
第
20
卷第
1
期
2006
年
2
月
高校化学工程学报
Joumal
of
Chemical
Engineering
of
Chinese
Universities
文章编号
1003-9015(2006)01-0018-07
硬球链流体在平板和硬球表面分布的密度泛函理论
叶负成,张书令,蔡钩,刘洪来,胡英
NO.l
Vo
l.20
Feb. 2006
(华东理工大学化学系结构可拉先进功能材料教育部重点实验室和国家重点化学工程联合实验室,
上海
200237)
摘
要:采用
Yethir
哥和
Woodward
的密度泛函理论方法,结合胡英和刘洪来等发展的硬球链流体状态方程,得到了自
由连接硬球链流体在平板狭缝中和球形固体颗粒表面附近的密度分布表达式,并计算了在两平行壁所组成的狭缝中和
直径大小不同的球形固体颗粒周围硬球链分子的链节密度分布.理论计算结果与作者采用Di
ckman
和
Hall
的方法进
行
Monte
Carlo
计算机模拟结果非常吻合。颗粒直径对链状分子的密度分布有一定的影响,随着固体颗粒直径的增加,
靠近颗粒表面附近的链节密度降低。
关键词:密度泛函理论,硬球链流体,密度分布,非均匀流体
中图分类号
0642.42
文献标识码
A
Density
Functional
Theoη'for
the
Density
Profile
ofHard-
Sphere
Chain
Fluid
Near
Solid
Plate
and
Spherical
Solid
Particle
Surface
YE Zhen-cheng, ZHANG Shu-ling, CAI
Jun
, LIU Hong-lai, HU Ying
(Department
of
Chemis
町,
Lab for Advanced Materials and State Key Laboratory
of
Chemical Engineering,
East China University ofScience and Technology, Shanghai 200237, China)
Abstract:
By
combining density functional theory presented by Yethiraj et
al.
and the equation
of
state for
hard sphere chain fluid developed by Hu
et al., a new method for the calculation
of
the density profiles
of
hard-sphere chain fluid near the hard wall and hard spherical particle was derived. The effect
of
chain length,
average density
of
system and diameter
of
hard sphere particle on the density profiles
of
hard-sphere chain fluid
∞
nfined
in a slot between two hard walls and that near the spherical particle surfaces was investigated.
Th
e
Monte Carlo simulation for the density profiles
of
hard
叩
here
chain fluid was also
performed
也
rough
the
method developed by Dickman and Hal
l.
The calculated results by density functional
the
。可
proposed
are in
good agreement with that by Monte Carlo simulation.
It
is
岛
und
that the diameter
of
solid particle has a little
influence on the adsurption
of
hard sphere chain fluid on the surface
of
solid spherical particle. The densities
near the surface
of
the
p
缸
ticle
decrease with the increase
of
the particle diameter. In the case
of
high packing
企
action
,也
e
density profile
of
short chain fluid shows greater fluctuation
than
由
at
of
long chain fluid.
Key words:
. density functional theory; hard-sphere chain fluid; density profile; non-uniform fluid
1
前言
精确描述具有相互作用的非均匀系统的结构和热力学性质是密度泛函理论的一个主要目的
[13]
,近年
来在研究限制空间中非均匀流体的结构和热力学性质方面受到了越来越多研究者的青睐,被成功地应用
于具有不同性质相互作用的非均匀流体[川],并进一步获得表面张力
[8
,
9]
和吸附
[10-12]
等表面性质。限制空
间相当于对其中的流体施加了一个外场,导致其密度分布的不均匀。一般而言,对于有外场存在的非均
收稿日期
2
∞
4-06-23;
修订日期
2
∞
4-12-10.
基金项目
g
囡家自然科学基金
(2
∞
25618
,
20236010)
、上海市高校网格技术
E
研究院。∞
303)
和上海市教委资助项目.
f
智者简介:叶贞成【
1977-)
,男,湖北槽江人,华东理工大学博士生.通讯联系人
2
刘洪来,
E-mail:
hlliu@
饵回
tωU.cn