Polymer Chemistry
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2018
·Vol. 9
·期 42
·5215-5223
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IF 4.927
Wei Yuan,Weiwen Chi,Ting Han,Jun Du,Hongkun Li,Yongfang Li,Ben Zhong Tang
Cu(I)-mediated and metal-free click polymerizations of azides and terminal alkynes have been developed into powerful techniques for constructing linear and hyperbranched polytriazoles. However, the 1,3-dipolar cycloaddition of azides with internal alkynes is rarely employed as a synthetic tool to prepare functional polymers. In this work, metal-free phenylpropiolate-azide polycycloaddition was developed for efficient synthesis of poly(phenyltriazolylcarboxylate)s (PPTCs), a kind of polyester. The aromatic and aliphatic diphenylpropiolates could readily react with diazides under heating, affording soluble PPTCs with high molecular weights (Mw up to 28 500) in excellent yields (up to 98%). The polymerization is insensitive towards oxygen and moisture, and can proceed smoothly in an open atmosphere. The obtained PPTCs are thermally stable with 5% weight loss temperatures higher than 318 °C. As the polymers contained ester groups, they exhibited fast degradation under basic conditions. The PPTC containing tetraphenylethene moieties shows a unique phenomenon of aggregation-induced emission, and can be employed as a fluorescent chemosensor to sensitively detect explosives. Its thin film can generate two-dimensional fluorescent photopatterns by UV irradiation.
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JOURNAL OF ALLOYS AND COMPOUNDS
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2013
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IF 2.39
Weidong Xiang,Cuiping Xie,Jing Wang,Jiasong Zhong,Xiaojuan Liang,Hailong Yang,Le Luo,Zhaoping Chen
Silver indium sulfide (AIS) quantum dots (QDs) with different Ag/In molar ratios were synthesized via a hot-injection method. Intense photoluminescence (PL) originating from the donor–acceptor pair recombination were observed for all the samples and the emission peak blue-shifted from 739 to 632 nm, being similar to the behavior of the absorption onset as the Ag/In ratios decreased. The highest PL quantum yield (QY) of the obtained ternary AIS QDs was ca. 62% with an optimum ratio of Ag/In = 1/4. Compared with AIS QDs, when Zn ions were introduced, the absorption spectra of the obtained quaternary Ag–Zn–In–S QDs were blue-shifted, and their emission peaks moved to higher energies accordingly, showing a tunable emission from red to green by altering the band gap energy. In order to further study the electroluminescence (EL) as well as looking forward to the applications in the optoelectronic devices of the obtained highly luminescent nanoparticles, the colloidal AIS QDs were deposited as thin films to the sandwich-like structured QD-LED. The experimental results showed that the obtained EL device exhibited EL emission originated from QDs thin films by adjusting the turn on voltage, which is for the first time to realize EL of AIS QDs in such QD-LED.
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HIGH PERFORMANCE POLYMERS
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2014
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IF 1.09
Yewei Xu,Yi Sun,Yonglin Lei,Jichuan Huo,Lin Zhang
Poly(N-arylenebenzimidazole ketone ketone pyridine)s have been prepared via N–C coupling reaction that removed the N–H sites from the novel bis(benzimidazoyl) derivatives with activated aromatic difluorides in sulfolane. The reaction was carried out at 210°C in the presence of anhydrous potassium carbonate. The structures of the polymers were characterized by means of Fourier transform infrared and proton nuclear magnetic resonance spectroscopies and elemental analysis. All resulting polymers showed essentially amorphous patterns. Differential scanning calorimetry and thermogravimetric measurements showed that the polymers had high glass transition temperatures (>179°C), good thermostability, and high decomposition temperatures (>401°C). These novel polymers also showed easy solubility.
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JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION
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2015
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IF 1.648
Zhenqian Gu,Fangjie Wang,Haoxiang Lu,Xinling Wang,Zhen Zheng
A new kind of biodegradable poly(urethane-urea)s based on poly-lysine oligomer used as the soft segment was synthesized and characterized. In vitro degradation behavior of poly (urethane-urea)s was investigated, and was assessed by 1H NMR and mass loss. The results indicated that the peptide bonds in poly(urethane-urea)s were effectively cleaved in simulated pancreatic juice containing trypsin, while those in buffer solution without trypsin remained unaffected. The degradability was obviously improved by introducing poly-lysine oligomer into the main chain of poly(urethane-urea)s. The results of cells viability test indicated that the poly (urethane-urea)s showed a good biocompatibility on endothelial cells. The thermostability and hydrophilicity of poly(urethane-urea)s increased with increase in poly-lysine oligomer content.
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Journal of Materials Chemistry A
·
2014
·Vol. 2
·期 33
·13565-13570
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IF 0
Yingying Fan,Dongxue Han,Bin Cai,Weiguang Ma,Mohsin Javed,Shiyu Gan,Tongshun Wu,M. Siddiq,Xiandui Dong,Li Niu
TiO2 is an abundant and environmentally benign material, but has a wide band gap, which greatly confines its applications in photocatalysis. Doping and modifying the material composition are both generally used to change and control the photocatalytic activity of semiconductors. Herein, we describe a method and resulting activity of depositing Ce-/S-codoped TiO2 nanoparticles (NPs) on water-soluble sulfonated graphene (SGE) sheets, which guarantees a direct contact and satisfactory electron transfer between the semiconductor and graphene. The Ce/S–TiO2 NPs are homogeneously fixed on the surface of SGE sheets with an average particle size of ∼7 nm. The resulting composite showed noticeable activity in photodegrading methyl orange (κ = 0.425 h−1). This improved performance can be attributed to the synergistic effects of Ce- and S-codoping toward TiO2 and the composite action between TiO2 NPs and SGE. This type of novel composite is expected to stimulate the development of doped and graphene-involved photocatalysts for addressing environmental problems.
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RSC Advances
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2016
·Vol. 6
·期 62
·57346-57356
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IF 3.289
Xue-ling Wu,Jun Zong,Han Xu,Wei Wang,Xing-jiang Liu
In this work, the solid electrolyte of Li1.5Al0.5Ge1.5(PO4)3 (LAGP) is used to suppress polysulfides shuttling in Li–S cells. Firstly, the H-type visible cell is assembled by using a LAGP glass ceramic plate and normal poly-propylene (PP) separator. It is demonstrated that the LAGP glass ceramic plate is quite effective in shutting-down the migration of polysulfide ions and improving the utilization ratio of the sulfur cathode. However, in the commercial production of Li–S batteries it is not possible to use the LAGP glass ceramic plate as a membrane due to its brittle characteristics. Herein, the LAGP modified separator has been prepared by a simple casting procedure and applied in Li–S cells. The Li-ion conductivity of the LAGP modified separator is 6.280 × 10−4 S cm−1 at room temperature. The Li-ion transference number and the Gurley value of the modified separator show that the diffusion of the polysulfide anions can be suppressed effectively. The discharge capacity of the Li–S cell with the modified separator at the 50th cycle can reach 770.1 mA h g−1, while that of the Li–S cell with the routine PP separator is only 658.4 mA h g−1 at the 50th cycle. The superior utilization of sulfur in the Li–S cells indicates that using the LAGP modified separator is a viable way to overcome the shuttling problem for practical Li–S batteries.
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Science China-Chemistry
·
2017
·Vol. 60
·期 9
·1191-1196
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IF 4.132
Ji Shaobo,El Mard Hicham,Smet Mario,Dehaen Wim,Xu Huaping
Macrocycles possess potential applications in supramolecular chemistry and biosystems. Thus development of new kinds of macrocycles is of significance. Herein, novel macrocycles containing Se–Se/Se–S bonds were synthesized via transformation between selenium related dynamic covalent bonds. A monomer containing two ebselen moieties was synthesized ( M1 ). The Se–N bonds in M1 were reduced by dithiothreitol, forming Se–S linked dimer ( D1 ). To realize the transformation from Se–S bonds to Se–Se bonds, guest molecules were added as template, triggering the formation of Se–Se linked dimer ( D2 ). The formation of these two new kinds of macrocycles was determined by 1 H NMR and 77 Se NMR, and the necessity of guest molecules was also confirmed. The introduction of ebselen moieties and Se–S bonds or Se–Se bonds into macrocycles may endow it with new responsiveness and bioactivities, as well as new types of host-guest chemistry.
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JOURNAL OF HAZARDOUS MATERIALS
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2016
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IF 4.836
Penghui Shao,Xiaoguang Duan,Jun Xu,Jiayu Tian,Wenxin Shi,Shanshan Gao,Mingjun Xu,Fuyi Cui,Shaobin Wang
Recently, tremendous efforts have been devoted to developing carbon-based metal-free catalysts as an alternative to metal-based catalysts for remediation of emerging contaminants. However, further investigations have demonstrated that the durability of carbocatalysts is poor. Therefore, it is extremely desirable to seek a novel metal-free catalyst with high efficiency and superb stability. Herein, we first discovered that amorphous boron (A-boron) can be used as a metal-free catalyst for peroxymonosulfate (PMS) activation to produce free radicals for effective degradation of bisphenol S (BPS), which is a newly-occurring estrogenic endocrine-disrupting chemical. It exhibited outstanding catalytic activity and superior stability as comparing to metal-based and metal-free carbon-based catalysts. Moreover, many other typical organic pollutants in water such as bisphenol F, sulfamethoxazole, rhodamine B and methyl orange can also be effectively decomposed in A-boron/PMS oxidative system. The effects of reaction parameters on BPS degradation were systematically investigated. The catalytic oxidation mechanism was proposed. The intriguing catalytic feature of A-boron discovered in this study will provide new opportunities for the future development of A-boron based materials with promising applications in water remediation.
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CONSTRUCTION AND BUILDING MATERIALS
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2017
·
IF 3.169
Jinfeng Sun,Hu Shi,Binbin Qian,Zhiqiang Xu,Weifeng Li,Xiaodong Shen
This work investigates the influence of synthetic C-S-H/polycarboxylate(PCE) nanocomposites (CPNs) on the hydration and properties of hydrated cement pastes. HPEG-PCE copolymers exhibiting side chain length of 45 ethylene oxide (EO) units was utilized to synthesize CPNs by precipitating C-S-H from Na 2 SiO 3 and Ca(NO 3 ) 2 in the PCE solution. A Box-Behnken Design (BBD) for the Response Surface Methodology (RSM) was employed to statistically optimize the sizes of the resultant. The prepared CPNs were characterized by particle size distribution (PSD), X-ray diffraction (XRD), Fourier transform infrared spectra (FT-IR) and thermo gravimetric/derivative thermo gravimetric (TG/DTG) analyses. The influence of CPNs on the hydration properties of cement were assessed and discussed in terms of hydration kinetics, mechanical properties, phase composition and pore structure analysis. The experimental results showed that the optimum synthetic parameters, an experimental temperature of 30.1 °C, reactant flow velocity of 0.63 ml/min and initial volume of PCE solution of 28.5 ml, produced CPNs with a minimum size of 329.12 nm. It was demonstrated that PCE polymers were either grafted on the surface or partially intercalated in the interlayer regions of C-S-H, and their introduction also increased the distance between C-S-H interlayers. Cement hydration was significantly promoted as a result of an increased heat release, even at low CPNs content. The early compressive strength of the mortar significantly improved with increasing CPNs content due to the accelerated cement hydration of the CPNs: the 0.6 wt.% CPNs content improved the compressive strength by 18.97%. Moreover, the inclusion of CPNs is advantageous for pore modification: the total porosity decreased by 25.77% after 3 days. Finally, phase composition analysis confirmed that no new crystalline phase was produced upon CPNs addition.
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JOURNAL OF APPLIED POLYMER SCIENCE
·
2016
·Vol. 134
·期 11
·
IF 1.866
Lei Huang,Yufen Jin,Li Sun,Feng Chen,Ping Fan,Mingqiang Zhong,Jintao Yang
Poly(ionic liquid)s have been demonstrated as high efficient CO 2 absorbents. In the current study, a kind of poly(ionic liquid)s, Poly[2-(methacryloyloxy)-ethyl] trimethylammonium tetrafluoroborate (P[MATMA][BF 4 ]) was used to functionalize graphene oxide (GO). The hybrid in which P[MATMA][BF 4 ] was covalently bonded on GO platelets was prepared by a simple method, that is, traditional radical polymerization. The characterizations based on transmission electron microscopy, scanning electron microscope, Fourier transform infrared spectroscopy, Raman spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy demonstrated the graft of P[MATMA][BF 4 ] on GO. N 2 adsorption measurements indicated that P[MATMA][BF 4 ] also greatly increased the specific surface area of GO. Due to the higher specific surface area and the CO 2 affinity of P[MATMA][BF 4 ], the GO-P[MATMA][BF 4 ] hybrid exhibited a much higher CO 2 adsorption capacity compared with GO, GO-NH 2 , and P[MATMA][BF 4 ]. Their study showed that the combinations of poly(ionic liquid)s and GO could be promising CO 2 absorbents. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44592.
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JOURNAL OF CATALYSIS
·
2024
·
IF 6.5
Gongcheng Sun,Subing Fan,Junmin Lv,Tiansheng Zhao
A hollow zeolite encapsulated Rh catalyst Rh@H-S-1 with an “eggshell” structure was prepared using the method of organic alkali treatment and recrystallization. Compared with catalysts with directly encapsulated Rh@S-1 and surface impregnated Rh/S-1, this catalyst exhibited both superior activity and a higher TOF value in hydroformylation of 1-hexene due to the high dispersion of Rh and high diffusion. The Rh element did not need to be reduced in the preparation, and it was in situ reduced by the syngas. The content of lower valence Rh δ+ gradually increased with the reaction procedure and played as an active center. The low oxidized state Rh + or Rh δ+ in the form of Rh(CO) 2 are proposed as active sites in hydroformylation, which were generated under the synergistic effect between CO and H 2 . Importantly, the hollow encapsulated catalyst effectively decreased Rh leaching to 0.1 ppm and showed better stability compared with the impregnated Rh/S-1 catalyst.
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ACTA PHYSICO-CHIMICA SINICA
·
2024
·
IF 10.8
Asif Hassan Raza,Shumail Farhan,Zhixian Yu,Yan Wu
This work illustrates the novelty of double S-scheme ZnS/ZnO/CdS ternary heterojunction photocatalyst with efficient photocatalytic activity. The sample with optimal CdS content, ZnS/ZnO/CdS-14% (ZZC14%), displayed the maximum H 2 evolution rate of 4.1 mmol·g ‒1 ·h ‒1 . The maximum photocatalytic performance was approximately 2 and 13 times higher than their corresponding counterparts, ZnS/CdS and ZnO/ZnS, respectively. A high AQE of 19.8% under 420 nm was obtained. Additionally, the slight changes in H 2 evolution activities and retentions of crystal structures after six successive cycles indicate the stability of the photocatalyst. In accordance with the theoretical calculations and experimental results, the remarkable enhancement in photocatalytic activity is attributed to fast electron transfer and separation as well as the intimate contact due to mutual interaction between S-scheme. This work highlights an innovative approach to constructing a dual S-scheme photocatalytic system with high separation and fast migration capabilities of photogenerated charge carriers for splitting water to produce hydrogen. Download: Download high-res image (131KB) Download: Download full-size image
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