SEPARATION SCIENCE AND TECHNOLOGY
·
2018
·
IF 1.2
Kai Xu,Haiming Jin,Linfang Wang,Yi Liu,Chen Zhou,Jürgen Caro,Aisheng Huang
A seeding-free synthesis method is developed for preparation of oriented zeolite LTA membranes by using 1,4-phenylene diisocyanate (PDI) as a molecular linker. Before hydrothermal synthesis, –NCO groups are introduced with the functionalization of Al2O3 supports by PDI. A thin, well intergrown zeolite LTA membrane with a thickness of about 4.0 µm can be formed on the PDI-modified Al2O3 supports. The zeolite LTA membrane displays high pervaporation performances for dehydration of alcohols. At 90°C, the separation factor of the zeolite LTA membrane is 4480 for dehydration of 95 wt% ethanol/water mixtures, with a high water flux of 3.4 kg·m−2·h−1.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
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
APPLIED SURFACE SCIENCE
·
2025
·
IF 6.9
Yue Liu,Meng Cai,ZhiHui Xie,Liangliang Xiong,Xiaoqiang Fan,Minhao Zhu
Graphene Oxide (GO) nanosheets show great potential in the field of corrosion protection owing to their lamellar structure and remarkable mechanical features. However, these nanosheets are highly susceptible to agglomerating in waterborne epoxy resin (EP) matrix, which results in their structure degradation and restricts their application in anti-corrosion field. To address this challenge, a novel approach is employed in this study, involving the synthesis of multiple molecular chains (PEI and EDTA) grafted GO nanosheets (designated as EAGO), and subsequently chelated with cerium cations (CEAGO). The grafting of multiple molecular chains solves the agglomeration phenomenon of GO nanosheets during the coating preparation process. Such an advanced structural design is crucial for corrosion protective coatings since the unique structure of grafted EDTA enables effective chelating of corrosion inhibitors to provide anti-corrosion and self-healing features, while the steric hindrance effect of multiple molecular chains restricts the mobility of EP molecular chains, thereby enhancing anti-wear properties. The CEAGO/EP coating achieves a corrosion protection efficiency of up to 96.53%, and the wear rate of the CEAGO/EP coating is approximately 62.88% lower than that of pure EP. Electrochemical Impedance Spectroscopy (EIS) and White-light interferometer (WLI) results demonstrated that the epoxy coating loaded with CEAGO nanosheets could provide robust corrosion protection and wear resistance for 6082 aluminum alloy.
研究领域:
材料科学
·
腐蚀与防护
·
表面工程
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产品关联
DOI
高影响因子
CHEMPHYSCHEM
·
2024
·Vol. 25
·期 14
·e202400103
·
IF 2.3
Na Li,Yeye Wang,Wendi Zhao,Zhihong Chen,Peipei Liu,Weiqiang Zhou,Fengxing Jiang,Congcong Liu,Jingkun Xu
Graphical The change in capacitance performance between PEDOT : PSS films can be attributed to the influence of the aggregation structure of specific molecular orientation on charge transport. Appropriate molecular orientation and molecular chain spatial configuration can effectively reduce the ion transport resistance while enhancing the interchain coupling to achieve efficient charge transfer. Conducting polymers (CPs), a significant class of electrochemical capacitor electrode materials, exhibit exceptional capacitive energy storage performance in aqueous electrolytes. Current research primarily concentrates on enhancing the electrical conductivity and capacitive performance of CPs via molecular design and structural control. However, the absence of a comprehensive understanding of the impact of molecular chain spatial order on ion/electron transport and capacitive performance impedes the development and optimization of advanced electrode materials. Here, a solvent treatment strategy is employed to modulate the molecular chain spatial order of PEDOT : PSS films. The results of electrochemical performance tests and Grazing Incidence Wide Angle X-ray Scattering (GIWAXS) show that Poly(3,4-ethylenedioxythiophene) : poly(styrenesulfonic acid) (PEDOT : PSS) films with both face-on and edge-on orientations exhibit exceptional electronic conductivity and ion diffusion efficiency, with capacitive performance 1.33 times higher than that of PEDOT : PSS films with only edge-on orientation. Consequently, molecular chain orientations conducive to charge transport not only enhance inter-chain coupling, but also effectively reduce ion transport resistance, enabling efficient capacitive energy storage. This research provides novel insights for the design and development of higher performance CPs-based electrode materials.
研究领域:
材料科学
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电化学
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产品关联
DOI
PubMed
高影响因子
AIP Advances
·
2024
·Vol. 14
·期 3
·
IF 1.4
Li Zhengqiu,Chen Yueling,Yang Wenchao,Ye Jingbiao,Song Xiangqian,Jin Ying,Liu Xiaoqing
This paper investigated the static in vitro degradation behavior of poly(L-lactic acid) (PLLA)-oriented microcellular materials. The study compared the influence of different molecular chains and internal morphological structures on water penetration into the material. Also, the relationship between thse self-accelerated degradation caused by ester bond breakage and reduced material molecular weight and mechanical properties was explored. Furthermore, the mechanism behind the static in vitro degradation of oriented microcellular PLLA materials in simulated human body fluid was explored, laying the foundation for regulating the mechanical performance decline of oriented microcellular biomimetic bone repair materials to match specific bone healing periods.
研究领域:
生物材料学
·
组织工程学
✓ 已验证
产品关联
DOI
高影响因子
SOFT MATERIALS
·
2021
·
IF 2.429
Dongxu Pei,Bing Lv,Jianhua Wang,Shengli Qi,Guofeng Tian,Dezhen Wu
In order to better understand the influences of polyimide (PI) skeleton structure and freeze-drying process on the properties of PI aerogel materials, PI molecular chains (ODPA-ODA, BPDA-ODA, BPDA-PPDA) with different stiffnesses and flexibilities were designed and a series of PI aerogels were accordingly fabricated by freeze-drying technique. The aerogels produced featured light weight (density of 0.01–0.16 g/cm3) and high flexibility, and their density, pore structure, and compress recovery performance could be well controlled by delicately tuning the molecular chain structure and solid contents of the poly (amic acid) salt solution. In addition, a hard PI aerogel with enhanced compressive strength was obtained by quick-freezing in liquid nitrogen.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES SCIENCE AND TECHNOLOGY
·
2024
·
IF 8.3
Fangcheng Lv,Lvqian Fu,Qibin Wang,Kaixuan Sun,Rui Yang,Sidi Fan,Xiang Yu
High-performance aramid papers are ideal insulating materials in the electric industry, due to their superior mechanical strength and insulation capabilities. However, when subjected to prolonged high-voltage and high-power operations, these papers are prone to electrical damage, such as breakdown or corona aging. Unfortunately, most damaged aramid papers are viewed as mere waste, discarded through landfill or other unsustainable disposal methods. It is not only contrary to circular economy principles but also poses a significant environmental threat due to the potential for pollution. Herein, a closed-loop recycling strategy is proposed that efficiently and effectively reclaims electrically damaged meta-aramid papers. Using the DMAc/LiCl deprotonation system, waste aramid papers are completely decomposed into molecular chains , exposing carbon residues resulting from electrical breakdown . These carbon residues are removed through a step-by-step purification process. A reprotonation treatment is then applied to regenerate new meta-aramid papers by reforming the intermolecular hydrogen bonds . This approach not only fully restores the original honeycomb-like structure but also ensures the crystallization and hydrogen bond content, maintaining both electrical and mechanical properties at above 90 % of their original values. Notably, our recycling method is also compatible with aramid-based composites, achieving exceptional recycling efficiency.
研究领域:
材料科学
·
环境工程
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电气工程
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产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2024
·
IF 3.8
Wang Jiang,Xin Meng,Weiguang Gong,Chenyang Li,Yichen Xu,Longjie Jiao,Pu Du,Zhong Xin
In this study, branched poly(lactic acid) (PLA) was synthesized through melt blending, which was blended with linear PLA (L-PLA) to enhance the crystallization. Nonisothermal and isothermal crystallization studies demonstrated that nucleated PLA exhibited a crystallization temperature and melt crystallinity of 119.0 °C and 48.0%, respectively, at the highest degree of entanglement of branched PLA (B-PLA). Following a simple annealing treatment, the Vicat softening temperature (VST) and heat deflection temperature (HDT) of nucleated PLA reached 157.2 and 94.3 °C, respectively. The presence of dipole interactions among molecular chain segments during the initial stages of nucleation was revealed via in situ infrared spectroscopy, which facilitated the adsorption of L-PLA onto B-PLA, thereby allowing branched segments to serve as nucleation sites for L-PLA. This comprehensive analysis elucidated the influence of B-PLA on the crystallization behavior of L-PLA and established a correlation between its degree of entanglement and nucleation efficacy. It could be concluded that nucleated PLA retains its biodegradability while demonstrating improved crystallization and heat resistance.
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
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Wen Yang,Chong Liu,Yongzhao Hou,Xiangjun Dai,Cheng Zhong,Yongqiang Ma,Meixian Jiang
In this work, a novel carbon-enriched SiC by the polymer derived ceramic (PDC-SiC) route was manufactured. By varying the branched chain of the preceramic polymer, the structure and electromagnetic properties of the obtained PDC-SiC ceramics can be effectively altered through carbon enrichment. Specially, PDC-SiC ceramics obtained from branched polysilylacetylene (PSA) constitute a composite material that contains nano-sized SiC grains, carbon nanotubes (CNTs), and silicon carbide nanowires (SiC nw ). Such PDC-SiC ceramics possess a complex three-dimensional network of CNT S /SiC nw , leading to remarkable microwave absorption properties. Notably, the PDC-SiC ceramics processed from dimethyl-polysilylacetylene (D-PSA) achieved a minimum reflection loss (RL min ) of −55.0 dB at 14.4 GHz, and an effective absorption bandwidth (EAB) extends across 5.5 GHz, with a thickness of 2 mm.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER
·
2025
·
IF 4.5
Minhui Zhu,Daomin Min,Shihang Wang,Yihang Jiang
Low-density polyethylene (LDPE) is an excellent insulating material that ensures the safe and reliable operation of high-voltage direct current (HVDC) cables. The insulation properties of LDPE can be improved by doping with voltage stabilizers. Due to its electron-withdrawing property, [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) has the potential to be used as a voltage stabilizer to improve the DC insulation performance of LDPE, especially the high temperature insulation performance of cable insulation. Therefore, the impact of PCBM on carrier trap characteristics and micro charge transport at high temperatures and high fields requires further study. LDPE is used as the matrix material to prepare composites with concentrations of 0.5 and 1 wt%. The experimental results show that the Weibull characteristic breakdown strength can be increased by 10.5 % and the DC electrical conductivity can be reduced by 73.6 % at 90 °C, when the PCBM doping concentration is 0.5 wt%. These results can be explained by trap characteristics and molecular chain displacement. It reveals that the introduction of PCBM can effectively increase the trap density, which can capture more charge carriers, resulting in a decrease in carrier mobility and electrical conductivity. Quantum chemical calculations indicate that owing to the high electron affinity and low ionization potential of PCBM, it is more prone to attracting and capturing electrons, thereby efficiently absorbing high-energy electron energy. Moreover, PCBM makes the amorphous region more tightly ordered, which manifests as an improvement in crystallinity. It also enhances the friction coefficient of the molecular chain and suppresses the molecular chain displacement in LDPE, which is verified by charge transport and molecular displacement modulated model simulations. This study provides a new method for improving the properties of cable insulation materials.
研究领域:
材料科学
·
电气工程
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2020
·Vol. 12
·期 10
·2305
·
IF 3.426
Dan Tian,Ji-Huan He
Mechanical property is one of the most important properties of nanofiber membranes. Electrospinning is widely used in the preparation of nanofibers due to its advantages such as good stability and easy operation. Compared with some nature silk, the mechanical properties of nanofibers prepared by electrospinning are poor. Based on the principle of vortex spinning and DNA structure, this paper designed an air vortex electrospinning device that can control the structure of macromolecular chains in nanofibers. When a weak air vortex is generated in the electrospinning process, the macromolecule chains will entangle with each other and form a DNA-like structure so as to improve the mechanical property. In addition, when a strong air vortex is generated during the electrospinning process, the nanofibers will adhere to each other, thereby enhancing the mechanical property and enlarging the pore size.
研究领域:
材料科学
·
生物工程
✓ 已验证
DOI
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2021
·
IF 3.196
Zechun Li,Changjin Yang,Yanchan Wei,Yuanbing Zhou,Shuangquan Liao
Natural rubber (NR) has excellent mechanical properties due to its unique molecular chain structure. In previous studies, the signal of the cis- and trans -isoprene units was deduced by 13 C-NMR spectrum of the low molecular weight fraction of NR. In this study, through investigating the 1 H-NMR spectra of ribbed smoked sheet 1 (RSS-1) and standard Chinese rubber whole fraction (SCR-WF), and Eucommia ulmoides gum (EUG), trans -1,4-polyisoprene (TPI), found that the methyl-proton in the cis- and trans -isoprene units in 1 H-NMR spectra of NR showed signals at 1.61 and 1.53 ppm, respectively. Further, the content of trans -structure in the molecular chain of NR of different producing areas was calculated. The results show that the content of trans -structure in the molecular chain structure of RSS-1 and SCR-WF were 1.500 and 1.054%, respectively.
研究领域:
高分子化学
·
材料科学
✓ 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）