe the emission peaks around 460 and 520 nm, respectively, to the S1 → S0 transition of the PPy molecule, and to the charge transfer between Ag and PPy, as well as the Ag plasmon. The two peaks shift with the changed doping level of the PPy shell, which can be elucidated by consideration of the energy levels of Ag and PPy. According to these results, we investigate the fast and reversible pH-sensing function of Ag@PPy nanoparticles on the basis of the doping effect on the interaction between the Ag core and the PPy shell.
Co-reporter:Sunjie Ye, Chen Shen, Huan Pang, Jing Wang, Yun Lu
Polymer 2011 Volume 52(Issue 12) pp:2542-2549
Publication Date(Web):26 May 2011
DOI:10.1016/j.polymer.2011.04.010
CdTe/PEDOT-PSS hybrid microspheres have been attained via the direct polymerization of EDOT-PSS on mercapopropionic acid capped CdTe quantum dot aggregates. The obtained hybrid microspheres provide multiple-color absorption and emission properties as a function of the pH value of the medium, which indicate the presence of both physical and electronic contact between the PEDOT and CdTe. The pH-dependent absorption and emission properties of the CdTe/PEDOT-PSS hybrid microspheres were relative to the doping–dedoping behavior of conducting PEDOT-PSS and insensitive to the morphology or distribution of the hybrid microspheres. This study gives a route for facile fabrication of semiconductor nanoparticle/conducting polymer microspheres applicable in optoelectronic and photovoltaic devices.
Co-reporter:Sunjie Ye, Shujun Chen, Li Fang and Yun Lu
Journal of Materials Chemistry A 2010 vol. 20(Issue 19) pp:3827-3830
Publication Date(Web):14 Apr 2010
DOI:10.1039/C0JM00391C
We synthesize a multifunctional coordination polymer film via the straightforward procedure coordinating the praseodymium ion (Pr3+) to the oxygen in polycarbonate (PC); the as-prepared films exhibit an attractive combination of the luminescence characteristics of Pr3+ ion and the mechanical performance as well as dielectric property of PC.
Co-reporter:Tingyang Dai;Kai Chen;Xutang Qing;Jinsong Zhu;Feng Gao
Macromolecular Rapid Communications 2010 Volume 31( Issue 5) pp:484-489
Publication Date(Web):
DOI:10.1002/marc.200900711
Co-reporter:Sunjie Ye;Li Fang;Zhanru Lin;Gi Xue
Macromolecular Chemistry and Physics 2010 Volume 211( Issue 11) pp:1238-1244
Publication Date(Web):
DOI:10.1002/macp.201000027
Co-reporter:Jianguo Jiang;Xiaoyan Lu
Journal of Applied Polymer Science 2010 Volume 116( Issue 5) pp:2610-2616
Publication Date(Web):
DOI:10.1002/app.31650
Abstract
The preparation of a polymer with both low polydispersity and high tacticity is one current challenge we face and warrants thorough investigation from both the theoretical and experimental standpoints. In this study, we synthesized polyacrylonitrile (PAN) with simultaneously controlled molecular weight and tacticity on the basis of the strategy of the atom transfer radical polymerization (ATRP) of acrylonitrile (AN) in the presence of Lewis acids. A new combined initiation system of 3-bromopropionitrile (3-BPN)/Cu2O/N,N,N′,N′-tetramethylethylenediamine (TMEDA) was used for the ATRP of AN for the first time. When the polymerization was performed with the ratio [AN]0/[Initiator]0/[Cu2O]0/[TMEDA]0 = 190/1/0.5/1.5 (where the subscript 0 indicates the initial conditions) in ethylene carbonate at 60°C for 48 h, the polydispersity of the obtained PAN was 1.13, and the molecular weight was up to 13,710. The polymerization kinetics results show that the polymerizations proceeded with a living/controlled nature except that an induction period existed during the polymerization process because of the lower initiating activity of 3-BPN. Also, two kinds of Lewis acid, AlCl3 and yttrium trifluororomethanesulflnate, were used in the ATRP system of AN for the tacticity control. The addition of 0.01 equiv (relative to AN) of the Lewis acid AlCl3 in the polymerization afforded PAN with an improved isotacticity [meso/meso triad (mm) = 0.32] and a very narrow polydispersity (1.06). © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Co-reporter:Youyi Xia
Polymer Composites 2010 Volume 31( Issue 2) pp:340-346
Publication Date(Web):
DOI:10.1002/pc.20811
Abstract
Polypyrrole/polyacrylonitrile, polyaniline/polyacrylonitrile, and poly(3,4-ethylenedioxythiophene)/polyacrylonitrile composite fibres were fabricated successfully by in situ polymerization. The morphologic observations confirmed the uniformly-covered polyacrylonitrile fiber surface by conductive conjugated polymers. These composite fibers exhibited conductivity in the range of 1.4 × 10−2 to 5.2 × 10−1 S cm−1. Improved thermal stability of the composite fibers was observed from thermogravimetric analysis results. Structural analysis indicated that the interactions of both hydrogen-bonding and the electrostatic attraction existed between polyacrylonitrile chains and conjugated polymers. These novel composite fibers still possessed original fibrillar morphology and strength properties and showed a good stability to atmosphere and washing. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers
Co-reporter:Min Wei, Tingyang Dai, Yun Lu
Synthetic Metals 2010 Volume 160(9–10) pp:849-854
Publication Date(Web):May 2010
DOI:10.1016/j.synthmet.2010.01.032
Polypyrrole (PPy) with variable nanostructure such as nanotubes, nanorods and networks has been fabricated by employing an ion association of heparin–methylene blue as new morphology-directing agent. The ion association exhibited both advantages of hard and soft template in template-induced chemical polymerization of pyrrole. By altering the ration of ion association component, PPy could be easily switched in morphology between nanotubes and nanorods. With the coordination effect of ion association and oxidant Fe3+, PPy networks with high conductivity could also be obtained in static condition. The achieved nanostructured polypyrrole were all doped with heparin, a biochemical material, and had potential exploitation value in electrochemistry and biochemistry.
Co-reporter:Zhiquan Shi, Hongjuan Wang, Tingyang Dai, Yun Lu
Synthetic Metals 2010 Volume 160(19–20) pp:2121-2127
Publication Date(Web):October 2010
DOI:10.1016/j.synthmet.2010.07.042
Two kinds of Ag/polypyrrole composite nanoparticles have been prepared via a one-step redox reaction between silver nitrate and pyrrole monomer at room temperature. One is Ag@polypyrrole core–shell nanoparticles that were synthesized by making use of synergic inducing effect of polyvinyl pyrrolidone and p-toluenesulfonic acid existing in aqueous solutions. The other is AgCl@Ag/polypyrrole core–shell composite nanoparticles that were synthesized in the presence of HCl using the in situ-formed AgCl particles as the template. For the latter, its core can be easily removed via a simple dissolving procedure in sodium hyposulfite or ammonium chloride aqueous solutions, obtaining the Ag/polypyrrole hollow composite capsules. Experimental results suggest that the shell thickness and core diameter of the resulting composites can be controlled expediently by adjusting reaction time and concentration of pyrrole monomer.
Co-reporter:Hui Zhou, Zhiquan Shi, Yun Lu
Synthetic Metals 2010 Volume 160(17–18) pp:1925-1930
Publication Date(Web):September 2010
DOI:10.1016/j.synthmet.2010.07.011
A composite conductive polymer film, polyaniline-coated polytetrafluoroethylene, noted as PANI/PTFE, has been successfully synthesized by a simple chemical oxidation polymerization approach. The observed surface morphology of the PANI/PTFE film confirms that the network structural PTFE film acted as template in the synthesis of the composite film to get PANI@PTFE coaxial-line structure at a relative low oxidant concentration. By regulating the molar ratio of oxidant to monomer, the morphological evolution of the composite film could be controlled, resulting in the tunable hydrophilicity. As a consequence of an optimal combination of the characteristic features of PANI and PTFE, a composite film with excellent mechanical properties, high conductivity, easy processability, adjustable hydrophilicity and reversible conversion between hydrophobicity and hydrophilicity have been obtained.
Co-reporter:Tingyang Dai, Xutang Qing, Hui Zhou, Chen Shen, Jing Wang, Yun Lu
Synthetic Metals 2010 Volume 160(7–8) pp:791-796
Publication Date(Web):April 2010
DOI:10.1016/j.synthmet.2010.01.024
Mechanically strong conducting hydrogels composed of poly(acrylamide) (PAAm) and poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT-PSS) have been synthesized through the construction of a special double-network (sDN) structure. The novelty of the sDN hydrogels lies in the introduction of PEDOT-PSS semi-interpenetrating polymer network (semi-IPN) hydrogel as the second network. Based on the experimental results and the double-network theory, an additional strengthening effect resulting from the formation of the PEDOT clusters in a three-step fracture process is proposed. The applicability of as-prepared PAAm/PEDOT-PSS sDN hydrogels in electromechanical actuators is also briefly discussed.
Co-reporter:Tingyang Dai, Zhiquan Shi, Chen Shen, Jing Wang, Yun Lu
Synthetic Metals 2010 Volume 160(9–10) pp:1101-1106
Publication Date(Web):May 2010
DOI:10.1016/j.synthmet.2010.02.034
Conducting polymer hydrogels of poly(3,4-ethylenedioxythiophene)–poly(styrenesulfonate) (PEDOT–PSS) with self-strengthening functions have been synthesized via a facile one-step procedure. The enhanced mechanical toughness, directly established in the materials in their formation process, results from the effective transfer of the local stress between the two components of PEDOT and PSS, which is closely related to the homogeneity of the microstructure and the phase structure. The experimental conditions for the fabrication of the hydrogels have been optimized, and samples prepared with suitable reagent concentrations can sustain a stress in the order of megapascals and a strain higher than 90%. The electrical conductivity of the hydrogels, in the order of 10−2 S/cm, is demonstrated to be determined by the surface composition and the compactness of the samples. The contribution of this work lies in not only the invention of a new type of conducting polymer hydrogels with outstanding mechanical properties, but also the creation of a novel method to achieve facile preparation of multifunctional mechanically strong hydrogels through the combination of suitable components into proper structures.
Co-reporter:Yongqin Han, Xutang Qing, Sunjie Ye, Yun Lu
Synthetic Metals 2010 Volume 160(11–12) pp:1159-1166
Publication Date(Web):June 2010
DOI:10.1016/j.synthmet.2010.03.002
Conducting polypyrrole (PPy) with nanoscale hierarchical structure is chemically synthesized in an aqueous solution in the presence of cetyltrimethylammonium bromide (CTAB) and 1,5-naphthalene disulfonic acid (1,5-NDA). The effect of synthetic conditions including concentration of CTAB and pyrrole, reaction temperature, oxidants and their introduced modes on the PPy hierarchical nanostructure is systematically investigated. A hypothesis for the hierarchical structure formation of PPy with the aid of CTAB/1,5-NDA/pyrrole supramolecular template is presented, in which the pyrrole is polymerized in imitation of the CTAB/1,5-NDA/pyrrole crystal shape. The electrochemical performances of representative PPy sample show that the PPy with hierarchical nanostructures has potential application as supercapacitor materials.
Co-reporter:Youyi Xia, Zhiquan Shi, Yun Lu
Polymer 2010 Volume 51(Issue 6) pp:1328-1335
Publication Date(Web):11 March 2010
DOI:10.1016/j.polymer.2009.12.043
Monodisperse gold microspheres with novel hierarchical structure and their composite integrated with a conducting film obtained from a new conducting copolymer, poly(acrylonitrile-co-vinyl acetate) -graft- poly(3,4-ethylenedioxythiophene), have been successfully prepared in one step via the in-situ reduction of AuCl4- on the conducting film surface. The morphology and structure of the as-prepared composite film are characterized, and its catalytic effect on reduction of p-nitrophenol is investigated. By controlling the concentration of HAuCl4 and the conductivity (or PEDOT content) of P(AN-co-VA)-g-PEDOT copolymer film, the amount and the size of gold microspheres can be effectively adjusted. It is suggested that the side poly(3,4-ethylenedioxythiophene) chains of the conducting copolymer play both reducing and structure-directing roles during the formation of Au microspheres with hierarchical structure.
Co-reporter:Sunjie Ye, Li Fang and Yun Lu
Physical Chemistry Chemical Physics 2009 vol. 11(Issue 14) pp:2480-2484
Publication Date(Web):12 Feb 2009
DOI:10.1039/B816070H
A unique surface-enhanced infrared absorption phenomenon was found and investigated for Ag@polypyrrole nanoparticles. Enhancement of the peak at 1384 cm−1, corresponding to a C–H bending vibration, gave information on the orientation of the polypyrrole (PPy) molecule in Ag@PPy nanoparticles. It was observed that the contribution of the charge-transfer effect can be amplified with an increased quantity of oxidant FeCl3 in the polymerization of pyrrole on the Ag core, suggesting that the doped Cl− ions in the conductive PPy shell may bring an alteration of the local Fermi level of the Ag nanoparticles and the energy levels in the PPy moleclue, thus achieving an optimal energy matching. These results demonstrated the potential of Ag@PPy nanoparticles as photonics and electronics devices and opened out the applicability of the SEIRA in more-interesting and practical systems.
Co-reporter:Yongqin Han, Yun Lu
Composites Science and Technology 2009 Volume 69(7–8) pp:1231-1237
Publication Date(Web):June 2009
DOI:10.1016/j.compscitech.2009.02.028
Conductive polymers such as polypyrrole (PPy) and poly(3,4-ethylenedioxythiophene) (PEDOT) have been synthesized in the presence of colloidal graphite oxide (CGO) prepared via Hummers and Offerman’s method, thus obtaining PPy/CGO and PEDOT/CGO nanocomposites. The resulted nanocomposites provide high and adjustable electrical conductivity when doped with different dopants, and a much better thermal stability than pristine CGO. For the case of doped PPy/CGO nanocomposites, CGO is confirmed experimentally to be exfoliated and thus could offer more “active sites” for the polymerization of pyrrole. For the case of doped PEDOT/CGO nanocomposites, X-ray diffraction analyses indicate the formation of PEDOT with the aid of CGO in aqueous media in spite of its monomeric water insolubility and a possible part intercalation of PEDOT between the layers of CGO. The temperature dependence of conductivity supports the three-dimensional Mott’s variable range hopping mechanism for doped PPy/CGO and PEDOT/CGO nanocomposites. The Fourier-transform infrared (FTIR) spectroscopy and electron spin resonance (ESR) spectra data, as evidence verifies that the charge carriers in doped PPy/CGO nanocomposites are polarons, while bipolarons serve as charge carriers in doped PEDOT/CGO nanocomposites.
Co-reporter:Youyi Xia, Min Wei, Yun Lu
Synthetic Metals 2009 Volume 159(5–6) pp:372-376
Publication Date(Web):March 2009
DOI:10.1016/j.synthmet.2008.10.004
Poly(3,4-ethylenedioxythiophene) (PEDOT) hollow spheres with the size ranged from 130 to 820 nm and a conductivity of 8 × 10−2 S cm−1 were prepared simply and directly via a one-step self-assembly approach in the presence of poly(vinylpyrrolidone) (PVP) as a soft template. It was found that the formation probability of PEDOT hollow spheres depended on the concentration of PVP. Bulk quantities of PEDOT hollow spheres can be obtained readily under the optimal conditions such as the concentration of PVP > 0.175 mM and PVP/EDOT molar ratio <1.4. The electron-rich oxygen atoms on the lactam groups in PVP were proposed to act as the chemically active sites to anchor EDOT cation radicals by virtue of electrostatic interaction and cause the self-assembly of PEDOT hollow spheres. Our investigation for the formation mechanism of PEDOT hollow spheres may shed some light on preparing of other hollow materials by proper molecular design and experimental condition optimization.
Co-reporter:Li Fang, Tingyang Dai, Yun Lu
Synthetic Metals 2009 Volume 159(19–20) pp:2101-2107
Publication Date(Web):October 2009
DOI:10.1016/j.synthmet.2009.07.043
The preparation of free-standing electromagnetic composite films based on conductive polypyrrole (PPy) hydro-sponge and the Fe3O4 ferrofluid have been successfully accomplished via self-assembly in the presence of β-cyclodextrin sulfate and under static condition. Transmission electron microscope (TEM), scanning electron microscope (SEM) and X-ray diffraction (XRD) are used to study the morphology of the PPy-Fe3O4 composite. Structural characterizations by Fourier transform infrared (FTIR) and thermogravimetric analysis (TGA) have proved the interactions between Fe3O4 and PPy chains. As-prepared films possess high electrical conductivity, remarkable magnetic response as well as appropriate flexility. Both the conductivity and magnetization of the composite, the latter in particular, depend strongly on the Fe3O4 content and thus can be optimized by adjusting the relative content of Fe3O4 in the composite. The combination of both magnetic and conducting activities of the resulting composite makes it be a potential candidate as functional material in electromagnetic devices, such as magnetic-controlled switches.
Co-reporter:Min Wei, Yun Lu
Synthetic Metals 2009 Volume 159(Issue 11) pp:1061-1066
Publication Date(Web):June 2009
DOI:10.1016/j.synthmet.2009.01.031
Nanostructured polypyrrole have been fabricated in high yield by chemical oxidation polymerization using one-dimensional rod-like aggregates of 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrin (TPPS4) as a template. This aggregate has the advantages of both soft and hard template such as stable, good versatility (for hard template), cheap, and easy removal (for soft template). Also, the molar ratio of TPPS4 and pyrrole monomer could be as low as 1:1000, showing a high efficiency of the template. Polypyrrole nanorods with variational size have been achieved successfully by using this versatile template and cooperating with the oxidants with different redox potentials. Moreover, in the presence of TPPS4 template and polyvinylpyrrolidone (PVP), Polypyrrole (PPy) nanofibers were obtained even though using a weak oxidant. The formation of PPy nanorods/nanofibers was discussed and their properties including conductivity and thermalstability were evaluated.
Co-reporter:Yongqin Han
Journal of Applied Polymer Science 2009 Volume 111( Issue 5) pp:2400-2407
Publication Date(Web):
DOI:10.1002/app.29271
Abstract
Montmorillonite, organically modified by octadecylammine salt, has been adopted to successfully fabricate the exfoliated organic montmorillonite/poly(3,4-ethyldioxythiophene) (OMMT/PEDOT) nanocomposites by in situ polymerization in aqueous media. Hydrochloric acid, 1,5-naphthalenedisulfonic acid, and sodium benzenesulphonate have been employed to activate the polymerization of 3,4-ethyldioxythiophene by offering active sites on the layers of montmorillonite. The resulting exfoliated nanocomposites have been characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, thermogravimetric analysis, and electrical conductivity measurement and showed controllable conductivity in the range of 10−7 to 10−2 S/cm and improved thermal stability compared with pure PEDOT. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Co-reporter:Youyi Xia, Qing Su, Yun Lu
Polymer 2009 50(21) pp: 5065-5070
Publication Date(Web):
DOI:10.1016/j.polymer.2009.08.039
Co-reporter:Tingyang Dai, Xutang Qing, Yun Lu, Youyi Xia
Polymer 2009 50(22) pp: 5236-5241
Publication Date(Web):
DOI:10.1016/j.polymer.2009.09.025
Co-reporter:Tingyang Dai, Xiujuan Jiang, Shouhu Hua, Xiaoshu Wang and Yun Lu
Chemical Communications 2008 (Issue 36) pp:4279-4281
Publication Date(Web):16 Jul 2008
DOI:10.1039/B807116K
We describe a simple and versatile method to fabricate conducting polymer hydrogels via supramolecular self-assembly between polymers and multivalent cations; the as-prepared hydrogels are potentially applicable in the fields of electrosensors, chemical release and artificial muscles.
Co-reporter:Youyi Xia, Yun Lu
Composites Science and Technology 2008 Volume 68(Issue 6) pp:1471-1479
Publication Date(Web):May 2008
DOI:10.1016/j.compscitech.2007.10.044
Highly conductive polymers (polypyrrole, polyaniline or poly3,4-ethylene-dioxythiophene)/silk fibroin composite fibers were fabricated successfully and expediently by in situ polymerization without any modification of silk fibroin surface. Scanning electron microscopy (SEM) and optical microscope confirmed the silk fibroin fiber surface covered entirely by conductive polymers. Polypyrrole/silk fibroin (PPY/SF), polyaniline/silk fibroin (PANI/SF), and poly3,4-ethylene-dioxythiophene/silk fibroin (PEDOT/SF) composite fibers exhibited varied conductivity in the range of 3.8–4.2 × 10−1, 0.9–1.2 × 10−2 and 4.9–5.2 × 10−3 S cm−1, respectively. Improved thermal stability of silk fibroin fiber via coating process was observed from thermogravimetric analysis (TGA) results. Structural analysis indicated that the interactions including hydrogen-bonding and electrostatic attraction existed between silk fibroin macromolecules and conductive polymers. The peptide linkages bearing on silk fibroin macromolecules played an important role in the in situ polymerization by attracting conjugated cation radicals. These composite fibers still possessed former fibrillar morphology and strength properties.
Co-reporter:Jianguo Jiang, Xiaoshu Wang, Xiaoyan Lu, Yun Lu
Applied Surface Science 2008 Volume 255(Issue 5) pp:1888-1893
Publication Date(Web):30 December 2008
DOI:10.1016/j.apsusc.2008.06.119
Abstract
Two kinds of polymer brushes, the single one with stereospecific polyacrylamide (PAAM) chains and the dual-component one with random poly(methyl methacrylate) (PMMA) segments grafting from stereospecific PAAM chains, were prepared on silicon wafer for the first time by combining the immobilization of initiator and the stereospecific living radical in situ polymerization. With the addition of the Lewis acid AlCl3 into the polymerization system, the PAAM brushes obtained exhibited an increased stereospecificity as well as a decreased hydrophilicity, which might attribute to the reduced thickness of PAAM brushes on the silicon wafer and the handicap of the free rotation of the stereospecific molecular chain. The smoother surface morphology of the stereospecific PAAM brushes shown in AFM images was in good agreement with the experimental data of water contact angle. Also, block amphiphilic copolymer brushes were prepared with the stereospecific PAAM formed first on silicon wafer as the anchored-initiator and revealed a novel surface self-assembly behavior after being treated with different solvent such as toluene or water. The stereospecificity of PAAM chains in the polymer brushes could be modulated by adjusting reaction conditions according to the requirement of applications for surface hydrophilicity.
Co-reporter:Yongqin Han, Yun Lu
Synthetic Metals 2008 Volume 158(19–20) pp:744-748
Publication Date(Web):November 2008
DOI:10.1016/j.synthmet.2008.04.028
3,4-Ethylenedioxythiophene is difficult to be polymerized in aqueous media due to its water insolubility. The negatively charged graphite oxide is employed as the “aided soil” to make 3,4-ethylenedioxythiophene cations attractive to be polymerized easily even in aqueous media. The synthesized poly(3,4-ethylenedioxythiophene) shows ordered nanorod-like or needle-like structure depositing on the graphite oxide layer surface as well as settling on/around the edge of the graphite oxide layers. The electrical conductivity of the resulting graphite oxide/poly(3,4-ethylenedioxythiophene) nanocomposites and 1,5-naphthalene disulfonic acid-doped graphite oxide/poly(3,4-ethylenedioxythiophene) nanocomposites is 3.3 and 15.0 S/cm, respectively, 7 and 8 orders of magnitude higher than that of pristine graphite oxide.
Co-reporter:Sunjie Ye and Yun Lu
The Journal of Physical Chemistry C 2008 Volume 112(Issue 24) pp:8767-8772
Publication Date(Web):May 27, 2008
DOI:10.1021/jp077710c
The unique optical properties of Ag@polypyrrole composite nanoparticles were systematically investigated in theory and experiment for the first time. On the basis of the classical Mie theory, the extinction, absorption, and scattering efficiencies of the Ag@polypyrrole nanoparticles were theoretically calculated. In addition, their theoretical UV−vis extinction spectra were plotted and compared with the corresponding experimental results. For Ag@polypyrrole nanoparticles, the influence of the microstructure factors, including Ag core size, the thickness and oxidation degree of the polypyrrole shell, and homogeneity of the particle size and shape, on the optical properties of the composite nanoparticle were qualitatively analyzed and discussed in detail. The understanding to the optical properties of Ag@polypyrrole composite nanoparticles could help us to control either parameters in order to design the optimal functional composite particles and to match the practical applications in common or special.
Co-reporter:Tingyang Dai and Yun Lu
Journal of Materials Chemistry A 2007 vol. 17(Issue 45) pp:4797-4802
Publication Date(Web):28 Sep 2007
DOI:10.1039/B711790F
Polypyrrole hydro-sponges with macroscopic features similar to polymer gels were synthesized by assembling polypyrrole microtubules into mesoscale networks. An employed static condition was demonstrated to play an important role in the formation of the new materials. The granules of polypyrrole introduced via the inducement of β-cyclodextrin sulfate or the modulation of the template acted as a “mesoscale cross-linker”. The swellability of the materials was successfully improved with the increased degree of mesoscopic cross-linking. The crystallinity of the polypyrrole in the products was confirmed by XRD measurements. The repeat length along the chain direction and the coherence length were determined. The compressed pellet of the resulting materials showed an electrical conductivity as high as 126 S cm−1. The investigation gives valuable hints for achieving controlled fabrication of materials with complicated superstructures and macroscopic sizes.
Co-reporter:Yongqin Han, Yun Lu
Carbon 2007 Volume 45(Issue 12) pp:2394-2399
Publication Date(Web):October 2007
DOI:10.1016/j.carbon.2007.07.007
Graphite oxide (GO)/polypyrrole (PPy) composites (GPs) and 1,5-naphthalene disulfonic acid (1,5-NDA) doped GPs (1,5-NGPs) have been successfully synthesized via in situ polymerization of pyrrole on GO. The conductivity of 1,5-NGPs is as high as 7 S/cm, seven orders of magnitude higher than that of pristine GO. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) results show PPy “dressed” on the surface of GO layers, while Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analyses confirm the interaction between GO and PPy. The results of thermogravimetric analysis (TGA) and heat treatment at 1000 °C show that the “dressed” PPy on the surface of GO layers in GPs and 1,5-NGPs has effectively prevented the deflagration of GO.
Co-reporter:Yun Lu;Tingyang Dai
Macromolecular Rapid Communications 2007 Volume 28(Issue 5) pp:629-633
Publication Date(Web):12 MAR 2007
DOI:10.1002/marc.200600697
One-dimensional methyl orange fibrils can be easily prepared. They are stable in acidic aqueous solutions and soluble in neutral water. When used to synthesize conducting polymer microtubules, the fibrils act as “hard templates” formally but as “soft templates” effectively. Microtubular structures of polypyrrole, polyaniline, and poly(3,4-ethylenedioxythiophene) have been achieved successfully via such water-soluble versatile templates.
Co-reporter:Hongyan Yang, Wei Jiang, Yun Lu
Materials Letters 2007 Volume 61(Issue 6) pp:1439-1442
Publication Date(Web):March 2007
DOI:10.1016/j.matlet.2006.07.051
Co-reporter:Tingyang Dai, Xiaoming Yang, Yun Lu
Materials Letters 2007 Volume 61(14–15) pp:3142-3145
Publication Date(Web):June 2007
DOI:10.1016/j.matlet.2006.11.012
Co-reporter:Jianguo Jiang;Xiaoyan Lu
Journal of Polymer Science Part A: Polymer Chemistry 2007 Volume 45(Issue 17) pp:3956-3965
Publication Date(Web):17 JUL 2007
DOI:10.1002/pola.22149
Atom transfer radical polymerization (ATRP) of acrylamide was successfully carried out with chloroacetic acid as initiator and CuCl/N,N,N′,N′-tetramethylethylenediamine (TMEDA) as catalyst either in water at 80 °C or in glycerol–water (1:1 v/v) medium at 130 °C. In both cases, carboxyl-end-group polyacrylamide was obtained with lower polydispersity ranging from 1.03 to 1.44 depending on the polymerization condition. Polymerization kinetics showed that the polymerizations proceeded with a living/controlled nature and accelerated at a higher temperature. The effect of pH in the reaction system on the polymerizations was further studied, revealing that chloroacetic acid not only served as a functional initiator for the ATRP of acrylamde but also provided the acidic polymerization condition, which effectively protected the ATRP of acrylamide from the unexpected complexation and cyclization side-reactions. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3956–3965, 2007
Co-reporter:Bing Xu, Xiaoshu Wang, Yun Lu
Applied Surface Science 2006 Volume 253(Issue 5) pp:2695-2701
Publication Date(Web):30 December 2006
DOI:10.1016/j.apsusc.2006.05.044
Abstract
In this work, sized polyacrylonitrile (PAN)-based carbon fibers were chemically modified with nitric acid and maleic anhydride (MA) in order to improve the interaction between carbon fiber surface and polyimide matrix. Bismaleimide (BMI) was selected as a model compound of polyimide to react with modified carbon fiber. The surface characteristic changing after modification and surface reaction was investigated by element analysis (EA), scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and surface enhanced Raman scattering (SERS). The results indicated that the modification of carbon fiber surface with MA might follow the Diels Alder reaction mechanism. In the surface reaction between modified fibers and BMI, among the various surface functional groups, the hydroxyl group provided from phenolic hydroxyl group and bridged structure on carbon fiber may be the most effective group reacted with imide structure. The results may shed some light on the design of the appropriate surface structure, which could react with polyimide, and the manufacture of the carbon fiber-reinforced polyimide matrix composites.
Co-reporter:Tingyang Dai;Xiaoming Yang;Zhengxi Zhu
Macromolecular Rapid Communications 2005 Volume 26(Issue 21) pp:1736-1740
Publication Date(Web):21 OCT 2005
DOI:10.1002/marc.200500514
Summary: Polypyrrole nanotubes with high electric conductivity and azo function have been fabricated in high yield via an in-situ polymerization. During the process fibrillar complex of FeCl3 and methyl orange (MO), acting as a reactive self-degraded template, directed the growth of polypyrrole on its surface and promoted the assembly into hollow nanotubular structures.
Co-reporter:Xiaoming Yang, Yun Lu
Materials Letters 2005 Volume 59(19–20) pp:2484-2487
Publication Date(Web):August 2005
DOI:10.1016/j.matlet.2005.03.033
The silver/polypyrrole core/shell nanoparticles with diameter less than 60 nm were successfully synthesized in the presence of polyvinylpyrrolidone by one-step UV-induced polymerization. The nanoparticles were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR). Possible mechanism was proposed for the formation of the silver/polypyrrole core/shell nanostructure during the photopolymerization.
Co-reporter:Xueqing Hu;Jinhui Liu
Macromolecular Rapid Communications 2004 Volume 25(Issue 11) pp:1117-1120
Publication Date(Web):21 MAY 2004
DOI:10.1002/marc.200400067
Summary: Polypyrrole (PPy) microtubes with an actinomorphic morphology are synthesized by a chemical method in the presence of an inclusion complex (IC) of mono [6-deoxy-6-(2-butenedinitrile-2,3-dimercapto sodium salt)]-β-cyclodextrin (6-mnt-β-CD) with methyl orange (MO) as a dopant in aqueous solution. The morphologies of the obtained PPy were studied using transmission electron microscopy (TEM). It was found that the IC of 6-mnt-β-CD with MO significantly affects the morphology of the resulting PPy.
Co-reporter:Jinbo He, Hongjun Zhou, Fen Wan, Yun Lu, Gi Xue
Vibrational Spectroscopy 2003 Volume 31(Issue 2) pp:265-269
Publication Date(Web):6 May 2003
DOI:10.1016/S0924-2031(03)00015-8
Surface enhanced Raman scattering (SERS) technique was used to monitor and analyze the electrochemically polymerized polythiophene (PT) layer on several metal electrodes, such as stainless steel and aluminum, during the different reaction stage. The SERS spectra were directly achieved from the PT films after silvering. The result of spectral measurement indicated that in the films formed at the initial moment of electropolymerization the thiophene rings in polymer chains have an ordered arrangement in the form of an alternate-layer parallel.
Co-reporter:Yun Lu, Liping Zhu, Fengting Li, Gi Xue
Vibrational Spectroscopy 2001 Volume 26(Issue 2) pp:227-231
Publication Date(Web):8 November 2001
DOI:10.1016/S0924-2031(01)00125-4
FT-surface enhancing Raman scattering (FT-SERS) spectra were detected for benzyldisulfide (BDS) and 4-aminophenyl disulfide (APDS) on stainless steel. The FT-SERS spectra show that BDS and APDS can cleave and chemisorb on the etched stainless steel plate to form assembled-films. The results showed that BDS and APDS were adsorbed in the same adsorption state on stainless steel and silver. For steel, the preparation of SERS-active surface by HCl etching and silver deposition was as convenient as HNO3 etching method for silver.
Co-reporter:Sunjie Ye, Li Fang and Yun Lu
Physical Chemistry Chemical Physics 2009 - vol. 11(Issue 14) pp:NaN2484-2484
Publication Date(Web):2009/02/12
DOI:10.1039/B816070H
A unique surface-enhanced infrared absorption phenomenon was found and investigated for Ag@polypyrrole nanoparticles. Enhancement of the peak at 1384 cm−1, corresponding to a C–H bending vibration, gave information on the orientation of the polypyrrole (PPy) molecule in Ag@PPy nanoparticles. It was observed that the contribution of the charge-transfer effect can be amplified with an increased quantity of oxidant FeCl3 in the polymerization of pyrrole on the Ag core, suggesting that the doped Cl− ions in the conductive PPy shell may bring an alteration of the local Fermi level of the Ag nanoparticles and the energy levels in the PPy moleclue, thus achieving an optimal energy matching. These results demonstrated the potential of Ag@PPy nanoparticles as photonics and electronics devices and opened out the applicability of the SEIRA in more-interesting and practical systems.
Co-reporter:Tingyang Dai and Yun Lu
Journal of Materials Chemistry A 2007 - vol. 17(Issue 45) pp:NaN4802-4802
Publication Date(Web):2007/09/28
DOI:10.1039/B711790F
Polypyrrole hydro-sponges with macroscopic features similar to polymer gels were synthesized by assembling polypyrrole microtubules into mesoscale networks. An employed static condition was demonstrated to play an important role in the formation of the new materials. The granules of polypyrrole introduced via the inducement of β-cyclodextrin sulfate or the modulation of the template acted as a “mesoscale cross-linker”. The swellability of the materials was successfully improved with the increased degree of mesoscopic cross-linking. The crystallinity of the polypyrrole in the products was confirmed by XRD measurements. The repeat length along the chain direction and the coherence length were determined. The compressed pellet of the resulting materials showed an electrical conductivity as high as 126 S cm−1. The investigation gives valuable hints for achieving controlled fabrication of materials with complicated superstructures and macroscopic sizes.
Co-reporter:Chen Shen, Jing Wang, Yi Cao and Yun Lu
Journal of Materials Chemistry A 2015 - vol. 3(Issue 26) pp:NaN6675-6675
Publication Date(Web):2015/05/22
DOI:10.1039/C5TC01156F
A green and facile hydrothermal approach for carbonizing boric acid and ethylenediamine into B-doped carbon dots (CDs) has been proposed, providing a new method to synthesize functional carbon dots on a large scale. The obtained B-doped CDs exhibit favorable aqueous solubility and strong fluorescence in both aqueous and solid states. Especially, the unique solid-state fluorescence properties of the B-doped CDs inspire new thoughts for other applications, accordingly a yellowish-green light emitting diode with the as-obtained CDs as light converters is demonstrated. Meanwhile, the as-prepared CDs also display intensely low toxicity and excellent multicolour fluorescence imaging ability in live cells.
Co-reporter:Sunjie Ye, Yibo Liu, Shujun Chen, Shuang Liang, Ronan McHale, Negar Ghasdian, Yun Lu and Xiaosong Wang
Chemical Communications 2011 - vol. 47(Issue 24) pp:NaN6833-6833
Publication Date(Web):2011/05/09
DOI:10.1039/C1CC11424G
We fabricated PPy/PB core/shell nanoparticles via one-step miniemulsion polymerization using a metallosurfactant of EPE-Fe. The defined hollow structure endows PB nanoshells with an emission band at 612 nm. On incorporating PPy inside PB shells, a blue shift and enhanced fluorescence were observed due to charge transfer from PPy to PB.
Co-reporter:Sunjie Ye, Shujun Chen, Li Fang and Yun Lu
Journal of Materials Chemistry A 2010 - vol. 20(Issue 19) pp:NaN3830-3830
Publication Date(Web):2010/04/14
DOI:10.1039/C0JM00391C
We synthesize a multifunctional coordination polymer film via the straightforward procedure coordinating the praseodymium ion (Pr3+) to the oxygen in polycarbonate (PC); the as-prepared films exhibit an attractive combination of the luminescence characteristics of Pr3+ ion and the mechanical performance as well as dielectric property of PC.
Co-reporter:Sunjie Ye, Shujun Chen, Hongjuan Wang and Yun Lu
Physical Chemistry Chemical Physics 2011 - vol. 13(Issue 10) pp:NaN4673-4673
Publication Date(Web):2011/01/31
DOI:10.1039/C0CP02184A
We measure the emission spectra and quantum yields of Ag@PPy nanoparticles with different volume ratios of Ag core and PPy shell, and ascribe the emission peaks around 460 and 520 nm, respectively, to the S1 → S0 transition of the PPy molecule, and to the charge transfer between Ag and PPy, as well as the Ag plasmon. The two peaks shift with the changed doping level of the PPy shell, which can be elucidated by consideration of the energy levels of Ag and PPy. According to these results, we investigate the fast and reversible pH-sensing function of Ag@PPy nanoparticles on the basis of the doping effect on the interaction between the Ag core and the PPy shell.
Co-reporter:Tingyang Dai, Xiujuan Jiang, Shouhu Hua, Xiaoshu Wang and Yun Lu
Chemical Communications 2008(Issue 36) pp:NaN4281-4281
Publication Date(Web):2008/07/16
DOI:10.1039/B807116K
We describe a simple and versatile method to fabricate conducting polymer hydrogels via supramolecular self-assembly between polymers and multivalent cations; the as-prepared hydrogels are potentially applicable in the fields of electrosensors, chemical release and artificial muscles.
