A coarse-grained model for polyethylene oxide and polyethylene glycol: conformation and hydrodynamics.
A coarse-grained model for polyethylene oxide and polyethylene glycol: conformation and hydrodynamics.
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DOI：
10.1021/jp9058966
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发表时间：
2009-10-08
期刊：
影响因子：
--
通讯作者：
Pastor RW
中科院分区：
文献类型：
--
作者：
Lee H;de Vries AH;Marrink SJ;Pastor RW
利用CHARMM全原子力场中键、角和二面角的分布，在MARTINI CG力场框架内建立了聚环氧乙烷（PEO）和聚乙二醇（PEG）的粗粒（CG）模型.纯的低分子量PEO的密度与实验一致，并且对于76-mer的PEO（Mw为3400），回转半径Rg = 19.1 π ±0.7，与对于相同尺寸的PEG的中子散射结果非常一致。CG PEO的9、18、27、36、44、67、76、90、112、135和158-mer的模拟（442 < Mw < 6998）在水中低浓度下显示在1600 < Mw < 2000下实验观察到的从理想链到真实的链行为的转变，与实验观察到的PEG流体动力学半径的依赖性非常一致。从高分子量PEO的扩散系数计算的PEO的流体动力学半径也符合实验。从PEO 76在21和148 mg/cm 3的全原子和CG模拟计算的Rg被发现几乎相等。这种浓度依赖性的缺乏意味着在高浓度下的散射实验的表观Rg不应该被认为是链尺寸。模拟PEO接枝到非吸附表面产生蘑菇刷过渡，这是很好地描述了亚历山大德Gennes形式主义。
A coarse-grained (CG) model for polyethylene oxide (PEO) and polyethylene glycol (PEG) developed within the framework of the MARTINI CG force field (FF) using the distributions of bonds, angles, and dihedrals from the CHARMM all-atom FF is presented. Densities of neat low molecular weight PEO agree with experiment, and the radius of gyration Rg = 19.1 ű0.7 for 76-mers of PEO (Mw ≈ 3400), in excellent agreement with neutron scattering results for an equal sized PEG. Simulations of 9, 18, 27, 36, 44, 67, 76, 90, 112, 135, and 158-mers of the CG PEO (442 < Mw < 6998) at low concentration in water show the experimentally observed transition from ideal chain to real chain behavior at 1600 < Mw < 2000, in excellent agreement with the dependence of experimentally observed hydrodynamic radii of PEG. Hydrodynamic radii of PEO calculated from diffusion coefficients of the higher Mw PEO also agree well with experiment. Rg calculated from both all-atom and CG simulations of PEO76 at 21 and 148 mg/cm3 are found to be nearly equal. This lack of concentration dependence implies that apparent Rg from scattering experiments at high concentration should not be taken to be the chain dimension. Simulations of PEO grafted to a nonadsorbing surface yield a mushroom to brush transition that is well described by the Alexander-de Gennes formalism.
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影响因子：
3.3
作者：
Chen, Ting;Hynninen, Antti-Pekka;Panagiotopoulos, Athanassios Z.
通讯作者：
Panagiotopoulos, Athanassios Z.
DOI：
10.1016/0005-2736(91)90246-5
发表时间：
1991-07-01
期刊：
BIOCHIMICA ET BIOPHYSICA ACTA
影响因子：
--
作者：
ALLEN, TM;HANSEN, C;YAUYOUNG, A
通讯作者：
YAUYOUNG, A
影响因子：
2.9
作者：
HOOVER, WG
通讯作者：
HOOVER, WG
影响因子：
3
作者：
BROOKS, BR;BRUCCOLERI, RE;KARPLUS, M
通讯作者：
KARPLUS, M
影响因子：
15.6
作者：
DEGENNES, PG
通讯作者：
DEGENNES, PG