JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
·
2024
·
IF 5.9
Yanping Ren,Xiaoqiang Fan,Kaiyue Lin,Shipeng Chen,Minhao Zhu
The preparation of a low shearing shell on the surface of carbon spheres (CS) is an attractive strategy to improve the lubrication properties of CS. In this study, core–shell structural C@Ag particles were prepared using CS as the hard core and Ag nanoparticles as the soft shell. Then, the additives were mixed with Polyalphaolefin 20 to prepare the C@Ag core–shell-enhanced lithium complex grease (C@Ag-LCG). The physicochemical properties, corrosion resistance, and tribological behaviors of LCGs were investigated. C@Ag-LCG exhibited the best high-temperature resistance and colloidal stability compared with the CS-enhanced lithium complex grease (LCG) and pure LCG. The dropping point and oil separation rate of 0.05 wt% C@Ag-LCG were 255 °C and 2.36 %, respectively. The tribological behavior of greases was tested using a four-ball friction tester, and the main damage mechanism was abrasive wear. The C@Ag additive reduced the average friction coefficient and wear spot diameter by 27.17 % and 26.12 %, respectively. The improved properties were attributed to the synergistic lubrication of hard CS core and soft Ag shell with the rolling, filling, and self-repairing effects, C@Ag deposit films and the self-lubricating oil film, as well as the thickener film and the tribochemical film at the frictional interfaces.
研究领域:
材料科学
·
润滑工程
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2024
·
IF 4.9
Yang Xiao,Lin Zhang,Bin Wei,ChangFeng Lu,Ling Li
Generally, modification of materials by adding multiple types of nano particles could cause dispersion problems, generally limited the performance improvement effect. Herein, we report the modification of UHMWPE materials by organic-inorganic core-shell particles with PTFE as the core and Al(OH) 3 as the shell, which prepared by in-situ polymerization of sodium bicarbonate and aluminum sulfate solution . Core-shell particles were filled in UHMWPE matrix and sintered into composite by spark plasma sintering (SPS). The mechanical and tribological properties of the composites were characterized by tensile compression testing machine, universal micro tribometer (UMT-5), three-dimensional white light interferometer and scanning electron microscope (SEM). The results showed that the addition of core-shell structural materials effectively improved the tribological properties (friction coefficient decreased by 40%, wear rate decreased by 30%) and mechanical properties (compression strength increased by 2.4 times) of the composites. It was demonstrated that the inorganic framework provided strength to improve the mechanical properties and wear resistance of materials, and the organic phase was used as a lubricating phase to reduce the friction coefficient of materials. Surface treatment of core-shell particles both improved the binding between particles and matrix and decreased the formation of agglomerations, thus significantly reducing ploughing phenomena’s effect produced by abrasive wear of agglomeration
研究领域:
材料科学
·
机械工程
✓ 已验证
产品关联
DOI
高影响因子
POLYMER ENGINEERING AND SCIENCE
·
2024
·
IF 3.2
Yangbo Xu,Rulin Shen,Juntao Tang,Xiangfu Zou,Wenhu Wan,Haibo Guo
Shell materials play significant impact on corrosion resistance and mechanical properties on self-healing coating of composite with core-shell nanofiber. In this paper, three promising shell materials were investigated to optimize the performance of self-healing coating. Self-healing core-shell nanofibers with different shell materials were prepared with coaxial electrospinning. The resulting nanofibers were used to prepare self-healing corrosion resistance coating. The tensile test revealed a notable enhancement in the tensile strength of PA6 core-shell nanofiber epoxy composite coatings compared with the epoxy coating, demonstrating increase of 26.92%. Friction and wear test indicated reductions in the friction coefficients of PAN, PVDF, and PA6 core-shell nanofibers by 13.82%, 12.44%, and 26.27%, respectively. The self-healing and anti-corrosion abilities were evaluated through electrochemical impedance spectroscopy (EIS) test. All three coatings exhibited exceptional self-healing efficiencies exceeding 90%, highlighting the substantial potential of the chosen shell materials as nanocontainers for self-healing agent. Results indicate that the nanofibers with PA6 as shell material can achieve the best enhancement performance, which has a greater potential for the corrosion protection and long-lasting use of offshore wind turbine tower coatings. Highlights Optimizing coating performance by screening coaxial nanofibers for shell materials Shell material can improve the tensile strength of coating up to 26.92% Friction coefficient of PA6 nanofiber coating was about 15% lower than PAN and PVDF All three coatings exhibited exceptional self-healing efficiencies exceeding 90%
研究领域:
材料科学
·
腐蚀与防护
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Inorganic Chemistry Frontiers
·
2024
·
IF 6.1
Tianhao Yu,peng gao,Hong Du,ling dong
The oxygen evolution reaction (OER) requires the development of a strong and efficient electrocatalyst due to its slow mechanism and high overpotential. Hence, we assembled POM and NiCo-ZIF-67 to obtain the amorphous hollow core-shell material NiCo-ZIF-67@POM (donated as NiCo-ZIF@POM) with high catalytic activity. NiCo-ZIF@POM (1:3) presents a low overpotential (η≈150 mV@10 mA cm-2), a small Tafel slope (100 mV dec-1), and great stability for OER in 1 M KOH solution. Theoretical calculations indicate that the excellent activity of NiCo-ZIF@POM might be attributed to the charge rearrangement due to the interaction between Co and W. In addition, the low electronegativity of P and the high oxidation state of W in POM could accelerate the rapid OH- transfer and induce the intermediates to adsorb on the Co-O-W bridge bond conformation, which improves the performance of the catalytic OER. This study provides a new idea for the secondary assembly of POM and MOF materials.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Analytical Methods
·
2015
·Vol. 7
·期 8
·3486-3492
·
IF 1.821
Houmei Liu,Yong Guo,Xusheng Wang,Xiaojing Liang,Xia Liu
In this paper, a novel sorbent, nano-Al2O3 coated mesoporous silica (Al2O3/SiO2), was prepared and used as a sorbent for solid-phase extraction of flavonoids. The synthesized sorbent material was characterized by X-ray photoelectron spectroscopy, energy dispersive spectroscopy and inductively coupled plasma emission spectrometry. The extraction properties of the resultant sorbent were evaluated by using four flavonoids (myricetin, quercetin, luteolin and kaempferol) as the test analytes. The extraction efficiencies of Al2O3/SiO2 were apparently superior to those of commercial C18 sorbents. Under optimal conditions, good linearities with R2 ranging from 98.8% to 99.8% were obtained and the LODs and LOQs were found to be in the range of 0.5–1 μg L−1 and 2.5–3 μg L−1, respectively. The proposed method was successfully applied for the real sample analysis of wild honey and red grape juice.
研究领域:
分析化学
·
材料科学
·
食品科学
✓ 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）