Co-reporter:Yiwu Liu;Zhuxin Zhou;Lunjun Qu;Bing Zou;Zhiquan Chen;Yi Zhang;Siwei Liu;Zhenguo Chi;Xudong Chen
Materials Chemistry Frontiers 2017 vol. 1(Issue 2) pp:326-337
Publication Date(Web):2017/02/16
DOI:10.1039/C6QM00027D
A series of high-performance multifunctional polyimides with exceptional thermostability and solubility (Tg as high as 494 °C and, at the same time, well soluble in common organic solvents) were successfully designed and synthesized by introducing a typical aromatic rigid trifluoromethyl-containing moiety with special non-planar and conjugated characteristics into the polymer backbone. Additionally, these polyimides show light color (one even colorlessness) and transparency, intrinsic ultralow dielectric constant (k, k ≈ 1.93), and electrical bistability characteristics (ON/OFF ratio as high as 107, working voltage as low as 1.5 V) simultaneously. The excellent thermal stability and solubility allow them to undergo the high temperature process (over 400 °C) in the preparation of photoelectric devices (like PVD or PECVD), or the highly efficient, continuous roll-to-roll process. The as-synthesized polymers are ideal potential candidates for practical applications in the fields of ultra-large-scale integration (ULSI), high-performance polymer memory devices, flexible displays, thin film PV industries, and wearable electronics.
Co-reporter:Bingjia Xu, Jiajun He, Yingxiao Mu, Qiangzhong Zhu, Sikai Wu, Yifan Wang, Yi Zhang, Chongjun Jin, Changcheng Lo, Zhenguo Chi, Alan Lien, Siwei Liu and Jiarui Xu
Chemical Science 2015 vol. 6(Issue 5) pp:3236-3241
Publication Date(Web):18 Mar 2015
DOI:10.1039/C5SC00466G
Organic materials exhibiting mechanoluminescence (ML) are promising for usage in displays, lighting and sensing. However, the mechanism for ML generation remains unclear, and the light-emitting performance of organic ML materials in the solid state has been severely limited by an aggregation-caused quenching (ACQ) effect. Herein, we present two strongly photoluminescent polymorphs (i.e., Cg and Cb) with distinctly different ML activities based on a tetraphenylethene derivative P4TA. As an aggregation-induced emission (AIE) emitter, P4TA perfectly surmounted the ACQ, making the resultant block-like crystals in the Cg phase exhibit brilliant green ML under daylight at room temperature. The ML-inactive prism-like crystals Cb can also have their ML turned on by transitioning toward Cg with the aid of dichloromethane vapor. Moreover, the Cg polymorph shows ML and mechanochromism simultaneously and respectively without and with UV irradiation under a force stimulus, thus suggesting a feasible design direction for the development of efficient and multifunctional ML materials.
Co-reporter:Shidang Xu;Dr. Tingting Liu;Dr. Yingxiao Mu;Dr. Yi-Fan Wang; Zhenguo Chi;Dr. Chang-Cheng Lo; Siwei Liu; Yi Zhang;Dr. Alan Lien; Jiarui Xu
Angewandte Chemie International Edition 2015 Volume 54( Issue 3) pp:874-878
Publication Date(Web):
DOI:10.1002/anie.201409767
Abstract
Compounds displaying delayed fluorescence (DF), from severe concentration quenching, have limited applications as nondoped organic light-emitting diodes and material sciences. As a nondoped fluorescent emitter, aggregation-induced emission (AIE) materials show high emission efficiency in their aggregated states. Reported herein is an AIE-active, DF compound in which the molecular interaction is modulated, thereby promoting triplet harvesting in the solid state with a high photoluminescence quantum yield of 93.3 %, which is the highest quantum yield, to the best of our knowledge, for long-lifetime emitters. Simultaneously, the compound with asymmetric molecular structure exhibited strong mechanoluminescence (ML) without pretreatment in the solid state, thus exploiting a design and synthetic strategy to integrate the features of DF, AIE, and ML into one compound.
Co-reporter:Bingjia Xu, Jiajun He, Yang Liu, Bin Xu, Qiangzhong Zhu, Mingyuan Xie, Zebo Zheng, Zhenguo Chi, Wenjing Tian, Chongjun Jin, Fuli Zhao, Yi Zhang and Jiarui Xu
Journal of Materials Chemistry A 2014 vol. 2(Issue 17) pp:3416-3428
Publication Date(Web):22 Jan 2014
DOI:10.1039/C3TC32052A
Two novel quadrupolar D–π–D type two-photon absorption (2PA) luminophores PA2F4H8E8 and AnA2F4H8E8 were synthesized by Wittig–Horner reaction in high yields. By using distyrylbenzene as the π-bridge center, PA2F4H8E8 shows two-photon absorption aggregation-induced emission enhancement (2PA-AIEE) and exhibits exceptionally large 2PA and 2PA action cross-sections up to ∼6300 GM and ∼1400 GM at 800 nm in THF, respectively. A non-doped electroluminescent (EL) device of PA2F4H8E8 displays good performance with an extremely low turn-on voltage of 2.6 V and a high brightness of 9837 cd m−2.
Co-reporter:Yiwu Liu, Yi Zhang, Xinhui Wu, Qi Lan, Chuansen Chen, Siwei Liu, Zhenguo Chi, Long Jiang, Xudong Chen and Jiarui Xu
Journal of Materials Chemistry A 2014 vol. 2(Issue 6) pp:1068-1075
Publication Date(Web):07 Nov 2013
DOI:10.1039/C3TC31825G
We have designed and synthesized a novel deep-blue luminescent compound (WuFDA), which can emit efficiently both in solution and in the aggregated state; the fluorescence emission maximum of WuFDA in the aggregated state shows a remarkable blue-shift from that shown in the dilute solution. Moreover, WuFDA shows interesting fluorescent behaviour in mixed solvent systems of THF–H2O, and a solvent effect in different polar solvents. These unusual phenomena have been interpreted by studies of the single crystalline structure of WuFDA and density functional theory (DFT) investigations. The special chemical structure (containing a planar conjugated fluorene core and strong polar groups (–NH and –F)) and their location in the molecule formed a typical non-planar D–π–A molecule with strong internal charge transfer (ICT). Such a polar molecule possesses the ability to form hydrogen bond interactions with itself, as well as with the polar solvents. Both the ICT effect and the intermolecular hydrogen bond interactions play very important roles in the geometrical manner of aggregation and the fluorescent behaviours of the WuFDA. In addition, WuFDA exhibited good thermal stability, with 5% and 10% weight-loss temperatures (Td) of WuFDA in nitrogen of 399 and 414 °C, respectively, and the glass transition temperature (Tg) was about 161 °C.
Co-reporter:Huawei Sun, Yi Zhang, Wei Yan, Wenxin Chen, Qi Lan, Siwei Liu, Long Jiang, Zhenguo Chi, Xudong Chen and Jiarui Xu
Journal of Materials Chemistry A 2014 vol. 2(Issue 29) pp:5812-5817
Publication Date(Web):12 May 2014
DOI:10.1039/C4TC00553H
A novel ultrasonic-sensitive mechanofluorochromic AIE-compound (ITPADA) has been designed and synthesized. The fluorescent properties of the ITPADA suspensions were greatly affected by the ultrasonic treatment and extremely sensitive to its power, which show remarkable blue-shifting and enhanced emission. Moreover, perfect ITPADA nano-sheets could be obtained by facile ultrasonic treatment.
Co-reporter:Chunping Ma, Bingjia Xu, Gaoyi Xie, Jiajun He, Xie Zhou, Bangyin Peng, Long Jiang, Bin Xu, Wenjing Tian, Zhenguo Chi, Siwei Liu, Yi Zhang and Jiarui Xu
Chemical Communications 2014 vol. 50(Issue 55) pp:7374-7377
Publication Date(Web):16 May 2014
DOI:10.1039/C4CC01012D
A novel luminophore TPENSOH was facilely synthesized from the building blocks of tetraphenylethylene and 6-hydroxylbenzothiazole and exhibited unique AIE properties. This new dye was found to show a remarkable and reversible four-color switching based on a single molecule in the solid state.
Co-reporter:Yupeng Wu, Siwei Liu, Yangchun Tao, Chunping Ma, Yi Zhang, Jiarui Xu, and Yen Wei
ACS Applied Materials & Interfaces 2014 Volume 6(Issue 3) pp:1470
Publication Date(Web):January 22, 2014
DOI:10.1021/am404696u
A series of amphiphlic diblock polymers, tetraaniline block with different length of poly(N-isopropylacrylamide) (TA-b-PNIPAM), have been successfully synthesized. In a suitable solution, the as-synthesized diblock polymers can form stable large compound vesicles (LCVs) with multiple bimolecular-layer structure through self-assembly. These factors, such as the block length, different organic solvent, solvent ratio, pH value, temperature, and voltage, which affect the morphology and properties of the assembled aggregates, are systematically investigated. When the degree of polymerization of PNIPAM block is close to 10, the as-synthesized diblock polymer may form stable LCVs with the uniform size as well as few defects in the mixed solvent of dimethylformamide/water (v/v = 3:7). The assembled LCVs possess the properties of triple-responsive capacity on temperature, pH, and voltage. Variation in any of these factors can cause some changes in the morphology of LCVs. The drug release properties for doxorubicin (DOX) loaded by LCVs affected by temperature, voltage, and different pH values have been investigated. It is interesting that the structure of LCVs can be destructed completely by applying a voltage at 0.6 V. With such an advantage, the drugs loaded by the LCVs could burst release into designated place by using appropriate circuit design or instrument, thus achieving maximum efficacy of the loaded drugs or other bioactive molecules without any unnecessary chemical substances added. This approach allows us to concentrate more on material design aspects only, without regard to the complex targeting issue which is the biggest obstacle of such materials in practical applications.Keywords: drug release; large compound vesicle; multiresponse; pinpoint targeting; self-assembly; tetraaniline diblock polymer;
Co-reporter:Chunping Ma;Qingqing Ling;Shidang Xu;Hongni Zhu;Ge Zhang;Xie Zhou;Zhenguo Chi;Siwei Liu;Yi Zhang
Macromolecular Bioscience 2014 Volume 14( Issue 2) pp:235-243
Publication Date(Web):
DOI:10.1002/mabi.201300259
A series of new homopolymers with various degrees of polymerization derived from vinyl tetraphenylethene, that is, poly[2-(4-vinylphenyl)ethene-1,1,2-triyl)tribenzene] homopolymers, is synthesized by reversible addition–fragmentation chain transfer (RAFT) polymerization. The homopolymers exhibit a significant aggregation-induced emission (AIE) effect and an ability to assemble themselves into AIE polymer nanoparticles (NPs) during precipitation in a water/tetrahydrofuran (THF) mixture. The NPs also exhibit good dispersibility, stability, and biocompatibility. The AIE polymer NPs are used in imaging studies of HeLa cells.
Co-reporter:Miao Luo, Xie Zhou, Zhenguo Chi, Siwei Liu, Yi Zhang, Jiarui Xu
Dyes and Pigments 2014 Volume 101() pp:74-84
Publication Date(Web):February 2014
DOI:10.1016/j.dyepig.2013.08.026
•Two novel aggregation-induced emission compounds were synthesized.•The compounds possess different gelation behavior in organic solvents.•Their emission was reversibly changed with the gel–solution transition.•The emission color of one compound could be switched by external stimuli.•Both of them possessed mesomorphic properties.Two novel aggregation-induced emission compounds derived from tetraphenylethylene and gallic acid were synthesized and characterized. Both of the emission compounds possessed mesomorphic properties and exhibited mesomorphic phases over a wide temperature range and the thermal-induced mesomorphic transition from metastable to stable phases accompanied by a change of the luminescent color. The mesomorphic transition may be ascribed to liquid crystalline phase transition. The emission compounds possess different gelation behavior in organic solvents. The emission intensities of the emission compounds can be reversibly changed with the gel–solution transition by alternate cooling and heating. Moreover, the color and emission of these organogelators can be repeatedly switched by various external stimuli including pressing, heating and solvent-fuming. These new compounds may offer potential as external stimuli-responsive materials.
Co-reporter:Xiqi Zhang, Zhenguo Chi, Yi Zhang, Siwei Liu and Jiarui Xu
Journal of Materials Chemistry A 2013 vol. 1(Issue 21) pp:3376-3390
Publication Date(Web):13 Mar 2013
DOI:10.1039/C3TC30316K
Mechanochromic luminescent metal complexes have recently attracted considerable interest as smart materials for use in the fields of luminescence switches, mechanosensors, mechanohistory indicators, security papers, optoelectronic devices, and data storage. In this review, recent advancements in metal complex mechanochromic luminescence are summarized. The majority of the reported mechanochromic luminescent metal complex systems are discussed, including Zn(II), Au(I), Pt(II), Ag(I), Cu(I), Al(III), and Ir(III) complexes. Aggregation-induced emission (AIE) complexes are described based on the existence of a structural relationship between AIE compounds and mechanochromism. It is expected that AIE complexes may become important alternative sources of mechanochromic luminescent complexes.
Co-reporter:Caimin Feng, Yi Zhang, Dong Liang, Siwei Liu, Zhenguo Chi, Jiarui Xu
Journal of Analytical and Applied Pyrolysis 2013 Volume 104() pp:59-67
Publication Date(Web):November 2013
DOI:10.1016/j.jaap.2013.09.009
•The synergistic effects of manganese dioxide (MnO2) on the flame retardancy of the PP/IFR systems were studied.•A small amount of MnO2 could dramatically improve the flame retardancy properties of PP/IFR system.•MnO2 could change the degradation behavior and increase the char residue of the IFR and PP/IFR.•MnO2 could help to form continuous and compact intumescent char layer on the outer surface of PP/IFR.•The existence of MnO2 could promote to remain more P and O in the char layer.The flame retardancy and thermal degradation behavior of polypropylene composites containing ammonium polyphosphate (APP), novel charring agent (CNCA-DA) and manganese dioxide (MnO2) were characterized by limiting oxygen index (LOI), UL-94 measurement, cone calorimeter test (CCT), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and energy dispersive spectrometry (EDS). It was found that a small amount of MnO2 could dramatically increase the LOI value, UL rating of the PP/IFR systems, and reduce the combustion parameters of PP/IFR system from CCT test, including peak heat release rate (p-HRR), total heat release (THR), and smoke production rate (SPR). The catalytic effectivity (CAT-EFF) results showed that when 1 wt% MnO2 was added, it had the highest CAT-EFF, and could promote the LOI value of the composites from 27.1 to 30.7. The TGA data revealed that MnO2 could change the degradation behavior of the IFR and PP/IFR, improve the thermal stability of the PP/IFR systems at high temperature and increase the char residue. The morphological structures observed by digital photos and SEM indicated that MnO2 could effectively help to form more continuous and compact intumescent char layer on the outer surface to protect the underlying materials from burning. The EDS results illustrated that the existence of MnO2 could promote to remain more P and O in the char layer.
Co-reporter:Caimin Feng;Yi Zhang;Siwei Liu;Zhenguo Chi
Polymers for Advanced Technologies 2013 Volume 24( Issue 5) pp:478-486
Publication Date(Web):
DOI:10.1002/pat.3108
The synergistic effects of 4A zeolite (4A) on the thermal degradation, flame retardancy and char formation of a novel halogen-free intumescent flame retardant polypropylene composites (PP/IFR) were investigated by the means of limiting oxygen index (LOI), vertical burning test (UL-94), digital photos, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), cone calorimeter test (CCT), laser Raman spectroscopy (LRS) and X-ray photoelectron spectroscopy (XPS). It was found that a small amount of 4A could dramatically enhance the LOI value of the PP/IFR systems and the materials could pass the UL-94 V-0 rating test. Also, it could enhance the fire retardant performance with a great reduction in combustion parameters of PP/IFR system from CCT test. The morphological structures observed by digital and SEM photos revealed that 4A could promote PP/IFR to form more continuous and compact intumescent char layer. The LRS measurement, XPS and TGA analysis demonstrated that the compactness and strength of the outer char surface of the PP/IFR/4A system was enhanced, and more graphite structure was formed to remain more char residue and increase the crosslinking degree. Copyright © 2013 John Wiley & Sons, Ltd.
Co-reporter:Tao Han;Yi Zhang;Qiaoying Cao;Siwei Liu;Zhenguo Chi
Polymers for Advanced Technologies 2013 Volume 24( Issue 9) pp:807-813
Publication Date(Web):
DOI:10.1002/pat.3146
A series of novel optically active poly(ester-imide)s (ter-PEIs) with high glass transition temperature (Tg), good thermal stability, and solubility were successfully designed and synthesized by direct polycondensation reactions, using p-hydroxybenzoic acid (PHB), 4,4’-dihydroxybenzophenone, and a chiral diacid, N,N'-(pyromellitoyl)-bis-L-phenylalanine diacid as monomers. The resulting terpolymers were characterized by1H-NMR, FTIR, element analysis, thermogravimetric analysis, different scanning calorimeter and wide-angle x-ray diffraction, etc. The ter-PEIs are amorphous polymers with good heat resistance and high Tgs. They are soluble in many common polar organic solvents and show optically rotation property. The specific rotation values of the ter-PEIs increase with the molar ratio of the chiral diacid, and the rigid PHB monomer is beneficial to increase the Tgs of the polymers. Copyright © 2013 John Wiley & Sons, Ltd.
Co-reporter:Min-min Zhang;Si-wei Liu;Yi Zhang 张艺
Chinese Journal of Polymer Science 2013 Volume 31( Issue 6) pp:894-900
Publication Date(Web):2013 June
DOI:10.1007/s10118-013-1277-9
A new macromolecular surface modifier, a copolymer of lauryl methacrylate (LMA) and poly(ethylene glycol) methyl methacrylate (PEGMA), was synthesized through free radical polymerization. The copolymer was characterized by nuclear magnetic resonance spectrum (1H-NMR) and thermogravimetric analysis (TGA). The copolymer was used to blend with polyethylene. The binary blends have been characterized by attenuated total reflection/Fourier transform infrared (ATRFTIR), contact-angle measurements (CDA) and scanning electron microscopy (SEM). The results indicated that poly(ethylene glycol) methyl methacrylate-co-lauryl methacrylate (PEGMA-co-LMA) could diffuse preferably onto the surface of the polyethylene (PE) film, and thus can be used as an efficient surface modifier for PE.
Co-reporter:Zhenguo Chi, Xiqi Zhang, Bingjia Xu, Xie Zhou, Chunping Ma, Yi Zhang, Siwei Liu and Jiarui Xu
Chemical Society Reviews 2012 vol. 41(Issue 10) pp:3878-3896
Publication Date(Web):26 Mar 2012
DOI:10.1039/C2CS35016E
Mechanofluorochromic materials, which are dependent on changes in physical molecular packing modes, have attracted considerable interest over the past ten years. In this review, recent progress in the area of pure organic mechanofluorochromism is summarized, and majority of the reported organic mechanofluorochromic systems are discussed, along with their derived structure–property relationships. The existence of a structural relationship between aggregation-induced emission compounds and mechanofluorochromism is recognized based on our recent results, which considered aggregation-induced emission compounds as a well of mechanofluorochromic materials. The established structure–property relationship will guide researchers in identifying and synthesizing more mechanofluorochromic materials.
Co-reporter:Yiwu Liu, Yi Zhang, Qi Lan, Siwei Liu, Zexin Qin, Lianghui Chen, Cunyuan Zhao, Zhenguo Chi, Jiarui Xu, and James Economy
Chemistry of Materials 2012 Volume 24(Issue 6) pp:1212
Publication Date(Web):February 28, 2012
DOI:10.1021/cm3003172
A novel, simple but efficient diamine (TriPEDA) containing rigid nonplanar conjugated triphenylethylene moieties was designed and synthesized through Wittig–Horner and Suzuki coupling reactions. Four kinds of high-performance functional polyimides were thus prepared by the dipolymerization of TriPEDA and four dianhydrides, respectively. Because of the introduction of the aromatic rigid nonplanar triphenylethylene structure, the polyimides exhibited special fluorescent and resistive switching (ON-OFF) characteristics, as the maximum fluorescence emission of the four polyimides was observed at 472–505 nm in NMP solution and at 473–541 nm in film state. Also these organo-soluble polyimides showed outstanding properties, such as low dielectric constant (even without fluorinated substituents), light color, high glass transition temperatures (359–409 °C), thermal stability, and excellent mechanical properties. The memory devices with the configuration of indium tin oxide/polyimides/aluminum (ITO/PI/Al) exhibited distinct volatile memory characteristics of static random access memory (SRAM), with an ON/OFF current ratio of 1 × 105 to 1 × 106. These functional polyimides showed attractive potential applications in the field of high-performance flexible polymer photoconducting devices or polymer memory devices.Keywords: fluorescent; functional polyimide; resistive switching characteristic; rigid nonplanar conjugated moieties;
Co-reporter:Caimin Feng, Yi Zhang, Siwei Liu, Zhenguo Chi, Jiarui Xu
Polymer Degradation and Stability 2012 Volume 97(Issue 5) pp:707-714
Publication Date(Web):May 2012
DOI:10.1016/j.polymdegradstab.2012.02.014
The synergistic effects of lanthanum oxide (La2O3) on the thermal degradation and flame retardancy of a novel intumescent flame retardant polypropylene composites (PP/IFR) were investigated by the means of limited oxygen index (LOI), catalytic effectivity analysis (CAT-EFF), vertical burning test (UL-94), thermogravimetric analysis (TGA), cone calorimeter test (CCT), scanning electron microscopy (SEM), Laser Raman spectroscopy (LRS) and X-ray photoelectron spectroscopy (XPS). It was found that a small amount of La2O3 could enhance the LOI value of the PP/IFR composite dramatically and the materials can pass the UL-94 V-0 rating test. The catalytic effectivity (CAT-EFF) results showed that when 1wt.% La2O3 was added, it had the highest CAT-EFF, and could promote the LOI value of the composites from 27.1 to 32.5. The TGA data revealed that La2O3 could change the degradation behavior of the IFR and PP/IFR, enhance the thermal stability of the PP/IFR systems at high temperature and increase the char residue, especially in the air environment. The presence of La2O3 could change the decomposition behavior of the PP/IFR, and enhance the fire retardant performance, resulting consequently in a great reduction in peak heat release rate (p-HRR), total heat release (THR), smoke production rate (SPR) and total smoke production (TSP) of the PP/IFR system. The morphological structures observed by digital photos and SEM demonstrated that La2O3 could promote to form the more continuous and more compact intumescent char layer. The LRS measurements illustrated that the strength of the outer surface of the char residue with La2O3 is enhanced. The XPS analysis indicated that La2O3 can remain more O, N and P to enhance the strength of outer and inner char. Thus, a suitable amount of La2O3 plays an excellent synergistic effect with IFR on the flame retardancy, thermal degradation at high temperature, smoke suppression of IFR composites, and promotes the formation of compact char structures in the PP/IFR composites.
Co-reporter:Xie Zhou, Haiyin Li, Zhenguo Chi, Xiqi Zhang, Jianyong Zhang, Bingjia Xu, Yi Zhang, Siwei Liu and Jiarui Xu
New Journal of Chemistry 2012 vol. 36(Issue 3) pp:685-693
Publication Date(Web):13 Dec 2011
DOI:10.1039/C1NJ20782B
A new piezofluorochromic aggregation-induced emission compound was synthesized. The compound had morphology-alterable emission property and its amorphous and crystalline aggregates with various emissions were obtained through evaporation from the solutions in different solvent systems. The spectroscopic properties and morphological structures of the compound were reversed upon pressing and annealing (or fuming). The results show that the piezofluorochromic nature is generated through crystalline–amorphous phase transformation under external pressure. The reason for the phase transformation is ascribed to the twisted conformation of the molecule which leads to poor solid molecular packing and formation of some cavities in the interfaces of lamellar layers, as confirmed by single crystal X-ray diffraction analysis.
Co-reporter:Xie Zhou;Hai-yin Li;Zhen-guo Chi;Bing-jia Xu;Xi-qi Zhang
Journal of Fluorescence 2012 Volume 22( Issue 2) pp:565-572
Publication Date(Web):2012 March
DOI:10.1007/s10895-011-0990-4
A novel piezochromic fluorescent (PCF) compound with aggregation-induced emission (AIE) effect and morphology-alterable emission property was developed. The amorphous and crystalline aggregates were obtained, and their spectroscopic properties and morphological structures were reversibly and repeatedly exhibited upon pressing (fuming) or annealing. The piezochromic fluorescent nature was generated through crystalline-amorphous phase transformation. It was proposed that AIE compounds existing a twisted propeller-shaped conformation will exhibit PCF activity. The common relationship betweeen AIE and PCF established will guide researchers in identifying and synthesizing more piezochromic fluorescent materials.
Co-reporter:Xiqi Zhang, Zhenguo Chi, Haiyin Li, Bingjia Xu, Xiaofang Li, Siwei Liu, Yi Zhang and Jiarui Xu
Journal of Materials Chemistry A 2011 vol. 21(Issue 6) pp:1788-1796
Publication Date(Web):07 Dec 2010
DOI:10.1039/C0JM02824J
A novel class of compounds containing tetraphenylethylene and dicarbazolyl triphenylethylene moieties combined with different spacers is synthesized. The compounds exhibit high thermal stabilities and aggregation-induced emission properties. The different spacers lead to differences in spatial conformation structures and spatial electron distributions, and markedly affect the thermal and photophysical properties of the compounds. The size of the aggregates formed in water–THF mixtures decreases with increasing water fractions. The time-resolved emission decay behaviors of the synthesized compounds in water–THF mixtures with water fractions from 60% to 99% show three relaxation pathways in their fluorescence decays.
Co-reporter:Haiyin Li, Zhenguo Chi, Bingjia Xu, Xiqi Zhang, Xiaofang Li, Siwei Liu, Yi Zhang and Jiarui Xu
Journal of Materials Chemistry A 2011 vol. 21(Issue 11) pp:3760-3767
Publication Date(Web):31 Jan 2011
DOI:10.1039/C0JM02571B
New compounds containing triphenylamine-anthrylenevinylene and tetraphenylethene moieties are synthesized by the Wittig–Horner reaction. The compounds exhibit weak emission in good solvents, but strong fluorescence in aggregates or in the solid state, indicating that they are aggregation-induced emission enhancement compounds. The symmetry of their molecular structure affects their aggregation structures and photoluminescence emission properties in aggregation. These compounds show high thermal stabilities with glass transition temperatures between 168–177 °C and decomposition temperatures between 521–537 °C. The HOMO levels of the compounds are in the region of 4.92–4.94 eV, very close to the work function of indium tin oxide anode (4.8–5.0 eV). One of the compounds exhibits obvious piezofluorochromic behavior. The piezofluorochromic nature is generated through changing the mode of molecular packing under external pressure.
Co-reporter:Yi Zhang, Shanxiong Xiao, Qianyi Wang, Siwei Liu, Zhengping Qiao, Zhenguo Chi, Jiarui Xu and James Economy
Journal of Materials Chemistry A 2011 vol. 21(Issue 38) pp:14563-14568
Publication Date(Web):18 Aug 2011
DOI:10.1039/C1JM12450A
Novel thermally conductive, insulated polyimide nanocomposite films are reported here for microelectronics applications. A thermally conductive, insulated inorganic nanolayer of AlO(OH) was successfully coated onto the surface of MWCNTs, which, on the one hand, can effectively avoid the formation of MWCNT electrically conductive networks in the PI matrix and, on the other, can provide the advantage of excellent thermal conductivity properties of the MWCNTs.
Co-reporter:Haiyin Li, Zhenguo Chi, Xiqi Zhang, Bingjia Xu, Siwei Liu, Yi Zhang and Jiarui Xu
Chemical Communications 2011 vol. 47(Issue 40) pp:11273-11275
Publication Date(Web):19 Sep 2011
DOI:10.1039/C1CC14642D
New thermally stable aggregation-induced emission enhancement compounds were synthesized. A non-doped red device showed a maximum brightness of 13535 cd m−2, a maximum current efficiency of 6.81 cd A−1, a maximum power efficiency of 4.96 lm W−1 and a low turn-on voltage of 4.3 V.
Co-reporter:Bingjia Xu, Zhenguo Chi, Xiqi Zhang, Haiyin Li, Chengjian Chen, Siwei Liu, Yi Zhang and Jiarui Xu
Chemical Communications 2011 vol. 47(Issue 39) pp:11080-11082
Publication Date(Web):30 Aug 2011
DOI:10.1039/C1CC13790E
A new ligand containing tetraphenylethylene and terpyridine moieties, and its zinc ion complex were synthesized. Both of them exhibit an aggregation-induced emission effect. Their colors and emissions can be smartly switched by various external stimuli including grinding, heating and solvent-fuming, as well as exposure to acid and base vapors.
Co-reporter:Xiqi Zhang, Zhenguo Chi, Bingjia Xu, Haiyin Li, Zhiyong Yang, Xiaofang Li, Siwei Liu, Yi Zhang, Jiarui Xu
Dyes and Pigments 2011 Volume 89(Issue 1) pp:56-62
Publication Date(Web):April 2011
DOI:10.1016/j.dyepig.2010.09.003
A series of new aggregation-induced emission enhancement derivatives from bis(triphenylethylene) with strong blue-light-emitting properties and high thermal stability have been synthesized. Their maximum fluorescence emission wavelengths range between 464–468 nm, with fluorescence quantum yields of 0.58–0.88. Their glass transition temperatures range from 125 °C to 178 °C. The obtained experimental results demonstrate the different aggregation-induced emission enhancement phenomena caused by the effect of solvent and formation of both H- and J- aggregation states. An emitting device was fabricated using a bis(triphenylene) derivative in the emitting layer which exhibited a luminance efficiency of up to 2 cd/A with a maximum brightness of 548 cd/m2.
Co-reporter:Xi-qi Zhang;Zhen-guo Chi;Bing-jia Xu;Hai-yin Li;Wei Zhou
Journal of Fluorescence 2011 Volume 21( Issue 1) pp:133-140
Publication Date(Web):2011 January
DOI:10.1007/s10895-010-0697-y
Two cinnamic acid derivatives (CPA and CPC) containing carbazolyl triphenylethylene moiety have been synthesized and characterized. The two derivatives possessed aggregation-induced emission property. They exhibited different and interesting responsive behaviors to solvents, water and metal ions. Considering the structural differences between the two derivatives resulting in different interactions between their molecules and the various media was proposed as a possible explanation for these observations. The intermolecular interactions of CPC were much stronger than those of CPA, which promoted molecular association through intermolecular hydrogen bonding to form multimers. It was found that CPC and CPA exhibited high sensitivity to K+ and Mn2+, respectively. It is suggested that the derivatives have potential technological applications in chemosensor fields.
Co-reporter:Shanshan Wei;Yi Zhang
Journal of Polymer Research 2011 Volume 18( Issue 1) pp:125-130
Publication Date(Web):2011 January
DOI:10.1007/s10965-010-9398-0
Poly(acrylic acid-co-styrene)/Fe3O4 nanocomposites were prepared using poly(acrylic acid-co-styrene) (P(AA-co-St)) and nano-Fe3O4 particles. The resultant materials were characterized by transmission electron microscope (TEM), Fourier transform infrared (FTIR), thermogravimetric analysis (TGA), advanced rheology expand system and superconducting quantum interference device (SQUID) magnetometer. The diameter of the magnetic particles was around 3–14 nm. The experimental results reveal that the acrylic acid segment of P(AA-co-St) can react with nano-Fe3O4. With increasing reaction time the storage modulus, loss modulus, complex viscosity and shear stress of the P(AA-co-St)/Fe3O4 ethanol suspension were increased, and the suspension changed from liquid-like behavior to gel-like behavior for the reaction between P(AA-co-St) and Fe3O4, as found during the rheology measurements. The thermal stability of P(AA-co-St) decreased with the addition of nano-Fe3O4, and the nanocomposites exhibited superparamagnetic properties above the blocking temperature.
Co-reporter:Xiqi Zhang, Zhenguo Chi, Jianyong Zhang, Haiyin Li, Bingjia Xu, Xiaofang Li, Siwei Liu, Yi Zhang, and Jiarui Xu
The Journal of Physical Chemistry B 2011 Volume 115(Issue 23) pp:7606-7611
Publication Date(Web):May 18, 2011
DOI:10.1021/jp202112e
A fluorescent compound, 9,10-bis(2-(10-hexyl-10H-phenothiazin-3-yl)vinyl) anthracene, has been synthesized and studied. The results show that the compound possesses piezofluorochromic properties as well as aggregation-induced emission enhancement effect. The spectroscopic properties and morphological structures are reversibly exhibited upon pressing (or grinding) or annealing (or fuming). The piezofluorochromic nature is generated through phase transformation under the stimulus of external pressure. The reason for the phase transformation caused by external pressure is ascribed to the twisted conformation of the molecule which leads to poor solid molecular packing and weak interactions in the interfaces of lamellar layers confirmed by its single-crystal X-ray diffraction analysis.
Co-reporter:Bingjia Xu, Zhenguo Chi, Haiyin Li, Xiqi Zhang, Xiaofang Li, Siwei Liu, Yi Zhang, and Jiarui Xu
The Journal of Physical Chemistry C 2011 Volume 115(Issue 35) pp:17574-17581
Publication Date(Web):July 28, 2011
DOI:10.1021/jp205525s
Aggregation-induced emission compounds containing triphenylethene and tetraphenylethene moieties with high thermal stability and good device properties have been synthesized. Their maximum fluorescence emission wavelengths are 469–493 nm in solid states. The glass transition temperatures range from 138 to 180 °C and the decomposition temperatures are 495–557 °C. The unoptimized device fabricated with the triphenylethene compound combined with three tetraphenylethene groups as emitters turns on at ∼6 V and the maximum luminance is observed at ∼1908 cd/m2 and 15.5 V. The electroluminescence peak of the device is at 474 nm and the Commission Internationale de l’Eclairage (CIE) chromaticity coordinate values are (0.18, 0.31) at 10 V.
Co-reporter:Xiqi Zhang, Zhiyong Yang, Zhenguo Chi, Meina Chen, Bingjia Xu, Chengcheng Wang, Siwei Liu, Yi Zhang and Jiarui Xu
Journal of Materials Chemistry A 2010 vol. 20(Issue 2) pp:292-298
Publication Date(Web):09 Nov 2009
DOI:10.1039/B910718E
A new cyanoacrylic acid derivative of carbazole-triphenylethylene as a fluorescent probe has been synthesized and characterized. The derivative exhibits not only aggregation-induced effect (AIE) properties, but also interesting fluorescence multi-responses to solvents, water, ethanol and metal ions due to its chemical structure. Responses of the compound solution in DMF to water can be explained in terms of H-bond, multimer and AIE effects. In addition, the derivative was found to be highly sensitive to potassium ions. It is suggested that the compound has potential applications in chemosensors.
Co-reporter:Bingjia Xu, Zhenguo Chi, Zhiyong Yang, Jingbo Chen, Shaozhi Deng, Haiyin Li, Xiaofang Li, Yi Zhang, Ningsheng Xu and Jiarui Xu
Journal of Materials Chemistry A 2010 vol. 20(Issue 20) pp:4135-4141
Publication Date(Web):15 Apr 2010
DOI:10.1039/C0JM00229A
A series of new aggregation-induced emission compounds with strong blue light-emitting properties derived from triphenylethylene were facilely synthesized by a Wittig–Horner reaction of bis(4-bromophenyl)methanone with diethyl 4-bromobenzylphosphonate, followed by a Suzuki reaction with arylboronic acids. Their maximum fluorescence emission wavelengths were 452–462 nm. The glass transition temperatures ranged from 70–145 °C, and the decomposition temperatures were 360–508 °C. The unoptimized device fabricated with benzofuranyl substituted compound as emitter turned on at ∼6 V, and the maximum luminance was ∼1500 cd m−2.
Co-reporter:Zhiyong Yang, Zhenguo Chi, Bingjia Xu, Haiyin Li, Xiqi Zhang, Xiaofang Li, Siwei Liu, Yi Zhang and Jiarui Xu
Journal of Materials Chemistry A 2010 vol. 20(Issue 35) pp:7352-7359
Publication Date(Web):03 Aug 2010
DOI:10.1039/C0JM00712A
A new class of carbazole derivatives was facilely synthesized by Wittig–Horner and Suzuki reactions, and their thermal and photophysical properties were investigated. They exhibited aggregation-induced emission enhancement (AIEE) characteristics and high thermal stability. The glass transition temperatures (Tg) of these compounds ranged from 178 to 231 °C, while their decomposition temperatures (Td) ranged from 496 to 535 °C. The solubility of the derivatives did not monotonically change with an increasing number of phenylene bridges, but exhibited a clear odd-even effect.
Co-reporter:Haiyin Li, Zhenguo Chi, Bingjia Xu, Xiqi Zhang, Zhiyong Yang, Xiaofang Li, Siwei Liu, Yi Zhang and Jiarui Xu
Journal of Materials Chemistry A 2010 vol. 20(Issue 29) pp:6103-6110
Publication Date(Web):16 Jun 2010
DOI:10.1039/C0JM00599A
A new class of compounds containing triarylamine and dicarbazolyl triphenylethylene moieties with high thermal stability and aggregation-induced emission enhancement properties was synthesized. The glass transition temperature and 5% weight loss temperature of 3B-TPA are up to 214.3 °C and 516.8 °C, respectively. The compounds exhibited significant photoinduced intramolecular charge-transfer properties. The aggregation considerably affected the π–π* transition and resulted in 6–7 nm red shift of the π–π* absorption wavelength at the peak in UV-vis spectra. The compounds could emit intense blue-green light in aggregated states.
Co-reporter:Hanjia Chen;Xuhua Shi;Yafei Zhu;Yi Zhang
Frontiers of Chemical Science and Engineering 2010 Volume 4( Issue 3) pp:336-341
Publication Date(Web):2010 September
DOI:10.1007/s11705-009-0230-5
The diffusion of poly(ethylene glycol) (PEG) in polypropylene (PP) was investigated using attenuated total reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR), Atomic Force Micrograph (AFM), and Scanning Electron Microscopy (SEM). It has been found that the diffusion of PEG in PP was greatly affected by the annealing temperature and the molecular weight of PEG. Higher temperature was in favor of PEG to diffuse in PP with fast velocity and reached diffusion equilibrium with shorter time. PEG with higher molecular weight was distributed in PP with bigger phase domains and had lower diffusivity, which resulted in its lesser enrichment on the surface of the PP blend film.
Co-reporter:Zhiyong Yang, Zhenguo Chi, Tao Yu, Xiqi Zhang, Meina Chen, Bingjia Xu, Siwei Liu, Yi Zhang and Jiarui Xu
Journal of Materials Chemistry A 2009 vol. 19(Issue 31) pp:5541-5546
Publication Date(Web):19 Jun 2009
DOI:10.1039/B902802A
A new class of aggregation-induced emission (AIE) compounds with strong blue-light-emitting properties and a high thermal stability, derived from triphenylethylene carbazole, has been synthesized. Their glass transition temperatures range from 126–151 °C and the maximum fluorescence emission wavelengths are 451–466 nm.
Co-reporter:Zhiyong Yang, Zhenguo Chi, Lin Zhou, Xiqi Zhang, Meina Chen, Bingjia Xu, Chengcheng Wang, Yi Zhang, Jiarui Xu
Optical Materials 2009 Volume 32(Issue 2) pp:398-401
Publication Date(Web):December 2009
DOI:10.1016/j.optmat.2009.06.011
A new series of fluorescent compounds containing tricarbazolyl groups have been synthesized. The compounds have very high glass transition temperatures in the range 243–266 °C, high decomposition temperatures of 506–527 °C, and exhibit strong blue fluorescence with maximum emission wavelengths at 445–457 nm. The compounds have good solubility in common solvents even though they contain rather rigid wholly aromatic structures. The thermal stability of these compounds exhibits a marked odd–even effect corresponding to the number of phenylene bridges in the compound. In the solid, the maximum photoluminescence emission wavelength with n odd have a slight bathochromic shift in comparison to those with n even.
Co-reporter:Xiqi Zhang, Zhenguo Chi, Zhiyong Yang, Meina Chen, Bingjia Xu, Lin Zhou, Chengcheng Wang, Yi Zhang, Siwei Liu, Jiarui Xu
Optical Materials 2009 Volume 32(Issue 1) pp:94-98
Publication Date(Web):November 2009
DOI:10.1016/j.optmat.2009.06.009
A series of fluorescent compounds derived from carbazole were synthesized via the Wittig–Horner reaction. The compounds had high glass transition temperatures (Tg), in the region of 172–232 °C, and high decomposition temperatures (Td), ranging from 456 to 491 °C. The derivatives showed very high fluorescence efficiency in solution, with fluorescence quantum yields in the range of 0.88–1.00. The substituent effects on fluorescence emission differed between solution and solid state. In dichloromethane solutions, the substituents had only a minimal effect on the maximum emission wavelength of the compounds with the same bridge.
Co-reporter:Yigao Yin, Yi Zhang, Zhenguo Chi, Jiarui Xu
European Polymer Journal 2008 Volume 44(Issue 7) pp:2284-2294
Publication Date(Web):July 2008
DOI:10.1016/j.eurpolymj.2008.04.045
Some kinds of aminomethyl triethoxysilanes, cross-linkers of α,ω-dihydroxy poly(dimethylsiloxane) (PDMS), can act as catalyst to self-catalyze the cross-linking reaction with PDMS, as found in our studies. Three kinds of α-aminomethylsilanes, [(diethyl)aminomethyl triethoxysilane (DMTS), anilinomethyl triethoxysilane (AMTS) and cyclohexylaminomethyl triethoxysilane (CMTS)], and two kinds of γ-aminopropyl silanes, [(γ-aminopropyl triethoxysilane (APTS) and (N-β-aminoethyl)-γ-aminopropyl triethoxysilane (AATS)] were selected to study the self-catalytic cross-linking reaction and its mechanism. The reactivity of the cross-linkers determined by n-hexane extraction experiments, was found to be DMTS > CMTS ≫ AMTS, but APTS and AATS could not react with PDMS without catalysis. The cross-linking degree was increased with the reactivity. The results of extraction experiments and Fourier transform infra-red (FT-IR) spectra indicated that the cross-linking reaction was an equimolar reaction between the Si–OH groups and Si–OC2H5 groups. Formation of electron conjugation of N and Si in α-aminomethyl triethoxysilane molecules has been proposed to elucidate the mechanism of the self-catalytic cross-linking reaction. The Modulated Differential Scanning Calorimeter (MDSC) results showed that the increase of the glass-transition temperature (Tg) of the cross-linked products was dependent on the reactivity of the cross-linkers. The thermo-gravimetric analysis (TGA) results demonstrated that the thermal stabilities of the cross-linked products were also related to the reactivity and the structures of the cross-linkers.
Co-reporter:Han Jia Chen, Xu Hua Shi, Ya Fei Zhu, Yi Zhang, Jia Rui Xu
Applied Surface Science 2008 Volume 254(Issue 6) pp:1763-1770
Publication Date(Web):15 January 2008
DOI:10.1016/j.apsusc.2007.07.141
Abstract
Poly(methyl methacrylate) (PMMA) and its graft copolymer of polybutadiene were used as the macromolecular surface modifiers of polypropylene. The enrichment and diffusion of the modifiers onto the surface of polypropylene blends were investigated using FTIR-ATR, CDA and SEM. It has been found that the selective aggregation of the modifier component on the surface of polypropylene was mainly affected by the content, molecular weight and size of the segregated domains. Lower content and higher surface energy die were in favor of the enrichment of the additive. PMMA with higher molecular weight showed larger domain phase and lower diffusion velocity which resulted in less enrichment on the surface of PP blends.
Co-reporter:H.J. Chen, X.H. Shi, Y.F. Zhu, Y. Zhang, J.R. Xu
Applied Surface Science 2008 Volume 254(Issue 8) pp:2521-2527
Publication Date(Web):15 February 2008
DOI:10.1016/j.apsusc.2007.09.077
Abstract
Surface modification of polypropylene was carried out by entraping a copolymer of polypropylene grafted poly(butyl methacrylate) into polypropylene. The effects of structure of copolymers, contact die and content of modifiers on their surface enrichment were studied by attenuated total reflection infrared spectroscopy (ATR-FTIR), contact angle measurements and scanning electron microscopy (SEM). The results indicated that PPw-g-PBMA could diffuse preferably onto the surface and effectively increase the hydrophilicity of PP. Lower content and higher surface energy die were in favor of the copolymer to enrich on the PP surface. PPw-g-PBMA with low PBMA contents, short length of PBMA distributed in PP with smaller phase domains and favored its selective enrichment on the surface of PP, especially at lower loadings in blends. The modified material exhibited excellent solvent-resistance.
Co-reporter:Hanjia Chen;Xuhua Shi;Yafei Zhu;Yi Zhang
Journal of Applied Polymer Science 2008 Volume 107( Issue 5) pp:3049-3057
Publication Date(Web):
DOI:10.1002/app.27490
Abstract
The enrichment and diffusion of poly (butyl methacrylate) (PBMA) and its graft copolymer of polybutadiene on the surface of polypropylene (PP) blends were investigated using attenuated total reflection infrared spectroscopy (ATR-FTIR), contact angle measurements (CDA), and scanning electron microscopy (SEM). It has been found that the selective aggregation of the PBMA and its copolymers on the surface of blends is mainly affected by the content, molecular weight, and the segregated domains. Lower content and higher surface energy die are in favor of the enrichment of additives on the surface of PP. PBMA with higher molecular weight has lower diffusivity and bigger phase domains, which results in its lower enrichment on the surface of PP blend film. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Co-reporter:Hanjia Chen;Xuhua Shi;Yafei Zhu;Yi Zhang
Frontiers of Chemical Science and Engineering 2008 Volume 2( Issue 1) pp:102-108
Publication Date(Web):2008 March
DOI:10.1007/s11705-008-0018-z
A novel macromolecular surface modifier, polypropylene-grafted-poly(ethylene glycol) copolymer (PP-g-PEG), was synthesized by coupling polypropylene containing maleic anhydride with monohydroxyl-terminated poly(ethylene glycol). The effects of the reaction condition on the graft reactions were studied. The copolymers were characterized by IR, 1H NMR, thermogravimetry (TG) and differential scanning calorimetry (DSC). The results indicated that the graft reactions were hindered by increasing the molecular weight of PP or PEG. The graft copolymer was found to have a higher initial thermal degradation temperature and lower crystallization capacity as compared with pure PP, and the side chain of PEG hindered the PP chain from forming a perfect β crystal. The thermal stability of PP-g-PEG decreased with the increasing content or molecular weight of PEG. The copolymers were blended with polypropylene to modify the surface hydrophilicity of the products. The results of attenuated total reflectance FTIR spectroscopy (ATR-FTIR) showed that PP-g-PEG could diffuse preferably onto the surface of the blends and be suitable as an effectual macromolecular surface modifier for PP.
Co-reporter:Jun Xu;Yafei Zhu;Yi Zhang;Yimin Zheng;Zhenguo Chi
Journal of Applied Polymer Science 2007 Volume 103(Issue 5) pp:3183-3193
Publication Date(Web):19 DEC 2006
DOI:10.1002/app.25504
A series of poly(ester imide ketone)s (PEIKs) with varied p-hydroxybenzoic acid (HBA) molar fraction derived from N,N′-hexane-1,6-diylbis(trimellitimide), 4,4′-dihydroxybenzophenone, and p-hydroxybenzoic acid were synthesized by a “step-feeding” polycondensation method in benzene sulfonyl chloride, dimethylformamide, and pyridine. High field 1H, 13C, and 2D NMR spectroscopy measurements were combined to determine the assignments of hydrogen and carbon atoms in the copolymers. 13C inverse gated decoupling NMR spectra were taken and used as a quantitative method to analyze the chain sequence structures of these copolymers. The liquid crystalline behaviors and thermal properties of the PEIKs were characterized by polarized light microscopy (PLM), wide-angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The NMR studies show that the monomeric unit ratios of the PEIKs are very close to the ratios of the monomers added into the polycondensation process. The analytical results of sequence distribution indicate that the sequence ratios of I-H, H-D, and H-H dias rise with the increase of HBA molar fraction, while that of I-D decrease. It is worth noting that the sequence ratios of H-H are always very small among the four sequence ratios although the HBA molar fraction varied from 0 to 50%. It was shown that the copolymers possess a typical nematic thermotropic liquid crystalline character and high thermal stability, which is strongly related with the changes in sequence structure of the molecular chains. This type of liquid crystalline polymers also exhibits excellent fiber-forming character in the melting state, which would find its potential usages in high performance fiber and fiber modification materials. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3183–3193, 2007
Co-reporter:Shanshan Wei;Yi Zhang
Frontiers of Chemical Science and Engineering 2007 Volume 1( Issue 3) pp:233-237
Publication Date(Web):2007/07/01
DOI:10.1007/s11705-007-0042-4
PAA/Fe3O4 nanocomposites were prepared by mixing nano-Fe3O4 and polyacrylic acid (PAA) ethanol solution and then evaporating the solvent. The materials were characterized by transmission electron microscope (TEM), Fourier transform infrared spectroscope (FTIR), thermogravimetry analysis (TGA), dynamic ultra-micro hardness tester (DUMHT) and superconducting quantum interference device (SQUID) magnetometer. Results showed that PAA coordinated with nano-Fe3O4 to form a cross-linking structure. The presence of nano-Fe3O4 enhanced the thermal stability of the nanocomposite. The elasticity and hardness of the nanocomposite increased, and the indentation depth reduced with the increase of Fe3O4 content in the composites. The nanocomposites showed superparamagnetic properties at 300 K.
Co-reporter:Gufeng Chen;Yi Zhang;Yafei Zhu
Frontiers of Chemical Science and Engineering 2007 Volume 1( Issue 2) pp:128-131
Publication Date(Web):2007 May
DOI:10.1007/s11705-007-0024-6
Linear low-density polyethylene (LLDPE) was melt and blended with styrene-maleic anhydride copolymer (SMA). The blending films were then immersed in poly(ethylene glycol)400 (PEG400) at room temperature. The surface composition of the blend films was determined by Fourier transform infra-red spectroscopy coupled with a variable incidence angle attenuated total reflection accessory (ATR-FTIR). Results show that PEG400 can be grafted onto the surface of the films via esterification with SMA. The immersion of PEG promotes the enrichment of SMA onto the surface of the films. The water contact angle data show that grafting of PEG400 onto PE can greatly improve the hydrophilicity of the PE surface. These experiments show that surface functionalization of polyethylene films by blending SMA and then surface grafting of PEG is feasible, which suggest an effective and simple route for PE surface modification via blending and grafting.
Co-reporter:Hanjia J. Chen;Yafei F. Zhu;Yi Zhang;Jiarui R. Xu
Journal of Polymer Research 2007 Volume 14( Issue 6) pp:
Publication Date(Web):2007 December
DOI:10.1007/s10965-007-9134-6
To overcome disadvantage of polypropylene induced by its low surface energy, poly(methyl methacrylate) was grafted onto polypropylene and entrapped into polypropylene as macromolecular surface modifier. The effects of copolymer structures, contact dies and content of modifiers on their surface enrichment were studied by attenuated total reflection infrared spectroscopy (ATR-FTIR), contact angle measurements (CDA) and scanning electron microscopy (SEM). Lower content and higher surface energy dies were in favor of the copolymer to enrich on the PP surface. PPw-g-PMMA with low PMMA graft density, long length of PMMA was distributed in PP with smaller phase domains and concentration gradient, especially at lower loadings in blends, which favored its selective enrichment on the surface of PP. The modified material exhibited excellent solvent-resistance. The results indicated that PPw-g-PMMA can transfer to the surface of blends and effectively increase the hydrophilicity of PP, which offer a convenient technique to functionalize the surface of polymers with lasting-effectiveness compared with modification by homopolymers.
Co-reporter:Xiaolong Lu, Yi Zhang, Jiarui Xu
Scripta Materialia 2006 Volume 54(Issue 9) pp:1617-1621
Publication Date(Web):May 2006
DOI:10.1016/j.scriptamat.2006.01.012
Chain-shaped short nylon 6 fibers and their polymer composites were prepared, and single fiber pull-out tests for different embedded depths were carried out to reveal the influence of the chain-shape geometry on the properties of the composites. A particular phenomenon of multiple peaks in the pulling-out load vs. displacement curves was observed which is not seen for normal straight short fibers, and the number of the peaks was found to be closely related to the number of repeated units, as well as the embedded length of the chain-shaped fiber in the matrix, resulting in the improvement of the toughness and strength of the composites.
Co-reporter:Bingjia Xu, Zhenguo Chi, Zhiyong Yang, Jingbo Chen, Shaozhi Deng, Haiyin Li, Xiaofang Li, Yi Zhang, Ningsheng Xu and Jiarui Xu
Journal of Materials Chemistry A 2010 - vol. 20(Issue 20) pp:NaN4141-4141
Publication Date(Web):2010/04/15
DOI:10.1039/C0JM00229A
A series of new aggregation-induced emission compounds with strong blue light-emitting properties derived from triphenylethylene were facilely synthesized by a Wittig–Horner reaction of bis(4-bromophenyl)methanone with diethyl 4-bromobenzylphosphonate, followed by a Suzuki reaction with arylboronic acids. Their maximum fluorescence emission wavelengths were 452–462 nm. The glass transition temperatures ranged from 70–145 °C, and the decomposition temperatures were 360–508 °C. The unoptimized device fabricated with benzofuranyl substituted compound as emitter turned on at ∼6 V, and the maximum luminance was ∼1500 cd m−2.
Co-reporter:Zhiyong Yang, Zhenguo Chi, Bingjia Xu, Haiyin Li, Xiqi Zhang, Xiaofang Li, Siwei Liu, Yi Zhang and Jiarui Xu
Journal of Materials Chemistry A 2010 - vol. 20(Issue 35) pp:NaN7359-7359
Publication Date(Web):2010/08/03
DOI:10.1039/C0JM00712A
A new class of carbazole derivatives was facilely synthesized by Wittig–Horner and Suzuki reactions, and their thermal and photophysical properties were investigated. They exhibited aggregation-induced emission enhancement (AIEE) characteristics and high thermal stability. The glass transition temperatures (Tg) of these compounds ranged from 178 to 231 °C, while their decomposition temperatures (Td) ranged from 496 to 535 °C. The solubility of the derivatives did not monotonically change with an increasing number of phenylene bridges, but exhibited a clear odd-even effect.
Co-reporter:Haiyin Li, Zhenguo Chi, Bingjia Xu, Xiqi Zhang, Zhiyong Yang, Xiaofang Li, Siwei Liu, Yi Zhang and Jiarui Xu
Journal of Materials Chemistry A 2010 - vol. 20(Issue 29) pp:NaN6110-6110
Publication Date(Web):2010/06/16
DOI:10.1039/C0JM00599A
A new class of compounds containing triarylamine and dicarbazolyl triphenylethylene moieties with high thermal stability and aggregation-induced emission enhancement properties was synthesized. The glass transition temperature and 5% weight loss temperature of 3B-TPA are up to 214.3 °C and 516.8 °C, respectively. The compounds exhibited significant photoinduced intramolecular charge-transfer properties. The aggregation considerably affected the π–π* transition and resulted in 6–7 nm red shift of the π–π* absorption wavelength at the peak in UV-vis spectra. The compounds could emit intense blue-green light in aggregated states.
Co-reporter:Xiqi Zhang, Zhenguo Chi, Haiyin Li, Bingjia Xu, Xiaofang Li, Siwei Liu, Yi Zhang and Jiarui Xu
Journal of Materials Chemistry A 2011 - vol. 21(Issue 6) pp:NaN1796-1796
Publication Date(Web):2010/12/07
DOI:10.1039/C0JM02824J
A novel class of compounds containing tetraphenylethylene and dicarbazolyl triphenylethylene moieties combined with different spacers is synthesized. The compounds exhibit high thermal stabilities and aggregation-induced emission properties. The different spacers lead to differences in spatial conformation structures and spatial electron distributions, and markedly affect the thermal and photophysical properties of the compounds. The size of the aggregates formed in water–THF mixtures decreases with increasing water fractions. The time-resolved emission decay behaviors of the synthesized compounds in water–THF mixtures with water fractions from 60% to 99% show three relaxation pathways in their fluorescence decays.
Co-reporter:Haiyin Li, Zhenguo Chi, Bingjia Xu, Xiqi Zhang, Xiaofang Li, Siwei Liu, Yi Zhang and Jiarui Xu
Journal of Materials Chemistry A 2011 - vol. 21(Issue 11) pp:NaN3767-3767
Publication Date(Web):2011/01/31
DOI:10.1039/C0JM02571B
New compounds containing triphenylamine-anthrylenevinylene and tetraphenylethene moieties are synthesized by the Wittig–Horner reaction. The compounds exhibit weak emission in good solvents, but strong fluorescence in aggregates or in the solid state, indicating that they are aggregation-induced emission enhancement compounds. The symmetry of their molecular structure affects their aggregation structures and photoluminescence emission properties in aggregation. These compounds show high thermal stabilities with glass transition temperatures between 168–177 °C and decomposition temperatures between 521–537 °C. The HOMO levels of the compounds are in the region of 4.92–4.94 eV, very close to the work function of indium tin oxide anode (4.8–5.0 eV). One of the compounds exhibits obvious piezofluorochromic behavior. The piezofluorochromic nature is generated through changing the mode of molecular packing under external pressure.
Co-reporter:Yiwu Liu, Zhuxin Zhou, Lunjun Qu, Bing Zou, Zhiquan Chen, Yi Zhang, Siwei Liu, Zhenguo Chi, Xudong Chen and Jiarui Xu
Inorganic Chemistry Frontiers 2017 - vol. 1(Issue 2) pp:NaN337-337
Publication Date(Web):2016/08/12
DOI:10.1039/C6QM00027D
A series of high-performance multifunctional polyimides with exceptional thermostability and solubility (Tg as high as 494 °C and, at the same time, well soluble in common organic solvents) were successfully designed and synthesized by introducing a typical aromatic rigid trifluoromethyl-containing moiety with special non-planar and conjugated characteristics into the polymer backbone. Additionally, these polyimides show light color (one even colorlessness) and transparency, intrinsic ultralow dielectric constant (k, k ≈ 1.93), and electrical bistability characteristics (ON/OFF ratio as high as 107, working voltage as low as 1.5 V) simultaneously. The excellent thermal stability and solubility allow them to undergo the high temperature process (over 400 °C) in the preparation of photoelectric devices (like PVD or PECVD), or the highly efficient, continuous roll-to-roll process. The as-synthesized polymers are ideal potential candidates for practical applications in the fields of ultra-large-scale integration (ULSI), high-performance polymer memory devices, flexible displays, thin film PV industries, and wearable electronics.
Co-reporter:Bingjia Xu, Jiajun He, Yang Liu, Bin Xu, Qiangzhong Zhu, Mingyuan Xie, Zebo Zheng, Zhenguo Chi, Wenjing Tian, Chongjun Jin, Fuli Zhao, Yi Zhang and Jiarui Xu
Journal of Materials Chemistry A 2014 - vol. 2(Issue 17) pp:NaN3428-3428
Publication Date(Web):2014/01/22
DOI:10.1039/C3TC32052A
Two novel quadrupolar D–π–D type two-photon absorption (2PA) luminophores PA2F4H8E8 and AnA2F4H8E8 were synthesized by Wittig–Horner reaction in high yields. By using distyrylbenzene as the π-bridge center, PA2F4H8E8 shows two-photon absorption aggregation-induced emission enhancement (2PA-AIEE) and exhibits exceptionally large 2PA and 2PA action cross-sections up to ∼6300 GM and ∼1400 GM at 800 nm in THF, respectively. A non-doped electroluminescent (EL) device of PA2F4H8E8 displays good performance with an extremely low turn-on voltage of 2.6 V and a high brightness of 9837 cd m−2.
Co-reporter:Haiyin Li, Zhenguo Chi, Xiqi Zhang, Bingjia Xu, Siwei Liu, Yi Zhang and Jiarui Xu
Chemical Communications 2011 - vol. 47(Issue 40) pp:NaN11275-11275
Publication Date(Web):2011/09/19
DOI:10.1039/C1CC14642D
New thermally stable aggregation-induced emission enhancement compounds were synthesized. A non-doped red device showed a maximum brightness of 13535 cd m−2, a maximum current efficiency of 6.81 cd A−1, a maximum power efficiency of 4.96 lm W−1 and a low turn-on voltage of 4.3 V.
Co-reporter:Yi Zhang, Shanxiong Xiao, Qianyi Wang, Siwei Liu, Zhengping Qiao, Zhenguo Chi, Jiarui Xu and James Economy
Journal of Materials Chemistry A 2011 - vol. 21(Issue 38) pp:NaN14568-14568
Publication Date(Web):2011/08/18
DOI:10.1039/C1JM12450A
Novel thermally conductive, insulated polyimide nanocomposite films are reported here for microelectronics applications. A thermally conductive, insulated inorganic nanolayer of AlO(OH) was successfully coated onto the surface of MWCNTs, which, on the one hand, can effectively avoid the formation of MWCNT electrically conductive networks in the PI matrix and, on the other, can provide the advantage of excellent thermal conductivity properties of the MWCNTs.
Co-reporter:Xiqi Zhang, Zhenguo Chi, Yi Zhang, Siwei Liu and Jiarui Xu
Journal of Materials Chemistry A 2013 - vol. 1(Issue 21) pp:NaN3390-3390
Publication Date(Web):2013/03/13
DOI:10.1039/C3TC30316K
Mechanochromic luminescent metal complexes have recently attracted considerable interest as smart materials for use in the fields of luminescence switches, mechanosensors, mechanohistory indicators, security papers, optoelectronic devices, and data storage. In this review, recent advancements in metal complex mechanochromic luminescence are summarized. The majority of the reported mechanochromic luminescent metal complex systems are discussed, including Zn(II), Au(I), Pt(II), Ag(I), Cu(I), Al(III), and Ir(III) complexes. Aggregation-induced emission (AIE) complexes are described based on the existence of a structural relationship between AIE compounds and mechanochromism. It is expected that AIE complexes may become important alternative sources of mechanochromic luminescent complexes.
Co-reporter:Chunping Ma, Bingjia Xu, Gaoyi Xie, Jiajun He, Xie Zhou, Bangyin Peng, Long Jiang, Bin Xu, Wenjing Tian, Zhenguo Chi, Siwei Liu, Yi Zhang and Jiarui Xu
Chemical Communications 2014 - vol. 50(Issue 55) pp:NaN7377-7377
Publication Date(Web):2014/05/16
DOI:10.1039/C4CC01012D
A novel luminophore TPENSOH was facilely synthesized from the building blocks of tetraphenylethylene and 6-hydroxylbenzothiazole and exhibited unique AIE properties. This new dye was found to show a remarkable and reversible four-color switching based on a single molecule in the solid state.
Co-reporter:Zhiyong Yang, Zhenguo Chi, Tao Yu, Xiqi Zhang, Meina Chen, Bingjia Xu, Siwei Liu, Yi Zhang and Jiarui Xu
Journal of Materials Chemistry A 2009 - vol. 19(Issue 31) pp:NaN5546-5546
Publication Date(Web):2009/06/19
DOI:10.1039/B902802A
A new class of aggregation-induced emission (AIE) compounds with strong blue-light-emitting properties and a high thermal stability, derived from triphenylethylene carbazole, has been synthesized. Their glass transition temperatures range from 126–151 °C and the maximum fluorescence emission wavelengths are 451–466 nm.
Co-reporter:Yiwu Liu, Yi Zhang, Xinhui Wu, Qi Lan, Chuansen Chen, Siwei Liu, Zhenguo Chi, Long Jiang, Xudong Chen and Jiarui Xu
Journal of Materials Chemistry A 2014 - vol. 2(Issue 6) pp:NaN1075-1075
Publication Date(Web):2013/11/07
DOI:10.1039/C3TC31825G
We have designed and synthesized a novel deep-blue luminescent compound (WuFDA), which can emit efficiently both in solution and in the aggregated state; the fluorescence emission maximum of WuFDA in the aggregated state shows a remarkable blue-shift from that shown in the dilute solution. Moreover, WuFDA shows interesting fluorescent behaviour in mixed solvent systems of THF–H2O, and a solvent effect in different polar solvents. These unusual phenomena have been interpreted by studies of the single crystalline structure of WuFDA and density functional theory (DFT) investigations. The special chemical structure (containing a planar conjugated fluorene core and strong polar groups (–NH and –F)) and their location in the molecule formed a typical non-planar D–π–A molecule with strong internal charge transfer (ICT). Such a polar molecule possesses the ability to form hydrogen bond interactions with itself, as well as with the polar solvents. Both the ICT effect and the intermolecular hydrogen bond interactions play very important roles in the geometrical manner of aggregation and the fluorescent behaviours of the WuFDA. In addition, WuFDA exhibited good thermal stability, with 5% and 10% weight-loss temperatures (Td) of WuFDA in nitrogen of 399 and 414 °C, respectively, and the glass transition temperature (Tg) was about 161 °C.
Co-reporter:Xiqi Zhang, Zhiyong Yang, Zhenguo Chi, Meina Chen, Bingjia Xu, Chengcheng Wang, Siwei Liu, Yi Zhang and Jiarui Xu
Journal of Materials Chemistry A 2010 - vol. 20(Issue 2) pp:NaN298-298
Publication Date(Web):2009/11/09
DOI:10.1039/B910718E
A new cyanoacrylic acid derivative of carbazole-triphenylethylene as a fluorescent probe has been synthesized and characterized. The derivative exhibits not only aggregation-induced effect (AIE) properties, but also interesting fluorescence multi-responses to solvents, water, ethanol and metal ions due to its chemical structure. Responses of the compound solution in DMF to water can be explained in terms of H-bond, multimer and AIE effects. In addition, the derivative was found to be highly sensitive to potassium ions. It is suggested that the compound has potential applications in chemosensors.
Co-reporter:Huawei Sun, Yi Zhang, Wei Yan, Wenxin Chen, Qi Lan, Siwei Liu, Long Jiang, Zhenguo Chi, Xudong Chen and Jiarui Xu
Journal of Materials Chemistry A 2014 - vol. 2(Issue 29) pp:NaN5817-5817
Publication Date(Web):2014/05/12
DOI:10.1039/C4TC00553H
A novel ultrasonic-sensitive mechanofluorochromic AIE-compound (ITPADA) has been designed and synthesized. The fluorescent properties of the ITPADA suspensions were greatly affected by the ultrasonic treatment and extremely sensitive to its power, which show remarkable blue-shifting and enhanced emission. Moreover, perfect ITPADA nano-sheets could be obtained by facile ultrasonic treatment.
Co-reporter:Bingjia Xu, Zhenguo Chi, Xiqi Zhang, Haiyin Li, Chengjian Chen, Siwei Liu, Yi Zhang and Jiarui Xu
Chemical Communications 2011 - vol. 47(Issue 39) pp:NaN11082-11082
Publication Date(Web):2011/08/30
DOI:10.1039/C1CC13790E
A new ligand containing tetraphenylethylene and terpyridine moieties, and its zinc ion complex were synthesized. Both of them exhibit an aggregation-induced emission effect. Their colors and emissions can be smartly switched by various external stimuli including grinding, heating and solvent-fuming, as well as exposure to acid and base vapors.
Co-reporter:Bingjia Xu, Jiajun He, Yingxiao Mu, Qiangzhong Zhu, Sikai Wu, Yifan Wang, Yi Zhang, Chongjun Jin, Changcheng Lo, Zhenguo Chi, Alan Lien, Siwei Liu and Jiarui Xu
Chemical Science (2010-Present) 2015 - vol. 6(Issue 5) pp:NaN3241-3241
Publication Date(Web):2015/03/18
DOI:10.1039/C5SC00466G
Organic materials exhibiting mechanoluminescence (ML) are promising for usage in displays, lighting and sensing. However, the mechanism for ML generation remains unclear, and the light-emitting performance of organic ML materials in the solid state has been severely limited by an aggregation-caused quenching (ACQ) effect. Herein, we present two strongly photoluminescent polymorphs (i.e., Cg and Cb) with distinctly different ML activities based on a tetraphenylethene derivative P4TA. As an aggregation-induced emission (AIE) emitter, P4TA perfectly surmounted the ACQ, making the resultant block-like crystals in the Cg phase exhibit brilliant green ML under daylight at room temperature. The ML-inactive prism-like crystals Cb can also have their ML turned on by transitioning toward Cg with the aid of dichloromethane vapor. Moreover, the Cg polymorph shows ML and mechanochromism simultaneously and respectively without and with UV irradiation under a force stimulus, thus suggesting a feasible design direction for the development of efficient and multifunctional ML materials.
Co-reporter:Zhenguo Chi, Xiqi Zhang, Bingjia Xu, Xie Zhou, Chunping Ma, Yi Zhang, Siwei Liu and Jiarui Xu
Chemical Society Reviews 2012 - vol. 41(Issue 10) pp:NaN3896-3896
Publication Date(Web):2012/03/26
DOI:10.1039/C2CS35016E
Mechanofluorochromic materials, which are dependent on changes in physical molecular packing modes, have attracted considerable interest over the past ten years. In this review, recent progress in the area of pure organic mechanofluorochromism is summarized, and majority of the reported organic mechanofluorochromic systems are discussed, along with their derived structure–property relationships. The existence of a structural relationship between aggregation-induced emission compounds and mechanofluorochromism is recognized based on our recent results, which considered aggregation-induced emission compounds as a well of mechanofluorochromic materials. The established structure–property relationship will guide researchers in identifying and synthesizing more mechanofluorochromic materials.
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