POLYMERS FOR ADVANCED TECHNOLOGIES
·
2018
·Vol. 29
·期 12
·2982-2991
·
IF 2.137
Zhiyong Zhang,Miaojun Xu,Bin Li
The polymethacrylimide/silicate (PMI/silicate) composites were successfully prepared from the monomers of acrylonitrile (AN) and methacrylic acid (MAA) via the monomer in situ intercalation polymerization and free foaming. The formation of imide groups was monitored by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The results of FTIR and XPS indicated that the imide groups were gradually formed and cyano groups were dwindling but still existed during foaming and thermal treatment. The thermogravimetric analysis results revealed that the thermal stability of the PMI/silicate composites was improved, the rate of thermal degradation was reduced, and the residue was increased because of the addition of silicates. The results of dynamic mechanical analysis revealed that the rigidity and the glass transition temperature of the composites were improved. The limit oxygen index (LOI) and cone calorimeter (CONE) test showed that the fire-retardant properties were improved because of the barrier effect of silicates. The cell morphologies of the PMI/silicate composites were characterized by scanning electron microscopy (SEM), and the results showed that the silicate particles were distributed on the cell walls, but the cells slightly cracked. The mechanical properties were measured by tensile, flexural, and compressive strength. The mechanical strength, especially flexural strength, was significantly improved. The flexural strength of PMI/MMT, PMI/kaolin, and PMI/talc containing 8 wt% silicates was improved to 172%, 240%, and 233%.
研究领域:
高分子材料
·
复合材料科学
·
材料化学
·
防火材料
·
多孔材料
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2024
·Vol. 35
·期 2
·140
·
IF 2.8
Ma Di,He Hao,Huang Xinglan,Wang Jingcheng,Hu Xuebu
The inhomogeneous plating/stripping of zinc and side reactions originating from the dissolution of the cathode material in water lead to the poor stability of zinc anode, which inevitably limits the practical application of zinc-based aqueous batteries. Therefore, a novel hydrogel electrolyte made of hydroxyethyl cellulose/polyacrylamide (HEC/PAM) with a 3D network-like structure is synthesized by radical polymerization and cross-linking reinforcement. Thanks to the porous crosslinked network and massive hydrophilic groups, the electrolyte has high ion conductivity of 3.17 × 10 –2 S cm −2 and decomposition voltage of 2.6431 V. The ion conductive hydrophilic groups facilitate the interfacial compatibility of the electrode with the electrolyte and stabilize zinc plating/stripping, which suppresses the formation of zinc dendrites. Meanwhile, the hydrogel electrolyte effectively alleviates the dissolution of the positive electrode and the occurrence of side reactions, and subsequently improves the stability of the electrode. As a result, the assembled Zn–Zn symmetric cell with HEC/PAM hydrogel electrolyte is stable without short circuit and rapid increase of overvoltage at 5 mA cm −2 . The polarization voltage of the assembled Zn–Cu half-cell is 59.2 mV and initial coulomb efficiency reaches 94.3%. The assembled Zn–V 2 O 5 ·nH 2 O/CNT full cell delivers an excellent cycling stability of 186.9 mAh g −1 at 0.5 A g −1 after 500 cycles with a high-capacity retention of 92.5% (only 52.1% in aqueous system). The new idea is provided for further development of functional hydrogel electrolytes in zinc-ion batteries.
研究领域:
电化学
·
能源材料
·
功能高分子
·
电池技术
·
界面化学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 62
·57009-57012
·
IF 3.289
Di Wu,Jing Ye,Lie Chen,Yongzheng Wang,Kai Fang,Mingjiang Xie,Luming Peng,Xuefeng Guo,Weiping Ding
Crystalline mesoporous γ-Fe2O3 with a high surface area was prepared by a novel solvent-free route. This material exhibits a high reversible capacity with superior cycle performance and an exceptional high-rate capability as an anode material for Li-ion batteries.
研究领域:
材料科学
·
电化学
·
纳米材料
·
能源存储
·
固体化学
·
电池技术
✓ 已验证
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2017
·
IF 6.395
Zongbao Zhang,Yang Zhou,Yangyang Cai,Hui Liu,Qiqi Qin,Xubing Lu,Xingsen Gao,Lingling Shui,Sujuan Wu,Jun-Ming Liu
Planar perovskite solar cells (PSCs) based on CH 3 NH 3 PbI 3- x (SCN) x (SCN: thiocyanate) active layer and low-temperature processed TiO 2 films are fabricated by a sequential two-step method in ambient air. Here, alkali thiocyanates (NaSCN, KSCN) are added into Pb(SCN) 2 precursor to improve the microstructure of CH 3 NH 3 PbI 3- x (SCN) x perovskite layers and performance of the as-prepared PSCs. At the optimum concentrations of alkali thiocyanates as additives, the as-prepared NaSCN-modified and KSCN-modified PSCs demonstrate the efficiencies of 16.59% and 15.63% respectively, being much higher than 12.73% of the reference PSCs without additives. This improvement is primarily ascribed to the enhanced electron transport , reduced recombination rates and much improved microstructures with large grain size and low defect density at grain boundaries. Importantly, it is revealed that the modified PSCs at the optimized concentrations of alkali thiocyanates additives exhibit remarkably improved stability than the reference PSCs against humid circumstance, and a continuous exposure to humid air without encapsulation over 45 days only records about 5% degradation of the efficiency. These findings provide a facile approach to fabricate efficient and stable PSCs by low processing temperature in ambient air, both of which are highly preferred for future practical applications of PSCs.
研究领域:
材料科学
·
能源科学
·
纳米技术
·
光电化学
·
半导体器件
·
薄膜物理
✓ 已验证
DOI
高影响因子
Nano Energy
·
2020
·
IF 16.602
Long Li,Chun Fang,Wenfei Wei,Lei Zhang,Zhao Ye,Gang He,Yunhui Huang
The huge volume change of silicon anode during cycling results in unstable solid electrolyte interface (SEI), causing rapid performance degradation . Natural SEI layer has a heterogeneous structure, results in the inhomogeneous Li + diffusion. The repeated destruction and regeneration of SEI aggravate the inhomogeneity of Li + diffusion at the interface, leading to non-uniform alloy reaction in the Si bulk. In this work, the silicon surface is passivated by an ultrathin uniform chitosan layer with abundant lithiophilic groups. The capacity of chitosan-coated Si (Si@CS) could reach 1500 mAh g −1 at a current density of 1 A g −1 , and the capacity retention remains 91% after 400 cycles. It is demonstrated that the oxygen and nitrogen atoms in chitosan are coordinated with Li + , providing uniformly distributed Li + transfer sites, results in a homogeneous Li + flux in the surface layer. Interestingly, a nano-scale ordered atomic arrangement is observed in the delithiated Si@CS, which contributes to more stable and reversible lithiation/delithiation reaction of the Si@CS electrode. It is proposed that optimizing the reaction interface on the Si surface is able to alter the Li-ion diffusion kinetics and structure transition behavior of silicon, which can improve the structure reversibility and stability during cycling.
研究领域:
材料科学
·
电化学
·
纳米科技
·
能源存储
·
表面工程
·
锂离子电池
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Decai Huang,Sisi Liang,Dejian Chen,Jie Hu,Kunyuan Xu,Haomiao Zhu
The emerging applications of near-infrared (NIR) spectroscopy technology in medicine and food security call for compact and efficient NIR light source such as NIR phosphor converted LEDs (pc-LED). Currently, most of the NIR phosphors suffer from low photoluminescence (PL) quantum yield and poor thermal or chemical stability. Herein, a fluoride garnet NIR Na 3 Al 2 Li 3 F 12 :Cr 3+ phosphor was successfully synthesized via coprecipitation method. It can be excited efficiently by blue or red light and shows a broad emission band covering 650–1000 nm (bandwidth of ~110 nm) with a PL quantum yield of 78%. The fine electronic structure of Cr 3+ ions in the host was revealed by the measurement of temperature-dependent (8–300 K) excitation and emission spectra analysis. Particularly, at 423 K, the Na 3 Al 2 Li 3 F 12 :5%Cr 3+ sample retained ~99% of the PL intensity at room temperature, exhibiting excellent PL thermal stability. A NIR pc-LED was fabricated by combining the Na 3 Al 2 Li 3 F 12 :5%Cr 3+ phosphor with a commercial blue LED chip, and radiant flux of 14.3 mW in NIR region was obtained at 60 mA drive current. Furthermore, the penetration of NIR light generated by this pc-LED in chicken breast was reached. The results suggested that Na 3 Al 2 Li 3 F 12 :Cr 3+ is a promising candidate for broadband pc-LED in NIR spectroscopy applications.
研究领域:
材料科学
·
光学工程
·
生物医学光子学
·
半导体器件
·
分析化学
✓ 已验证
DOI
高影响因子
MATERIALS LETTERS
·
2014
·
IF 2.269
Yaguang Yuan,Yanping Yuan,Nan Zhang,Yanxia Du,Xiaoling Cao
Capric–myristic–palmitic acid ternary eutectic mixture (CA–MA–PA) was prepared as phase change material (PCM). A novel composite PCM of CA–MA–PA/expanded graphite (EG) with an optimum mass ratio (CA–MA–PA:EG=13:1) was prepared by uniformly absorbing CA–MA–PA into the porous network structure of the EG. The melting and freezing temperatures of CA–MA–PA/EG composite PCM were measured by differential scanning calorimeter as 18.61 °C and 16.58 °C, respectively, while the melting and freezing latent heats were 128.2 J/g and 124.5 J/g, respectively. The thermal conductivity of the CA–MA–PA/EG composite PCM was measured as 3.67 W/m K and thus the thermal storage and release rates were significantly increased. The thermal cycling test results showed that CA–MA–PA/EG composite PCM has a good thermal reliability. All the above results show that the CA–MA–PA/EG composite PCM is a potential solution for latent heat storage system.
研究领域:
材料科学
·
能源化学
·
热物理
·
功能材料
·
储能技术
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Zuocheng Luo,Qingfeng Zhang,Wei Xie,Tong Yuan,Qisheng Zang,Ning Wang,Hanxiao Fan,Shuhong Xie,Xiaoping Ouyang
Potassium ion hybrid capacitors (PIHCs) have attracted widespread attention as combining the advantages of potassium ion batteries (PIBs) with supercapacitors . However, the sluggish kinetics caused by the large radius of K + hinder the practical application of PIHCs. Herein, we synthesized a boron and fluorine co-doping interlaced network porous carbon nanofibers (BF-PCNFs), which was used as the freestanding anode of PIHCs the freestanding anode of PIHCs to alleviate large volume expansion and increase conductivity. Benefiting from the B, F co-doping and porous interlace nanostructure of BF-PCNFs, the anode shows 185 mA h g −1 under a load of 12.6 mg cm −2 , a reversible capacity of 176 mA h g −1 at 1000 mA g −1 after 6000 cycles, and the capacity retention from 100 mA g −1 to 5000 mA g −1 is 62%. Furthermore, the PIHCs based on BF-PCNFs as anode and activated carbon as cathode exhibit an energy density of 87 Wh kg −1 and a power density of 393 W kg −1 . The capacity retention is as high as 78% over 4000 cycles. Considering the exceptional rate performance, long cyclability and high-mass-loading, our work may supply a new strategy for designing novel energy storage devices with outstanding performance.
研究领域:
材料科学
·
电化学
·
能源存储
·
纳米科技
·
功能材料
✓ 已验证
DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2024
·
IF 5.3
C. Wang,X.Z. Zheng,L. Yue,P.J. Xia,M. Xu,W.B. Dai
The exploration of stable/efficient phosphor for n -UV chip pumped white light-emitting diodes ( w LEDs) remains an arduous task. Herein, a novel series of color tunable Eu 2+ /Tb 3+ /Sm 3+ tridoped Sc-based cyclosilicate phosphors (KBaScSi 3 O 9 : Eu 2+ /Tb 3+ /Sm 3+ ) have successfully designed and obtained via facile solid-state reaction based on comprehensive consideration of rigidly structural network of host, weak electron-phonon coupling strength and spectral adjustability of codopants via energy transfer (ET). The crystallographic occupancies of Eu, Tb and Sm primary in Ba/K, Ba and Ba sites in the monoclinic host, respectively were determined on the basis of the Rietveld refinements and crystal chemistry rules. The photoluminescence (PL) properties were systematically investigated in conjunction with structural analyses, implying that the ‘warm’ white light with excellent thermal stability is stemmed from combination of optimized blue (Eu 2+ ), green (Tb 3+ ) and red (Sm 3+ ) emissions via Eu → Tb → Sm ET strategy. Interestingly, Tb ions play both roles of green light luminescent center and ET bridge to achieve cascade ET for connecting Eu/Sm ion pairs because of the adverse metal-metal charge transfer (MMCT) effect (Eu 2+ + Sm 3+ → Eu 3+ + Sm 2+ ). Furthermore, the phosphor-converted w LEDs (pc- w LEDs), by encapsulating the optimal KBS: 4 %Eu/4 %Tb/6 %Sm with commercial n -UV LED chip, show high thermal stability with satisfactory electroluminescence (EL) performances. These results indicate the KBS: Eu/Tb/Sm phosphors are potential candidates for application in high power n -UV pumped pc- w LEDs.
研究领域:
材料科学
·
发光材料
·
固态照明
·
无机化学
·
光电子学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 27
·22908-22916
·
IF 3.289
Jianwen Tian,Xiaohui He,Jingyin Liu,Xiaodan Deng,Defu Chen
Palladium(II) and copper(II) chloride complexes bearing bulky 9,10-dihydro-9,10-ethanoanthracene-11,12-diimine ligands were synthesized and sufficiently characterized by elemental and spectroscopic analysis along with X-ray diffraction analysis. The X-ray diffraction demonstrated that palladium(II) complexes (C1–C2) and copper(II) complexes (C3–C4) were four-coordinated. All these complexes displayed catalytic activities up to 105 gpolymer molMt−1 h−1 for norbornene vinyl-addition polymerization on treatment with excess methylaluminoxane (MAO). The parameters of the reaction conditions, the type of metals and steric effects of coordinative ligands had influences on the catalytic properties. C2 was selected as a catalyst precursor for the copolymerization of norbornene (NB) with 2-butyloxymethylene norbornene (BN), which exhibited catalytic activities up to 1.1 × 105 gpolymer molPd−1 h−1 and produced copolymers with relatively high molecular weights. The fraction of BN in the copolymer could reach up to 9.8–62.1% by controlling the monomer feed ratio range from 10–80%. The achieved vinyl-addition type poly(NB-co-BN) displayed high thermal stability and was soluble in common organic solvents, such as CHCl3 and THF.
研究领域:
高分子化学
·
配位化学
·
催化化学
·
有机金属化学
·
功能高分子材料
✓ 已验证
DOI
高影响因子
RSC Advances
·
2014
·Vol. 4
·期 78
·41398-41410
·
IF 3.708
Xiuhua Li,Jinxiong Tao,Guanghui Nie,Liuchan Wang,Liuhong Li,Shijun Liao
A series of cross-linked multiblock copoly(arylene ether sulfone) ionomer/nano-ZrO2 (CLQCPAES/nano-ZrO2) composite anion exchange membranes were prepared via block copolymerization, bromomethylation, ultrasonication blending, self-crosslinking, quaternization and alkalization. The structure, and the surface and cross section morphology of the CLQCPAES/nano-ZrO2 composite membranes were characterized by solubility tests, FT-IR, XRD and SEM analyses. The combination of the determined results revealed that the CLQCPAES/nano-ZrO2 composite membranes are a complex cross-linking networks of hydrophobic domains/hydrophilic domains/nano-ZrO2 with a clear zonal distribution of uniform nano-sized particles in the hydrophilic domains, when the nano-filler loading was below 7.5%. Basic performances of the CLQCPAES/nano-ZrO2 composite membranes were assessed to investigate their application in fuel cells in terms of the water uptake, swelling ratio, ion exchange capacity (IEC), hydroxide conductivity, thermal and mechanical properties, and alkaline stability. The modification of anion exchange membranes with multiblock ionomer structures, the use of a cross-linking technique and the introduction of nano-ZrO2 particles greatly enhanced the water uptake, hydroxide conductivity, mechanical properties and alkaline stability of the composite membranes. In particular, the CLQCPAES/7.5%ZrO2 membrane with an IEC value of 1.23 mmol g−1 exhibited the best comprehensive properties and constitutes a good potential candidate for an anion exchange membrane to be used in AEMFCs.
研究领域:
高分子材料科学
·
电化学
·
能源材料
·
膜科学与技术
·
燃料电池
·
纳米复合材料
·
功能高分子
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2014
·Vol. 132
·期 7
·
IF 1.64
Pan Dongdong,Tian Hengshui
Soluble and thermally stable polycarbonate polyurethane elastomers were synthesized through a solvent-free and nonisocyanate melt transesterification process. The conditions of this process were studied, and the optimum conditions were as follows: the catalyst dibutyltin oxide dosage was 0.125 wt %, the raw material molar ( n ) ratio of dimethyl 1,6-hexamethylene dicarbamate (HDC) to poly(carbonate macrodiol) (PCDL) was n (HDC)/ n (PCDL) = 1:0.99, the reactants were prepolymerized under 100°C for 1 h and then under 185°C and a high vacuum for 4 h. Three different PCDLs were selected to participate in the reaction under the conditions mentioned previously, and their structures were characterized by Fourier transform infrared spectroscopy and X-ray diffraction. The products obtained from this process were still stable under 280°C. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132 , 41377.
研究领域:
高分子化学
·
生物材料
·
聚合物科学
·
材料化学
·
医用高分子
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）