SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Weilin Feng,Lu Xu,Yuji Chen,Jiaqi Li,Hukang Guo,Mengxiao Zhang,Xiaohe Wang,Jianyu Wang,Chuanjie Fang,Liping Zhu
Integrally-skinned asymmetric (ISA) polymer membranes show enormous potential in efficiently energy-saving organic solvent nanofiltration (OSN) due to their excellent structural stability. However, the control of their microstructures at the nanoscale is technically challenging, making it difficult to simultaneously achieve high separation resolution and high solvent permeance. In this work, we report the in-situ evolution of polyimide ISA membranes from ultrafiltration to nanofiltration through thermal-induced densification of the surfaces. This process was attributed to the surface dynamics of polymers — i.e., the polymer segments on surface are more freely movable than that in bulk. The optimum treatment temperature was located between the glass transition temperatures of surface and bulk, which were measured based on porosity changes. The as-prepared ISA membranes with thin and dense skin layers exhibited high solvent permeance (e.g., over 5 L m −2 h −1 bar −1 for ethanol) and favorable molecular weight cut-off of around 300 Da. The membranes rivaled the state-of-the-art thin film composite membranes, demonstrating great potential in fast and precise molecular separation in OSN.
研究领域:
材料科学
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化学工程
·
膜技术
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Linkai Ren,Quanxing Ren,Ziqiang Yin,Tihao Cao,Xuxin Ping,Fangfang Ge,Zhengren Huang,Qing Huang,Yinsheng Li
In order to achieve low-temperature densification of SiC ceramic, β-SiC nanopowder was doped with Li 2 O together with Y 2 O 3 –Al 2 O 3 –MgO as sintering aids, and then spark plasma sintered at temperatures ranging from 1450 °C to 1600 °C for 30 min under 30 MPa pressure in argon. The densities, microstructures and mechanical properties of SiC ceramics were systematically investigated, in comparison to the counterparts sintered with Y 2 O 3 –Al 2 O 3 –MgO additives. Since Li 2 O has a low melting point, Li 2 O addition effectively decreased the formation temperature of liquid secondary phase, enabling SiC ceramics to obtain higher density and lower porosity after low-temperature sintering (T ≤ 1550 °C). Besides, Li 2 O addition was found to decrease the viscosity of liquid phase and enhance grain growth of SiC through dissolution-reprecipitation process. When sintered at 1550 °C, Li 2 O addition led to a remarkable increase of density from 3.03 g/cm 3 to 3.21 g/cm 3 for SiC ceramic. Meanwhile, the SiC ceramic with Li 2 O addition exhibited a high Vickers hardness of 22.75 ± 0.35 GPa and a good fracture toughness of 3.83 ± 0.27 MPa m 1/2 . The research results are expected to benefit the low-cost fabrication of SiC ceramics based on pressure-assisted sintering and alleviate the thermal damage of SiC fiber in hot-pressed SiC f /SiC composites.
研究领域:
材料科学
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陶瓷工程
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DOI
高影响因子
iScience
·
2022
·
IF 6.107
Bin Xia,Zhe Wang,Tingting Wang,Shuaishuai Chen,Han Wu,Binbin Zhang,Yunfa Si,Zibo Chen,Bao-Wen Li,Zongkui Kou,Daping He
Summary Numerous voids among the incompact layer-structure of MXene films result in their low ambient stability and poor innate conductivity for electromagnetic interference (EMI) shielding. Herein, we report a bridging-sheet-size-controlled densification process of MXene films by applying graphene oxide (GO) as a bridging agent. Specifically, the sheet size of GO is tailored to quantify a negative correlation of sheet size with densification for directing the preparation of most compact MXene-GO films. Benefiting from the shortest electron-transport-distance in the most compact structure, the conductivity of the MXene-GO film achieves 1.7 times (∼1.6 × 10 5 S/m) that of MXene film. The EMI shielding performance (5.2 × 10 6 dB/m) reaches the record-value among reported MXene films at 10 μm-scale thickness. Moreover, the compact structure boosts the ambient stability of MXene-GO films where the conductivity and EMI shielding performance remain 88.7% and 90.0% after 15 days, respectively. The findings rationale the structure-activity relationship of compact MXene films for flexible electronics.
研究领域:
材料科学
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电子工程
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DOI
高影响因子
Materials Today Communications
·
2022
·
IF 3.662
Chen Li,Yahan Liu,Mengjiao Chi,Xinjiang Luo,Bing Liu,Minmin Mao,Hadi Barzegar Bafrooei,Ge Wang,Ehsan Taheri-Nassaj,Kaixin Song
Highly-density Zn 3 B 2 O 6 (ZBO) ceramics were firstly prepared via a two-step cold sintering and ultra-low temperature sintering process (CSP-plus ULTCC post annealing). In this study, pre-densified ZBO ceramics (relative density∼ 92 %) is initially obtained under the condition of 200 ℃/60 min/300 MPa via CSP using acetic acid as a liquid phase, yielding microwave properties of ε r = 5.05, Q × f = 6353 GHz and τ f = −69.51 ppm/℃. After annealing at 550 ℃, relative dielectric properties are significantly improved, resulting in the microwave dielectric properties of ε r = 5.95, Q × f = 20620 GHz, τ f = −67 ppm/℃ achieved in a ZBO ceramics with relative density> 95 %. Many fine grains are observed to precipitate between the larger grains of cold-sintered ZBO ceramics, as evident by SEM images, exhibiting disordered grain and porosity distribution. At contrast, a uniform microstructure with fine grain and less porosity are observed after annealing procedure. The densification process of ZBO ceramics prepared by this method is further investigated to validate cold sintering "dissolution-precipitation" mechanism, as a critical factor, for promoting the densification of ZBO ceramics.
研究领域:
材料科学
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电子材料
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DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
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2023
·Vol. 106
·期 10
·5723-5734
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IF 3.9
Yi Zhong,Yun Wang,Zhenliang Yang,Bingqing Li,Jingkun Xu,Zhiyi Wang,Liang Xie,Limei Duan,Fengyun Hu,Mingfu Chu,Rui Gao,Pengcheng Zhang,Bin Bai
In this work, the sintering kinetics of pure UO 2 and 0.5 wt.%MnO-doped UO 2 was studied by a high-temperature dilatometer heated up to 1500°C. In addition, the sintering behavior of pure UO 2 and 0.5 wt.%MnO-doped UO 2 was studied by pressureless sintering technique. The results showed that MnO doping enhanced the grain boundary diffusion of UO 2 , which can effectively decrease the densification temperature and promote grain growth. The sintering temperature of UO 2 was significantly reduced by about 200°C with the addition of 0.5 wt.%MnO. The microscopic morphology studies showed that there were still fine particles agglomerated, forming sintered spheres in the matrix even if no severe agglomeration and bimodal size distribution were observed in raw UO 2 powder. The microstructure evolution of the sintered sphere and UO 2 matrix during the densification process was studied by isothermal sintering. Finally, the present analyses indicated that the densification of UO 2 matrix can be accelerated by adding MnO or increasing the sintering temperature, thus improving the densification inhomogeneity of UO 2 matrix.
研究领域:
材料科学
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核工程
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DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2018
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IF 3.779
Lianbing Zhong,Limeng Liu,Guihong Geng,Yujin Wang,Feng Ye
Tantalum carbide ceramics containing 0.25–3.40 wt% Al as densifying aid were prepared by hot pressing at 1900 °C under 30 MPa for 60 min. Effects of Al addition on densification, phase composition, microstructure and mechanical properties of the TaC-Al ceramics were investigated. Al was an effective oxygen getter which reacted with volatile oxygen impurities such as Ta 2 O 5 on surfaces of TaC particles to form non-volatile minor phase of Al 2 O 3 , thus slowed TaC grain growth via inhibiting the non-densifying matter transport by evaporation-condensation. When Al content was larger than the value that was needed for complete impurity reaction of 10Al + 3Ta 2 O 5 = 6Ta + 5Al 2 O 3 , presence of Al liquid at high temperatures improved densification of the TaC-Al ceramics because Al liquid spread along the grain boundaries and wet the TaC grains. The TaC ceramic with 0.75, 1.50 and 3.40 wt% Al addition reached a relative density value of 91.6, 97.5 and 100%, respectively, with a similar average grain size of 3.5–4.8 μm. Fe impurity dissolved in Al and formed Al 6 Fe; slight reaction of Al with TaC formed a thin layer of Ta-Al-C compound around TaC grains. The TaC ceramic with 1.50–3.40 wt% Al additions showed good Vickers hardness , Young's modulus and flexural strength in the range of 12.4–13.2 GPa, 413–479 GPa and 532–673 MPa, respectively. Increase in oxidation resistance of TaC ceramics was observed at 600 °C in air with a few percentages of Al additions.
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2026
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IF 9.6
Bing Yang,Jiacheng Ding,Yandong Che,Xu Wang,Lingru Kong,Tõnu Pullerits,Peng Song,Yanqiu Yang
Surface-enhanced Raman scattering (SERS) has emerged as a powerful technique for the rapid and sensitive detection of pesticide residues, particularly targeted pesticides of concern in food safety. However, hotspot intensification strategies in hydrogel-based SERS substrates that rely on solvent-exchange-induced shrinkage often suffer from concomitant analyte loss, thereby limiting detection reliability. Herein, an interface-engineered Ag-PAM-GO hydrogel was developed by integrating graphene oxide (GO) into a polyacrylamide (PAM) network to simultaneously achieve structural regulation and interfacial interactions. The incorporation of GO tailors the pore architecture and promotes coordination-driven Ag + enrichment together with confined in situ nanoparticle growth, enabling the uniform generation of plasmonic hotspots. Meanwhile, solvent-exchange-induced volumetric shrinkage effectively increases hotspot density, leading to an enhanced electromagnetic (EM) effect. Focusing on thiram, a widely used dithiocarbamate fungicide, the proposed substrate achieves ultrasensitive detection with a limit of detection of 7.12 × 10 −4 mg/L, while maintaining excellent signal uniformity and reproducibility. Interfacial Lewis acid-base interactions and hydrogen bonding cooperatively drive the preferential retention and local enrichment of thiram molecules during solvent exchange. Density functional theory calculations further revealed pronounced charge-transfer (CT) characteristics, confirming the contribution of the CT mechanism, while the increased adsorption energy supported strengthened molecule−substrate interactions. Benefiting from the synergistic interplay between the EM and CT mechanisms, the developed platform enables the reliable detection of thiram residues in fruit juices as well as on curved fruit surfaces, providing an effective strategy for the rational design of high-performance flexible SERS substrates for selective thiram residue detection. Download: Download high-res image (172KB) Download: Download full-size image
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Energy & Environmental Materials
·
2026
·
IF 13.8
Lingni Yang,Wei Li,Chunran Wu,Qing Zhang,Fenglin Wang,Xingyu Chen,Haijun Mao,Zhuofeng Liu,Hu Ye,Yujiu Zhou,Fujia Chen,Weijun Zhang
Dielectric capacitors are pivotal components in advanced electronic systems, yet their practical applications are hindered by the low volumetric energy density of commercial dielectric materials. Herein, a facile and scalable densification strategy is proposed to fabricate high-performance all-organic composite films by incorporating sucrose, a cost-effective and hydroxyl-rich disaccharide, into a poly(vinylidene fluoride-co-hexafluoropropylene) [P(VDF-HFP)] matrix. Benefitting from its abundant hydrogen-bonding sites, sucrose forms robust hydrogen-bonded crosslinking networks with P(VDF-HFP) chains. Those networks untangle and rearrange molecular chains, prompting the transformation from the non-polar α phase to the polar β / γ phases, while simultaneously elevating crystallinity and constricting amorphous chain spacing to diminish free volume for film densification. By integrating density functional theory calculations, molecular dynamics simulations, and comprehensive experimental characterizations, this study elucidates a novel “Hydrogen-bond Crosslinking-Densification” synergistic regulation mechanism at the molecular and mesoscopic scales. Consequently, the optimized P(VDF-HFP) composite film with 0.8 wt% sucrose achieves a significant breakdown strength of 627.84 MV m −1 and an ultrahigh discharged energy density of 31.86 J cm −3 , exhibiting a competitive discharged energy density among all-organic counterparts. This work bridges the gap between molecular-scale interactions and macroscopic dielectric performance via free volume theory, offering a scalable and cost-effective pathway for designing high-performance dielectric materials.
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MATERIALS RESEARCH BULLETIN
·
2026
·
IF 5.8
Yuran Yang,Gongwen Gan,Yue Cheng,Kui Liu
A phase-assisted densification mechanism induced by V 5+ substitution is identified. • Secondary phase formation significantly reduces the sintering temperature by 100 °C. • Dielectric loss is dominated by phonon damping rather than lattice energy • Optimal Q×f is achieved through minimized Raman FWHM and reduced phonon scattering. • Improved τ f originates from reduced Nb/VO 6 octahedral distortion. Microwave dielectric ceramics with low ε r , high Q×f, and near-zero τ f are essential for advanced wireless communication systems. In this work, Li 3 Mg 4 Nb 1- x V x O 8 (0.00 ≤ x ≤ 0.10) ceramics were synthesized, and the effects of V 5+ substitution on phase evolution, sintering behavior, and dielectric properties were systematically investigated. V 5+ doping induces the formation of a Mg 4 (Nb/V) 2 O 9 secondary phase, enabling a phase-assisted densification mechanism that reduces the optimal sintering temperature from 1175 °C to 1075 °C. The optimal composition ( x = 0.02) exhibits ε r = 13.65 and Q×f = 121,296 GHz. Raman and chemical bond analyses reveal that dielectric loss is primarily governed by phonon damping behavior, with the minimum Raman peak width corresponding to the highest Q×f . In contrast, lattice energy shows no direct correlation with dielectric loss. The improved τ f is attributed to reduced Nb/VO 6 octahedral distortion. These results demonstrate that synergistic regulation of phase evolution and lattice vibration provides an effective strategy for optimizing microwave dielectric performance. Download: Download high-res image (187KB) Download: Download full-size image
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JOURNAL OF ALLOYS AND COMPOUNDS
·
2026
·
IF 6.7
Guobin Zhu,Jiali Huang,Zhong Zheng,Feng Qiao,Hua Su
Mg 2+ substitution suppresses Jahn-Teller distortion of the [Cu/MgO 4 ] unit. • P-V-L lattice energy trends serve as a qualitative descriptor of Q × f variation. • Dense sintering at 925 °C and compatibility with Ag meet LTCC requirements. • Optimum properties: ε r = 8.01, Q × f = 49,558 GHz, and τ f = −30.6 ppm/°C. BaCu 2 Si 2 O 7 is a promising low-permittivity microwave dielectric ceramic; however, its high sintering temperature (>1000 °C) limits c°mpatibility with the low-temperature co-fired ceramics (LTCC) process. Herein, Mg 2+ was partially substituted for Cu 2+ in BaCu 2- x Mg x Si 2 O 7 ( x = 0–0.20) ceramics, with 2 wt% MBSCA glass. All compositions were densified at 925 °C. The average bond-length difference Δ d of the four-coordinate [Cu/MgO 4 ] unit decreases with Mg substitution up to x = 0.10, indicating suppressed local structural distortion, before a slight rebound at higher x . The measured Q × f and Δ d exhibit consistent composition-dependent trends, both reaching their optimum at x = 0.10, where reduced structural distortion and improved densification jointly contribute to the enhanced Q × f . The optimized composition achieves (measured at 14.74 GHz) ε r = 8.01, Q × f = 49,558 GHz, and τ f = –30.6 ppm/°C, along with excellent chemical compatibility with silver electrodes; although |τ f | increases with Mg content, it remains moderate at the optimum. These results demonstrate that BaCu 2- x Mg x Si 2 O 7 + 2 wt% MBSCA ceramics are promising candidates for LTCC applications.
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CERAMICS INTERNATIONAL
·
2026
·
IF 6
Chunyu Yuan,Haolong Han,Xiaofeng Tong,Shuaijia Du,Zongzhe Li,Hang Guo,Yumeng Zhang,Ping Li,Ligang Wang,Zhongliang Zhan
The electrolyte membrane plays a central role in determining the electrochemical performance of proton-conducting solid oxide electrolysis cells (H-SOECs). However, obtaining dense membranes with high proton conductivity remains challenging because widely used barium cerate–zirconate perovskite oxides exhibit low sintering activity and typically require high processing temperatures. Here, a pre-reacted powder approach is proposed to enhance electrolyte densification while preserving high conductivity. Powders synthesized directly in the perovskite phase with a compact particle structure achieve full densification at a shrinkage of 13%, whereas conventionally processed precursors remain porous even at 17% shrinkage. The strategy is effective for both BaCe 0.7 Zr 0.1 Y 0.2 O 3−δ (BCZY) and BaCe 0.7 Zr 0.1 Y 0.1 Yb 0.1 O 3−δ (BCZYYb) electrolytes, resulting in conductivity increases of approximately 150% and 60%, respectively. The improvement arises from enhanced bulk transport and reduced grain boundary resistance. When combined with a shrinkage-assisted support design, thin electrolyte membranes can be densified at 1400 °C, lower than conventional sintering temperatures. The resulting H-SOEC single cells exhibit 20-50% higher current density, and resistance contributions are analyzed by electrochemical impedance spectroscopy. This reduced-shrinkage densification strategy provides a scalable route for high-quality proton-conducting electrolytes and offers potential applicability to other ceramic membrane systems.
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高影响因子
ChemSusChem
·
2026
·Vol. 19
·期 13
·e70859
·
IF 5.9
Lele Qiu,Tong Li,Wanyu Tian,Fangjing Liu,Zhonghai Ni,Zhenkun Guo,Yunpeng Zhao
Crystallization management and defect passivation are essential for fabricating high-performance perovskite solar cells. However, structural decomposition and grain loosening of perovskite arising from additive side effects remain critical barriers to device advancement. Herein, we design and synthesize a series of axisymmetric multifunctional molecules based on silicon phthalocyanine to regulate both the crystallization and stability of perovskite films. The axial molecular engineering of silicon phthalocyanine effectively suppresses disordered aggregation and preferential crystallization of macromolecular additives within the precursor perovskite film. By optimizing the type and strength of interactions between silicon phthalocyanine and perovskite, highly compact and uniform perovskite films with reinforced interfacial connections in the resulting solar cells are achieved. These modified perovskite films exhibit superior optoelectronic properties, enabling a champion power conversion efficiency of 23.18%. Benefiting from the rational multisite passivation, defect-induced perovskite decomposition is substantially inhibited. In situ Fourier transform infrared spectroscopy further reveals that the modified perovskite resists thermally induced structural decomposition and mitigates the loss of organic components. Remarkably, the modified devices retain approximately 75% of their initial efficiency after 1000 h of aging at 85°C in a nitrogen atmosphere, demonstrating significantly enhanced stability compared to reference devices. Graphical Silicon phthalocyanine-based multifunctional molecules are employed to improve perovskite film crystallization, thereby promoting film densification and interface adhesion. These enhancements effectively boost carrier extraction and transport, yielding devices with superior optoelectronic performance and thermal stability.
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DOI
PubMed
高影响因子
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