A facile method to fabricate wettability pattern(two extreme wettabilities arranged in a pattern)to realize water self-pumping is proposed on cemented carbide while not necessarily depositing other materials on substr...A facile method to fabricate wettability pattern(two extreme wettabilities arranged in a pattern)to realize water self-pumping is proposed on cemented carbide while not necessarily depositing other materials on substrate surface.The water self-pumping is achieved by arranging wedge shaped superhydrophilic domain in superhydrophobic substrate using laser machining.Through single factor experiments,it is found that the key to the extreme wettabilities,micro⁃and nano⁃structures,is rendered by laser machining processes and is influenced by laser parameters.Meanwhile,the proper laser parameters that are used to fabricate required micro-and nano⁃structures are obtained.Finally,the water transport experiment is carried out,which shows that the velocity of water bulge could be up to 362 mm/s when the wedge angle is 3°.The mechanism of the water self-pumping is analyzed and it is found that the migration of water bulge is governed by Laplace pressure of the water bulge induced by the wedge micro-groove.展开更多
Superhydrophilic–superhydrophobic patterned surfaces constitute a branch of surface chemistry involving the two extreme states of superhydrophilicity and superhydrophobicity combined on the same surface in precise pa...Superhydrophilic–superhydrophobic patterned surfaces constitute a branch of surface chemistry involving the two extreme states of superhydrophilicity and superhydrophobicity combined on the same surface in precise patterns.Such surfaces have many advantages,including controllable wettability,enrichment ability,accessibility,and the ability to manipulate and pattern water droplets,and they offer new functionalities and possibilities for a wide variety of emerging applications,such as microarrays,biomedical assays,microfluidics,and environmental protection.This review presents the basic theory,simplified fabrication,and emerging applications of superhydrophilic–superhydrophobic patterned surfaces.First,the fundamental theories of wettability that explain the spreading of a droplet on a solid surface are described.Then,the fabrication methods for preparing superhydrophilic–superhydrophobic patterned surfaces are introduced,and the emerging applications of such surfaces that are currently being explored are highlighted.Finally,the remaining challenges of constructing such surfaces and future applications that would benefit from their use are discussed.展开更多
Thermocapillary migration in lubrication systems is a phenomenon in which the lubricant migrates via the interfacial tension difference caused by the nonuniform temperature generated by the wear behavior,which leads t...Thermocapillary migration in lubrication systems is a phenomenon in which the lubricant migrates via the interfacial tension difference caused by the nonuniform temperature generated by the wear behavior,which leads to lubricant starvation and results in severe damage.This paper proposes a novel method to eliminate the thermocapillary migration phenomenon,in which we successfully fabricate a surface that combines a shape gradient and wettability pattern on 316 L stainless steel,and the results prove that the prepared surface can not only effectively obstruct liquid paraffin droplet migration but also directionally transport liquid paraffin to the center of the wear track under the thermocapillary migration effect.The results of the wear tests further demonstrated that only the surface combination of a shape gradient and wettability pattern can achieve a decrease in the friction coefficient by means of external lubricant feeding in the state of lubricant starvation,which provides a strategy for improving and developing new types of lubrication enhancement for mitigating starvation lubrication.展开更多
基金the National Natural Science Foundation of China(No.51875285)the Natural Science Foundation of Jiangsu Province(No.BK20190066)+1 种基金the Fundamental Research Funds for the Central Universities(No.NE2020005)the Foundation of the Graduate Innovation Center,Nanjing University of Aeronautics and Astronautics(No.kfjj20190508).
文摘A facile method to fabricate wettability pattern(two extreme wettabilities arranged in a pattern)to realize water self-pumping is proposed on cemented carbide while not necessarily depositing other materials on substrate surface.The water self-pumping is achieved by arranging wedge shaped superhydrophilic domain in superhydrophobic substrate using laser machining.Through single factor experiments,it is found that the key to the extreme wettabilities,micro⁃and nano⁃structures,is rendered by laser machining processes and is influenced by laser parameters.Meanwhile,the proper laser parameters that are used to fabricate required micro-and nano⁃structures are obtained.Finally,the water transport experiment is carried out,which shows that the velocity of water bulge could be up to 362 mm/s when the wedge angle is 3°.The mechanism of the water self-pumping is analyzed and it is found that the migration of water bulge is governed by Laplace pressure of the water bulge induced by the wedge micro-groove.
基金This work was supported by the Independent Innovation Fund of Tianjin University(Grant No.2022XJS-0003)the National Key Research and Development Program of China(Grant No.2019YFA0905804).
文摘Superhydrophilic–superhydrophobic patterned surfaces constitute a branch of surface chemistry involving the two extreme states of superhydrophilicity and superhydrophobicity combined on the same surface in precise patterns.Such surfaces have many advantages,including controllable wettability,enrichment ability,accessibility,and the ability to manipulate and pattern water droplets,and they offer new functionalities and possibilities for a wide variety of emerging applications,such as microarrays,biomedical assays,microfluidics,and environmental protection.This review presents the basic theory,simplified fabrication,and emerging applications of superhydrophilic–superhydrophobic patterned surfaces.First,the fundamental theories of wettability that explain the spreading of a droplet on a solid surface are described.Then,the fabrication methods for preparing superhydrophilic–superhydrophobic patterned surfaces are introduced,and the emerging applications of such surfaces that are currently being explored are highlighted.Finally,the remaining challenges of constructing such surfaces and future applications that would benefit from their use are discussed.
基金supported by the National Natural Science Foundation of China(No.52205204)the Outstanding Youth Innovation Team in Universities of Shandong Province(No.2023KJ116).
文摘Thermocapillary migration in lubrication systems is a phenomenon in which the lubricant migrates via the interfacial tension difference caused by the nonuniform temperature generated by the wear behavior,which leads to lubricant starvation and results in severe damage.This paper proposes a novel method to eliminate the thermocapillary migration phenomenon,in which we successfully fabricate a surface that combines a shape gradient and wettability pattern on 316 L stainless steel,and the results prove that the prepared surface can not only effectively obstruct liquid paraffin droplet migration but also directionally transport liquid paraffin to the center of the wear track under the thermocapillary migration effect.The results of the wear tests further demonstrated that only the surface combination of a shape gradient and wettability pattern can achieve a decrease in the friction coefficient by means of external lubricant feeding in the state of lubricant starvation,which provides a strategy for improving and developing new types of lubrication enhancement for mitigating starvation lubrication.
