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Direct measurement and theoretical prediction model of interparticle adhesion force between irregular planetary regolith particles

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International Journal of Mining Science and Technology 2023年第11期33卷 1425-1436页

作者： Heping Xie Qi Wu Yifei Liu Yachen Xie Mingzhong Gao Cunbao Li State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering Shenzhen UniversityShenzhen 518060China Guangdong Provincial Key Laboratory of Deep Earth Sciences and Geothermal Energy Exploitation and Utilization Shenzhen UniversityShenzhen 518060China Department of Civil&Mineral Engineering University of TorontoToronto M5S 1A1Canada

Interparticle adhesion force has a controlling effect on the physical and mechanical properties of planetary regolith and *** current research on the adhesion force of planetary regolith and rock particles has been primarily based on the assumption of smooth spherical particles to calculate the intergranular adhesion force;this approach lacks consideration for the adhesion force between irregular shaped *** our study,an innovative approach was established to directly measure the adhesion force between the arbitrary irregular shaped particles;the probe was modified using simulated lunar soil particles that were a typical representation of planetary *** experimental results showed that for irregular shaped mineral particles,the particle size and mineral composition had no significant influence on the interparticle adhesion force;however,the complex morphology of the contact surface predominantly controlled the adhesion *** the contact surface roughness increased,the adhesion force gradually decreased,and the rate of decrease gradually slowed;these results were consistent with the change trend predicted via the theoretical models of quantum ***,a theoretical model to predict the adhesion force between the irregular shaped particles was constructed based on Rabinovich’s theory,and the prediction results were correlated with the experimental measurements.

关键词： Planetary regolith adhesion force Particle morphology Prediction model

adhesion forces for water/oil droplet and bubble on coking coal surfaces with different roughness

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International Journal of Mining Science and Technology 2021年第4期31卷 681-687页

作者： Chunyun Zhu Guosheng Li Yaowen Xing Xiahui Gui Chinese National Engineering Research Center of Coal Preparation and Purification China University of Mining and TechnologyXuzhou 221116China School of Chemical Engineering and Technology China University of Mining and TechnologyXuzhou 221116China School of Chemical Engineering and Technology Zhengzhou UniversityZhengzhou 450052China

Surface roughness plays a significant role in floatability of *** the present paper,coking coal surface was polished by three different sandpapers and the surface properties were characterized by contact angle and roughness *** effect of surface roughness on floatability was investigated by adhesion force measurement system for measuring interaction forces between droplets/bubbles and coking coal surfaces with different *** results showed that the contact angle decreased with increasing roughness yet the adhesion force between the water droplet and coal surface increased owing to the increased contact line and the appearance of line *** adhesion forces between water and surfaces were 111.70,125.48,and 136.42μN when the roughness was 0.23,0.98,and 2.79 μm,*** contrast,under a liquid environment,the adhesion forces between air bubble/oil droplet and coal surfaces were decreased with increasing roughness because of the restriction by *** adhesion forces of increasing roughness were 97.14,42.76,and 17.86 μN measured at interfaces between air bubble and coal surfaces and 169.48,145.84,and 121.02 lN between oil droplet and surfaces,*** roughness could be beneficial to the spreading of oil droplets and the adhesion of bubbles which is conducive to flotation separation.

关键词： adhesion force Water/oil droplet Air bubble Roughness Floatability

MEASUREMENT OF adhesion forceS IN AIR WITH THE VIBRATION METHOD

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China Particuology 2005年第1期3卷 3-9页

作者： Siegfried Ripperger Konrad Hein Lehrstuhl für Mechanische Verfahrenstechnik Technische Universit(a|¨)t Kaiserslautern67653 Kaiserslautern Germany Lehrstuhl für Mechanische Verfahrenstechnik Technische Universit(a|¨)t Dresden 01062 Dresden Germany

The vibration method represents a practical method for the measurement of adhesion forces and adhesion force distributions. This method causes sinusoidally alternating stresses and yields detachment and contact forces between particles and substrate of the same order of magnitude. Alternating contact forces of the vibration method can cause an adhesion force intensification through flattening of asperities. The measuring principle of the vibration method and the analysis of experimental results are described in the article. Normal adhesion forces (pull-off forces) are measured using the vibration method and the colloidal probe technique. The results of both methods show good agreement for small particle sizes. The influence of the detachment force direction is shown by comparing tangential and normal adhesion forces measured using particle reentrainment in a turbulent air flow and the vibration method, respectively. The surface roughness of the substrate and the relative humidity are shown to significantly influence the measured adhesion forces. For the calculation of the adhesion forces, an approach by Rabinovich was combined with approximations of plastic micro asperity flattening. The Rabinovich approach accounts for roughness effects on the van der Waals force by incorporating the rms roughness of the interacting surfaces, rms-values of the particles and substrates were measured with atomic force microscopy at different scanning areas.

关键词： adhesion force vibration method roughness

Investigation on the intrinsic wetting thresholds of liquids by measuring the interaction forces of self-assembled monolayers

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Nano Research 2022年第5期15卷 4344-4349页

作者： Yulong Li Shaofan He Zhe Xu Zhonglong Luo Hongyan Xiao Ye Tian Lei Jiang Key Laboratory of Bio-inspired Materials and Interfacial Science Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing 100190China School of Future Technology University of Chinese Academy of SciencesBeijing 100049China School of Chemistry and Environment Beihang UniversityBeijing 100191China School of Mechanical Engineering Anhui University of TechnologyMa’anshan 243032China Ji Hua Laboratory Foshan 528000China

90°is the limitation oflyophilicity and lyophobicity for ideal surface for centuries,but it has been proved to be contradictory on some *** symmetrical surfaces with different surface tensions can attract or repel each other in ***,at the molecular level,the Iyophilicity or lyophobicity is the results of interactions between the liquids and ***,using atomic force microscope(AFM)to measure interaction forces between symmetrical self-assembled monolayers(SAMs)in different liquids,we found that the SAMs repel each other when the surfaces are hydrophilic whereas attract when hydrophobic in *** contact angle corresponding to the transition of attraction to repulsion is approximate to 65°,defined as the intrinsic wetting threshold(IWT)of *** ethylene glycol(EG),dimethyl sulfoxide(DMSO),N,N-dimethyl formamide(DMF),the IWTs could be determined by changes of adhesion forces between *** research redefined the IWTs for liquids,which is the essential guide to both basic theory and applications of wettability.

关键词： wettability intrinsic wetting threshold force curve adhesion force hydrogen bond

Origin of friction hysteresis on monolayer graphene

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Friction 2022年第4期10卷 573-582页

作者： Deliang ZHANG Yuge ZHANG Qiang LI Mingdong DONG Key Laboratory of Colloid and Interface Chemistry of the Ministry of Education School of Chemistry and Chemical EngineeringShandong UniversityJinan 250100China Interdisciplinary Nanoscience Center(iNANO) Aarhus UniversityAarhus C DK-8000Denmark

Load-dependent friction hysteresis is an intriguing phenomenon that occurs in many materials,where the friction measured during unloading is larger than that measured during loading for a given normal ***,the mechanism underlying this behavior is still not well *** this work,temperaturecontrolled friction force microscopy was utilized to explore the origin of friction hysteresis on exfoliated monolayer *** experimental observations show that environmental adsorbates from ambient air play an important role in the load dependence of ***,the existence of environmental adsorbates between the tip and graphene surface gives rise to an enhanced tip–graphene adhesion force,which leads to a positive friction hysteresis where the friction force is larger during unloading than during *** contrast to positive friction hysteresis,a negative friction hysteresis where the friction force is smaller during unloading than during loading is observed through the removal of the environmental adsorbates upon in situ *** is proposed that the measured friction hysteresis originates from the hysteresis in the contact area caused by environmental adsorbates between the tip and *** findings provide a revised understanding of the friction hysteresis in monolayer graphene in terms of environmental adsorbates.

关键词： friction hysteresis friction force microscopy graphene environmental adsorbates adhesion force

Microstructure,mechanical and thermal properties of Ni-P(-SiC)coating on high volume fraction SiC_(p)/Al composite

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Rare Metals 2023年第2期42卷 705-712页

作者： Gui-Wu Liu Wen-Qiang Luo Xiang-Zhao Zhang Hai-Cheng Shao Tie-Zheng Pan Guan-Jun Qiao School of Materials Science and Engineering Jiangsu UniversityZhenjiang212013China Suzhou Pant Piezoelectric Tech Co.Ltd. Suzhou215300China State Key Laboratory for Mechanical Behavior of Materials Xi’an Jiaotong UniversityXi’an710049China

Ni-P(-SiC)composite coatings were successfully deposited on 70 vol%SiC_(p)/Al composite by electroless *** surface microstructures and the phase structures of the Ni-P(-SiC)coatings were examined and analyzed by scanning electron microscopy(SEM)and X-ray diffraction(XRD)before and after heat-treatment at200-400℃for 2 *** thermal diffusivity of the deposited samples and the interface adhesion between the coating and the substrate were *** experimental results show that SiC content in the coatings increases obviously and XRD peaks are enhanced with SiC content in the bath increasing from 3 to 9 g·L^(-1).After heat-treatment,the surface of the coating becomes smoother and no diffusion layer is produced at the interface.A new phase Ni3P forms in the coating during heat-treatment at 400℃.The critical load(L_(c))of Ni-P-SiC composite coating on SiC_(p)/Al composite reaches the maximum value of 84.9 N with SiC content of 3 g·L^(-1)after heat-treatment at 200℃and more or less decreases with the increase in SiC content and heat-treatment *** thermal diffusivity of deposited samples gradually increases as the temperature increases;however,it reduces firstly and then climbs with the increase in SiC content.

关键词： Ni-P-SiC coating SiC_(p)/Al composite Microstructure adhesion force Thermal diffusivity

Self-healing elastomer modified proppants for proppant flowback control in hydraulic fracturing

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Petroleum Science 2022年第1期19卷 245-253页

作者： Jian-Da Li Gui-Cai Zhang Ji-Jiang Ge Wen-Li Qiao Ping Jiang Hai-Hua Pei School of Petroleum Engineering China University of Petroleum(East China)Qingdao266580ShandongPR China

To address proppant flowback issues during post-fracturing treatments and production,self-healing elastomer modified proppants(SMPs)are *** to their inherent self-aggregation behavior,the SMPs can aggregate together spontaneously to prevent proppant flowback and increase the pack *** is noteworthy that the SMPs have a firm and dry self-healing elastomer(SE)coating,making their storage,transport and use as conventional proppants *** SE synthesized through polymerization is rich in amidogens and carbonyl groups as characterized by Fourier transform infrared spectroscopy and the proton nuclear magnetic *** and thermomechanical properties of the SE coating are revealed by the thermogravimetric analysis,the differential scanning calorimetry and the rheological *** self-aggregation behavior of the SMPs is demonstrated by the adhesion force *** reversible hydrogen bonding interactions in SE coating contribute to the self-aggregation behavior of the SMPs,which is revealed by the thixotropy test and the FTIR analysis at different *** the self-aggregation behavior,the crushed proppants can aggregate in situ to form a stable structure again and therefore reduce the threat of narrowing down the fracture and proppant flowback,which has an important practical significance during oil and gas production.

关键词： Proppant flowback Self-healing elastomer Self-aggregation adhesion force

Exploration of the enhanced performances for silk fibroin/sodium alginate composite coatings on biodegradable Mg-Zn-Ca alloy

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Journal of Magnesium and Alloys 2021年第5期9卷 1594-1610页

作者： Hui Fang Chenxi Wang Shicheng Zhou Ge Li Yanhong Tian Tadatomo Suga State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001China Collaborative Research Center Meisei UniversityHinoTokyo 191-8506Japan

To expand the future clinic applications of biodegradable magnesium alloy,polymer coatings with excellent biocompatibility are the keys to solve the local alkalinity and rapid hydrogen ***-organic silk fibroin provides an approach to fabricate a protective coating on biomedical Mg-Zn-Ca alloy,however,the adhesion force and mechanical properties of the coating on substrates are ought to be further improved without any chemical conversion/intermediate ***,based on VUV/O;surface activation,a hybrid of silk fibroin and sodium alginate is proposed to enhance the adhesion force and mechanical properties of the composite coatings on hydrophilic Mg-Zn-Ca alloy *** mass ratios of sodium alginate addition were investigated to achieve the optimum coating *** nanoscratch test and nanoindentation test confirmed that the adhesion force was tripled and mechanical properties index was significantly improved when the mass ratio of silk fibroin/sodium alginate was 70/30 compared to pure silk fibroin or sodium alginate ***,the corrosion rate of the coated Mg-Zn-Ca alloy was significantly delayed with the addition of sodium alginate,resulting in a reaction layer during corrosion ***,the mechanisms for both adhesion and corrosion processes were discussed in *** findings offer more possibilities for the controllable surface performance of degradable metals.

关键词： Mg-Zn-Ca alloy Silk fibroin Sodium alginate adhesion force Mechanical property Corrosion resistance

Design and mechanism of agglomeration of aspirin crystals in pure solvents

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Particuology 2023年第11期82卷 146-156页

作者： Lihong Jia Degui Wu Pingping Cui Ling Zhou Qiuxiang Yin School of Chemical Engineering and Technology State Key Laboratory of Chemical EngineeringTianjin UniversityTianjin300072China Haihe Laboratory of Sustainable Chemical Transformations Tianjin300192China Tianjin Key Laboratory of Modern Drug Delivery and High Efficiency Tianjin300072China

Agglomeration with improved flowability for platy crystals is desirable in pharmaceutical downstream processing. The formation of agglomerates in pure solvents without the aid of bridging liquids is a convenient and low-cost method compared with complex spherical crystallization. In this work, the adhesion free energies between aspirin crystals in six solvents were calculated using Lifshitz-van der Waals acid-base theory to screen suitable solvents for agglomeration. The maximum stirring rate for agglomeration was determined by adhesion forces and dispersion forces. Then the agglomerates of plate-shaped aspirin were successfully prepared in acetone, methanol, ethanol, 2-propanol, and ethylene glycol without additives by simple cooling crystallization. The interactions between solvent and crystal surfaces were also used to explain the outcomes. A feasible mechanism for the agglomeration process of platy crystals was elucidated, involving the adhesion of dominant crystal facets at the beginning. The effect of stirring rate, cooling rate, and initial supersaturation on agglomeration degree and particle size of aspirin agglomerates were studied. The obtained aspirin agglomerates under the optimal conditions exhibited a uniform particle size distribution, a high agglomeration degree, and superior flowability.

关键词： Agglomeration Platy crystal Aspirin adhesion force