Modeling of Bottle-Brush Polymer Adsorption onto Mica and Silica Surfaces
Modeling of Bottle-Brush Polymer Adsorption onto Mica and Silica Surfaces
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DOI：
10.1021/ma900896y
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发表时间：
2009-08-25
期刊：
影响因子：
5.5
通讯作者：
Claesson, Per M.
中科院分区：
文献类型：
--
作者：
Linse, Per;Claesson, Per M.
用格子平均场理论模拟了一系列侧链固定的带电刷状聚合物在云母和二氧化硅表面的吸附行为，并与相应的实验数据进行了比较。瓶刷聚合物由两种类型的主链链段组成：带电链段和带有侧链的未带电链段。组成变量X表示带电的主链链段的百分比，并且范围从X=0(不带电的瓶刷聚合物)到X=100(线性聚电解质)。类云母表面具有恒定的负表面电荷密度，没有特殊的亲和力，而类二氧化硅表面具有恒定的负表面电位和对瓶刷聚合物侧链的正亲和力。该模型能够再现一些显著的实验特征，这些特征表征了在组成变量X的整个范围内瓶刷聚合物在两个表面上的吸附，从而量化了两个表面相对于聚合物的静电性质和非静电亲和力的不同性质。特别是，对于云母表面，表面过剩在X接近50处表现出最大值，对于二氧化硅表面，在X接近10处表现出最大值。当X=10-25时，吸附层厚度最大。
The adsorption of a series of charged bottle-brush polymers with side chains of constant length on mica and silica surfaces is modeled using a lattice mean-field theory, and the predicted results are compared to corresponding experimental data. The bottle-brush polymers are modeled as being composed of two types of main-chain segments: charged segments and uncharged segments with an attached side chain. The composition variable X denotes the percentage of charged main-chain segments and ranges from X = 0 (uncharged bottle-brush polymer) to X = 100 (linear polyelectrolyte). The mica-like surface possesses a constant negative surface charge density and no special affinity, whereas the silica-like surface has a constant negative surface potential and a positive affinity for the side chains of the bottle-brush polymers. The model is able to reproduce a number of salient experimental features characterizing the adsorption of the bottle-brush polymers for the full range of the composition variable X on the two surfaces, and thereby quantifying the different nature of the two surfaces with respect to electrostatic properties and nonelectrostatic affinity for the polymer. In particular, the surface excess displays a maximum at X approximate to 50 for the mica surface and at X approximate to 10 for the silica surface. Moreover, the thickest adsorbed layer is obtained at X = 10-25.