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水玻璃化过程的氢键结构特性
  • ISSN号:1000-3258
  • 期刊名称:低温物理学报
  • 时间:2011.9.9
  • 页码:219-226
  • 分类:O561.3[理学—原子与分子物理;理学—物理]
  • 作者机构:[1]上海理工大学生物系统热科学实验室,上海200093
  • 相关基金:国家自然科学基金(批准号:50776060); 教育部新世纪优秀人才计划(批准号:07-0559); 上海市东方学者计划 上海市重点学科(批准号:530503)资助的课题
  • 相关项目:纳米微粒增强玻璃化低温保护剂传热性能的研究
中文摘要:

为了解玻璃化过程氢键结构特性,采用分子模拟的手段计算了三种压力下的水玻璃化过程氢键的角度、距离、生命期和数量.计算结果显示:(i)氢键角度呈现泊松分布的特征,随着温度降低分布氢键角度分布范围变窄,峰值变高,在0-13°范围,随温度降低,分布数值变大;而在大于13°,随温度降低,分布数值变小;(ⅱ)氢键距离也呈现泊松分布的特征,随着温度降低分布氢键距离分布范围变窄,峰值变高,在0.15-0.18nm范围,随温度降低,分布数值变大;而在0.18-0.27 nm范围,随温度降低,分布数值变小;(ⅲ)氢键生命周期以类似自变量系数为负的幂函数或者指数函数形式分布,随温度降低,氢键生命期的分布范围和分布数值都呈现明显差异;(ⅳ)压力对氢键生命期分布曲线的趋势无明显影响,但是低于一定温度不同压力下的氢键生命期分布曲线波动程度出现差异,导致平均生命期出现差异,(ⅴ)三种压力下氢键总量和每个水分子氢键平均数量都随温度的降低而上升,并且数值很接近.随着玻璃化进程的进行,完全自由的水分子数(f0)逐渐降低,形成四面体状的氢键数(f4)从290 K到260 K时有急剧上升的过程,以后就变化不大.形成一个,两个,三个氢键的份额总体上呈现变大的趋势.f4跟f1,f2,f3,比起来很小,反映了结晶度很低.

英文摘要:

For the purpose of understanding properties of hydrogen bonds during vitrification,molecular simulations were carried to calculate hydrogen bonds for water cooled under three pressures.We have calculated hydrogen bond life distributions.The results show :(ⅰ)hydrogen bond angles distribute in a way similar to Poisson distribution,and as temperature drop,distributing range become narrower,peak become higher,values of distribution become higher when hydrogen bond angles is in the region between 0 and 13°,but lower when hydrogen bond angles 13°,(ⅱ) hydrogen bond distances also distribute in a way similar to Poisson distribution,and as temperature drop,distributing range become narrower,peak become higher,values of distribution become higher when hydrogen bond angles is in the region between 0.15 and 0.18 nm,but lower when hydrogen bond angles are in 0.18 -0.27 nm,(ⅲ) hydrogen bond life distribute in a way similar to power or exponential functions in which independent variable is multiplied by a negative factor,and with temperatures dropping,both the range and the values of life distribution show significant differences,(ⅳ) pressure has weak effects on the trend of life distributions,but oscillations of life distribution curves show differences when temperatures is below a temperature,leading to significant differences of average life at different pressures,(ⅴ) the total number of hydrogen bonds and average hydrogen bonds number of each H2O both increase as temperature drop.During vitrifying process,completely free water portion get low,portion of water molecules with four hydrogen bonds forming tetrahedron get high dramatically from 290 K to 260 K,then shows little change,and portions of those with one,two,or three hydrogen bonds show a overall tendency to get higher as temperature decrease.f4 is much less than f1,f2,f3,showing extremly low degree of crystallization.

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期刊信息
  • 《低温物理学报》
  • 北大核心期刊(2011版)
  • 主管单位:中国科学院
  • 主办单位:中国科学技术大学
  • 主编:赵忠贤
  • 地址:安徽省合肥市金寨路96号
  • 邮编:230026
  • 邮箱:LiBiyou@ustc.edu.cn
  • 电话:0551-3601359
  • 国际标准刊号:ISSN:1000-3258
  • 国内统一刊号:ISSN:34-1053/O4
  • 邮发代号:26-136
  • 获奖情况:
  • 国内外数据库收录:
  • 美国化学文摘(网络版),日本日本科学技术振兴机构数据库,中国中国科技核心期刊,中国北大核心期刊(2004版),中国北大核心期刊(2008版),中国北大核心期刊(2011版),中国北大核心期刊(2014版),中国北大核心期刊(2000版)
  • 被引量:1577