Adsorption of hydrophobic silica nanoparticles at the PDMS droplet-water interface
Adsorption of hydrophobic silica nanoparticles at the PDMS droplet-water interface
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DOI：
10.1021/la0347197
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发表时间：
2003-08
期刊：
影响因子：
3.9
通讯作者：
S. Simović;C. Prestidge
中科院分区：
文献类型：
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作者：
S. Simović;C. Prestidge
通过颗粒吸附等温线研究了疏水性二氧化硅纳米颗粒在聚二甲基硅氧烷（PDMS）液滴-水界面的吸附，并通过冷冻断裂SEM对吸附层结构进行了补充研究。pH值和电解质浓度以及液滴交联（变形性）的影响报告。液滴的吸附等温线为S形，而交联液滴的吸附等温线为“低亲和力”或“亲和力增加”型。表面覆盖率达到对应于多个紧密堆积层的值，并且受到液滴交联的显著影响，从而赋予广泛的界面渗透，如通过SEM所证实的。在很宽的溶液条件下观察到密集的吸附颗粒层与界面聚集。液体和交联的PDMS液滴都显示出pH依赖性吸附，与DLVO理论一致;这与亲水性二氧化硅吸附相反[Langmuir 20…
The adsorption of hydrophobic silica nanoparticles at the poly(dimethylsiloxane) (PDMS) droplet−water interface has been investigated through particle adsorption isotherms, with complementary studies of the adsorbed layer structure by freeze-fracture SEM. The influences of pH and electrolyte concentration as well as droplet cross-linking (deformability) are reported. Adsorption isotherms for liquid droplets are sigmoidal, whereas those for cross-linked droplets are of “low affinity” or “affinity increase” type. The surface coverage reaches values that correspond to multiple close-packed layers and are significantly influenced by droplet cross-linking, conferring extensive interfacial penetration, as confirmed by SEM. Densely packed adsorbed particle layers with interfacial aggregation are observed over a wide range of solution conditions. Both liquid and cross-linked PDMS droplets show pH-dependent adsorption, in agreement with DLVO theory; this is in contrast to hydrophilic silica adsorption [Langmuir 20...