WATER AIR AND SOIL POLLUTION
·
2016
·Vol. 227
·期 12
·1-12
·
IF 1.551
Zhang Zhan-hang,Zhang Jing-li,Liu Jian-ming,Xiong Zhen-hu,Chen Xu
Zeolitic imidazole frameworks (ZIFs), a new adsorbent with a high chemical and thermal stability and a high adsorption capacity, are used for adsorptive removal of azo dyes. The synthesized ZIF-67 was characterized with Fourier transform infrared spectroscopy (FTIR), thermogravimetric–differential thermal analysis (TG–DTA) and zeta potential instrument. The adsorption of some azo dyes on ZIF-67 in the single dye systems showed that the removal efficiencies are congo red > methyl orange > methyl red > methyl blue. The highest adsorption capacity of congo red and methyl orange were 3900 and 1340 mg/g, respectively. In a binary dye system the adsorption capacity of congo red decreased, while the removal efficiency of methyl orange increased in comparison with the single systems, indicating that a competitive adsorption of congo red and methyl orange over the ZIF-67 occurred. The experimental data indicate that the electrostatic attraction between ZIF-67 and congo red is the major driving force and the π – π stacking is also responsible for dye adsorption. After 5 cycles of ZIF-67 adsorption and desorption, the congo red removal efficiency maintained more than 95%.
The adsorption of Congo red and Methyl orange on the ZIF-67
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
MACROMOLECULES
·
2015
·
IF 5.8
Jiang Zhong,Shu Gao,Guobin Xue,Bo Wang
Polypyrrole (PPy)/graphene oxide (GO) nanosheet composites with different GO content have been successfully prepared. The morphology, microstructure, defect property and conducting mechanism were examined by Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), field-emission scanning electron microscope (FE-SEM), X-ray photoelectron spectra (XPS), positron annihilation technology (PAT), and electrical conductivity measurements for PPy/GO conducting nanocomposites, respectively. Experimental results indicated that PPy was deposited onto the GO surface homogeneously. Four orders of magnitude increase in electrical conductivity was successfully achieved with small quantities of GO compared to pristine PPy. In order to elucidate the conducting mechanism, an electron transfer model was used to describe bipolaronic formation, which can be confirmed by XPS and positron annihilation parameters measured including positron annihilation lifetimes, positron annihilation Doppler broadening spectroscopy (DBS) and continuous distribution of positron lifetime. Electronic conductivity enhancement can be attributed to (a) the interfacial interaction between the GO layers and PPy results in the electron transfer, which leads to the increase of bipolaronic concentration, and (b) the π–π stacking between the GO layers and PPy can improve the conjugation degree of the PPy chains and the longer conjugation length makes the conducting particle delocalization more easily, leading to the increase in electron mobility. On the other hand, the continuous conducting network structure of graphene nanosheets homogeneously dispersed in the PPy matrix and carriers between localized states formed at the graphene–PPy interfaces where hopping occurred, also result in increase of conductivity.
研究领域:
材料科学
·
物理化学
✓ 已验证
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2019
·
IF 3.621
Weilong Chen,Kun Wu,Zhencai Qu,Mangeng Lu
It has been known that phonon mean free path along polymer chains is much larger than in transverse directions because weak interaction between polymer chains leads to chain distortion and entanglement. In order to improve intensity of intermolecular interaction, a series of co-polyesters (CPE) containing different content of offset π-π stacking structure in side chains were synthesized by means of polycondensation and transesterification in this work. WAXD patterns unfolded diffraction peak at 2θ of 27.6°, standing for structure of offset π-π stacking. On enlarging intensity of offset π-π stacking interaction, specific heat capacity of CPE increased from 1.140 Jg −1 K −1 to 1.410 Jg −1 K −1 and thermal diffusivity rose from 0.194mm 2 s −1 to 0.245mm 2 s −1 . As a result, CPE sample exhibited excellent thermal conductivity (TC) of 0.381 Wm −1 K −1 , which is around twice that of traditional thermoplastics. Hence offset π-π stacking interaction could strengthen capacity of heat absorption and thermal conduction at the same time, which might be a good candidate for enhancing thermal conductivity of intrinsic polymers. Furthermore, strong π-π interaction in side chains could maintain modulus when temperature is over glass temperature. And the Young modulus grew from 0.14 GPa to 0.44 GPa with the augment of offset π-π stacking structure.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2024
·
IF 6.3
Xiangming Hu,Jingran Mao,Qian Zhang,Xuechao Dong,Haigang Du,Mingyue Wu,Weimin Cheng,Zhenyu Yang
Understanding the adhesion mechanism between polydopamine (PDA) and coal surface is crucial for implementing the mussel strategy in self-adhesive gel for fire suppression. In this study, a combination of experiments and molecular simulations was utilized to explore the interfacial adhesion mechanism between PDA and coal. Initially, the adhesion potential of varying concentrations of PDA solutions was evaluated using a UV–Vis spectrophotometer, and in conjunction with contact angle/surface tension measurements, it was observed that adhesion strength did not show a direct correlation with PDA concentration. Subsequently, the adhesion sites of PDA on the coal surface were identified through spectroscopic analysis and confirmed using Dmol3 simulations. The study revealed that the amino and phenolic hydroxyl groups in the PDA structure could establish hydrogen bonds with oxygen-containing functional groups on the coal surface (e.g., COOH, OH, R-O-R'), while the aromatic rings in the molecules engaged in π-π stacking interactions. These non-covalent forces collectively facilitated the adhesion process. Molecular dynamics (MD) simulations were then employed to validate the relationship between PDA solution concentration and adhesion strength, which aligned with the experimental findings. Furthermore, the MD simulations elucidated how the concentration of PDA solution influenced its interfacial adhesion strength with coal by considering water molecule diffusion. Overall, this research offers a theoretical foundation for designing self-adhesive gel for fire suppression.
研究领域:
材料科学
·
化学工程
·
分子生物学
✓ 已验证
产品关联
DOI
高影响因子
MACROMOLECULES
·
2021
·
IF 5.985
Haoran Xu,Guanghu He,Sheng Chen,Shaonan Chen,Rui Qiao,Hang Luo,Dou Zhang
Although polymer dielectrics show wide application prospects in electronic and electrical fields, a low relative dielectric constant and a low energy density restrict their rapid developments. To overcome these shortcomings, a strategy is proposed to facilitate orientational polarization through the incorporation of the π–π stacked biphenyl side groups in dipolar polymers. In this study, sulfonyl-containing poly(norbornene)s with and without biphenyl groups were synthesized by ring-opening metathesis polymerization, denoted as PBTMD-SO2 and PTMD-SO2, respectively. Their dielectric behaviors and energy-storage properties were investigated. The dielectric constant of PBTMD-SO2 with the biphenyl side groups was as high as 11.1 at 25 °C and 1 kHz, which was nearly 35% higher than that of PTMD-SO2 due to the stronger orientational polarization. In addition, the dielectric loss in the range of 1 kHz to 1 MHz increased from 0.061 to 0.172 for PTMD-SO2 and from 0.075 to 0.110 for PBTMD-SO2. Electric displacement–electric field loops studies indicated that the discharge energy density of PBTMD-SO2 reached 1.69 J/cm3 at 180 MV/m with a high efficiency of 87.1%, which exceeded the discharge energy density of 1.29 J/cm3 for PTMD-SO2 at 200 MV/m. This work offers a new idea for the design of high-performance dielectric polymers.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
GREEN CHEMISTRY
·
2025
·
IF 9.2
Hanwen Ge,Jiahui Wei,Shenglin Wang,Zexu Yan,Jiang Mingzhe,Lingxiao Zhu,Chao Liu,Bin Li,Caoxing Huang,Huanfei Xu
Heightened requirements in terms of environment, economy, and efficiency had been imposed on solvents used in the treatment of lignocellulose by the upgrading of the concept of green chemistry. Limitations were imposed on studies that only focus on enhancing a single interaction within the system due to the lack of understanding of the molecular-level mechanism in the solvent-biomass system. In this work, four novel ternary deep eutectic solvents (DES) were synthesized by adopting a new strategy in which the synergistic effect of hydrogen bonds (H-bonds), van der Waals (vdW) interactions and π-π stacking was used to enhance the delignification ability of DES. It was indicated by the results of quantum chemical calculation based on density functional theory (DFT) and molecular dynamics (MD) simulation that 84.26% and 68.72% of the electrostatic energy and vdW interaction energy in the DES-Lignin system were contributed, on average, by choline chloride (ChCl) and p-hydroxybenzoic acid (PB), with increases of 21.60% and 27.71% successively. This improvement was attributed to the increased molecular polarity resulting from the N⁺ on ChCl, the enhanced dispersion attraction due to the arrangement of methyl groups around the sp³-hybridized N⁺, and the π-π stacking interaction formed between the benzene ring structure of PB and lignin, which resulted in the enhancement of vdW interaction within the system. Affected by the ortho-substituents on the benzene ring, among the six investigated lignin dimers, stronger interactions with DES were exhibited by β-1 and β-O-4. The delignification ability of ChCl-LA-PB (strongest calculated interaction energy, reaching -92.37 kcal/mol) was demonstrated in the experiment of treating xylose residue. The delignification rate of lignin was increased by 1.86 times (up to 61.91%) compared with that of ChCl-LA. It was confirmed by the characterization resulted that the excessive depolymerization and condensation of lignin were avoided by the p-π conjugation effect of the phenolic hydroxyl group on PB through inhibiting the ionization of H⁺. Designing DES from the origin of molecular structure and adopting a strategy of multiple interactions in synergy provided novel insights and green methods for the high-value utilization of lignocellulose.
研究领域:
生物质化学
·
绿色化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2025
·
IF 9
Baozeng Sun,Yanchao Zhang,Yiman Gu,Zhanyu Li,Xiaoyu Yu,Wei Fan,Shiyao Sun,Jiayao Yang,Ruonan Zhao,Zhe Wang,Hongzhe Ni
Anion exchange membrane fuel cells (AEMFCs) have attracted much attention due to their advantages of being green, inexpensive and efficient. However, as the key to AEMFCs, anion exchange membranes (AEMs) still face challenges in balancing ionic conductivity and dimensional stability, limiting their application in fuel cells. In response, we report here an AEM strategy based on phenanthrene π-π stacking. The phenanthrene in the polymer backbone drives self-aggregation of cations to widen ionic transport channels, achieving a high ionic conductivity of 136.06 mS cm −1 and a low swelling ration of 19.37 % at 80 °C. Moreover, the as-prepared AEMs retained 96.2 % conductivity after immersion in 2 M NaOH solution at 80 °C for 1400 h, demonstrating excellent alkali stability. In addition, the developed novel AEM demonstrated a peak power density of 452.88 mW cm −2 in single fuel cells and a voltage drop of only 3.82 % after 50 h in-situ durability testing, highlighting the significant potential for wider application in fuel cells.
研究领域:
材料科学
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
ORGANIC & BIOMOLECULAR CHEMISTRY
·
2013
·Vol. 11
·期 45
·7931-7937
·
IF 3.568
Xinhua Cao,Aiping Gao,Haiting Lv,Yan Wu,Xiuxiu Wang,Yang Fan
A new gelator 1 that included m-methyl red was synthesized and fully characterized. It was found that the organogel of 1 was stable in DMSO even if the organogel was stimulated by acid or light. The organogel was thoroughly characterized using various microscopic techniques including field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), UV-vis and Fourier transform infrared (FTIR) spectra. The organogel exhibited tunable structures and optical properties under different stimulation. The regular nanoring structure was turned into microspheres after the organogel in DMSO was stimulated at 254 nm light or acid. At the same time, the color of molecule 1 in gel state and solution state was all changed after stimulation by light or acid. The hydrogen bonding and π–π stacking were found to be the main driving forces for gel formation. This dual-responsive gel held promise for soft materials application in upscale smart responsive materials.
研究领域:
材料化学
·
软物质科学
✓ 已验证
DOI
PubMed
高影响因子
CRYSTAL GROWTH & DESIGN
·
2021
·
IF 4.076
Zhijie Tao,Renfu Li,Xiao Xu,Aihui Cao,Weifeng You,Ying He,Weifeng Huang,Longtian Kang,Xueyuan Chen
A variety of organic semiconductor nanostructures have been already reported for photoelectric applications; however, there are a few systematic studies on the dependence of their photocurrent on nanostructures. Here, 0D, 1D, 2D, and 3D nanostructures of 5,10,15,20-tetrakis(4-carboxyphenyl) porphyrin copper (CuTCPP) are successfully constructed via liquid-phase chemical methods. Structural characterization shows that 0D and 1D nanostructures should result from the π–π stacking of CuTCPP molecules, while 2D and 3D ones are mainly from the in-plane aggregation via the linkage of −COOH with the Cu ion. The photoelectric properties of CuTCPP-based nanostructures are investigated to evaluate the effect of shape, size, and structure. A huge difference in photocurrent response is found, as compared to the raw material (0.09 μA/cm2) and 0D (0.17 μA/cm2), 1D (2.24 μA/cm2), 2D (0.4 μA/cm2), and 3D (0.93 μA/cm2) nanostructures. Further study reveals that the 1D nanostructure exhibits the lowest impedance and the longest exciton lifetime, strongly indicating that the photocurrent of the metal porphyrin nanostructure should be mainly limited in an in-plane exciton with a shorter lifetime than in an intermolecular one. This work provides a clear strategy to design molecule-based photoelectric nanomaterials.
研究领域:
材料科学
·
光电子学
✓ 已验证
产品关联
DOI
高影响因子
WATER ENVIRONMENT RESEARCH
·
2019
·Vol. 92
·期 5
·740-748
·
IF 1.24
Mingyan Li,Dasheng Gao,Shuang Cui,Yan Shi,Ningning Liu
Fe 3 O 4 /ZIF-67 composite was successfully fabricated by a facile method and used as adsorbent to remove direct blue 80 (DB80, azo dye) from water. Characterizations of Fe 3 O 4 /ZIF-67 composite were performed by scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), X-ray photoelectron spectroscopy (XPS), N 2 adsorption/desorption isotherms, Fourier transform infrared spectroscopy (FTIR), and magnetic property analysis. As an adsorbent, the factors (such as adsorbent dose, pH, initial concentration, contact time, and temperature) affecting the adsorption performance of adsorbent were investigated. The optimal adsorption condition is 5 mg of Fe 3 O 4 /ZIF-67 composite in 8 ml of DB80 solution (70 mg/L) for 60 min at 318 K, and the pH value has little effect on the adsorption performance. The adsorption isotherm, kinetics, and thermodynamics of DB80 adsorbed on the Fe 3 O 4 /ZIF-67 composite were also studied. The experimental results revealed that the experimental data followed the Langmuir model and the adsorption behavior could be well explained by pseudo-second-order kinetic model. Thermodynamic analysis indicated that the adsorption was a spontaneous and endothermic process. Furthermore, the mechanism of DB80 adsorbed on the Fe 3 O 4 /ZIF-67 composite was proposed. The occurrence of adsorption might be caused by the π-π stacking interaction between Fe 3 O 4 /ZIF-67 composite and DB80. Practitioner points Fe 3 O 4 /ZIF-67 composite was successfully fabricated via a facile method. Fe 3 O 4 /ZIF-67 composite was used to the adsorptive removal of direct blue 80 (azo dye). The kinetic characteristics and thermodynamic parameters were analyzed. The adsorption behavior might be ascribed to the π-π stacking interaction between Fe 3 O 4 /ZIF-67 composite and DB80.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Batteries-Basel
·
2023
·Vol. 9
·期 6
·318
·
IF 4
Yuyan Tang,Shaohui Li,Meng-Fang Lin,Jingwei Chen,Alice Lee-Sie Eh,Qun Xu
Sustainable organic materials have gained considerable attention as electrodes for zinc-ion batteries (ZIB) due to their high theoretical capacity, structural versatility, and environmental friendliness. However, issues of inferior capacities and poor rate performance owing to limited inherent electronic conductivity and severe dissolution still persist. Herein, sandwich-structured perylene diimide-ethylene diamine/graphene (PDI-EDA/EG) composites are judiciously designed and synthesized. The two-dimensional graphene host can interact with the PDI-EDA polymer throughπ–πstacking, endowing accelerated ion/electron transfer, abundant active sites, excellent structural integrity, and mitigated solubility of the hybrid electrodes. When evaluated as an anode in ZIB, the hybrid electrode delivers a high capacity (110.2 mAh g−1at 0.1 A g−1), superior rate capability (88.9 mAh g−1at 5 A g−1), and exceptional durability (93.4% capacity retained after 1000 cycles). The structure evolution of the hybrid electrode during the insertion/extraction cycle was investigated by ex-situ Fourier transform infrared spectra (FTIR) and X-ray photoelectron spectroscopy (XPS), revealing the reversible Zn2+storage at carbonyl sites. In addition, a prototype rocking-chair ZIB cell was constructed with a zinc pre-intercalated MnO2cathode, displaying an ultrahigh energy density of 54.9 Wh kg−1at a power density of 42.5 W kg−1and excellent stability with negligible capacity decay after 1000 cycles.Keywords:zinc-ion battery;rocking-chair battery;organic anode;aqueous electrolyte;perylene diimide-ethylene diamine
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
POLYMER BULLETIN
·
2024
·
IF 3.1
Yan Xin,Yang Jianming,Zhang Hexin,Yoon Keun-Byoung,Chen Min
The single-sited metallocene catalyst has attracted significant attention due to its high activity and application in olefin polymerization industry. In this work, we introduced a strategy of in situ modification of metallocene catalyst with pyrene through π–π stacking to study the effect in olefin polymerization. After activated by MMAO, the pyrene-modified metallocene catalyst exhibited high activities (up to 1333 kg mol −1 h −1 ) in ethylene polymerization, which was 1.9 times higher than that of the pyrene free catalyst system. This could be because the electron-donating ability of cyclopentene to the transition metal was enhanced through π–π interaction of pyrene with cyclopentene. The copolymerization of ethylene and 1-hexene was also studied. The pyrene-modified metallocene catalyst system performs with higher activity in the copolymerization with a lower monomer incorporation ratio. Density functional theory (DFT) calculations indicated the formation of π–π interaction between the Zr center with pyrene molecule leading to the increase in steric hindrance and electron density. Graphical abstract
研究领域:
高分子化学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）