CARBOHYDRATE POLYMERS
·
2019
·
IF 6.044
Ke Li,Xiao Zhang,Chen Du,Jinwan Yang,Bolang Wu,Zhiwei Guo,Conglin Dong,Ning Lin,Chengqing Yuan
With the increasing requirement of environmental protection, the development of lubricating materials with non-toxicity and good biodegradability becomes more and more significant. As the novel green nanomaterial derived from natural cellulose, cellulose nanocrystals (CNCs) in the present work were prepared from native cotton and added into polyalphaolefin (PAO) base oil as the lubricant additive. To improve the compatibility of CNCs with PAO, the surface of CNCs were grafted by stearoyl chains, which entangled with polyolefin chains and led to a good dispersibility and stability of the colloidal solution. This hybrid oil with the elevated viscosity improved the formation of lubricant film in the boundary lubrication regime. Combining with the mending effect of CNC particles on the surface roughness and scars, both the friction and the wear were dramatically reduced. Specifically, the introduction of 2 wt% modified nanocrystals (mCNC) in PAO base oil reduced the coefficient of friction (COF) by 30%. The results of this study suggest that cellulose nanocrystal is a promising ecofriendly and effective lubricant additive.
研究领域:
材料科学
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环境科学
·
生物工程
✓ 已验证
DOI
PubMed
高影响因子
Lubricants
·
2024
·Vol. 12
·期 12
·416
·
IF 3.1
Haiyang Wang,Zhongyi He,Liping Xiong,Liang Qian,Lili Li,Qiyang Long
This research thoroughly examined the tribological characteristics of polyalphaolefin (PAO4) oil, both with and without the incorporation of methyl silicone resin. The evaluation of anti-wear properties and friction reduction was conducted using a four-ball tester for friction and wear. The incorporation of methyl silicone resin into PAO4 at 25 °C significantly reduced the wear scar diameter (WSD), achieving minimum values at a concentration of 0.02 wt.%. PAO4 with 0.02 wt.% methyl silicone resin shows excellent wear resistance at different temperatures. A detailed analysis of the wear scar surfaces and wear debris was conducted using scanning electron microscope (SEM), energy dispersive spectrometer (EDS), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, 3D surface profiler and TEM. The results compellingly demonstrate that the remarkable improvement in wear resistance is predominantly due to the strategic formation of SiO2nanoparticles during the friction process. These SiO2particles not only adeptly fill the surface gaps at the friction interface but also crucially contribute to the formation of a robust tribochemical film, which is instrumental in enhancing wear performance.
研究领域:
材料科学
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表面工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
TRIBOLOGY INTERNATIONAL
·
2019
·
IF 3.517
Zhengquan Jiang,Guangbin Yang,Yujuan Zhang,Chuanping Gao,Jingyi Ma,Shengmao Zhang,Pingyu Zhang
Ultrathin oil-soluble tungsten disulfide nanosheets surface-capped with oleylamine (OA-capped WS 2 ) were prepared by liquid phase thermal decomposition method without any solid by-products, a facile method with potential for large-scale production. OA-capped WS 2 nanosheets exhibit good dispersibility and long-term stability in poly alpha olefin oil and significantly enhance the lubricating properties of the base oil over a wide temperature range (from 25 °C to 200 °C). This is because the surface-capped WS 2 nanosheets can be well adsorbed on friction surfaces forming a lubricating film (mainly WS 2 ) and participate in tribological chemical reaction to generate a chemical reaction film consisting of WO 3 , FeS, FeSO 4 , iron oxides , and FeOOH on the worn steel surfaces during friction process .
研究领域:
材料科学
·
润滑工程
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2025
·
IF 8.5
Danni Hu,Huangjuan Li,Zhenfei Feng,Huayu Hu,Yanjuan Zhang,Tao Gan,Zuqiang Huang
Two-dimensional composites with a core-shell structure used as lubricant additives tend to experience separation and delamination of the core and shell materials under high loads, resulting in poor tribological performance. Herein, monodisperse and spherical cellulose acetate-laurate/calcium borate/cellulose acetate-laurate (CAL/CB/CAL) nanocapsules with three-dimensional network structure were prepared by high-pressure homogenization combined with solvent evaporation method. CAL/CB/CAL exhibited good dispersibility and long-term dispersion stability in polyalphaolefin (PAO) oil, and only slight stratification appeared after 21 d. Moreover, CAL/CB/CAL used as a lubricant additive for PAO oil demonstrated excellent anti-wear and extreme pressure properties under 392 N at 75 °C. Particularly, the wear scar diameter and coefficient of friction of CAL/CB/CAL were reduced by 14.1 and 26.4 % under 490 N, respectively, relative to CB@CAL with a core-shell structure. The excellent tribological properties of CAL/CB/CAL under low load were attributed to the synergistic action between the rolling effect of CB and the sliding effect of CAL, while under high load, its three-dimensional network structure could avoid the separation and delamination of CB and CAL, thus evenly penetrating into the friction surface to form tribochemical films. This study provides feasible approach to address the limitations of two-dimensional core-shell composites in lubrication applications.
研究领域:
材料科学
·
摩擦学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FUEL
·
2021
·
IF 6.609
Yumeng Chen,Dian Zhang,Junguo Li,Changning Wu,Ke Liu
Waste coal is a major environmental hazard produced in the traditional coal preparation unit operations. In this paper, a case study is presented for further scavenging the combustible matter in waste coal using flotation with a self-designed collector (Ksw) consisted of kerosene (K), span (S) and water. The said collector took advantage of both the emulsification and pre-dispersion technique so that the waste coal processability could be improved to a greater extent. Our flotation tests have shown comparable combustible matter recovery when using Ksw and emulsified kerosene (Ks), and both collectors significantly outperformed that of K. At 4 kg/t collector dosage, combustible matter recovery was at 54.9%, 64.9% and 65.3% for K, Ks and Ksw respectively. However, Ksw represented an economically superior option due to its specific composition features. The zeta potential measurements and interaction energy calculations have suggested that although there existed an electrostatic repulsion between the selected oil droplets and coal particles, flotation of waste coal was still feasible because of the hydrophobic force dominating the interaction process. Further, it was found that the interaction energy calculation results could not sufficiently account for the superior flotation performance of using Ksw as collector. Dynamic light scattering (DLS) measurement has shown that the other key instruments at play were the diameter and number of the oil droplets. At 400 mg/L collector suspensions, emulsification reduced the effective diameters of K from 4.23 to 1.62 μm (Ks), and further decreasing to 1.12 μm (Ksw) when dispersion was imposed. The outcomes of this work have suggested Ksw as an economically and technically superior reagent over the conventional hydrocarbon oil collectors for waste coal reprocessing.
研究领域:
环境科学
·
化学工程
·
材料科学
·
矿物加工
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2021
·
IF 6.165
Siyuan Wang,Zhao Liang,Ling Liu,Yucheng Cao,Yingliang Cheng,Ding Chen
Despite being regarded as one of the most promising lubricant additives, poor dispersion remains a huge obstacle for graphene applications. To solve this problem, the traditional method is to modify graphene with chemical functionalization under harsh conditions. The present investigation prepared modified reduced graphene oxide by the traditional method (MRGO-1) and microwave-assisted ball milling (MRGO-2). The chemical and structural features of MRGO-1 and MRGO-2 are examined by SEM, TEM, XRD, Raman, FTIR, and TGA analyses. The results indicate the microwave-assisted ball milling enables MRGO-2 to be more efficiently dispersed and functionalized than MRGO-1. MRGO-1 and MRGO-2 were introduced into poly alpha-olefin oil (PAO6) as lubricant additives, and the dispersion and tribological performances were tested. Compared with MRGO-1, the dispersion stability of MRGO-2 is increased by 73.8%. Due to its excellent dispersion performance, MRGO-2 can consistently maintain a low friction coefficient during the friction process, and the average friction coefficient is 49.01% lower than that of MRGO-1. Furthermore, the EDS on the worn area demonstrates the most efficient transfer of MRGO-2 on the friction contact interfaces. Finally, the reasons for the improvement in dispersion stability and tribological properties of graphene by microwave-assisted ball milling are explained.
研究领域:
材料科学
·
化学工程
·
机械工程
✓ 已验证
产品关联
DOI
高影响因子
KOREAN JOURNAL OF CHEMICAL ENGINEERING
·
2022
·Vol. 39
·期 7
·1936-1945
·
IF 3.146
Niu Hui,Feng Yuyu,Ding Jie,Zhang Wei,Hu Chenxing,Zhang Qingxiang,Zhang Chen,Li Cuiqing
This study reports reactive adsorptive dechlorination of hydrocarbon oil over TiO 2 -based metal oxides at the temperatures of 20–150 °C. TiO 2 and a series of TiO 2 -CeO 2 were prepared by precipitation method and characterized by N 2 adsorption, XRD, FT-IR, pyridine-IR, NH 3 -TPD and CO 2 -TPD. The characterization results showed that both the acidity and basicity of the adsorbent had a significant impact on its dechlorination capacity. TiO 2 -U precipitated by urea exhibited higher dechlorination capacity than TiO 2 -A precipitated by ammonia due to the higher surface area, more acid and base amounts of the former. Among various Ti (1− x ) Ce x O 2 (x=0.1, 0.3, 0.5, 0.7, 0.9, 1) oxides, Ti 0.7 Ce 0.3 O 2 and Ti 0.3 Ce 0.7 O 2 bimetallic oxides showed higher dechlorination capacity than TiO 2 -U, and the chlorine removal over Ti 0.7 Ce 0.3 O 2 reached 82.8% after adsorption at 150 °C for 3 h. Mixing 5 wt% of alkali earth metal oxide into Ti 0.7 Ce 0.3 O 2 mechanically enhanced its dechlorination capacity, and the chlorine removal over Ti 0.7 Ce 0.3 O 2 -BaO reached as high as 92.1%. The chlorine removal increased with increasing the adsorption temperature. Ion chromatography and GC-MS analysis revealed that organochlorine compound was converted into Cl − and its corresponding alcohol over the adsorbent at 150 °C. Finally, the mechanism of reactive adsorption dechlorination was proposed.
研究领域:
化学工程
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
WEAR
·
2025
·
IF 6.1
Yuchen Sun,Chaoyang Zhang,Qiangliang Yu,Mohamed Kamal Ahmed Ali
This study aims to synthesize oil additives tailored for harsh space conditions, particularly atomic oxygen (AO) exposure, to enhance the lubrication performance of aerospace systems. To achieve this, polyhedral oligomeric silsesquioxane (POSS)-based ionic liquid (IL) with varying alkyl chain lengths (n = 8,16) were synthesized through nucleophilic substitution reactions, using octyl-functionalized polyhedral oligomers and halogenated hydrocarbons as precursors. The tribological and resistance AO irradiation properties of POSS-based IL additives (POSS-8-DOSS and POSS-16-DOSS) into PAO10 base oil were systematically investigated in atmospheric and vacuum environments. The properties of the formulated oil revealed that adding 1 wt% POSS-8-DOSS resulted in improved thermal stability compared to POSS-16-DOSS. Conversely, POSS-16-DOSS exhibited better performance in terms of corrosion resistance. Notably, the formulated oil containing POSS-based IL additives reduced the friction coefficient by 39.67–40.38 % in the atmospheric environment and by 65.94–79.89 % in the atomic oxygen radiation environment. Furthermore, the antiwear properties improved by 77.50–90.14 % in the atmospheric environment. Eventually, the results of this study provide valuable insights for advancing the field of aerospace lubrication.
研究领域:
航空宇航科学与技术
·
材料科学
·
摩擦学
·
化学合成
·
表面工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2021
·
IF 8.198
Xiaobin Han,Sanpeng Mao,Shi Xu,Jianying Yu,Zhilong Cao,Ruiyang Wang,Peng He,Shangheng Zeng
In this study, the reactive chain extension rejuvenators (RCERs) and aromatic hydrocarbon oil (AHO) were applied to construct the reactive chain extension rejuvenation systems (RCERs-AHO), and the effect of RCERs-AHO on the viscosity–temperature characteristics, rheological properties, and morphology of aged styrene–butadiene–styrene (SBS)-modified bitumen (ASMB) was thoroughly studied. Meanwhile, the rejuvenation effect of RCERs-AHO and TDI/HDI-AHO (toluene-2, 4-diisocyanate/hexamethylene diisocyanate and AHO) on ASMB was compared. The results indicated that the RCERs-AHO were more effective in restoring the viscosity of ASMB compared with TDI/HDI-AHO. The critical temperatures of the rutting factor at G*/sinδ = 1.0 kPa of rejuvenated SBS-modified bitumen (RSMB) regenerated by RCERs-AHO were higher than those of RSMB rejuvenated by TDI/HDI-AHO, revealing that RCERs-AHO could better increase the high-temperature rutting resistance of RSMB. Also, the low-temperature cracking resistance of RSMB was obviously enhanced by RCERs-AHO in comparison with TDI/HDI-AHO. The results of the average recovery rate of RSMB revealed that RCERs-AHO could better enhance the deformation recovery ability of RSMB. In addition, fluorescence morphology images clearly indicated that RCERs-AHO could better reconstruct the cross-linking structures of aged SBS compared with TDI/HDI-AHO. The comprehensive analysis of the research results showed that RCERs-AHO could efficiently restore the performances of ASMB to the level of fresh SBS-modified bitumen, and the rejuvenation ability of RCERs-AHO was more obviously excellent than TDI/HDI-AHO.
研究领域:
材料科学
·
土木工程
·
化学工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）