w********h
发帖数: 12367 | 1 Everaers R, Sukumaran SK, Grest GS, et al.
Rheology and microscopic topology of entangled polymeric liquids
SCIENCE 303 (5659): 823-826 FEB 6 2004
我刚通读一遍，
意见先保留，
懂polymer dynamics的一定要看，
看了之后过来发表意见。 | t******l
发帖数: 3060 | 2 ft...
what's polymer dynamics?
follow general logic, Science publish it means it is important.
may not be absolutely right.
but IMPORTANT at this moment.
【在 w********h 的大作中提到】
: Everaers R, Sukumaran SK, Grest GS, et al.
: Rheology and microscopic topology of entangled polymeric liquids
: SCIENCE 303 (5659): 823-826 FEB 6 2004
: 我刚通读一遍，
: 意见先保留，
: 懂polymer dynamics的一定要看，
: 看了之后过来发表意见。
| c*****e
发帖数: 238 | 3 I read the abstract when it was on-line, thought it was something mathematical
but turns out to be simulations...
【在 w********h 的大作中提到】
: Everaers R, Sukumaran SK, Grest GS, et al.
: Rheology and microscopic topology of entangled polymeric liquids
: SCIENCE 303 (5659): 823-826 FEB 6 2004
: 我刚通读一遍，
: 意见先保留，
: 懂polymer dynamics的一定要看，
: 看了之后过来发表意见。
| w********h
发帖数: 12367 | 4 I'd like to invite you to give some comments.
I am just wondering why Science and Nature so favor various experiments to
verify reptation theory.
seems this time, that guy together with Grest and Kremer used Fetters et al's
old concept of packing length to win a big deal...
mathematical
【在 c*****e 的大作中提到】
: I read the abstract when it was on-line, thought it was something mathematical
: but turns out to be simulations...
| c*****e
发帖数: 238 | 5 Well, I just finished reading this paper.
First I really can not imagine that stiff chains are more strongly entangled
than flexible ones. As this paper dealt with static properties, this might be
plausible, but I doubt that this could be the case in the dynamic or physical
regime.
Personally I think the entanglement problem is purely a topological problem,
i.e., I prefer the knot approach (approach C they mentioned). I expect those
that matters to be the permanent topological constraints. The l
【在 w********h 的大作中提到】
: I'd like to invite you to give some comments.
: I am just wondering why Science and Nature so favor various experiments to
: verify reptation theory.
: seems this time, that guy together with Grest and Kremer used Fetters et al's
: old concept of packing length to win a big deal...
:
: mathematical
| w********h
发帖数: 12367 | 6 thanks for your discussion.
I will think about that tonight.
now I only ask one question about your speculation in the last paragraph:
There is a transition from Rouse to Reptation when the
concentration increases. I cannot see why there is trouble
not to form tube-like entangled structure. explain?
be
physical
constraint
may
them,
guys
of
al's
【在 c*****e 的大作中提到】
: Well, I just finished reading this paper.
: First I really can not imagine that stiff chains are more strongly entangled
: than flexible ones. As this paper dealt with static properties, this might be
: plausible, but I doubt that this could be the case in the dynamic or physical
: regime.
: Personally I think the entanglement problem is purely a topological problem,
: i.e., I prefer the knot approach (approach C they mentioned). I expect those
: that matters to be the permanent topological constraints. The l
| w********h
发帖数: 12367 | 7 OK, now I can reply to you more.
(1) I don't think this paper describes the properties of stiff chains, but
flexible monodisperse linear chains. For semi-rigid or rigid polymer chains,
there are some other descriptions for both static and dynamic properties
though
Kas, Strey, and Sackmann reported the tube-like motion of actin in 1994 (as
Ref.12 in the paper).
(2) Is entanglement problem a topological problem purely? I doubt. In this
paper, they mainly talked on Scheme D (also tube model) and us
【在 c*****e 的大作中提到】
: Well, I just finished reading this paper.
: First I really can not imagine that stiff chains are more strongly entangled
: than flexible ones. As this paper dealt with static properties, this might be
: plausible, but I doubt that this could be the case in the dynamic or physical
: regime.
: Personally I think the entanglement problem is purely a topological problem,
: i.e., I prefer the knot approach (approach C they mentioned). I expect those
: that matters to be the permanent topological constraints. The l
| c*******n
发帖数: 1648 | 8 hoho,好贴，触及核心了。到底什么是ENTANGLEMENT，和到底能不能从统计力学导出tube
的微观基础。这个够大家喝一壶了。
simple
SANS
identical.
polymers?
entangled
problem,
those
【在 w********h 的大作中提到】
: OK, now I can reply to you more.
: (1) I don't think this paper describes the properties of stiff chains, but
: flexible monodisperse linear chains. For semi-rigid or rigid polymer chains,
: there are some other descriptions for both static and dynamic properties
: though
: Kas, Strey, and Sackmann reported the tube-like motion of actin in 1994 (as
: Ref.12 in the paper).
: (2) Is entanglement problem a topological problem purely? I doubt. In this
: paper, they mainly talked on Scheme D (also tube model) and us
| c*****e
发帖数: 238 | 9 What I am saying is that, statically the entangled structure is there,
for no problem. But in real cases, not all these entanglements have significant
effects.
The tube model should be adequate in studying single chain dynamics, but may not
be equally well in accounting for fluctuations of the tube or cooperative motion
This is the reason that I think permanent entanglement, the knots should be the
fundamental objects.
To me the tube model is an averaged model for the environment surrounding one
【在 w********h 的大作中提到】
: OK, now I can reply to you more.
: (1) I don't think this paper describes the properties of stiff chains, but
: flexible monodisperse linear chains. For semi-rigid or rigid polymer chains,
: there are some other descriptions for both static and dynamic properties
: though
: Kas, Strey, and Sackmann reported the tube-like motion of actin in 1994 (as
: Ref.12 in the paper).
: (2) Is entanglement problem a topological problem purely? I doubt. In this
: paper, they mainly talked on Scheme D (also tube model) and us
| w********h
发帖数: 12367 | 10 that's what I mentioned about "Constraint Release" and "Contour Length
Fluctuations" corrections to the initial Tube model designed by de Gennes.
significant
not
motion
the
one
effects.
chains,
(as
to
simple
SANS
approach.
they
are
people
references
identical.
see
length
polymers?
entangled
might
【在 c*****e 的大作中提到】
: What I am saying is that, statically the entangled structure is there,
: for no problem. But in real cases, not all these entanglements have significant
: effects.
: The tube model should be adequate in studying single chain dynamics, but may not
: be equally well in accounting for fluctuations of the tube or cooperative motion
: This is the reason that I think permanent entanglement, the knots should be the
: fundamental objects.
: To me the tube model is an averaged model for the environment surrounding one
|
|
