Infrared spectroscopic analysis of O-H bond dynamics in one-dimensional confined water and bulk water  

一维受限水和体相水中O-H键动力学的红外光谱分析

作　　者：ZHANG Lei WANG Tian-Qi FAN Yan-Ping 张磊;王天棋;范彦平(上海理工大学光电信息与计算机工程学院,上海200093)

机构地区：[1]School of Optical-Electrical and Computer Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China

出　　处：《红外与毫米波学报》2025年第1期78-85,共8页Journal of Infrared and Millimeter Waves

基　　金：Supported by the Natural Science Foundation of China(51705326,52075339)。

摘　　要：In sub nanometer carbon nanotubes,water exhibits unique dynamic characteristics,and in the high-frequency region of the infrared spectrum,where the stretching vibrations of the internal oxygen-hydrogen(O-H)bonds are closely related to the hydrogen bonds(H-bonds)network between water molecules.Therefore,it is crucial to analyze the relationship between these two aspects.In this paper,the infrared spectrum and motion characteristics of the stretching vibrations of the O-H bonds in one-dimensional confined water(1DCW)and bulk water(BW)in(6,6)single-walled carbon nanotubes(SWNT)are studied by molecular dynamics simulations.The results show that the stretching vibrations of the two O-H bonds in 1DCW exhibit different frequencies in the infrared spectrum,while the O-H bonds in BW display two identical main frequency peaks.Further analysis using the spring oscillator model reveals that the difference in the stretching amplitude of the O-H bonds is the main factor causing the change in vibration frequency,where an increase in stretching amplitude leads to a decrease in spring stiffness and,consequently,a lower vibration frequency.A more in-depth study found that the interaction of H-bonds between water molecules is the fundamental cause of the increased stretching amplitude and decreased vibration frequency of the O-H bonds.Finally,by analyzing the motion trajectory of the H atoms,the dynamic differences between 1DCW and BW are clearly revealed.These findings provide a new perspective for understanding the behavior of water molecules at the nanoscale and are of significant importance in advancing the development of infrared spectroscopy detection technology.在亚纳米碳纳米管中,水表现出独特的动力学特性,在红外光谱的高频区域,水分子内部氧-氢(O-H)键的伸缩振动与其氢键网络密切相关。因此,深入分析这两者间的关系至关重要。本文通过分子动力学模拟,研究了(6,6)单壁碳纳米管(SWNT)中一维受限水(One-Dimensional Confined Water,1DCW)与体相水(Bulk water,BW)的O-H键伸缩振动的红外光谱及其运动特性,结果表明,1DCW中两个O-H键的伸缩振动在红外光谱中展现出不同的吸收峰频率,而BW的O-H键都呈现两个相同的主频率峰。进一步使用弹簧谐振子模型分析揭示,O-H键伸缩幅度的差异是导致其振动频率变化的主要因素,伸缩幅度增加导致弹簧刚性降低,进而振动频率降低。更深入的研究发现,水分子间的氢键相互作用是O-H键伸缩幅度增加和振动频率降低的根本原因。最后,通过分析H原子的运动轨迹,清楚地揭示了1DCW和BW之间的动态差异。这些发现为理解纳米尺度下水分子行为提供了新视角,并对推动红外光谱探测技术的发展具有重要意义。

关 键 词：one-dimensional confined water infrared spectroscopy hydrogen bonds 

分 类 号：O433.4[机械工程—光学工程]