Co-reporter:Hao Wu, Zhimin Chen, Jialin Zhang, Feng Wu, Chunying He, Zhiyu Ren, and Yiqun Wu
Chemistry of Materials November 14, 2017 Volume 29(Issue 21) pp:9509-9509
Publication Date(Web):October 20, 2017
DOI:10.1021/acs.chemmater.7b03645
Manipulating the morphology and protonic acid doping of polyaniline (PANI) is significant for optimizing its NH3-sensing. Herein, tetra-β-carboxyphthalocyanine cobalt(II) (TcPcCo) acted as the dopant and structure-directing agent simultaneously to fabricate the uniform fibrous network-like PANI (PANI-TcPcCo hybrids) by a one-step polymerization at low temperature. During the reaction process, the protonic acid groups in TcPcCo not only induced the aniline monomers polymerizing into one-dimensional nanofibers (consist of both solid and hollow cylinders) with abundant tiny protuberances on the surface but also successfully doped into PANI. The resulting PANI-TcPcCo hybrids displayed the enhancement in terms of the good conductivity, the large gas adsorption capacity, and the unobstructed channels for the electron and gas transport. The central metal atoms of TcPcCo present the strong and selective affinity to NH3. Meanwhile, the deep-seated conversion of PANI’s molecular structure after exposure in NH3 could occur due to the presence of TcPcCo. Thus, the PANI-2.5TcPcCo sensor showed the excellent NH3-sensing performance at room temperature, including an ultrahigh and fast response (802.7% and ∼17.0 s for 100 ppm of NH3), a very low detection limit of 10 ppb (about 5000 parts of human olfaction limit of detection, 55 ppm), and superior NH3-sensing stability and selectivity. The strategy developed here provides a reliable and valid way to synthesize functional PANI-based hybrids with unique morphology and appropriate doping, which are able to be extended to other areas.
Co-reporter:Yong Li;Bin Wang;Zheying Yu;Xiaoqing Zhou;Di Kang;Zhimin Chen;Chunying He;Xin Zhou
RSC Advances (2011-Present) 2017 vol. 7(Issue 54) pp:34215-34225
Publication Date(Web):2017/07/04
DOI:10.1039/C7RA06081E
Cost-efficient, highly sensitive, selective and stable sensing materials play a key role in developing NH3 sensors. Herein, a series of tetra-β-aminephthalocyanines metal(II) (aPcMs M = Cu, Ni, Co, Fe) have been successfully covalently bonded on the surface of graphene oxide (GO) by a facile amidation reaction. The obtained aPcM–GO hybrids display good dispersibility, which is beneficial to construct uniform sensing devices. The aPcM–GO sensors exhibit excellent sensing performance in terms of sensitivity, reversibility, reproducibility, selectivity and stability, especially the aPcCo–GO sensor which exhibited a response of about 11.6% (50 ppm), a limit of detection as low as 800 ppb, and a recovery time of about as fast as 350 s at room temperature. The enhanced NH3-sensing performance is mainly due to the synergistic effect between aPcM and GO, e.g. the stronger adsorption interaction of aPcM with NH3, the high electrical conductivity of GO, and the fast charge transfer between aPcM and GO. By comparison, the response of aPcM–GO hybrids to ammonia decreases gradually in the following order of Co > Cu > Ni > Fe ≫ GO, indicating that the central metals play a critical role in gas sensitivity toward NH3, which is further confirmed by first-principle density functional theory.
Co-reporter:Zheying Yu;Bin Wang;Yong Li;Di Kang;Zhimin Chen
RSC Advances (2011-Present) 2017 vol. 7(Issue 36) pp:22599-22609
Publication Date(Web):2017/04/19
DOI:10.1039/C7RA02740K
Herein, we report a type of enhanced ammonia (NH3) sensing materials formed by the functionalization of reduced graphene oxide (RGO) with 1,8,15,22-tetra-(4-tert-butylphenoxyl)-metallophthalocyanine (TBPOMPc, M = Cu, Ni, and Pb) via a solution self-assembly method based on π–π stacking interactions. The RGO/TBPOMPc hybrids exhibit excellent sensitivity, high response value, and fast response and recovery at room temperature, especially the RGO/TBPOPbPc sensor. The enhancement of the NH3-sensing performance by TBPOMPc with a rigid phenoxyl-substituted group is attributed to the self-assembly behavior of TBPOMPc molecules. The rigid structure of TBPOMPc effectively prevents the intermolecular aggregation behavior. On the one hand, it expands the specific surface area of the RGO/TBPOMPc hybrids, which is propitious for the physical adsorption and diffusion of NH3 molecules and reduces the response and recovery time. On the other hand, it weakens the electronic interaction between TBPOMPc molecules and results in reducing the resistance of charge transfer from NH3 to TBPOMPc. Moreover, TBPOMPc is beneficial to enhance the sensitivity and selectivity of the RGO/TBPOMPc sensors towards NH3. By contrast, the response of various RGO/TBPOMPc sensors decreases in the order of RGO/TBPOPbPc > RGO/TBPOCuPc > RGO/TBPONiPc. Furthermore, the rigid structure and central metals of TBPOMPc play a critical role in the sensitivity of NH3, as evidenced from the scanning tunneling microscopy, current–voltage characteristics, and electrochemical impedance spectra.
Co-reporter:Kui Zhang;Zhimin Chen;Jingsong Wei;Tao Wei;Youyong Geng;Yang Wang
Physical Chemistry Chemical Physics 2017 vol. 19(Issue 20) pp:13272-13280
Publication Date(Web):2017/05/24
DOI:10.1039/C7CP00477J
Semiconductor diode-based laser patterning with visible light has been extensively applied to the fabrication of arbitrary structures. However, recently, the technique has faced a great challenge because it cannot meet nanoscale-resolved patterning fabrication due to the optical diffraction limit, which is an inherent drawback in the field of optics. To attack the question, copper(II)–hydrazone-complex (CuL2) thin films are used as laser patterning materials. Under the heating of a writing laser spot, one-step laser nanopatterning on the CuL2 thin films is obtained. The convex-type and concave-type pattern structures are directly written without wet-etching and developing processes. The minimum pattern feature size is about 31 nm, which is far smaller than the diffraction limit and only ∼1/20 the writing spot size. Analysis indicates that the laser nanopatterning originates from obvious photothermal localization responses to the writing spot. Compared with common organic resists, the exposure dose of CuL2 is several orders higher than that of the polymer; thus CuL2 thin film materials are suitable for maskless direct laser writing lithography. This work also provides an effective method for one-step nanopatternings through diode-based laser writing at visible light wavelengths.
Co-reporter:Shuheng Chi, Liang Li and Yiqun Wu
RSC Advances 2016 vol. 6(Issue 74) pp:69748-69757
Publication Date(Web):15 Jul 2016
DOI:10.1039/C6RA12193D
A series of novel pyridine mono-cationic two-photon fluorescent probes based on different central π-conjugated bridges, fluorenone (W-pyI), dibenzothiophene (S-pyI), and dibenzofuran (F-pyI), were prepared and studied. Under one-photon excitation in a N,N-dimethylformamide solution, W-pyI, S-pyI, and F-pyI displayed fluorescence quantum yields of 0.401, 0.425, and 0.09, respectively. The two-photon fluorescence performance indicated that these probes possessed two-photon absorption cross-sections of 681 GM (W-pyI), 630 GM (S-pyI), and 620 GM (F-pyI) at 800 nm femtosecond laser excitation. The luminance “turn-on” effect of W-pyI, S-pyI, and F-pyI bonding with calf thymus DNA in Tris–HCl buffer solutions displayed 58-fold, 30-fold, and 25-fold fluorescence quantum yield increments, respectively, and 350–450% two-photon absorption cross-section enhancement. The confocal fluorescence imaging showed clear one- and two-photon fluorescence imaging. The mean co-localization coefficients between these probes and Hoechst 33342 in 3T3 cells ranged from 0.89–0.92, indicating that they showed excellent nuclear targeting abilities. The counterstaining experiments showed these probes possessed good counterstaining compatibility and membrane permeability in the application of multicolor targeting. A time-dependent fluorescence intensity test under continuous femtosecond laser irradiation showed that W-pyI possessed a longer observation time (3000 seconds) and a lower fluorescence attenuation amplitude (7.1%) in the first 300 seconds than S-pyI, F-pyI and other previously reported pyridinium derivatives, demonstrating that the central π-conjugated bridge “fluorenone” played a key role in improving photostability during probe designing for two-photon bioimaging applications.
Co-reporter:Shoulei Miao, Haiqiu Zhang, Xiaobo Li, Yiqun Wu
International Journal of Hydrogen Energy 2016 Volume 41(Issue 1) pp:331-341
Publication Date(Web):5 January 2016
DOI:10.1016/j.ijhydene.2015.10.080
•The sulfonic acid groups adequately functionalized graphene oxide (FGO) was prepared.•The relationships between the properties and morphologies of the membranes were established.•The properties of the composite membrane with 5% FGO was blended is more super than Nafion117®.In this study, the sulfonic acid groups' adequately functionalized graphene oxide (FGO) was prepared using a temperate and controllable method. The morphological changes of the FGO and sulfonated polyarylene ether sulfone (SPES) composite membranes were investigated in detail by using X-ray scattering (SAXS), atom force microscopy (AFM), transmission electron microscopy (TEM), scanning with an electron microscope (SEM), and so on. The SAXS showed an increscent d-spacing, and reflected the enlargement of the ionic clusters, which was caused by the addition of sulfonated groups into the composite membranes. The AFM and TEM showed phase separation phenomenon. The phase separations led to the formation of more continuous and larger channels for proton conducting. Also, the SEM pictures intuitively showed the inner-structures of the membranes. When a small amount of the FGO was blended, the structure of the composite membrane was compact. The compact structures resulted in the improvement of the mechanical properties and methanol resistance. However, when more of the FGO was blended, the structures became loose and caused damage to the mechanical properties. The FGO can effectively hinder the methanol passing through and enhance the water retention by its special sheeted structure. The properties of the composite membrane with a 5% blended FGO was found to be superior to that of Nafion117® and other samples. It was determined that the changed properties of the composite membranes must have been derived from the different microstructures. The relationships between the properties and the morphologies of the samples were established in detail. Therefore, this study provides helpful information regarding the design of excellent proton exchange membranes.
Co-reporter:Shuheng Chi, Liang Li, Yiqun Wu
Sensors and Actuators B: Chemical 2016 Volume 231() pp:811-829
Publication Date(Web):August 2016
DOI:10.1016/j.snb.2016.03.006
In this study, a series of novel dibenzothiophene-based two-photon excited fluorescence (TPEF) probes with excellent nuclear staining ability were prepared and investigated. The one-photon photophysical properties indicated these labels possessed UV absorption wavelength of 390–393 nm and quantum yields of 0.425–0.71. The two-photon photophysical performance exhibited two-photon absorption (TPA) cross-sections of 506–630 GM by excitation of femtosecond laser at a wavelength of 800 nm. 18–30-fold one-photon excited fluorescence (OPEF) enhancement and 300–450% TPEF increment binding with calf thymus DNA in Tris-HCl buffer solutions displayed obvious fluorescence “turn-on” effect. The co-localization studies showed mean co-localization coefficients of 0.88–0.94 by double-staining with commercial nuclear staining reagent DAPI in 3T3 cells, indicating accurate nuclear localization ability. The confocal fluorescence imaging displayed clear TPEF nuclear imaging. The staining penetration depth of 0–9 μm exhibited good membrane permeability and three dimensional imaging ability. The observation time of 1800 s and fluorescence decay amplitude of 8–10% within 300 s under persistent irradiation were achieved in TPEF imaging for nuclear labeling. The DNA binding mechanism was discussed as well.
Co-reporter:Shuheng Chi
The Journal of Physical Chemistry C 2016 Volume 120(Issue 25) pp:13706-13715
Publication Date(Web):June 6, 2016
DOI:10.1021/acs.jpcc.6b02827
A series of fluorenone-based two-photon fluorescent probes with high photostability for nucleus imaging are prepared and developed. The one- and two-photon photophysical properties exhibit these new probes possess 0.448–0.634 of fluorescence quantum yields and 469–495 GM of two-photon absorption cross sections at 800 nm femtosecond laser excitation. The luminescence “turn-on” experiment in buffer solutions indicates that 35-fold of fluorescence intensity and 68-fold fluorescence quantum yield enhancement appear between new probes and calf thymus DNA. In the nuclear double-staining experiment, the high mean colocalization coefficients of 0.92–0.96 between new probes and nuclear labeling dye Hoechst 33342 are acquired, demonstrating excellent nuclear localization in 3T3 cells. The counterstain studies by introducing commercial mitochondrial staining reagent MTR and nuclear staining dye DAPI further show good membrane permeability and counterstain compatibility in multicolor cell labeling application. The photostability studies show that 3000 s of observation time and 0.028%/s–0.03%/s of mean fluorescence attenuation rates under persistent laser irradiation in two-photon nuclear imaging are achieved. Meanwhile, the cause of fluorescence attenuation in the photostability test for cellular nuclei monitoring are discussed as well.
Co-reporter:Weina Song, Chunying He, Yongli Dong, Wang Zhang, Yachen Gao, Yiqun Wu and Zhimin Chen
Physical Chemistry Chemical Physics 2015 vol. 17(Issue 11) pp:7149-7157
Publication Date(Web):05 Feb 2015
DOI:10.1039/C4CP05963H
Reduced graphene oxide–metal(II) phthalocyanine (RGO–MPc, M = Cu, Zn and Pb) hybrid materials have been prepared by the covalent functionalization method. The resultant RGO–MPc hybrids are characterized by scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared, ultraviolet-visible absorption and fluorescence spectroscopy. The RGO–MPc hybrids exhibit strong fluorescence quenching by means of the photo-induced electron transfer or the energy transfer (PET/ET) process between the RGO and MPc moieties. The PET/ET process particularly depends on the fluorescence quantum yield of MPc molecules with different central metals. The nonlinear optical (NLO) properties of the RGO–MPc hybrids are investigated by using the Z-scan technique at 532 nm with 4 ns laser pulses. The results show that the NLO properties of MPc molecules increase in the order of Zn < Pb < Cu, but the RGO–MPc hybrids exhibit NLO performance in the inverse sequence of Zn > Pb > Cu, implying that the NLO response arising from the efficient PET/ET process between RGO and MPc may play a more important role in the NLO properties of RGO–MPc hybrids than that originating from the MPc moiety.
Co-reporter:Liang Li, Ping Wang, Yanlei Hu, Geng Lin, Yiqun Wu, Wenhao Huang, Quanzhong Zhao
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 2015 Volume 139() pp:243-252
Publication Date(Web):15 March 2015
DOI:10.1016/j.saa.2014.10.122
•Novel carbazole derivatives containing quinoline were synthesized.•Electronic transition of carbazole derivatives were theoretically studied by TD-DFT.•Two-photon absorption of compounds was measured by 120 fs pulse at 800 nm.•7-layer data storage was realized by two-photon 3D optical data storage system.We designed carbazole unit with an extended π conjugation by employing Vilsmeier formylation reaction and Knoevenagel condensation to facilitate the functional groups of quinoline from 3- or 3,6-position of carbazole. Two compounds doped with poly(methyl methacrylate) (PMMA) films were prepared. To explore the electronic transition properties of these compounds, one-photon absorption properties were experimentally measured and theoretically calculated by using the time-dependent density functional theory. We surveyed these films by using an 800 nm Ti:sapphire 120-fs laser with two-photon absorption (TPA) fluorescence emission properties and TPA coefficients to obtain the TPA cross sections. A three-dimensional optical data storage experiment was conducted by using a TPA photoreaction with an 800 nm-fs laser on the film to obtain a seven-layer optical data storage. The experiment proves that these carbazole derivatives are well suited for two-photon 3D optical storage, thus laying the foundation for the research of multilayer high-density and ultra-high-density optical information storage materials.
Co-reporter:Kui Zhang;Yongyou Geng;Yang Wang
Frontiers of Optoelectronics 2014 Volume 7( Issue 4) pp:475-485
Publication Date(Web):2014 December
DOI:10.1007/s12200-014-0418-2
The era of big data has necessitated the use of ultra-high density optical storage devices. Super-resolution near-field structure (super-RENS), which has successfully surpassed the fundamental optical diffraction limit, is one of the promising next generation high-density optical storage technologies. This technology combines the traditional super-resolution optical disk with a near-field structure, and has the advantages of structural simplicity, strong practicability, and, more importantly, compatibility with the current optical storage pickup. The mask layer in super-RENS functions as the key to realizing super-resolution. Development of suitable materials and stack designs has greatly been improved in the last decade. This paper described several types of super-RENS, such as aperture-type, light scattering center-type, bubble-type, and other types (e.g., WOx and ZnO), particularly the newly proposed super-RENS technology and research achievements. The paper also reviews the applications of super-RENS in high-density optical data storage in recent years. After analyzing and comparing various types of super-RENS technology, the paper proposes the aperturetype based on the mechanism of nonlinear optics as the most suitable candidate for practical applications in the near future.
Co-reporter:Bin Wang, Yiqun Wu, Xiaolin Wang, Zhimin Chen, Chunying He
Sensors and Actuators B: Chemical 2014 190() pp: 157-164
Publication Date(Web):
DOI:10.1016/j.snb.2013.08.066
Co-reporter:Xiaoqing Zhou, Xiaolin Wang, Bin Wang, Zhimin Chen, Chunying He, Yiqun Wu
Sensors and Actuators B: Chemical 2014 193() pp: 340-348
Publication Date(Web):
DOI:10.1016/j.snb.2013.11.090
Co-reporter:Changmeng Deng, Yongyou Geng and Yiqun Wu
Journal of Materials Chemistry A 2013 vol. 1(Issue 13) pp:2470-2476
Publication Date(Web):11 Feb 2013
DOI:10.1039/C3TC00274H
The past 40 years have witnessed the rapid development of lithography technologies. New technologies in the field spring up every day. A technology with simple process steps, low cost and high output is always the dream target of the industry community. In this paper, a maskless and development-free lithography method is proposed based on two new calix[4]arene derivatives as the resists. By this method, micro/nano-pattern structures can be fabricated by means of a simple process, with short time and at relatively low cost. To achieve such a goal, the resist materials must meet certain requirements, and few papers in the literature have dealt with the method because a general resist cannot meet all the requirements. Two calix[4]arene derivatives with designed and optimized molecular structures are chosen as the resists to meet the requirements, and they exhibit different performances because of their different molecular structures. Concave and convex pattern structures are obtained using the two calix[4]arene derivative films i.e. TCHC and THMC films, by direct laser writing lithography. The concave pattern structures are formed on the TCHC films through directly vaporizing the TCHC films based on laser induced thermal effects, whereas the convex pattern structures are formed on the THMC films due to the enhancement of plasticity.
Co-reporter:Liang Li, Ping Wang, Yichi Zhang, Yiqun Wu, Zhimin Chen, Chunying He
Journal of Molecular Structure 2013 Volume 1051() pp:23-29
Publication Date(Web):5 November 2013
DOI:10.1016/j.molstruc.2013.07.042
•Novel carbazole derivatives containing quinoline were synthesized.•Electronic transition of carbazole derivatives were theoretically studied by TD-DFT.•Long fluorescence lifetime of carbazole derivatives was obtained.•Two-photon absorption of compounds was measured by 120 fs pulse at 800 nm.The carbazole derivatives are suitable for two-photon absorption optical storage and photoluminescence material. Two carbazole derivatives, asymmetrical and symmetrical type molecules containing quinoline rings as electron acceptors and an N-ethylcarbazole group as electron donor, 9-ethyl-3-(2-quinolin)viny-carbazole (4) and 9-ethyl-3,6-bis(2-(quinolin)vinyl)-carbazole (5), had been synthesized by the Vilsmeier reaction of formylation and Knoevenagel condensation. The one-photon properties including absorption, fluorescence emission spectra, fluorescence quantum yields and fluorescence decay behaviors were investigated in N,N-dimethylformamide. Meanwhile, these compounds were theoretically surveyed by the density functional theory (DFT) and the time-dependent functional theory (TD-DFT). The two-photon excited fluorescence and two-photon absorption cross-sections were measured for the compounds by 120 fs pulse at 800 nm Ti: sapphire laser operating at 1 kHz repetition rate. The results showed that both of the two compounds 4 and 5 had higher fluorescence quantum yield (Φ) of 0.77 and 0.81 comparing with carbazole. Compounds 5 with symmetric π conjugated structure possessed longer fluorescence lifetime (τ) of 21.4 ns and larger two-photon absorption cross-sections (δTPA) of 364 × 10−50 cm4 s/photon than those of compounds 4 with asymmetric π conjugated structure (τ = 10.03 ns and δTPA = 81 × 10−50 cm4 s/photon). It was indicated that the one and two-photon optical properties of carbazole derivatives are influenced strongly by the symmetry and length of π conjugated structure.
Co-reporter:Changmeng Deng, Yongyou Geng, Yiqun Wu, Yang Wang, Jinsong Wei
Microelectronic Engineering 2013 Volume 103() pp:7-11
Publication Date(Web):March 2013
DOI:10.1016/j.mee.2012.08.018
Adhesion of pattern structures is a very important issue in laser thermal lithography. In this paper, Si3N4 and ZnS–SiO2 were investigated as interface layers to improve patterns’ adhesion to substrate on pattern fabrication with Ge2Sb2Te5 as laser thermal lithography film. Patterns were fabricated by laser direct irradiation with 650 nm and 405 nm laser writing systems (both NA = 0.9) and wet etching with 25 wt.% tetramethylammonium hydroxide solution. Experimental results showed that patterns were flaked off mostly and partly from the substrate in wet-etching process for samples without interface layer and with Si3N4 film as interface layer, respectively; but for samples with ZnS–SiO2 film as interface layer, regular and clear patterns were fabricated successfully under different fabrication conditions, and sub-wavelength line structures with width approaching to 390 nm were achieved by 405 nm laser system. The mechanism analysis implied that the matches of materials’ thermal parameters might play important roles in the adhesion effect of interface layers on pattern fabrication.Graphical abstractHighlights► Adhesion effect of Si3N4 and ZnS–SiO2 on pattern fabrication is investigated. ► Regular patterns are fabricated successfully in Ge2Sb2Te5 thin films. ► Sub-wavelength line structures were achieved by a 405 nm writing system. ► Thermal properties’ matches play important roles in improving adhesion of patterns.
Co-reporter:Liang Li;Ningning Yuan;Ping Wang;Yinglin Song;Zhimin Chen;Chunying He
Journal of Physical Organic Chemistry 2012 Volume 25( Issue 10) pp:872-877
Publication Date(Web):
DOI:10.1002/poc.2937
Three-photon absorption (3PA) properties of symmetric-type carbazole derivatives show great potential for application in light-activated therapy and optical limiting. A novel symmetrical carbazole derivative (abbreviated as POCP) with end-groups of 1,10-phenanthroline rings as the donor moieties, chained via carbon–nitrogen (C = N) double bond, has been synthetized and its three photon absorption properties has been also determined by using a Q-switched Nd: YAG laser pumped with 30 ps pulses at 1064 nm in dimethylformamide. The measurement of 3PA cross-section of this compound is performed by open aperture Z-scan and σ3PA is 481 × 10–78 cm6 • s2/photon2 for the transition S0 S1. The influence of the molecular structure of this compound on three-photon absorption cross-sections is discussed micromechanically by Austin model 1 and Zerner's Intermediate Neglect of Differential Overlap/S method. Copyright © 2012 John Wiley & Sons, Ltd.
Co-reporter:Liang Li;Qinling Zhou;Chunying He
Journal of Physical Organic Chemistry 2012 Volume 25( Issue 5) pp:362-372
Publication Date(Web):
DOI:10.1002/poc.1923
Symmetric-type carbazole derivatives show great potential for application in two-photon absorption (TPA) materials and organic light-emitting diodes. The absorption spectra and fluorescence emission spectra of three different N-alkyl symmetric-type carbazole derivatives were investigated. The density functional theory (DFT) time-dependent-DFT//Becke, three-parameter, Lee–Yang–Parr/6-31 G* method has been used to theoretically study one-photon absorption properties. The computational results are in good agreement with the available experimental values. The two-photon excited fluorescence of the compounds was surveyed by 120 fs pulse at 790 nm Ti: sapphire laser operating at 1 kHz repetition rate. Two-photon excited fluorescence was obtained in the range of 380–600 nm, and TPA cross-sections were calculated. The TPA properties of the series of compounds were investigated by the ZINDO/single and double electronic excitation configuration interaction method. The influence of the chemical structure of the compounds on two-photon optical properties was discussed. The results show how the different changes in one-photon absorption and TPA properties on the basis of lengthening the conjugated bridge and the different carbazole N-alkyl substituents are attributed to the transition dipole moment in the excited process. Copyright © 2011 John Wiley & Sons, Ltd.
Co-reporter:Bin Wang, Xiaoqing Zhou, Yiqun Wu, Zhimin Chen, Chunying He
Sensors and Actuators B: Chemical 2012 s 171–172() pp: 398-404
Publication Date(Web):
DOI:10.1016/j.snb.2012.04.084
Co-reporter:Bin Wang, Xiaoqing Zhou, Yiqun Wu, Zhimin Chen, Chunying He, Xia Zuo
Sensors and Actuators B: Chemical 2012 Volume 161(Issue 1) pp:498-503
Publication Date(Web):3 January 2012
DOI:10.1016/j.snb.2011.10.067
Spin-coating films of copper, lead and nickel 1,8,15,22-tetra-iso-pentyloxyphthalocyanine (Cu, Pb and NiPc(iso-PeO)4) were obtained and characterized by absorption spectra and atomic force microscopy. The gas sensing behaviors of the films were investigated with respect to NH3 at room temperature. In addition, the effects of film morphology and center metal on gas sensing properties were also discussed. It was found that the MPc(iso-PeO)4 films exhibited good response, reversibility, stability and faster response and recovery characteristic to NH3. The responses were in the following order: CuPc(iso-PeO)4, PbPc(iso-PeO)4 and NiPc(iso-PeO)4, and the response and recovery were in the following order: CuPc(iso-PeO)4, NiPc(iso-PeO)4 and PbPc(iso-PeO)4.
Co-reporter:Bin Wang, Zhimin Chen, Xia Zuo, Yiqun Wu, Chunying He, Xiaolin Wang, Zan Li
Sensors and Actuators B: Chemical 2011 160(1) pp: 1-6
Publication Date(Web):
DOI:10.1016/j.snb.2011.06.049
Co-reporter:Bin Wang, Xia Zuo, Yiqun Wu, Zhimim Chen, Chunying He, Wubiao Duan
Sensors and Actuators B: Chemical 2011 Volume 152(Issue 2) pp:191-195
Publication Date(Web):1 March 2011
DOI:10.1016/j.snb.2010.12.006
Co-reporter:Zhimin Chen, Yiqun Wu, Donghong Gu, Fuxi Gan
Dyes and Pigments 2010 Volume 86(Issue 1) pp:42-49
Publication Date(Web):June 2010
DOI:10.1016/j.dyepig.2009.11.006
Using pivaloylacetonitrile as starting material and coupling component, a novel hydrazone ligand and four, highly organosoluble metal(II) complexes were synthesized via the procedure of oximation, cyclization, diazotization, coupling and metal chelation. In addition to elemental analysis, the structures of the novel compounds were postulated based on a series of spectroscopic methods. Smooth thin films of these metal(II) complexes on K9 glass substrates were prepared by spin-coating from 2,2,3,3-tetrafluoro-1-propanol solutions. The behaviour and relationships of the absorption bands both in solution and in spin-coated films are discussed; the thermal properties, photostability and the solubility of the metal(II) complexes were investigated. The synthesized Ni(II) complex exhibited a remarkable combination of excellent solubility and photostability, suitable absorption band and desirable thermal properties and, therefore, offers the potential of becoming a recording material for the recordable blu-ray disc system.
Co-reporter:Xiaoyi Li, Yiqun Wu, Donghong Gu, Fuxi Gan
Dyes and Pigments 2010 Volume 86(Issue 2) pp:182-189
Publication Date(Web):July 2010
DOI:10.1016/j.dyepig.2010.01.002
A novel ligand, (Z)-1,5-dimethyl-4-(2-(3-methyl-5-oxo-1-phenyl-1H-pyrazol-4(5H)-ylidene)hydrazinyl)-2-phenyl-1,2-dihydropyrazol-3-one] and its metal(II)–azo complexes were synthesized and characterized using elemental analyses, proton NMR, electrospray ionization mass spectrometry, FT-IR and UV–visible absorption. Smooth thin films of the metal(II)–azo complexes were prepared using spin-coating, and the absorption spectra of the films were measured. The thermal properties of the metal(ІІ)–azo complexes were investigated using TGA and DSC. The optical constants (complex refractive index N = n + ik) of the films on single-crystal silicon were determined using variable-angle scanning ellipsometry from which the complex dielectric function (ɛ) and absorption coefficient (α) were calculated. The photostabilities of the metal(II)–azo complex films were also investigated.
Co-reporter:Xiaoyi Li, Yiqun Wu, Donghong Gu, Fuxi Gan
Thermochimica Acta 2009 Volume 493(1–2) pp:85-89
Publication Date(Web):10 September 2009
DOI:10.1016/j.tca.2009.04.010
Thermal decomposition kinetics of ML2 (M = Ni(II) and Co(II); L = 5-(2-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)hydrazono)-1,3-dimethylpyrimidine-2,4,6(1H,3H,5H)-trione) complexes were investigated by thermogravimetric analysis (TGA). The first decomposition process of the NiL2 and CoL2 complexes occurs in the temperature range of 320–350 °C. Kinetics parameters corresponding to this step, such as activation energy, Eα, and apparent pre-exponential factor, ln Aaap, were calculated from the thermogravimetric data at the heating rates of 5, 10, 15 and 20 K min−1 by differential (Friedman's equation) and integral (Flynn–Wall–Ozawa's equation) methods. The results show that the activation energy evidently depends on the extent of conversion. As far as their activation energy is concerned, NiL2 complex shows a higher thermal stability than the CoL2 complex.
Co-reporter:X.Y. Li, Y.Q. Wu, D.D. Gu, F.X. Gan
Materials Science and Engineering: B 2009 Volume 158(1–3) pp:53-57
Publication Date(Web):25 February 2009
DOI:10.1016/j.mseb.2009.01.001
Smooth thin films of nickel(II), cobalt(II) and zinc(II) complexes with azo barbituric acid were prepared by the spin-coating method. Absorption spectra of the thin films on K9 glass substrates in 300–700 nm wavelength region were measured. Optical constants (complex refractive index N = n + ik) of the thin films prepared on single-crystal silicon substrates in 275–695 nm wavelength region were investigated on rotating analyzer–polarizer type of scanning ellipsometer, and dielectric constant ɛ (ɛ = ɛ1 + iɛ2) as well as absorption coefficient α of thin films were calculated at 405 nm. In addition, static optical recording properties of the cobalt(II) complex thin film with an Ag reflective layer was carried out using a 406.7 nm blue-violet laser and a high numerical aperture (NA) of 0.90. Clear recording marks with high reflectivity contrast (>60%) at proper laser power and pulse width were obtained, and the size of recording mark was as small as 250 nm. The results indicate that these metal(II) complexes are promising organic recording medium for the blu-ray optical storage system.
Co-reporter:Weina Song, Chunying He, Yongli Dong, Wang Zhang, Yachen Gao, Yiqun Wu and Zhimin Chen
Physical Chemistry Chemical Physics 2015 - vol. 17(Issue 11) pp:NaN7157-7157
Publication Date(Web):2015/02/05
DOI:10.1039/C4CP05963H
Reduced graphene oxide–metal(II) phthalocyanine (RGO–MPc, M = Cu, Zn and Pb) hybrid materials have been prepared by the covalent functionalization method. The resultant RGO–MPc hybrids are characterized by scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared, ultraviolet-visible absorption and fluorescence spectroscopy. The RGO–MPc hybrids exhibit strong fluorescence quenching by means of the photo-induced electron transfer or the energy transfer (PET/ET) process between the RGO and MPc moieties. The PET/ET process particularly depends on the fluorescence quantum yield of MPc molecules with different central metals. The nonlinear optical (NLO) properties of the RGO–MPc hybrids are investigated by using the Z-scan technique at 532 nm with 4 ns laser pulses. The results show that the NLO properties of MPc molecules increase in the order of Zn < Pb < Cu, but the RGO–MPc hybrids exhibit NLO performance in the inverse sequence of Zn > Pb > Cu, implying that the NLO response arising from the efficient PET/ET process between RGO and MPc may play a more important role in the NLO properties of RGO–MPc hybrids than that originating from the MPc moiety.
Co-reporter:Changmeng Deng, Yongyou Geng and Yiqun Wu
Journal of Materials Chemistry A 2013 - vol. 1(Issue 13) pp:NaN2476-2476
Publication Date(Web):2013/02/11
DOI:10.1039/C3TC00274H
The past 40 years have witnessed the rapid development of lithography technologies. New technologies in the field spring up every day. A technology with simple process steps, low cost and high output is always the dream target of the industry community. In this paper, a maskless and development-free lithography method is proposed based on two new calix[4]arene derivatives as the resists. By this method, micro/nano-pattern structures can be fabricated by means of a simple process, with short time and at relatively low cost. To achieve such a goal, the resist materials must meet certain requirements, and few papers in the literature have dealt with the method because a general resist cannot meet all the requirements. Two calix[4]arene derivatives with designed and optimized molecular structures are chosen as the resists to meet the requirements, and they exhibit different performances because of their different molecular structures. Concave and convex pattern structures are obtained using the two calix[4]arene derivative films i.e. TCHC and THMC films, by direct laser writing lithography. The concave pattern structures are formed on the TCHC films through directly vaporizing the TCHC films based on laser induced thermal effects, whereas the convex pattern structures are formed on the THMC films due to the enhancement of plasticity.
Co-reporter:Kui Zhang, Zhimin Chen, Jingsong Wei, Tao Wei, Youyong Geng, Yang Wang and Yiqun Wu
Physical Chemistry Chemical Physics 2017 - vol. 19(Issue 20) pp:NaN13280-13280
Publication Date(Web):2017/05/02
DOI:10.1039/C7CP00477J
Semiconductor diode-based laser patterning with visible light has been extensively applied to the fabrication of arbitrary structures. However, recently, the technique has faced a great challenge because it cannot meet nanoscale-resolved patterning fabrication due to the optical diffraction limit, which is an inherent drawback in the field of optics. To attack the question, copper(II)–hydrazone-complex (CuL2) thin films are used as laser patterning materials. Under the heating of a writing laser spot, one-step laser nanopatterning on the CuL2 thin films is obtained. The convex-type and concave-type pattern structures are directly written without wet-etching and developing processes. The minimum pattern feature size is about 31 nm, which is far smaller than the diffraction limit and only ∼1/20 the writing spot size. Analysis indicates that the laser nanopatterning originates from obvious photothermal localization responses to the writing spot. Compared with common organic resists, the exposure dose of CuL2 is several orders higher than that of the polymer; thus CuL2 thin film materials are suitable for maskless direct laser writing lithography. This work also provides an effective method for one-step nanopatternings through diode-based laser writing at visible light wavelengths.
