Co-reporter:Yang Li, Huijie Zhao, Mujie Yang
Journal of Colloid and Interface Science 2017 Volume 508(Volume 508) pp:
Publication Date(Web):15 December 2017
DOI:10.1016/j.jcis.2017.08.076
In this paper, a photocatalyst composed of TiO2 nanoparticles supported on the nanofibers of poly(methyl methacrylate) (PMMA) was successfully prepared by hydrothermally treating the electrospun PMMA nanofibers containing titanium n-butoxide precursor at 135 °C for 8 h. As-prepared composite was characterized by field-emission scanning electron microscopy, X-ray diffraction pattern, thermal gravimetric analysis and Brunauer–Emmett–Teller (BET) surface area measurements. It is revealed that high content (42%) of tetragonal anatase TiO2 nanoparticles are uniformly loaded on the PMMA nanofibers to constitute the composite (TiO2@PMMA) photocatalyst with BET surface area of 21.4 m2 g−1. The photocatalytic activity of TiO2@PMMA towards the degradation of methyl orange (MO), a model pollutant, has been investigated. It is observed that 0.1 g of the composite could degrade 100 mL of MO (10 mg/L) completely within 50 min under UV illumination, exhibiting a high catalytic activity. Moreover, the composite could be easily separated from the reaction system by filtration, and maintain high photocatalytic activity in five consecutive cycles of the degradation of MO, suggesting its potentials in recycling use. The work provides a new approach for the development of novel supported photocatalysts with high catalytic activity and good reusability.Download high-res image (81KB)Download full-size image
Co-reporter:Yang Li, Mingfei Jiao, Mujie Yang
Sensors and Actuators B: Chemical 2017 Volume 238() pp:596-604
Publication Date(Web):January 2017
DOI:10.1016/j.snb.2016.07.089
•Nanosized ZnO is obtained via electrospinning modified by hydrothermal treatment.•ZnO preparation is featured with a green approach in water at low temperature.•Nanohybrids of ZnO and polypyrrole reveal good contact with the substrate.•Nanohybrids show high sensitivity and good selectivity to NH3 at room temperature.ZnO nanoparticles or nanosheets have been in-situ grown on the substrate via a facile green approach featured with the hydrothermal treatment of electrospun nanofibers comprising polyvinyl alcohol and zinc acetate. The nanohybrids of ZnO with polypyrrole (PPy) were fabricated by the vapor phase polymerization of pyrrole on the surface of as-prepared nanostructured ZnO. The resulting nanohybrids were characterized by Fourier transform infrared spectroscopy, X-ray diffraction pattern, field emission scanning electron microscopy and high-resolution transmission electron microscopy and Brunauer–Emmett–Teller surface area measurements. Moreover, the electrical responses of the nanohybrids to NH3 have been examined at room temperature. It was found that the nanohybrids revealed much higher response magnitude than either of the constituent component. Additionally, the morphology of ZnO affected the response magnitude of PPy/ZnO nanohybrids. The hybrids of ZnO nanosheets with PPy showed wide sensing range (0.5–200 ppm), very high response magnitude (relative resistance change of ∼20% towards 0.5 ppm of NH3), good repeatability and selectivity. Attempts have been made to explore the gas sensing mechanism of the PPy/ZnO nanohybrids.
Co-reporter:Yang Li, Huitao Ban, Mujie Yang
Sensors and Actuators B: Chemical 2016 Volume 224() pp:449-457
Publication Date(Web):1 March 2016
DOI:10.1016/j.snb.2015.10.078
•SnO2 nanosheets are prepared by hydrothermal synthesis assisted by electrospinning.•SnO2/polypyrrole nanocomposite is obtained by vapor phase polymerization.•Nanocomposite reveals high sensitivity, selectivity and repeatability to NH3.•High performance of nanocomposite relates to nanostructure and p/n junction.Nanocomposites of SnO2 nanosheets and polypyrrole (PPy) were facilely prepared and their gas sensing properties towards low concentration of NH3 have been investigated at room temperature. Vertically aligned SnO2 nanosheets were in situ grown on the substrates via hydrothermal treatment of electrospun nanofibers containing SnCl2 precursors at a low temperature (135 °C), and coated with PPy by vapor phase polymerization of pyrrole. The SnO2 nanosheets and the nanocomposites were characterized by X-ray diffraction patterns, Fourier transform infrared spectroscopy, field emission scanning electron microscopy and high resolution transmission microscopy. The nanocomposite sensors exhibited much higher response magnitude towards NH3 than the sensors based on PPy alone. The effect of the type of doping acids and polymerization time of pyrrole on the sensing properties of the nanocomposites was examined. The nanocomposite sensors revealed sensitive (sensitivity of ∼6.2%/ppm in the range of 1–10.7 ppm of NH3, detection limit of ∼257 ppb), selective and repeatable response to NH3, and the sensing mechanism has been explored. This work could provide references for the facile preparation of advanced gas sensors based on in situ grown nanostructured metal-oxide semiconductors and their composites.
Co-reporter:Yang Li, Kaicheng Fan, Huitao Ban, Mujie Yang
Sensors and Actuators B: Chemical 2016 Volume 222() pp:151-158
Publication Date(Web):January 2016
DOI:10.1016/j.snb.2015.08.052
•Bilayer sensor based on polyelectrolyte and graphene was facilely prepared.•Bilayer sensor could detect very low humidity (0.18%RH) with high sensitivity.•Bilayer sensor is featured with small hysteresis and relatively fast response.•Humidity response of both layers affects sensing properties of bilayer sensor.An impedance-type humidity sensor was prepared by sequentially depositing the thin films of crosslinked and quaternized poly(4-vinylpyridine) (QC-P4VP) and reduced graphene oxide (RGO) onto interdigitated gold electrodes. The QC-P4VP/RGO bilayer sensor reveals much lower impedance than QC-P4VP based sensor in the environments with low relative humidity (RH) levels, and could detect ultra-low humidity (0.18%RH) with very high response magnitude (impedance increase of 500% between 2.1%RH and 0.18%RH) at room temperature. Moreover, the bilayer sensor shows small hysteresis (∼4.5%RH) and fast response (t90% of 21 s and 78 s for adsorption and desorption processes, respectively). The effect of the concentration of RGO precursor, the deposition order and thickness of the sensing films, temperature, and the structure of the electrodes on the humidity sensing behaviors of the bilayer-structured sensors has been thoroughly examined, and the humidity sensing mechanism was explored.
Co-reporter:Yang Li, Huitao Ban, Huijie Zhao and Mujie Yang
RSC Advances 2015 vol. 5(Issue 129) pp:106945-106952
Publication Date(Web):11 Dec 2015
DOI:10.1039/C5RA20879C
Gas sensors based on a composite of TiO2 nanosheets and polyaniline (PANI) were fabricated by the deposition of water-dispersible PANI on interdigitated gold electrodes decorated with TiO2 nanosheets via dip coating. Specifically, the TiO2 nanosheets were in situ grown on the electrodes by a simple hydrothermal treatment of the electrospun nanofibers of poly(methyl methacrylate) containing a tetrabutyl titanium precursor at a temperature as low as 135 °C in the presence of only water. The method circumvents high temperature calcination and is environmentally friendly. The structure and morphology of the TiO2 nanosheets and their nanocomposites with PANI were characterized by Fourier-transform infrared spectroscopy, X-ray diffraction spectroscopy, scanning electron microscopy, and high resolution transmission electron microscopy. The nanocomposite exhibited highly sensitive (detection limit as low as ∼45 ppb), selective and repeatable electrical responses towards NH3 at room temperature, which is better than those of the separate components and demonstrates an obvious synergetic effect. The enhanced sensing properties of the nanocomposite are proposed to relate to the high specific surface area and the p/n heterojunction between TiO2 nanosheets and PANI.
Co-reporter:Yang Li, Kaicheng Fan, Huitao Ban, Mujie Yang
Synthetic Metals 2015 Volume 199() pp:51-57
Publication Date(Web):January 2015
DOI:10.1016/j.synthmet.2014.11.009
•Bilayer humidity sensor is fabricated based on polyaniline and polyelectrolyte.•The composite sensor could sensibly detect humidity as low as 1%RH.•The composite sensor could detect humidity of full-range with high sensitivity.•The composite sensor is featured with fast response and small hysteresis.A bilayer-structured composite humidity sensor based on quaternized and crosslinked poly(4-vinylpyridine) (QC-P4VP) and polyaniline (PANI) was fabricated by depositing thin films of QC-P4VP and PANI onto interdigitated gold electrode in sequence. The composite was characterized by Fourier transform infrared spectroscopy, Ultraviolet–visible spectroscopy, scanning electron microscopy, and atomic force microscopy. The composite sensor could sensitively detect very low humidity (down to ∼1%RH) (impedance increase of ∼860% from 15% to 1%RH). Furthermore, the sensor exhibited relatively fast response (t90% of 24 s and 35 s for adsorption and desorption processes, respectively), small hysteresis (∼3%RH) and good repeatability. In addition, the composite sensor revealed impedance change close to 103 from 1% to 98%RH, suggesting its capability of detecting full-range humidity with high sensitivity. The effect of the concentration of poly(4-vinylpyridine) and PANI, deposition sequence of the sensitive layers on the humidity sensing characteristics of the composite has been examined. The humidity sensing mechanism of the composite sensor was proposed by considering the electrical properties of QC-P4VP and PANI at different humidity levels and the special bilayer structure.
Co-reporter:Yang Li, Taotao Wu, Mujie Yang
Materials Chemistry and Physics 2015 Volume 153() pp:346-352
Publication Date(Web):1 March 2015
DOI:10.1016/j.matchemphys.2015.01.024
•Bilayer-structured nanocomposite of Ag and polyelectrolyte are facilely prepared.•Nanocomposite could measure humidity as low as 1% RH and show small hysteresis.•Nanocomposite is capable of detecting full-range humidity with high sensitivity.Nanocomposites of quaternized and crosslinked poly(4-vinylpyridine) (QC-P4VP) and silver nanoparticles were prepared by a two-step procedure, and characterized by Fourier-transform infrared spectroscopy, Ultraviolet–visible spectroscopy and scanning electron microscopy. Bilayer-structured humidity sensors based on the nanocomposites were fabricated, and the effects of the concentration of silver salt precursor and poly(4-vinylpyridine), the method for the reduction of silver salt, the deposition order of the sensitive layers and environmental temperature on the humidity sensing characteristics of the composite sensor have been examined at room temperature. The composite sensor exhibited low impedance under dry atmosphere due to the introduction of Ag nanoparticles, and could detect very low relative humidity (RH) (down to 1% RH) with good sensitivity (impedance change of 2000% from 1% to 30% RH). In addition, the composite sensor demonstrated very wide measuring range (1–98% RH), and revealed faster response and smaller hysteresis than the sensor based on QC-P4VP alone. The complex impedance spectra of the composite sensor in the environments with different RH levels were investigated to explore its humidity sensing mechanism.
Co-reporter:Yang Li, Chao Deng, Mujie Yang
Sensors and Actuators B: Chemical 2014 194() pp: 51-58
Publication Date(Web):
DOI:10.1016/j.snb.2013.12.080
Co-reporter:Yang Li;Dan Luo ;Mujie Yang
Journal of Applied Polymer Science 2013 Volume 127( Issue 3) pp:2243-2250
Publication Date(Web):
DOI:10.1002/app.37936
Abstract
Multiwalled carbon nanotubes (MWCNTs) were functionalized with α,ω-diamino poly(propylene oxide) (Jeffamine) of different molecular weights and crosslinked with poly(acrylonitrile-co-glycidyl methacrylate) [P(AN-GMA)] to prepare a novel nanocomposite for applications in gel polymer electrolytes (GPEs). The synthesized copolymer was characterized by 1H-NMR, Fourier transform infrared, and thermal analysis. Scanning electron microscope observation revealed that the Jeffamine-functionalized MWCNTs distributed uniformly in the nanocomposite membrane. The mechanical behaviors of the nanocomposite membranes were investigated. It was found that the crosslinked nanocomposite membranes of P(AN-GMA) and Jeffamine-functionalized MWCNTs exhibited much higher mechanical strength than the counterpart nanocomposite obtained by physical blending. Moreover, the weight content and molecular weights of Jeffamine had an effect on the mechanical properties of the nanocomposites. Differential scanning calorimeter measurements showed that the crosslinked nanocomposite membranes were amorphous. GPEs based on the nanocomposite were prepared and characterized by complex impedance measurements. The GPE based on the nanocomposite of P(AN-GMA) crosslinked with 6 wt % of MWCNTs functionalized by Jeffamine D400 showed an ionic conductivity of about 3.39 × 10−4 S cm−1 at 25°C, which is much higher than the counterpart nanocomposite of physically blended P(AN-GMA) and MWCNTs. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Co-reporter:Qianqian Lin, Yang Li, Mujie Yang
Analytica Chimica Acta 2012 Volume 748() pp:73-80
Publication Date(Web):20 October 2012
DOI:10.1016/j.aca.2012.08.041
Polyaniline (PANi) composite nanofibers were deposited on surface acoustic wave (SAW) resonator with a central frequency of 433 MHz to construct humidity sensors. Electrospun nanofibers of poly(methyl methacrylate), poly(vinyl pyrrolidone), poly(ethylene oxide), poly(vinylidene fluoride), poly(vinyl butyral) (PVB) were characterized by scanning electron microscopy, and humidity response of corresponding SAW humidity sensors were investigated. The results indicated that PVB was suitable as a matrix to form nanofibers with PANi by electrospinning (ES). Electrospun PANi/PVB nanofibers exhibited a core–sheath structure as revealed by transmittance electron microscopy. Effects of ES collection time on humidity response of SAW sensor based on PANi/PVB nanofibers were examined at room temperature. The composite nanofiber sensor exhibited very high sensitivity of ∼75 kHz/%RH from 20 to 90%RH, ultrafast response (1 s and 2 s for humidification and desiccation, respectively) and good sensing linearity. Furthermore, the sensor could detect humidity as low as 0.5%RH, suggesting its potentials for low humidity detection. Attempts were done to explain the attractive humidity sensing performance of the sensor by considering conductivity, hydrophilicity, viscoelasticity and morphology of the polymer composite nanofibers.Graphical abstractHighlights► Polyanline/poly(vinyl butyral) nanofibers are prepared by electrospinning. ► Nanofiber-based SAW humidity sensor show high sensitivity and ultrafast response. ► The SAW sensor can detect very low humidity.
Co-reporter:Qianqian Lin, Yang Li, Mujie Yang
Synthetic Metals 2012 Volume 162(Issue 24) pp:2242-2249
Publication Date(Web):31 December 2012
DOI:10.1016/j.synthmet.2012.09.026
Electrostatic layer-by-layer (LbL) self-assembly (SA) was realized with processable polyaniline prepared with polystyrene sulfonic acid as a template (PANI-PSSA) and titanium dioxide sol as the starting materials, resulting in an ultrathin film of PANI-PSSA/TiO2. The SA process was confirmed by UV–vis spectra and quartz crystal microbalance measurements. The composite ultrathin film was characterized by X-ray photoelectron spectroscopy, X-ray diffraction patterns, field-emission scanning electron microscopy, transmission electron microscopy, and atomic force microscopy. It was revealed that the content of TiO2 in the composite film was much higher than that of PANI-PSSA, and the doping level of PANI-PSSA was as high as 19.1%. Gas sensors were fabricated by depositing self-assembled ultrathin film of PANI-PSSA/TiO2 on interdigital gold electrodes, then covering another layer of PANI-PSSA via dip-coating. Electrical response to NH3 of the sensor was investigated at room temperature. Gas sensitivity of the sensor was found to closely relate to the number of self-assembled bilayers. Under optimal conditions, the sensor displayed high sensitivity (26.5% and 81.2% towards NH3 of 10 and 100 ppm, respectively), fast response (response time ∼ 1 min; recovery time ∼ 2 min), good reversibility and repeatability.Graphical abstractHighlights► Polyanline/TiO2 ultrathin film was prepared by layer-by-layer self-assembly. ► TiO2 constitutes major part of the film and polyaniline shows a high doping level. ► Self-assembled polyanline/TiO2 films were employed to fabricate gas sensors. ► Sensors exhibit highly sensitive, fast, reversible and repeatable response to NH3.
Co-reporter:Qianqian Lin, Yang Li, Mujie Yang
Sensors and Actuators B: Chemical 2012 s 171–172() pp: 309-314
Publication Date(Web):
DOI:10.1016/j.snb.2012.03.082
Co-reporter:Yang Li, Chao Deng, Mujie Yang
Sensors and Actuators B: Chemical 2012 Volume 165(Issue 1) pp:7-12
Publication Date(Web):April 2012
DOI:10.1016/j.snb.2011.12.037
This paper presents a novel humidity sensor composed of a 433 MHz surface acoustic wave (SAW) resonator and an interdigitated gold electrode connected in series. The gold electrode was covered with a sensitive film of a composite of processable conductive polyaniline and polyvinyl alcohol. The frequency response of the novel SAW-impedance humidity sensor toward relative humidity (RH) was investigated at room temperature. The sensitivity of the SAW-impedance humidity sensors increased with the increase in the conductivity of the sensitive film. The sensor showed a sensitivity of ∼7.4 kHz/%RH at 30%RH, which was increased to 60 kHz/%RH at 47%RH. Moreover, such sensors exhibited short response and recovery times and good repeatability. It is worth noting that the sensor showed a linear frequency response to humidity over the range of 0.4–20%RH with a good sensitivity of ∼2 kHz/%RH, which reveals its potentials for detecting low humidity.
Co-reporter:Qianqian Lin, Yang Li, Mujie Yang
Sensors and Actuators B: Chemical 2012 173() pp: 139-147
Publication Date(Web):
DOI:10.1016/j.snb.2012.06.055
Co-reporter:Peng Li;Mujie Yang
Journal of Applied Polymer Science 2011 Volume 120( Issue 4) pp:1994-2000
Publication Date(Web):
DOI:10.1002/app.33297
Abstract
Hyperbranched polycarboxylates (HBPC) with different alkali metal cations (Li+, Na+, and K+) were prepared and characterized by 1H-NMR and thermal gravimetric analysis. Thin film humidity sensors based on HBPC and its composite with ZnO nanorods were fabricated. The morphologies of films of HBPC and the nanocomposite were investigated by atomic force microscopy, which revealed uniform distribution of ZnO nanorods in HBPC. The humidity-sensitive characteristics of HBPC and the nanocomposite were investigated at room temperature. It was found that the type of cations significantly affected the humidity-sensing behaviors of HBPC. In addition, the nanocomposite exhibited better humidity-sensitive properties than HBPC alone. Its impedance decreased for about three orders of magnitude over the range 19–97% RH, showing high sensitivity. Moreover, the nanocomposite exhibited fast response (∼ 9 and 10 s for response and recovery time between 97% RH and 33% RH, respectively) and small hysteresis (∼ 1.4% RH). The improved humidity-sensing behaviors of the nanocomposite over HPBC alone is explained by taking into account the hyperbranched structure of the polymer and the special interactions of the polymer and ZnO with water molecules. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Co-reporter:Dan Luo;Mujie Yang
Journal of Applied Polymer Science 2011 Volume 120( Issue 5) pp:2979-2984
Publication Date(Web):
DOI:10.1002/app.33363
Abstract
In this study, glycidyl methacrylate was copolymerized with poly(ethylene glycol) methyl ether methacrylate to obtain a copolymer {poly[glycidyl methacrylate–poly(ethylene glycol) methyl ether methacrylate] [P(GMA–PEGMA)]}, which was crosslinked with α,ω-diamino poly(propylene oxide) (Jeffamine) at various weight ratios and molecular weights to form novel gel polymer electrolytes (GPEs). The crosslinked copolymers were characterized by Fourier transform infrared spectroscopy and thermal analysis. The crosslinked polymers were amorphous in the pristine state and became crystallized after they were doped with lithium electrolyte. Furthermore, the crosslinking degree of the crosslinked polymers increased with increasing weight ratio of Jeffamine, and both the swelling properties and mechanical behaviors of the crosslinked polymers were heavily affected by the weight ratio and molecular weight of Jeffamine. The ionic conductivity (σ) of the GPEs from the crosslinked copolymers was determined by alternating-current impedance spectroscopy. A higher molecular weight and increased weight ratio of Jeffamine resulted in a higher σ. The GPE based on P(GMA–PEGMA) crosslinked with an equal weight of Jeffamine D2000 exhibited the highest σ of 8.29 × 10−4 S/cm at 25°C and had a moderate mechanical strength. These crosslinked copolymers could be potential candidates for the construction of rechargeable lithium batteries. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Co-reporter:Jichang Feng;Cong Zhang;Mujie Yang
Journal of Applied Polymer Science 2011 Volume 121( Issue 1) pp:217-225
Publication Date(Web):
DOI:10.1002/app.33527
Abstract
Two new hyperbranched fluorescent conjugated polymers containing pyridine units were synthesized via Heck coupling reaction and Sonogashira coupling reaction, respectively, and characterized by 1H NMR, 13C NMR, FTIR, and GPC. The copolymers are readily soluble in common organic solvents such as chloroform, THF, and DMF. Thermal analysis revealed that the copolymers had good thermal stability. The fluorescence quenching behaviors of the hyperbranched copolymers by metal ions were studied. It was found that the fluorescence of the copolymers can be effectively quenched by Pd2+. Moreover, the two hyperbranched copolymers exhibited different quenching efficiency, which may be related to difference in the hindrance for the chelation of pyridine unit with metal ions of the two polymers. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Co-reporter:Dan Luo, Yang Li, Mujie Yang
Materials Chemistry and Physics 2011 Volume 125(1–2) pp:231-235
Publication Date(Web):1 January 2011
DOI:10.1016/j.matchemphys.2010.09.012
Novel gel polymer electrolytes (GPEs) based on poly(acrylonitrile–glycidyl methacrylate) (P(AN–GMA)) crosslinked with α,ω-diamino poly(propylene oxide) (Jeffamine) of various weight ratios and molecular weights have been prepared, and the crosslinked polymers were characterized by FT-IR and thermal analysis. It is revealed that the crosslinked polymers were amorphous in pristine state and became crystallized when doped with lithium electrolyte. Their swelling properties and mechanical behaviors were investigated and found to be heavily affected by the weight ratio and molecular weight of Jeffamine. The effect of weight ratios and molecular weights of Jeffamine on the ionic conductivity of the GPEs based on the crosslinked polymers were determined by AC impedance spectroscopy. GPEs consisting of Jeffamine of higher molecular weights and increased weight ratios showed higher ionic conductivity. The GPE based on P(AN–GMA) crosslinked with Jeffamine D2000 at a weight ratio of 1.5 exhibited the highest ionic conductivity of 8.23 × 10−4 S cm−1 at 25 °C, and preserved a moderate mechanical strength. The crosslinked polymers can be potential candidates for the construction of rechargeable lithium batteries.
Co-reporter:Guoqiang Zhang, Hao Xu, Kuan Liu, Yang Li, Ligong Yang, Mujie Yang
Synthetic Metals 2010 Volume 160(17–18) pp:1945-1952
Publication Date(Web):September 2010
DOI:10.1016/j.synthmet.2010.07.014
Three new diketopyrrolopyrrole (DPP)-containing poly(phenylene vinylene)s varying at N-alkyl or 3,6-aryl substituents in DPP units, abbreviated as C6DPPDHPV, C6DTDPPDHPV, and C62DTDPPDHPV, were designed to comparatively study the structural effects on their photophysical, electrochemical properties, molecular organization and photovoltaic properties. The polymers exhibited remarkably broad UV–vis absorption spectra covering a major part of the wavelength range of visible light in the solar spectrum, and small bandgaps between 1.4 and 1.9 eV. X-ray diffraction and cyclic voltammetry measurements revealed that N-alkyl and 3,6-aryl in DPP unit played a key role in tuning their molecular organization as well as electrochemical behavior. The bulk heterojunction photovoltaic devices employing the three polymers as electron donors, together with PC61BM as electron acceptor, were examined. C6DPPDHPV based device showed the highest energy conversion efficiency of 0.72%. Lower hole mobilities and relatively higher HOMO energy levels may be responsible for inferior performance of C6DTDPPDHPV and C62DTDPPDHPV-based devices. Moreover, the C6DPPDHPV was preliminarily evaluated as active material in organic thin film transistor.
Co-reporter:Yang Li, Bangyu Ying, Lijie Hong, Mujie Yang
Synthetic Metals 2010 Volume 160(5–6) pp:455-461
Publication Date(Web):March 2010
DOI:10.1016/j.synthmet.2009.11.031
Water-soluble polyaniline (PANi) was prepared by a “green” method with poly (stryrenesulfonic acid) (PSSA) as a template, and characterized by UV–vis spectroscopy, FT-IR spectroscopy, transmission electron microscopy (TEM) and atomic force microscopy (AFM). It was found that the films of PANi and its composite with poly(vinyl alcohol) (PVA) were composed of nanoparticles. The humidity sensitive properties of the both PANi and its composite with PVA were investigated at room temperature. The water-soluble PANi exhibited high sensitivity (impedance change over three orders of magnitude in the range of 15–97%RH) and good sensing linearity on a semi-logarithmic scale, but a relatively large hysteresis of ∼8%RH. In contrast, the composite of PANi and PVA showed a very small hysteresis of ∼2%RH. Moreover, the response was fast and highly reversible. The humidity sensing mechanism of the composite of PANi with PVA was explored by measuring its complex impedance spectra under different humidities.
Co-reporter:Dan Luo;Peng Li;Mujie Yang
Journal of Applied Polymer Science 2010 Volume 118( Issue 3) pp:1527-1533
Publication Date(Web):
DOI:10.1002/app.32502
Abstract
Amphiphilic conetwork–structured copolymers containing different lengths of ethylene oxide (EO) chains as ionophilic units and methyl methacrylate (MMA) chains as ionophobic units were prepared by free radical copolymerization and characterized by FTIR and thermal analysis. Polymer gel electrolytes based on the copolymers complexed with liquid lithium electrolytes (dimethyl carbonate (DMC) : diethyl carbonate (DEC) : ethylene carbonate (EC) = 1 : 1 : 1 (W/W/W), LiPF6 1.0M) were characterized by differential scanning calorimetry and impedance spectroscopy. A maximum ion conductivity of 4.27 × 10−4 S/cm at 25oC was found for the polymer electrolyte based on (PEG2000-b-GMA)-co-MMA with long EO groups. Moreover, the effect of temperature on conductivity of the amphiphilic polymer electrolytes obeys the Arrhenius equation. The good room temperature conductivity of the polymer electrolytes is proposed to relate to the enhancement in the amorphous domain of the copolymers due to their amphiphilic conetwork structure. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Co-reporter:Lijie Hong, Yang Li, Mujie Yang
Sensors and Actuators B: Chemical 2010 Volume 145(Issue 1) pp:25-31
Publication Date(Web):4 March 2010
DOI:10.1016/j.snb.2009.11.057
A nanocomposite of polypyrrole (Ppy) and palladium was fabricated by a facile method involving thermal dynamic refluxing of palladium salt and encapsulation of Pd nanoclusters with Ppy by vapor phase polymerization. The composite film was characterized using transmission electron microscopy and atomic force microscopy. It was found that the morphologies of the composite film were heavily affected by concentration and ratio of the reactants, polymerization time and polymer additives. The nanocomposite showed a response magnitude of 13.9–58.9% towards NH3 gas of 50–2000 ppm at room temperature, which is higher than that of Ppy alone by a factor of two. Moreover, the electrical response was reversible, reproducible and fast, with response and recovery times of 14 s and 148 s for 1000 ppm NH3, respectively. Gas sensory properties of the nanocomposite greatly depended on the size of Pd nanoparticles and the morphology of the composite film.
Co-reporter:Jichang Feng, Yang Li, Mujie Yang
Sensors and Actuators B: Chemical 2010 Volume 145(Issue 1) pp:438-443
Publication Date(Web):4 March 2010
DOI:10.1016/j.snb.2009.12.056
Conjugated polymer-grafted silica nanoparticles were prepared by Sonogashira coupling reaction involving a two-step procedure. The resulting conjugated polymer-grafted silica nanoparticles were characterized by infrared spectroscopy, thermogravimetric analysis, transmission electron microscopy, and absorption and fluorescence spectroscopy. The conjugated polymer-grafted silica nanoparticles are highly fluorescent, and the fluorescent response of the nanoparticles of different size towards electron-deficient trinitrotoluene (TNT) was studied by examining how the steady state fluorescence intensity changes with the concentration of TNT. The conjugated polymer-grafted silica nanoparticles show high sensitivity toward TNT, with a detection limit down to 1 μM.
Co-reporter:Yang Li, Peng Li, Mujie Yang, Sheng Lei, Yuquan Chen, Xishan Guo
Sensors and Actuators B: Chemical 2010 Volume 145(Issue 1) pp:516-520
Publication Date(Web):4 March 2010
DOI:10.1016/j.snb.2009.12.062
Co-reporter:Guoqiang Zhang;Kuan Liu;Mujie Yang
Polymer International 2009 Volume 58( Issue 6) pp:665-673
Publication Date(Web):
DOI:10.1002/pi.2576
Abstract
BACKGROUND: Polymer-based light emitting diodes (PLEDs) have received considerable attention as they combine the good mechanical and processing properties of polymers with semiconducting behavior, and can be easily fabricated as flexible devices. To obtain high-performance PLED materials by balancing the carrier injection of poly(phenylene ethynylene)s (PPEs), polymers containing two aryl-heterocyclic rings, namely diketopyrrolopyrrole (DPP) or triphenylpyrazoline (TPP), have been synthesized and investigated.
RESULTS: PPE-type polymers containing DPP or TPP units were synthesized using Heck–Sonogashira coupling methodology and characterized by 1H NMR, Fourier transform infrared and UV-visible spectroscopies, elemental analysis, gel permeation chromatography, photoluminescence (PL), X-ray diffraction, thermogravimetic analysis and cyclic voltammetry. The polymers obtained are easily soluble in common solvents and form smooth and uniform films. They are yellow or red emitters as revealed by PL. In addition, they show large Stokes shifts, which is in agreement with their twisted molecular structures determined via quantum chemical calculations.
CONCLUSION: PPE-type polymers containing DPP or TPP units were successfully synthesized by coupling polymerization. They exhibit band gaps of 1.73 and 2.37 eV, respectively, and show potential as PLED materials. In addition, DPP-containing polymers with a very low band gap could be applied as potential photovoltaic materials. Copyright © 2009 Society of Chemical Industry
Co-reporter:Guoqiang Zhang, Kuan Liu, Haijun Fan, Yang Li, Xiaowei Zhan, Yongfang Li, Mujie Yang
Synthetic Metals 2009 Volume 159(19–20) pp:1991-1995
Publication Date(Web):October 2009
DOI:10.1016/j.synthmet.2009.07.005
The photovoltaic behaviors of diketopyrrolopyrrole (DPP) embedded poly(phenylenevinylene) (C8-DPP-PPV) and poly(phenyleneethynylene) (C10-DPP-PPE) were investigated. The two polymers exhibited good solubility in common organic solvents, high thermal stability and broad UV/visible absorption ranging from 300 to 600 nm in films. Their optical band gaps were found to be 1.94 eV for C8-DPP-PPV and 2.05 eV for C10-DPP-PPE. Moreover, their HOMO energy levels were relatively low at around −5.6 to −5.8 eV as estimated by electrochemical measurements. The polymer/PCBM bulk heterojunction solar cells exhibited a power conversion efficiency of 0.16% for C10-DPP-PPE. In addition, all-polymer solar cells consisting of C10-DPP-PPE/P3HT were also fabricated in view of the potential of C10-DPP-PPE as a polymeric acceptor, revealing an efficiency of 0.01%.
Co-reporter:Peng Li, Yang Li, Lijie Hong, Yousi Chen, Mujie Yang
Materials Chemistry and Physics 2009 Volume 115(Issue 1) pp:395-399
Publication Date(Web):15 May 2009
DOI:10.1016/j.matchemphys.2008.12.010
Poly(dimethylaminoethyl methacrylate) and poly(glycidyl methacrylate) were simultaneously cross-linked to form a polyelectrolyte humidity sensitive film on an interdigitated gold electrode, which was further coated with a layer of soluble polyaniline (PANI). The composite so prepared was characterized by UV–vis spectroscopy and scanning electron microscopy. Its electrical response towards humidity was investigated at room temperature and compared with that of PANI and the polyelectrolyte separately. It was revealed that the composite showed an impedance as low as 1.8 × 105 Ω even at 0%RH. In contrast, the impedance of the polyelectrolyte at less than 20%RH was too high to be measured, and PANI showed very low humidity sensitivity. The low impedance, good sensitivity as characterized by a linear change in impedance from 1.8 × 105 to 9 × 103 Ω over 0–95%RH, fast response and small hysteresis, makes the composite a promising candidate for humidity sensors capable of detecting very low humidity.
Co-reporter:Xin Lv, Yang Li, Peng Li, Mujie Yang
Sensors and Actuators B: Chemical 2009 Volume 135(Issue 2) pp:581-586
Publication Date(Web):15 January 2009
DOI:10.1016/j.snb.2008.10.008
2-(Dimethylamino) ethyl methacrylate was quaternized with n-butyl bromide and then copolymerized with 1,4-divinylbenzene to obtain a resistive-type crosslinked polyelectrolyte humidity sensitive material by UV irradiation at low temperature (≤60 °C) in a short time (<1 h). The humidity sensor based on the crosslinked polyelectrolyte was aged by immersion in water for 5 min to remove water-soluble materials. The aged sensor exhibited a high sensitivity (impedance change from ∼107 to 103 Ω in the humidity range of 22–97% RH), small hysteresis (∼1% RH) and fast response (t90% ∼9 and 32 s for adsorption and desorption between 33% RH and 97% RH, respectively). In addition, it showed good durability as indicated by slight impedance change after immersion in water. The effects of molar ratio of crosslinking agent to quaternary ammonium salt, UV irradiation time and environment temperature on its humidity sensing properties were investigated.
Co-reporter:Peng Li, Yang Li, Bangyu Ying, Mujie Yang
Sensors and Actuators B: Chemical 2009 Volume 141(Issue 2) pp:390-395
Publication Date(Web):7 September 2009
DOI:10.1016/j.snb.2009.07.006
Co-reporter:Kuan Liu, Yang Li, Guoqiang Zhang, Xin Lv, Mujie Yang
Sensors and Actuators B: Chemical 2009 Volume 135(Issue 2) pp:597-602
Publication Date(Web):15 January 2009
DOI:10.1016/j.snb.2008.09.052
A cationic conjugated polymer based on poly(phenylene vinylene) was prepared by Glich dehydrohalogenation polymerization. The structure of the polymer was characterized by 1H NMR, Fourier transformed infrared spectroscopy, UV–visible spectroscopy, photoluminescent spectroscopy and thermogravimetric analysis. The polymer was deposited on interdigitated gold electrodes by dip-coating, and its electrical responses to humidity were investigated at room temperature over the range of 22–97%RH. It was found that the polymer exhibited a high sensitivity, as characterized by impedance change almost linearly on a semi-logarithmic scale from 107 to 104 Ω when humidity decreased from 22 to 97%RH. In addition, fast response (t90% ∼7 s and ∼5 s for absorption and desorption, respectively) and moderate hysteresis (∼6%RH) were observed. It is proposed that both the pendant ionic group of the cationic conjugated polymer and the π-conjugated backbone affected its humidity sensing behaviors.
Co-reporter:Yang Li, Lijie Hong, Mujie Yang
Talanta 2008 Volume 75(Issue 2) pp:412-417
Publication Date(Web):15 April 2008
DOI:10.1016/j.talanta.2007.11.032
Poly(4-vinylpyridine) was crosslinked and quaternized with 1,4-bromobutane to form a polyelectrolyte humidity sensitive film on an interdigitated gold electrode, which was further coated with a layer of polypyrrole by a facile method of vapor phase polymerization. The composite so prepared was characterized by UV–vis spectroscopy and scanning electron microscopy. The investigations on the humidity sensitive properties of the composite revealed that it exhibited an impedance as low as 105 Ω even at 0%RH due to the existence of intrinsic conducting polypyrrole, thus conquering the difficulties in measuring low humidity with resistive-type humidity sensors. The impedance of the composite changed linearly with humidity in the range of 0–60%RH with good sensitivity. In addition, its response time (t90%) for adsorption and desorption between 33% and 97%RH was estimated to be 33 s and 110 s, respectively, and a hysteresis of 5%RH was observed. All these suggest it is promising as a sensitive material for low humidity detection. The effect of concentration and ratio of oxidizing agent to doping agent, polymerization temperature of pyrrole on the humidity sensitive properties of the composite have been investigated. A sensitive mechanism of the composite was proposed by taking into account the contribution of both the intrinsic electronic conduction and ionic conduction.
Co-reporter:Shanzuo Ji, Yang Li, Mujie Yang
Sensors and Actuators B: Chemical 2008 Volume 133(Issue 2) pp:644-649
Publication Date(Web):12 August 2008
DOI:10.1016/j.snb.2008.03.040
Poly(methyl methacrylate) (PMMA) nanofibers with different diameters were fabricated by electrospinning and their composites with polyaniline (PANI) were formed by virtue of in situ solution polymerization. The coaxial composite nanofibers so prepared were then transferred to the surface of a gold interdigitated electrode to construct a gas sensor. The structure and morphology of the PANI/PMMA composite fibers were characterized by UV–vis spectroscopy and scanning electron microscopy, which indicated that the coaxial nanofibres of PANI emeraldine salt and PMMA were successfully prepared. The electrical responses of the gas sensor based on the composite nanofibres towards triethylamine (TEA) vapors were investigated at room temperature. It was revealed that the sensor showed a sensing magnitude as high as 77 towards TEA vapor of 500 ppm. In addition, the responses were linear, reversible and reproducible towards TEA vapors ranging from 20 to 500 ppm. The diameters of the electrospun PMMA fibers had an effect on the sensing magnitude of the gas sensor, which is proposed to relate to the difference in the surface-to-volume ratio of the fibers. Furthermore, it was found that the concentration of doping acids only led to changes in resistance of the sensor, but could not affect its sensing characteristics. In contrast, the nature of the doping acids was determinative for the sensing magnitude of the sensor. The gas sensor with toluene sulfonic acid as the doping acid exhibited the highest sensing magnitude, which is explained by taking into account of the sensing mechanism and the interactions of doping acids with TEA vapor.
Co-reporter:Yang Li, Huicai Wang, Yousi Chen, Mujie Yang
Sensors and Actuators B: Chemical 2008 Volume 132(Issue 1) pp:155-158
Publication Date(Web):28 May 2008
DOI:10.1016/j.snb.2008.01.034
A composite of palladium and multi-walled carbon nanotubes was prepared by a simple method of reducing their aqueous mixtures with NaBH4. The morphology of the composite was investigated by transmission electron microscopy and atomic force microscopy. The electrical responses of the composite to methane were measured at room temperature. It exhibited a response magnitude of ∼4.5% towards 2% methane at room temperature. In addition, the responses were highly reversible and reproducible, suggesting its potential as a candidate for the room temperature detection of methane.
Co-reporter:H.C. Wang, Y. Li, M.J. Yang
Sensors and Actuators B: Chemical 2006 Volume 119(Issue 2) pp:380-383
Publication Date(Web):7 December 2006
DOI:10.1016/j.snb.2005.12.037
SnO2 thin film gas sensors operating at room temperature were prepared with SnCl4 as the starting material. The gas sensing characteristics of the sensors towards methyl alcohol vapor were investigated. The sensors exhibit ultra-fast and reversible electrical response (t90% ∼5 s for response and ∼1 s for recovery) at room temperature. In addition, the electrical responses are reproducible during cycling tests. The particle size of the hydrolyzed SnCl4 affects the sensitivity of the sensors, but does not have much effect on their response time. The sensors show different electrical response in the detection of the vapors of methyl, ethyl, isopropyl and butyl alcohol at room temperature, which is proposed to be related to the variation in the reducing ability of the alcohols with a different number of methyl groups.
Co-reporter:Y. Li, X.Y. Cheng, M.Y. Leung, J. Tsang, X.M. Tao, M.C.W. Yuen
Synthetic Metals 2005 Volume 155(Issue 1) pp:89-94
Publication Date(Web):15 October 2005
DOI:10.1016/j.synthmet.2005.06.008
Conductive-polymer coated fabrics have been investigated as intelligent materials in the past years. In this paper, a flexible strain sensor from polypyrrole-coated fabrics which is featured with high sensitivity, good stability is reported. The strategies used for enhancing the sensitivity and stability of the sensor include: (a) the formation of thin coatings of polypyrrole (PPy) on the surface of fabrics using the chemical vapor deposition (CVD) method, (b) low temperature polymerization of pyrrole, (c) introduction of large docecyl benzene sulfonate anion in PPy film and (d) annealing of the PPy-coated conductive fabrics. The conductivity–strain tests reveal that the developed sensor exhibits a high strain sensitivity of ∼80 for a deformation as large as 50%, while its good stability is supported by the small changes in conductivity and sensitivity over a storage time of 9 months. The effect of the temperature and humidity on the conductivity of the strain sensor is investigated.
Co-reporter:Huicai Wang, Yang Li, Yousi Chen, Mingyong Yuan, Mujie Yang, Wa Yuan
Reactive and Functional Polymers (October 2007) Volume 67(Issue 10) pp:977-985
Publication Date(Web):October 2007
DOI:10.1016/j.reactfunctpolym.2007.05.021
Co-reporter:Yang Li, Huijie Zhao, Huitao Ban, Mujie Yang
Sensors and Actuators B: Chemical (June 2017) Volume 245() pp:34-43
Publication Date(Web):June 2017
DOI:10.1016/j.snb.2017.01.103
Co-reporter:Shanzuo Ji, Yang Li, Mujie Yang
Sensors and Actuators B: Chemical (12 August 2008) Volume 133(Issue 2) pp:644-649
Publication Date(Web):12 August 2008
DOI:10.1016/j.snb.2008.03.040
Poly(methyl methacrylate) (PMMA) nanofibers with different diameters were fabricated by electrospinning and their composites with polyaniline (PANI) were formed by virtue of in situ solution polymerization. The coaxial composite nanofibers so prepared were then transferred to the surface of a gold interdigitated electrode to construct a gas sensor. The structure and morphology of the PANI/PMMA composite fibers were characterized by UV–vis spectroscopy and scanning electron microscopy, which indicated that the coaxial nanofibres of PANI emeraldine salt and PMMA were successfully prepared. The electrical responses of the gas sensor based on the composite nanofibres towards triethylamine (TEA) vapors were investigated at room temperature. It was revealed that the sensor showed a sensing magnitude as high as 77 towards TEA vapor of 500 ppm. In addition, the responses were linear, reversible and reproducible towards TEA vapors ranging from 20 to 500 ppm. The diameters of the electrospun PMMA fibers had an effect on the sensing magnitude of the gas sensor, which is proposed to relate to the difference in the surface-to-volume ratio of the fibers. Furthermore, it was found that the concentration of doping acids only led to changes in resistance of the sensor, but could not affect its sensing characteristics. In contrast, the nature of the doping acids was determinative for the sensing magnitude of the sensor. The gas sensor with toluene sulfonic acid as the doping acid exhibited the highest sensing magnitude, which is explained by taking into account of the sensing mechanism and the interactions of doping acids with TEA vapor.
.jpg)
![Ethanamine, 2-[2-[2-(2-azidoethoxy)ethoxy]ethoxy]-](/data/chemimg/114300/134179-38-7.png)
![Ethanamine, 2-[2-[2-(2-azidoethoxy)ethoxy]ethoxy]-](/data/chemimg/114300/134179-38-7_b.png)
![Acetic acid,2,2'-[1,2-phenylenebis(oxy)]bis-, 1,1'-dimethyl ester](http://img.cochemist.com/ccimg/27700/27648-87-9.png)
![Acetic acid,2,2'-[1,2-phenylenebis(oxy)]bis-, 1,1'-dimethyl ester](http://img.cochemist.com/ccimg/27700/27648-87-9_b.png)
![Indolo[2',3':3,4]pyrido[2,1-b]quinazolin-5(7H)-one,8,13,13b,14-tetrahydro-14-methyl- (6CI,9CI)](http://img.cochemist.com/ccimg/6000/5956-87-6.png)
![Indolo[2',3':3,4]pyrido[2,1-b]quinazolin-5(7H)-one,8,13,13b,14-tetrahydro-14-methyl- (6CI,9CI)](http://img.cochemist.com/ccimg/6000/5956-87-6_b.png)
![9-Octadecenoic acid(9Z)-, 1,1'-[2-[(1-oxohexadecyl)oxy]-1,3-propanediyl] ester](http://img.cochemist.com/ccimg/1800/1716-07-0.png)
![9-Octadecenoic acid(9Z)-, 1,1'-[2-[(1-oxohexadecyl)oxy]-1,3-propanediyl] ester](http://img.cochemist.com/ccimg/1800/1716-07-0_b.png)
![3,6-Bis(5-bromothiophen-2-yl)-2,5-dihexylpyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione](http://img.cochemist.com/ccimg/1215000/1214906-01-0.png)
![3,6-Bis(5-bromothiophen-2-yl)-2,5-dihexylpyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione](http://img.cochemist.com/ccimg/1215000/1214906-01-0_b.png)
![Pyrrolo[3,4-c]pyrrole-1,4-dione, 3,6-bis(5-bromo-2-thienyl)-2,5-bis(2-ethylhexyl)-2,5-dihydro-](/data/chemimg/139400/1000623-95-9.png)
![Pyrrolo[3,4-c]pyrrole-1,4-dione, 3,6-bis(5-bromo-2-thienyl)-2,5-bis(2-ethylhexyl)-2,5-dihydro-](/data/chemimg/139400/1000623-95-9_b.png)
![1-Propanesulfonic acid, 3,3'-[(2,5-diiodo-1,4-phenylene)bis(oxy)]bis-, sodium salt (1:2)](http://img.cochemist.com/data/images/856676-42-1.png)
![1-Propanesulfonic acid, 3,3'-[(2,5-diiodo-1,4-phenylene)bis(oxy)]bis-, sodium salt (1:2)](http://img.cochemist.com/data/images/856676-42-1_b.png)
![Pyridine, 2,5-bis[(trimethylsilyl)ethynyl]-](http://img.cochemist.com/ccimg/172900/172883-67-9.png)
![Pyridine, 2,5-bis[(trimethylsilyl)ethynyl]-](http://img.cochemist.com/ccimg/172900/172883-67-9_b.png)
![2-Propen-1-one, 1-[4-(dimethylamino)phenyl]-3-(3-pyridinyl)-](http://img.cochemist.com/ccimg/142300/142227-79-0.png)
![2-Propen-1-one, 1-[4-(dimethylamino)phenyl]-3-(3-pyridinyl)-](http://img.cochemist.com/ccimg/142300/142227-79-0_b.png)
![Poly[oxy(1-oxo-1,6-hexanediyl)]](http://img.cochemist.com/ccimg/25300/25248-42-4.png)
![Poly[oxy(1-oxo-1,6-hexanediyl)]](http://img.cochemist.com/ccimg/25300/25248-42-4_b.png)
