Kun Jia

Name:

Organization: University of Electronic Science and Technology of China

Department: Research Branch of Advanced Functional Materials, High Temperature Resistant Polymer and Composites Key Laboratory of Sichuan Province, School of Microelectronics and Solid-State Electronics

Title:

TOPICS

Material Chemistry

Carbon Nanotubes

Chemicals
References

Large scale synthesis of an amorphous polyester elastomer with tunable mechanoluminescence and preliminary application in optical strain sensing

Co-reporter:Hongguo Shou;Xin Zhou;Lingqiang Gao;Xiaohong He;Xuefei Zhou;Dawei Zhang;Xiaobo Liu

Journal of Materials Chemistry C 2017 vol. 5(Issue 17) pp:4134-4138

Publication Date(Web):2017/05/04

DOI:10.1039/C7TC00433H

In this work, a transparent thermoplastic elastomer, showing blue emission upon UV light excitation, has been synthesized via the block copolymerization of an amorphous polyester oligomer and flexible polyethylene glycol (PEG) on an industrial scale. Specifically, an alicyclic glycol named 1,4-cyclohexanedimethanol (CHDM) was introduced into the esterification of purified terephthalic acid (PTA) and ethylene glycol (EG) to synthesize the oligomer of glycol-modified polyethylene terephthalate (PETG), which was subsequently copolymerized with PEG to finally obtain the transparent thermoplastic elastomer. It should be noted that CHDM is found to break macromolecular regularity, which leads to the amorphous nature of the obtained copolyester. The flexible PEG not only contributes to the elasticity of the copolyester, but also in situ decomposes it into fluorescent carbon nanodots during polymerization, which finally endows the obtained elastomer with fluorescence that can be modulated by different mechanical stress (i.e. stretching and relaxing). Therefore, we have fabricated a prototype of a reusable strain sensor using the developed elastomer owing to its reversible mechanoluminescence.

Crystallized polyarylene ether nitrile blends with improved thermal, mechanical, dielectric properties, and processability

Co-reporter:

Polymer Composites 2017 Volume 38(Issue 1) pp:126-131

Publication Date(Web):2017/01/01

DOI:10.1002/pc.23567

In this work, the biphenol polyarylether nitrile (BP-PEN) films with improved processability were prepared by blending low molecular weight (LMW) with high molecular weight (HMW) of BP-PEN. The hybrid membrane exhibited excellent thermal stability and mechanical strength. The Tid values of the films were as high as 505°C–522°C. Melting behavior studies indicated that the crystallinity of LMW BP-PEN was higher than that of HMW, which was confirmed by the X-ray diffraction (XRD) patterns analysis as well. Scanning electron microscope (SEM) provided additional information on morphology and phase adhesion. Additionally, the polymer crystallinity dependent on dielectric properties of blends films is reported. Most importantly, it is found that the combination of LMW and HMW BP-PEN would be an effective method to simultaneously increase the mechanical, thermal, dielectric properties, and polymer processability. POLYM. COMPOS., 38:126–131, 2017. © 2015 Society of Plastics Engineers

CTAB induced emission from water soluble polyarylene ether nitrile carboxylate and selective sensing of Fe (III) ions

Co-reporter:Shiliang Wei, Kun Jia, Hongguo Shou, Xuefei Zhou, Pan Wang, Xiaobo Liu

Chemical Physics Letters 2017 Volume 678(Volume 678) pp:

Publication Date(Web):16 June 2017

DOI:10.1016/j.cplett.2017.04.007

•Water soluble polyarylene ether nitriles (PEN) are synthesized.•Fluorescence of ionic PEN in aqueous solution can be enhanced by CTAB.•The emission of PEN@CTAB colloids can be selectively quenched by Fe (III) ions.Polyarylene ether nitrile (PEN) is traditionally used as high performance thermoplastics in various advanced engineering materials fields. However, the preparation of optically active PEN based materials, especially in aqueous solution, is still a great challenge. In this work, the side chain carboxylated PEN can be readily dissolved in alkaline solution but showing strongly quenched luminescence. Fortunately, the cationic surfactant of cetyltrimethylammonium bromide (CTAB) was able to recover the fluorescence emission of water soluble PEN, which can be subsequently quenched by Fe3+ ions, leading to the selective determination of Fe3+ ions in aqueous solution.Download high-res image (105KB)Download full-size image

Novel cross-linked membrane for direct methanol fuel cell application: sulfonated poly(ether ether nitrile)s

Co-reporter:Penglun Zheng;Mingzhen Xu;Xiaobo Liu

Ionics 2017 Volume 23( Issue 1) pp:87-94

Publication Date(Web):2017 January

DOI:10.1007/s11581-016-1805-z

In order to reduce water uptake, swelling ratio, and methanol permeability in sulfonated proton exchange membranes (PEM), novel-sulfonated aromatic poly(ether ether nitrile)s-bearing pendant propenyl groups had been synthesized by direct copolymerization method. All the results showed that the propenyl groups were suitable cross-linkable groups, and that this method was an effective way to overcome the drawbacks of sulfonated polymers at high ion exchange capacity (IEC) values. By cross-linking, the water uptake, swelling ratio, and methanol diffusion could be restricted owing to the formation of compact network structure. For example, CSPEN-60 membranes showed the proton conductivity of 0.072 S cm−1 at 80 °C, while the swelling ratios and water uptake (17.9 and 60.7 %) were much lower than that of the SPEN-60 membrane (60.8 and 295.2 %). Meanwhile, a 1.1 × 10−7 cm2 s−1 of methanol diffusion was obtained which was much lower than that of Nafion 117 (14.1 × 10−7 cm2 s−1). Although the proton conductivity of the CSPEN-60 membranes is lower than that of the SPEN-60 membrane, the selectivity is much higher. The CSPEN-60 membrane exhibited the highest selectivity among the tested membranes, about 5.8 times higher compared with that of Nafion117.

Cross-linked sulfonated poly(arylene ether nitrile)s with high selectivity for proton exchange membranes

Co-reporter:Penglun Zheng, Jingchun Liu, Xiaobo Liu, Kun Jia

Solid State Ionics 2017 Volume 303(Volume 303) pp:

Publication Date(Web):1 May 2017

DOI:10.1016/j.ssi.2017.03.001

•The cross-linked membranes were prepared by simply thermal curing.•The sulfonic acid groups do not take part in the cross-linking reaction.•The nitrile groups can enhance intermolecular interaction.•All cross-linked membranes exhibit lower methanol permeability than that of Nafion117.•The selectivity of cross-linked CSPEN-70 membrane about 5 times higher compared with Nafion117.For the purpose of prepare a high performance proton exchange membrane with low methanol permeability and high proton conductivity, a sulfonated poly(arylene ether nitrile)s (SPEN) with carboxyl groups were synthesized. Then the cross-linked membranes were prepared by simply thermal curing in which the polymer network structures were covalent cross-linked. The chemical structures of the cross-linked membranes were characterized by Fourier transform infrared analysis. The resulting cross-linked membranes can effectively reduce water uptake, swelling ratio and methanol permeability. Among the cross-linked membranes, CSPEN-70 exhibits low water uptake, low swelling ratio (135.4% and 23.8% at 80 °C, respectively) and low methanol permeability coefficient (3.23 × 10− 7 cm2·s− 1), while maintaining proton conductivity of 0.148 S·cm− 1. More importantly, the selectivity of cross-linked CSPEN-70 is about 5 times higher than that of Nafion117. All the data prove that the cross-linked membranes may be potential proton exchange membrane for the direct methanol fuel cells (DMFCs) application.

Unification of molecular NIR fluorescence and aggregation-induced blue emission via novel dendritic zinc phthalocyanines

Co-reporter:Lin Pan;Hongguo Shou;Xuefei Zhou;Pan Wang

Journal of Materials Science 2017 Volume 52( Issue 6) pp:3402-3418

Publication Date(Web):29 November 2016

DOI:10.1007/s10853-016-0628-7

In this work, novel dendritic zinc phthalocyanines showing both molecular NIR fluorescence and aggregation-induced emission characteristics have been successfully synthesized via a two-step reaction on the basis of bisphthalonitrile precursors with different electron donor–conjugation–acceptor (D–π–A) structures. The luminescent properties of the resultant dendritic zinc phthalocyanines were fully investigated in N, N-dimethylformamide (DMF) solution, in DMF/H2O mixed solvent, in the solid state as well as polymethylmethacrylate composite film. The dendritic zinc phthalocyanines substituted with hydroquinone, naphthalenediol, or dihydroxybiphenyl moieties exhibited an unusual luminescence changes from highly near infrared (NIR) emitting in molecular state to strongly blue fluorescence in aggregated state as well as solid state, where the maximum fluorescent emission wavelength and highest quantum yield were detected from dendritic zinc phthalocyanines containing naphthalenediol and dihydroxybiphenyl groups, respectively. On the contrary, dendritic zinc phthalocyanines bearing diphenylmethane or bisphenol A units only exhibit NIR fluorescent emission in their molecular state. The distinct fluorescent emissions for these dendritic zinc phthalocyanines are rationalized in the framework of molecular configuration and electron density distribution as clarified by density functional theory (DFT) calculation. Moreover, the well-organized three-dimensional microspheres composed of abundant rod-like building blocks were discovered via the self-assembly of dendritic zinc phthalocyanine molecules in DMF/H2O (50/50 vol%) mixture.

Au nanorods modulated NIR fluorescence and singlet oxygen generation of water soluble dendritic zinc phthalocyanine

Co-reporter:Xuefei Zhou, Xiaohong He, Shiliang Wei, Kun Jia, Xiaobo Liu

Journal of Colloid and Interface Science 2016 Volume 482() pp:252-259

Publication Date(Web):15 November 2016

DOI:10.1016/j.jcis.2016.07.072

A novel cyano-terminated zinc phthalocyanine (ZnPc-CN) exhibiting visible near infrared (vis-NIR) emitting around 690 nm in N,N-dimethylformamide (DMF) solvent has been synthesized. Furthermore, the peripheral cyano groups of newly synthesized zinc phthalocyanine were hydrolyzed in strong basic solution, leading to water soluble carboxylated zinc phthalocyanine (ZnPc-COOH) with completely quenched fluorescence in aqueous solution. Interestingly, we found that the NIR fluorescence of aqueous ZnPc-COOH was dramatically recovered in the presence of gold nanorods (Au NR), which was due to the alternation of ZnPc-COOH molecules self-assembling via electrostatic interaction between cetyltrimethylammonium bromide (CTAB) on the surface of Au NR and peripheral carboxyl of ZnPc-COOH. In addition, ZnPc-COOH/Au NR conjugates demonstrated an improved singlet oxygen generation, which could be served as potential bioimaging probe and photosensitizer for photodynamic therapy.

Chain conformation dependent fluorescence of blue-emitting poly(arylene ether nitrile)

Co-reporter:Pan Wang, Lingyi Zhao, Hongguo Shou, Jiayi Wang, Lin Pan, Kun Jia, Xiaobo Liu

Journal of Luminescence 2016 Volume 179() pp:622-628

Publication Date(Web):November 2016

DOI:10.1016/j.jlumin.2016.07.063

Poly(arylene ether nitrile) (PEN) containing phenolphthalin moiety is an intrinsically blue-emitting fluorescent polymer with outstanding mechanical and thermal properties. Herein, the fluorescent properties of the fluorescent PEN (FPEN) have been, for the first time, correlated with the conformation manipulation of polymer chain that is enabled by the variation of concentration, molecular weight, polydispersity and aggregation states in solvent-nonsolvent system. The experimental results indicate that the fluorescent emission of FPEN is highly dependent on concentration, with the strongest fluorescence detected at a critical concentration in N,N-dimethylformamide (DMF). In the lower concentration range, where the polymer intermolecular interaction is minimized, the PEN fluorescence is mainly dependent on the molecular weight and local chain organization. On the contrary, the polydispersity index of FPEN plays a dominate role in the fluorescent emission when the concentration is higher than 50 mg mL−1.

Enhanced microscopic nonlinear optical properties of novel Y-type chromophores with dual electron donor groups

Co-reporter:Xiang Tang, Lin Pan, Kun Jia, Xianzhong Tang

Chemical Physics Letters 2016 Volume 648() pp:114-118

Publication Date(Web):16 March 2016

DOI:10.1016/j.cplett.2016.02.001

•Novel Y-type NLO chromophores containing dual donor groups were synthesized.•‘Total charge transfer’ from HOMO to LUMO of Y-type chromophores was discovered.•NLO properties of chromophores were enhanced due to efficient charge transfer.In this Letter, novel Y-type chromophores with dual electron donor groups, containing either styryl or azobenzene based π-conjugated bridge structures, were synthesized and their chemical structures, molecular configuration, microscopic optical properties as well as thermal properties were systematically characterized. The experimental results indicated that eight times increasing of second-order molecular hyperpolarizability as well as 50–100 nm blue shift of maximum absorption band for azobenzene based chromophore were observed by introducing Y-type dual electron donor groups, which was derived from the highly efficient ‘total charge transfer’ in this kind of chromophore as confirmed by the density functional theory calculation.

Incorporation of polyethylene glycol into polyethylene terephthalate towards blue emitting co-polyester

Co-reporter:Xiaohong He, Xuefei Zhou, Kun Jia, Dawei Zhang, Hongguo Shou, Xiaobo Liu

Materials Letters 2016 Volume 182() pp:367-371

Publication Date(Web):1 November 2016

DOI:10.1016/j.matlet.2016.07.022

•Fluorescent carbon dots were synthesized via thermal decomposition of PEG.•PET-PEG copolymer with good roughness and blue luminescence was prepared.•Crystalline behaviour of PET was obviously alternated by PEG modification.In this work, fluorescent co-polyester was prepared by incorporating polyethylene glycol (PEG) segment into backbone of polyethylene terephthalate (PET). The crystalline structures and fluorescence properties of obtained PET-PEG copolymers were systematically studied. It was found that the crystalline behaviour of PET was significantly alternated after incorporation of flexible PEG segment, meanwhile the ultrasmall sized carbon dots with blue emitting luminescence can be obtained from incorporated PEG segment, which contributed to the fluorescence property of resultant PET-PEG co-polyester solution and fiber.

Facile fabrication of white-emitting hybrid colloids and nanocomposite films using CdSe/CdS quantum dots and zinc phthalocyanines as building blocks

Co-reporter:Liting Yuan, Lin Pan, Kun Jia, Yiyao Liu, Zengfang Huang, Yumin Huang, Xiaobo Liu

Synthetic Metals 2016 Volume 218() pp:9-18

Publication Date(Web):August 2016

DOI:10.1016/j.synthmet.2016.04.030

•Zinc phthalocyanine (ZnPc) with emission bands at ∼450 nm and 690 nm was synthesized.•Green emitting CdSe/CdS quantum dots were obtained and assembled with ZnPc.•White-emitting colloids and flexible nanocomposites were successfully prepared.In this work, we have designed a facile protocol to prepare white emitting colloid solutions and polymer nanocomposite films via the self-assembly of zinc phthalocyanine (ZnPc) in the presence of semiconductor CdSe/CdS quantum dots (QD). Specifically, a dendritic zinc phthalocyanine showing two independent emission bands at blue (∼450 nm) and red region (∼690 nm) in N, N-dimethylformamide (DMF) solution was synthesized by using a biphenyl phthalonitrile based precursor. In order to fulfill the missing green emission band and overcome the strong intermolecular aggregation tendency of ZnPc that normally results to obviously quenched fluorescence in solution, an ultrasmall sized CdSe/CdS QD with green emitting capabilities, was synthesized, surface modified with a hydrophobic capping agent (oleic acid) and dispersed uniformly in nonpolar hexane. When the hexane solution of QD was introduced to the immiscible ZnPc solution in DMF, nanoconjugates exhibiting three independent emission bands can be formulated by using ZnPc and QD as building blocks via the non-covalent hydrophobic interaction established in the incompatible DMF/hexane interface. Furthermore, the white emitting ZnPc/QD colloid solutions and nanocomposite films can be readily obtained by controlling the relative concentration of ZnPc and QD.

Effect of surface functionalization on the properties (rheological, mechanical, and dielectric) and microtopography of PEN/CPEN-f-CNTs nanocomposites

Co-reporter:Zejun Pu;Penglun Zheng;Xiaobo Liu

Polymer Composites 2016 Volume 37( Issue 9) pp:2622-2631

Publication Date(Web):

DOI:10.1002/pc.23456

Novel carboxylic poly(arylene ether nitrile)s (CPEN) functionalized carbon nanotubes (CPEN-f-CNTs) were successfully prepared by a simple and effective solvent–thermal route. The CPEN-f-CNTs were subsequently used as the novel filler for preparation of high performance poly(arylene ether nitrile)s (PEN) nanocomposites. The SEM characterization of the PEN nanocomposites revealed that the CPEN-f-CNTs present better dispersion and interfacial compatibility in the PEN matrix, which was confirmed by the linear rheological analysis (Cole–Cole plots) as well. Consequently, the improved thermal stability (increased initial and maximum decomposition temperature) and enhanced mechanical properties (tensile strength and modulus) were obtained from nanocomposites using CPEN-f-CNTs. More importantly, the PEN/CPEN-f-CNTs nanocomposites not only show a high dielectric constant but also have low dielectric loss. For example, a dielectric constant of 39.7 and a dielectric loss of 0.076 were observed in the PEN composite with 5 wt% CPEN-f-CNTs loading at 100 Hz. Therefore, the flexible PEN/CPEN-f-CNTs nanocomposites with outstanding mechanical, thermal and dielectric properties will find wide application in the high energy density capacitors. POLYM. COMPOS., 37:2622–2631, 2016. © 2015 Society of Plastics Engineers

Curing behaviors and properties of allyl- and benzoxazine-functional phthalonitrile with improved processability

Co-reporter:Xingqiang Zou;Xulin Yang;Mingzhen Xu;Xiaobo Liu

Journal of Polymer Research 2016 Volume 23( Issue 1) pp:

Publication Date(Web):2016 January

DOI:10.1007/s10965-015-0891-3

Allyl-functional phthalonitrile monomer (DBPA-Ph) was blended with the phthalonitrile containing benzoxazine (BPNBZ) to achieve good processing property with low curing viscosity. The processing behavior of BPNBZ/DBPA-Ph system was studied by differential scanning calorimetric analysis (DSC) and dynamic rheological analysis. The result indicated that the BPNBZ/DBPA-Ph system exhibited relatively low viscosity, good reactivity and processing property. The similar thermal and thermo- stabilities of DBPA-Ph and BPNBZ polymer endued the BPNBZ/DBPA-Ph system stable thermal (T5% ≥ 437 °C) and thermo- stabilities (T5% ≥ 449 °C) with the change of BPNBZ content. Compared with the poor mechanical property of pure DBPA-Ph/GF composites, the introduction of BPNBZ enhanced the mechanical property of BPNBZ/DBPA-Ph/GF composites distinctly, especially at low curing temperature. Therefore, the low viscosity, good polymerization property, stable thermal and thermo- stabilities and improved mechanical property indicated wider application for DBPA-Ph polymer.

Effect of elevated annealing temperature on electrical conductivity and magnetic properties of iron phthalocyanine polymer

Co-reporter:Zicheng Wang;Xiaobo Liu

Journal of Polymer Research 2016 Volume 23( Issue 3) pp:

Publication Date(Web):2016 March

DOI:10.1007/s10965-016-0940-6

A novel iron phthaocyanine (FePc) polymer was prepared via the polymerization of phthalonitrile with ferrous chloride and investigated for morphology, crystallinity, conductivity, dielectric and magnetic properties at different annealing temperatures from 300 °C to 700 °C. The results showed that the elevating annealing temperature could significantly change the morphology and microstructure of FePc polymer, leading to the formation of the turbostratic carbon, α-Fe phase and cemetite, and enhance electrical conductivity and magnetic properties. It was worth noting that the dramatic transition of conductivity, dielectric and magnetic properties appeared when the annealing temperature was 550 °C. The electrical conductivity of the samples exhibited a transition of electrical behavior from an insulator to semiconductor. And the saturation and remanent magnetization of the annealed FePc polymer increased from 0.24 to 6.18 emu/g and from 0.03 to 2.38 emu/g, respectively. The pyrolysis of FePc polymer annealed at high temperature was believed to become a good way to get electrical or magnetic materials.

Facile synthesis of luminescent silver nanoparticles and fluorescence interactions with blue-emitting polyarylene ether nitrile

Co-reporter:Kun Jia, Pan Wang, Liting Yuan, Xuefei Zhou, Wenjin Chen and Xiaobo Liu

Journal of Materials Chemistry A 2015 vol. 3(Issue 15) pp:3522-3529

Publication Date(Web):05 Feb 2015

DOI:10.1039/C4TC02850C

In this work, fluorescent silver nanoparticles were synthesized in an organic phase via a facile one-step reaction. Their fluorescence emission is dependent on the excitation wavelength and can be effectively enhanced by a blue emitting intrinsic fluorescent polymer called polyarylene ether nitrile (PEN) via a resonance energy transfer process, which is confirmed by the time-correlated photoluminescence decay measurement and steady-state fluorescence spectroscopy. Specifically, luminescent Ag nanoparticles were synthesized by reducing silver nitrate (AgNO3) with polyvinylpyrrolidone (PVP) in N,N-dimethylformamide (DMF) solvent under a nitrogen atmosphere. It was found that obvious surface plasmon resonance combined with weak fluorescence under UV irradiation was observed from as-synthesized Ag nanoparticle stock solution. The larger sized silver nanoparticles (Ag NPs, 20 ± 4 nm) were responsible for the plasmonic extinction peak at 415 nm, while the weak fluorescence emission at around 550 nm was attributed to the presence of ultra-small silver nanostructures. Furthermore, the dramatically enhanced fluorescence was observed from smaller Ag nanoparticles (6 ± 2 nm) in the supernatant by removing the excess large sized Ag nanoparticles via high speed centrifugation. More interestingly, the purified smaller Ag nanoparticles showed an excitation wavelength dependent fluorescence emission profile, and their fluorescence under appropriate excitation can be further enhanced via the resonance energy transfer process from the energy donor of a blue emitting aromatic polymer that shows good spectral overlap with luminescent silver nanoparticles.

Sulfonated carbon nanotubes synergistically enhanced the proton conductivity of sulfonated polyarylene ether nitriles

Co-reporter:M. N. Feng, Z. J. Pu, P. L. Zheng, K. Jia and X. B. Liu

RSC Advances 2015 vol. 5(Issue 43) pp:34372-34376

Publication Date(Web):08 Apr 2015

DOI:10.1039/C5RA03973H

The addition of a small amount of sulfonated multi-walled carbon nanotubes (3 wt%) to a sulfonated polyarylene ether nitriles (SPEN) proton exchange membrane using an acyl chloride method was proved to be an effective way to improve the mechanical behaviour and proton conductivity performance.

Effect of SiO2 grafted MWCNTs on the mechanical and dielectric properties of PEN composite films

Co-reporter:Fei Jin, Mengna Feng, Xu Huang, Cheng Long, Kun Jia, Xiaobo Liu

Applied Surface Science 2015 Volume 357(Part A) pp:704-711

Publication Date(Web):1 December 2015

DOI:10.1016/j.apsusc.2015.09.086

Highlights

•: MWCNTs were grafted successfully by SiO₂.
•: The surface modified MWCNTs-SiO₂/PEN composite films possess high mechanical properties and excellent dielectric properties.
•: The composites containing such two deferent nanoscale materials were researched by TEM and SEM.
•: The interface adhesion was characterized by rheological test.

One-pot synthesis of Au/Ag bimetallic nanoparticles to modulate the emission of CdSe/CdS quantum dots

Co-reporter:Kun Jia, Liting Yuan, Xuefei Zhou, Lin Pan, Pan Wang, Wenjin Chen and Xiaobo Liu

RSC Advances 2015 vol. 5(Issue 72) pp:58163-58170

Publication Date(Web):25 Jun 2015

DOI:10.1039/C5RA08933F

In this work, gold/silver bimetallic nanoparticles (Au/Ag NPs) have been synthesized via a facile one-pot protocol involving co-reduction of chloroauric acid and silver nitrate with N,N-dimethylformamide (DMF) solvent in the presence of water soluble polyvinylpyrrolidone (PVP). The morphology of obtained Au/Ag NPs can be readily modified by changing the reaction time and relative concentration ratio of the gold/silver precursors. Subsequently, the synthesized Au/Ag NPs have been employed to modulate the fluorescent emission of CdSe/CdS quantum dots (QD) in the solution phase on the basis of plasmon controlled fluorescence. The experimental results demonstrated that the fluorescent emission of CdSe/CdS QD can be either obviously quenched or enhanced, depending on the spectral overlap and local distance control between CdSe/CdS QD and Au/Ag bimetallic NPs. Specifically, the as-synthesized Au/Ag NPs significantly quenched the fluorescent emission of CdSe/CdS QD and the quenching effect was enhanced when the plasmonic wavelength of Au/Ag NPs was tuned towards the fluorescent emission wavelength of the CdSe/CdS QD. On the contrary, the fluorescent emission of CdSe/CdS QD can be obviously enhanced in the presence of SiO2 coated Au/Ag NPs with appropriate layer thickness.

Influence of hyperbranched copper phthalocyanine grafted carbon nanotubes on the dielectric and rheological properties of polyarylene ether nitriles

Co-reporter:Zejun Pu, Lifen Tong, Mengna Feng, Kun Jia and Xiaobo Liu

RSC Advances 2015 vol. 5(Issue 88) pp:72028-72036

Publication Date(Web):18 Aug 2015

DOI:10.1039/C5RA13232K

Novel hyperbranched copper phthalocyanine covalently grafted carbon nanotube/polyarylene ether nitrile (HBCuPc-CNT/PAEN) flexile composite films were prepared via solution casting. The CNTs are enwrapped by a functional intermediate HBCuPc thin layer which forms a rough shell on the surface of the CNTs to ensure a good dispersion of CNTs in the PAEN matrix. The dielectric layer (HBCuPc-CNTs) is intercalated by insulating layers (pure PAEN, acting as the isolating layer). Due to the high capacitance of the dielectric layer and the effective blocking of the mobility of free charge carriers by the insulating layers, the polymer-based composite films exhibit not only a high permittivity but also an extremely low dielectric loss and excellent breakdown strength. SEM images show that HBCuPc-CNTs are perfectly embedded in the matrix and no pull-out phenomenon can be observed. In addition, the rheological properties of the resulting composite films also indicate that the grafted CNTs present a good dispersion and strong interactions with the PAEN resin, thus resulting in a significant improvement of the mechanical and thermal properties of the PAEN composite films.

Plasmon enhanced fluorescence of a bisphthalonitrile-based dye via a dopamine mediated interfacial crosslinking reaction on silver nanoparticles

Co-reporter:Kun Jia, Xuefei Zhou, Lin Pan, Liting Yuan, Pan Wang, Chunhui Wu, Yumin Huang and Xiaobo Liu

RSC Advances 2015 vol. 5(Issue 88) pp:71652-71657

Publication Date(Web):18 Aug 2015

DOI:10.1039/C5RA12242B

A fluorescent dye of a phenolphthalein derivative containing bisphthalonitrile groups was synthesized and subsequently chemically grafted onto dopamine modified silver nanoparticles via the interfacial crosslinking reaction, leading to enhanced fluorescent emission of dye molecules in a solution phase. Specifically, the non-fluorescent phenolphthalein (PP) molecule was end-capped with bisphthalonitrile (BPH) groups through nucleophilic substitution to obtain a violet/blue-emitting fluorescent dye PP-BPH due to the restriction of inter-molecular rotation. Furthermore, the PP-BPH dye can be immobilized on the surface of the dopamine modified silver nanoparticles, given the fact that bisphthalonitrile based monomers can be readily crosslinked in the presence of aromatic amine or phenol compounds (i.e. dopamine). Consequently, the fluorescent emission of the PP-BPH dye can be further enhanced via the plasmonic enhancement effects of silver nanoparticles. The preliminary results obtained in this communication will pave the way for the plasmon controlled photonic properties of PP-BPH based multifunctional polymers.

Novel polyarylene ether nitrile nanofibrous mats with fluorescence and controllable surface morphology

Co-reporter:Penglun Zheng, Hailong Tang, Kun Jia, Xiaobo Liu

Materials Letters 2015 Volume 156() pp:32-35

Publication Date(Web):1 October 2015

DOI:10.1016/j.matlet.2015.04.117

A novel series of fluorescent polyarylene ether nitrile (PEN) copolymers were successfully synthesized via nucleophilic aromatic substitution polymerization reaction from 2,6-dichlorobenzonitrile, 4, 4-Bis(4-hydroxyphenyl)valeric acid and biphenol. The obtained carboxylated PENs exhibit tunable fluorescent emission depending on the backbone structures of the copolymer. Most importantly, nanoporous mats were fabricated by electrospinning the synthesized PEN copolymers in the presence of water-soluble polyvinylpyrrolidone (PVP), followed by a selective removing PVP from washing with H2O in postelectrospinning progress. Thanks to their nanoscale porous structures and tunable fluorescent emission, the prepared PEN nano-fibers would find potential applications in chemosensing.

Effective thermal conductivity and thermal properties of phthalonitrile-terminated poly(arylene ether nitriles) composites with hybrid functionalized alumina

Co-reporter:Mengdie Liu;Xiaobo Liu

Journal of Applied Polymer Science 2015 Volume 132( Issue 10) pp:

Publication Date(Web):

DOI:10.1002/app.41595

ABSTRACT

A polymer-based thermal conductive composite has been developed. It is based on a dispersion of micro- and nanosized alumina (Al₂O₃) in the phthalonitrile-terminated poly (arylene ether nitriles) (PEN-t-ph) via solution casting method. The Al₂O₃ with different particle sizes were functionalized with phthalocyanine (Pc) which was used as coupling agent to improve the compatibility of Al₂O₃ and PEN-t-ph matrix. The content of microsized functionalized Al₂O₃ (m-f-Al₂O₃) maintained at 30 wt % to form the main thermally conductive path in the composites, and the nanosized functionalized Al₂O₃ (n-f-Al₂O₃) act as connection role to provide additional channels for the heat flow. The thermal conductivity of the f-Al₂O₃/PEN-t-ph composites were investigated as a function of n-f-Al₂O₃ loading. Also, a remarkable improvement of the thermal conductivity from 0.206 to 0.467 W/mK was achieved at 30 wt % n-f-Al₂O₃ loading, which is nearly 2.7-fold higher than that of pure PEN-t-ph polymer. Furthermore, the mechanical testing reveals that the tensile strength increased from 99 MPa for pure PEN-t-ph to 105 MPa for composites with 30 wt % m-f-Al₂O₃ filler loading. In addition, the PEN-t-ph composites possess excellent thermal properties with glass transition temperature (T_g) above 184°C, and initial degradation temperature (T_id) over 490°C. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41595.

Phthalonitrile end-capped polyarylene ether nitrile: crystals embedded in matrix through crosslinking reaction

Co-reporter:Lifen Tong;Xiaobo Liu

Polymer International 2015 Volume 64( Issue 10) pp:1361-1365

Publication Date(Web):

DOI:10.1002/pi.4924

Abstract

A novel single-component composite based on phthalonitrile end-capped polyarylene ether nitrile (PEN-Ph) which undergoes a crosslinking reaction combined with crystallization behavior has been prepared successfully by hot compressing. The project focuses on studying the influence of the processing temperature and curing time on the crosslinking reaction and crystallization behavior. Differential scanning calorimetry analysis indicates that the crosslinking degree increases with an increase of processing temperature and curing time. In contrast, the crystallinity increases first and then decreases as the curing time increases, owing to the effect of the restriction of the crosslinking reaction on the crystallization behavior. Thermal polarizing microscope images provide direct evidence for crystal formation as a result of crosslinking reaction. Moreover, through comparative analysis of amorphous and crystallized PEN-Ph sheets, the conclusion is drawn that the glass transition temperature and mechanical properties are affected by not only the degree of crosslinking but also by the crystallinity. © 2015 Society of Chemical Industry

In situ fabrication of MWCNTs reinforce dielectric performances of polyarylene ether nitrile nanocomposite

Co-reporter:Mengna Feng;Fei Jin;Xu Huang

Journal of Materials Science: Materials in Electronics 2015 Volume 26( Issue 1) pp:1-10

Publication Date(Web):2015 January

DOI:10.1007/s10854-014-2355-7

In this report, the dielectric properties of polyarylene ether nitrile (PEN)/multi-walled carbon nanotubes (MWCNTs) polymer composites were reinforced via in situ fabrication protocol for MWCNTs. The silanized MWCNTs were surface grafted with phenolphthalin (PPL), which is also one monomer involved in PEN synthesis. This is the premise for PPL can initiate cross-link behavior with the complex PEN and we called it as reactive MWCNTs. Therefore, the composite of PEN and reactive MWCNTs was readily fabricated by solution-casting method and the performance of this unique system was characterized by a range of different techniques. Fourier transform infrared spectroscopy confirmed that the MWCNTs have been bonded with PPL and silane functionalization agent. Based on the observation of scanning electron microscope, it was noted that the forming of reactive MWCNTs could improve the dispersion interfacial compatibility of PEN/MWCNTs nanocomposites. Consequently, the dielectric properties were improved, as lower dielectric loss and higher dielectric constant simultaneously obtained using reactive MWCNTs filler. Moreover, the results of thermal and mechanical performance tests provided additional evidences that the reactive MWCNTs synthesized via in situ fabrication can better reinforce PEN nanocomposites.

Introducing magnetic-responsive CNT/Fe3O4 composites to enhance the mechanical properties of sulfonated poly(arylene ether nitrile) proton-exchange membranes

Co-reporter:Mengna Feng;Fanbin Meng;Zejun Pu;Xiaobo Liu

Journal of Polymer Research 2015 Volume 22( Issue 3) pp:

Publication Date(Web):2015 March

DOI:10.1007/s10965-015-0682-x

To study the effect of magnetic-responsive CNT/Fe3O4 particles on the mechanical properties and proton conductivity of sulfonated poly(arylene ether nitrile) (SPEN) proton exchange membranes, a series of composite membranes consisting of magnetic carbon nanotube/iron oxide (CNT/Fe3O4) hybrid particles and SPEN were successfully fabricated using a solution casting method, and their proton conductivity and thermal and mechanical properties were investigated. To explore the effect of the orientation of magnetic CNT/Fe3O4 hybrid particles on proton exchange membranes, a magnetic field was applied beneath the casting membrane. Thermal analysis showed good thermal stability, with 5 % weight loss at temperatures in the range of 309 to 324 °C, and the mechanical properties of the composites were enhanced with increasing CNT/Fe3O4 content. Proton conductivity increased as the content of [CNT/Fe3O4] hybrid particle content regardless of the orientation or random distribution of CNTs, while the proton conductivity of SPENH membranes decreased slightly in the presence of a magnetic field. Therefore, we believe that these membranes would find potential applications as proton exchange membranes due to their enhanced mechanical strength and thermal stability.

Enhanced crystallinity, mechanical and dielectric properties of biphenyl polyarylene ether nitriles by unidirectional hot-stretching

Co-reporter:Yong You;Xu Huang;Zejun Pu;Xiaobo Liu

Journal of Polymer Research 2015 Volume 22( Issue 11) pp:

Publication Date(Web):2015 November

DOI:10.1007/s10965-015-0859-3

In this work, biphenyl polyarylene ether nitrile (BP-PEN) was synthesized via a solution nucleophilic aromatic substitution polymerization of biphenyl (BP) with 2, 6-dichlorobenzonitrile (DCBN). BP-PEN films were prepared by solution-casting process and then were unidirectional stretched with different ratios (0, 50, 100, 150 and 200 %) under high temperature (280, 300 and 320 °C) to enhance their crystallinity and degree of orientation. Results showed that the thermal, mechanical, crystallinity and dielectric properties of the BP-PEN films were significantly enhanced after the unidirectional hot-stretching process. The glass transition temperatures (Tg) of the films hot-stretched at 280 °C range from 214.2 to 218.2 °C and melting point was in the range from 330.4 to 346.3 °C. Besides, the percent crystallinity of them was increased from 4.92 to 19.16 %. Moreover the tensile strength and modulus of them increased from 121 to 451 MPa and from 1943 to 4938 MPa, respectively. Compared with BP-PEN films without stretch treatment, the dielectric constant of the film stretched at 280 °C also increased from 4.0 to 6.7 (1 kHz).

Electrospun fluorescent polyarylene ether nitrile nanofibrous mats and application as an adsorbent for Cu2+ removal

Co-reporter:Penglun Zheng;Shizhao Shen;Zejun Pu;Xiaobo Liu

Fibers and Polymers 2015 Volume 16( Issue 10) pp:2215-2222

Publication Date(Web):2015 October

DOI:10.1007/s12221-015-5425-4

Polyarylene ether nitrile (PEN) nanofibrous mat was fabricated by using the electrospinning technique and activated by using NaOH solution. The adsorption capacity of the activated PEN nanofibrous mat was evaluated using Cu2+ as the model hazardous metal ions. The effects of the contact time and the initial concentration of Cu2+ solution (C0) on the adsorption capacity of the mat were investigated. The adsorption kinetics was better described by the pseudo-second order equation, and the adsorption isotherm was better fitted for the Langmuir equation. Furthermore, the nanofibrous mat possesses the potential of regeneration and reuse. All of the results in this paper show that the PEN nanofibers produced via the electrospinning technique have excellent adsorbent properties toward Cu2+ ions.

Tuning of polyarylene ether nitrile emission profile by using red-emitting gold nanoclusters via fluorescence resonance energy transfer

Co-reporter:P. Wang, L. T. Yuan, X. Huang, W. J. Chen, K. Jia and X. B. Liu

RSC Advances 2014 vol. 4(Issue 87) pp:46541-46544

Publication Date(Web):18 Sep 2014

DOI:10.1039/C4RA07350A

Fluorescence resonance energy transfer (FRET) between blue fluorescent polyarylene ether nitrile (PEN) and red-emitting gold nanoclusters (Au NCs) has been firstly reported in this work. Consequently, the emission profile of PEN can be readily tuned depending on the loading content of Au NCs.

Synthesis, polymerization, and properties of the allyl-functional phthalonitrile

Co-reporter:Xingqiang Zou;Mingzhen Xu;Xiaobo Liu

Journal of Applied Polymer Science 2014 Volume 131( Issue 23) pp:

Publication Date(Web):

DOI:10.1002/app.41203

ABSTRACT

A novel bisphthalonitrile monomer containing allyl groups (DBPA-Ph) had been synthesized via the reaction of diallyl bisphenol A (DBPA) and 4-nitrophthalonitrile. The chemical structure of DBPA-Ph was confirmed by ¹HNMR, ¹³CNMR, and FTIR spectroscopy. The curing behaviors and processability of DBPA-Ph were studied by differential scanning calorimetry (DSC) and dynamic rheological analysis. The monomer manifested a two-stage thermal polymerization pattern. The first stage was attributed to the polymerization of allyl groups and the second to the ring-form polymerization of cyano groups. The result of dynamic rheological analysis indicated the monomer had wide curing window and the self-catalyzed curing behavior. DBPA-Ph polymers were prepared from the thermal polymerization with short curing time, showing high glass transition temperature (>350°C) and attractive thermal decomposition temperature (>430°C). The outstanding glass transition temperature, desirable thermo-oxidative stabilities, good processability and sound process conditions could provide more applications to the DBPA-Ph polymers. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41203.

Size dependent electromagnetic properties of Fe3O4 nanospheres

Co-reporter:Kun Jia, Jiandong Zhang, Xu Huang, Xiaobo Liu

Chemical Physics Letters 2014 Volume 614() pp:31-35

Publication Date(Web):20 October 2014

DOI:10.1016/j.cplett.2014.09.002

Large scale synthesis of an amorphous polyester elastomer with tunable mechanoluminescence and preliminary application in optical strain sensing

Co-reporter:Hongguo Shou, Kun Jia, Xin Zhou, Lingqiang Gao, Xiaohong He, Xuefei Zhou, Dawei Zhang and Xiaobo Liu

Journal of Materials Chemistry A 2017 - vol. 5(Issue 17) pp:NaN4138-4138

Publication Date(Web):2017/03/24

DOI:10.1039/C7TC00433H

Facile synthesis of luminescent silver nanoparticles and fluorescence interactions with blue-emitting polyarylene ether nitrile

Co-reporter:Kun Jia, Pan Wang, Liting Yuan, Xuefei Zhou, Wenjin Chen and Xiaobo Liu