Xujun Xu , Zhen Li , Yue Zhang , Chunlei Wang , Junhua Zhao , Ning Wei
{"title":"Anomalous friction of confined water in carbon nanotubes","authors":"Xujun Xu , Zhen Li , Yue Zhang , Chunlei Wang , Junhua Zhao , Ning Wei","doi":"10.1016/j.carbon.2024.119402","DOIUrl":null,"url":null,"abstract":"<div><p>The friction of water within a carbon nanotube (CNT) is influenced by the interplay between energy barriers and water structure. In this work, we employ a series of regular polygonal CNTs, whose energy barriers remain constant with size, to examine the influence of water structure on solid-water friction using the molecular dynamics (MD) method. Polygonal CNTs with radii under 0.45 nm show friction coefficients an order of magnitude higher than their circular counterparts. While water exhibits an ordered phase within 0.5–0.6 nm-radius polygonal CNTs, resulting in a significant 80 % reduction in the friction coefficients compared to bulk like water. The force distribution analysis confirms the constancy of energy barriers. Further analysis of water density, hydrogen bond number distribution, average structure factor, and density correlation time demonstrates that the density correlation time predominantly impacts solid-liquid friction. The observed reduction in friction is primarily due to the collective movement of water molecules in an ordered arrangement. These findings illuminate nanoscale drag reduction mechanisms, offering insights for micro-nano flow system design.</p></div>","PeriodicalId":262,"journal":{"name":"Carbon","volume":null,"pages":null},"PeriodicalIF":10.5000,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Carbon","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0008622324006213","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
引用次数: 0
Abstract
The friction of water within a carbon nanotube (CNT) is influenced by the interplay between energy barriers and water structure. In this work, we employ a series of regular polygonal CNTs, whose energy barriers remain constant with size, to examine the influence of water structure on solid-water friction using the molecular dynamics (MD) method. Polygonal CNTs with radii under 0.45 nm show friction coefficients an order of magnitude higher than their circular counterparts. While water exhibits an ordered phase within 0.5–0.6 nm-radius polygonal CNTs, resulting in a significant 80 % reduction in the friction coefficients compared to bulk like water. The force distribution analysis confirms the constancy of energy barriers. Further analysis of water density, hydrogen bond number distribution, average structure factor, and density correlation time demonstrates that the density correlation time predominantly impacts solid-liquid friction. The observed reduction in friction is primarily due to the collective movement of water molecules in an ordered arrangement. These findings illuminate nanoscale drag reduction mechanisms, offering insights for micro-nano flow system design.
期刊介绍:
The journal Carbon is an international multidisciplinary forum for communicating scientific advances in the field of carbon materials. It reports new findings related to the formation, structure, properties, behaviors, and technological applications of carbons. Carbons are a broad class of ordered or disordered solid phases composed primarily of elemental carbon, including but not limited to carbon black, carbon fibers and filaments, carbon nanotubes, diamond and diamond-like carbon, fullerenes, glassy carbon, graphite, graphene, graphene-oxide, porous carbons, pyrolytic carbon, and other sp2 and non-sp2 hybridized carbon systems. Carbon is the companion title to the open access journal Carbon Trends. Relevant application areas for carbon materials include biology and medicine, catalysis, electronic, optoelectronic, spintronic, high-frequency, and photonic devices, energy storage and conversion systems, environmental applications and water treatment, smart materials and systems, and structural and thermal applications.