CARBON
·
2023
·
IF 10.9
Xia Wang,Wenchang Zhang,Kun Ni,Fei Pan,Yanwu Zhu
It is well known that alkali metals can intercalate into graphite to form graphite intercalation compounds but the structural change of graphite induced by alkali metals has been paid less attention. Herein, we report that alkali metals (Li, Na, K) induce the phase transition from ABC-stacking (or 3R phase) to AB-stacking (or 2H phase) of graphite. Specifically, for the graphite powder containing ∼45% 3R phase in a mixed phase, the temperature needed to ensure a complete stacking phase transition is 600 °C, 500 °C or 350 °C, for Li, Na or K, respectively, much lower than that needed in bare annealing (1800 °C) while without these alkali metals. Simulations based on density functional theory (DFT) suggest that the charge transfer from alkali metals to graphene distinctly lowers the energy barrier of transition, explaining the different phase transition temperatures for these alkali metals.
研究领域:
材料科学
·
物理学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
TALANTA
·
2024
·
IF 5.6
Wen-Chao Deng,Hai-Long Qian,Cheng Yang,Shu-Ting Xu,Xiu-Ping Yan
Covalent organic frameworks (COFs) has shown great potential as stationary phase in gas chromatography separation. However, designing COF stationary phases with high separation performance remains challenging. Here, we report a novel strategy to enhance the separation ability of COF stationary phases through tuning the interlayer stacking of COF. A rare interlayer modulation of 2D COFs from eclipsed-AA to slipped-AA was achieved through a two-step synthesis method. Simply changing the solvent used in step 1 allowed an interlayer modulation from slipped-AA to eclipsed-AA. As the proof-of-concept, 5,10,15,20-tetrakis(4-aminophenyl)-21H,23H-porphyrin (Tph) and 2,5-dihydroxyterephthalaldehyde (DHTA) were condensed to prepare 2D COF Tph-DHTA. The interlayer stacking of the 2D COF Tph-DHTA was tuned from eclipsed-AA model to slipped-AA by changing the solvent from o -dichlorobenzene + n -butanol (3:1, v/v) to tetrahydrofuran + n -butanol (1:7, v/v) in step 1. The as-prepared Tph-DHTA with slipped-AA stacking ( s -Tph-DHTA) showed higher resolution and faster separation of C8 aromatic isomers than that with eclipsed-AA stacking ( e -Tph-DHTA). The formation of slipping stacking of s -Tph-DHTA facilitated the thermodynamics, but did not affect the mass transfer resistance for the separation of C8 aromatic isomers. This work not only provides a promising way to modulate the stacking structure of COFs, but also opens a new strategy to design COF stationary phases for the separation of intractable isomers.
研究领域:
材料科学
·
分离科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Polymers
·
2019
·Vol. 11
·期 9
·1463
·
IF 3.164
Xiaoxiao Zhang,Xuejuan Shi,Liang Ma,Xuan Pang,Lili Li
Chitosan (CS) stacking mats with excellent performance for adsorption of copper ions (Cu(II)) in wastewater were fabricated by alternating electrospinning/electrospraying. The hierarchical structure of the stacking membranes was designed by CS micro-hemispheres sandwiched between CS fibers. The CS stack membranes prepared by the electrospinning technology could effectively increase the specific surface area, and thus, facilitate the adsorption of copper ions. CS stacking membranes with three layers reached adsorption equilibrium within 60 min, and had a maximum absorbance of 276.2 mg/g. The absorbance performance was superior to most of the reported CS adsorbents. Compared with CS fiber mats which were dominated by CS chemical structure during adsorption, the stacking structure of CS membranes contributed to the high efficient capability, and exhibited the multilayer adsorption behavior. This study may develop a promising method for the design of environmentally-friendly natural polymer adsorbents to remove Cu(II) in wastewater.Keywords:chitosan;sandwiched stacking structure;copper ions;adsorption
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
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
·
2024
·
IF 8.1
Yang Zhao,Menglin Zhao,Siyuan Wang,Anyang Wang,Zhengping Chang,Zhongqi Wang
With the extensive research on ester-exchanged vitrimer, laminates utilizing vitrimer as matrix have garnered increasing attention due to their healability for achieving long-term durability of the composite structure. However, current research on the healing of mode II delamination for vitrimeric CFRP (vCFRP) laminates remains notably limited. In this study, the ENF tests were implemented to acquire load–displacement curves of eight typical vCFRP laminates with various interfaces. The results indicated a pronounced impact of the stacking interface on the fracture toughness values, the R -curves, fiber bridging effect, and crack growth behaviours . The continuous 0 ° fiber hindered the upward migration for the laminates with 0 ° / / θ ° interface, while the discontinuous θ 1 ° fabric had a lower in-plane strength and were more prone to cracking for the laminates with θ 1 ° / / θ 2 ° interface. Subsequently, the healing efficiencies of specimens were characterized. The healed laminates undergone three shear delamination damages could still achieve a substantial recovery of about 76.33 %.
研究领域:
材料科学
·
复合材料工程
✓ 已验证
产品关联
DOI
高影响因子
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
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2022
·
IF 24.319
Qixiang Wang,Huan Liu,Bin He,Ji Qi,Di Wang,Hang Xu,Nana Zhang,Jie Wang,Yanan Chen,Zhihong Wang,Zhengjia Wang,Xudong Qi,Limei Zheng,Ming Feng,Weiming Lü,Shishen Yan
Single-crystalline transition metal oxide thin film has been employed to perceive the fundamental functions of electronic structure and charge transfer processes in water splitting processes. However, the surface area enlargement and strain tunability in a single-crystalline transition metal oxide are restricted in conventional epitaxy . In this study, we report the oxygen evolution reaction (OER) enhancement by a stack of multilayer SrRuO 3 featured single-crystallinity, flexibility, and stackability. The controllable stack of multiple cylindrical SrRuO 3 for surface enlargement in a magnitude of order and the emergent electronic structure transition, from t 2g (3↑, 1↓) to t 2g (3↑) e g (1↑), of Ru efficiently enhances the OER performance, the overpotential can be reduced by ~74 % and ~78 % in KOH and HClO 4 respectively at 5 mA/cm 2 . Our study provides an approach for fine manipulation of single-crystalline freestanding oxide morphologically, and an efficient strategy aiming at the extreme enhancement of the electrochemically active surface area and the electronic structure engineering by strain.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Advanced Science
·
2024
·
IF 14.3
Wenhao Li,Jichuang Shen,Yaqing Ma,Xiang Xu,Han Chen,Lida Yu,Chen Ji,Menglin He,Kezhao Ma,Yiwei Duo,Li Wang,Tongbo Wei,Liping Shi,Muhong Wu,Kaihui Liu,Huaze Zhu,Wei Kong
2D stacking presents a promising avenue for creating periodic superstructures that unveil novel physical phenomena. While extensive research has focused on lateral 2D material superstructures formed through composition modulation and twisted moiré structures, the exploration of vertical periodicity in 2D material superstructures remains limited. Although weak van der Waals interfaces enable layer-by-layer vertical stacking, traditional methods struggle to control in-plane crystal orientation over large areas, and the vertical dimension is constrained by unscalable, low-throughput processes, preventing the achievement of global order structures. In this study, a supercell multiplying approach is introduced that enables high-throughput construction of 3D superstructures on a macroscopic scale, utilizing artificially stacked single-crystalline 2D multilayers as foundational repeating units. By employing wafer-scale single-crystalline 2D materials and referencing the crystal orientation of substrates, the method ensures precise alignment of crystal orientation within and across each supercell, thereby achieving controllable periodicity along all three axes. A centimeter-scale 3R-MoS₂ crystal is successfully constructed, comprising over 200 monolayers of single-crystalline MoS₂, through a bottom-up stacking process. Additionally, the approach accommodates the integration of amorphous oxide, enabling the assembly of 3D non-linear optical crystals with quasi-phase matching. This method paves the way for the bottom-up construction of macroscopic artificial 3D crystals with atomic plane precision, enabling tailored optical, electrical, and thermal properties and advancing the development of novel artificial materials and high-performance applications.
研究领域:
材料科学
·
凝聚态物理
✓ 已验证
DOI
PubMed
高影响因子
Journal of Spectroscopy
·
2025
·Vol. 2025
·期 1
·1359636
·
IF 2.1
Nannan Wu,Rui Ma,Gang Han,Shunli Ouyang,Liguo Ma,Dezhong Cai
Polyvinyl alcohol (PVA) is a widely utilized molecular polymer characterized by its strong water solubility, chemical resistance, and mechanical properties. Notably, it possesses the capability for biodegradation and finds extensive applications across various fields; thus, analyzing the fundamental properties of PVA is of paramount importance. Materials scientists have shown considerable interest in modifying polymers such as PVA. Among modification techniques, microwave irradiation has garnered significant attention due to its rapidity, efficiency, and cost-effectiveness. This study investigates the effects of temperature and microwave irradiation on PVA binary solutions using Raman spectroscopy while also analyzing intermolecular hydrogen bonding within these solutions. The results indicate that increasing temperature disrupts the tetrahedral structure formed between PVA and water, leading to a transition toward a chain-like configuration; however, an enhancement in partial hydrogen bonding occurs at 313.15 K. Furthermore, analysis of the PVA binary solution post-microwave irradiation reveals that exposure to microwaves enhances hydrogen bonding within PVA while inducing a depletion reaction after 180 s of irradiation. Atomic force microscopy further demonstrates that this duration leads to pronounced molecular chain stacking phenomena. This paper substantiates that microwave irradiation serves as an effective method for modifying PVA, thereby offering a robust strategy for polymer modification applicable in materials science, chemistry, and physics.
研究领域:
材料科学
·
化学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
Advanced Energy and Sustainability Research
·
2025
·
IF 5.7
Han Yang,Changsheng Min,Chao Li,Yuan Yu,Bangzhi Ge,Chongjian Zhou
Thermal transport in crystals highly depends on the vibrations of the lattice. If the intrinsic period of the lattice is disrupted, phonon transport within the lattice will be suppressed. Herein, a strategy is reported for thermal conductivity suppression in the 2D van der Waals semiconductor SnS 2 by layer period engineering. The stacking period for SnS 2 layers is broken by mechanical alloying combined with spark plasma sintering. Double Cs-corrected transmission electron microscopy reveals that 2H and 4H SnS 2 structures coexist by stacking along the c -axis, demonstrating the long-range ordered but short-range disordered arrangement. As a result, the lattice thermal conductivity of SnS 2 decreases from ≈2.0 to ≈1.18 W m −1 K −1 at 673 K. The strategy promises the potential application of SnS 2 in scenarios where low thermal conductivity is essential such as thermoelectric materials.
研究领域:
材料科学
·
热力学
·
半导体物理
✓ 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
CRYSTAL GROWTH & DESIGN
·
2021
·
IF 4.076
Maolin Li,Mengwei Wang,Yumin Liu,Ruiling Ouyang,Mingdi Liu,Dandan Han,Junbo Gong
Furosemide (FUR) is usually used to treat congestive heart failure and edema. Although bioavailability problems exist due to its poor solubility and unstable gastrointestinal absorption, preparing FUR/amino acid (AA) co-amorphous systems is regarded as a promising way to solve this problem. In this work, the oscillating ball milling method was successfully used to prepare the co-amorphous systems of FUR with l-cysteine, l-phenylalanine (PHE), l-arginine, l-tryptophan (TRP), and l-valine. Protonation of the secondary amino group (N2) in FUR probably results in interactions with the AA carboxyl group, which lead to excellent compatibility between FUR and AAs. The co-amorphous systems formed between FUR and PHE/TRP possess higher physical stability than other FUR/AA co-amorphous systems, which may be attributed to favorable aromatic stacking in FUR/PHE and FUR/TRP systems. Additional experiments were performed to explore the impact of co-former loadings on the stability of co-amorphous systems, which revealed that the co-amorphous systems are most stable when the molar ratios are at 0.527 and 0.423 for FUR in FUR/PHE and FUR/TRP systems, respectively. Finally, powder dissolution tests of the FUR/PHE and FUR/TRP co-amorphous systems were carried out, and the results demonstrated that the selected most stable co-amorphous systems have excellent dissolution advantage with a two-fold improvement of dissolution rate compared to pure FUR.
研究领域:
药剂学
·
药物化学
✓ 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
危险品化学品经营许可证（带存储）