Interactions between Solid Surfaces Mediated by Polyethylene Oxide Polymers: Effect of Polymer Concentration
Publication in refereed journal


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其它資訊
摘要Using total internal reflection microscopy (TIRM), we have systematically measured the interactions between a microsphere and a flat hydrophilic surface in the presence of polyethylene oxide (PEO) polymer solution. Our results reveal that PEO significantly mediates the interaction forces between the two surfaces. At low polymer. concentration, the interactions between two surfaces in the presence of PEO are mainly dominated by repulsive forces, originating from diffuse layer overlap. At intermediate polymer concentration, a long-range and weak attraction sets in This force is likely attributed to the depletion attraction due to the presence of free PEO chains in bulk solution; however, a simple hard sphere AO model fails to precisely describe the attraction. At high polymer concentration where PEO chains overlap, the attraction disappears, and levitation of the microsphere probe is detected. We argue that at this overlapping region, the correlation length of PEO chains is much smaller than the size of single PEO molecule, leading to weakening and disappearing of the depletion attraction. Finally, at very high concentration, oscillatory structural force is obviously found, indicating the significant structural ordering of the PEO chains under confinement.
著者Wei XL, Gong XJ, Ngai T
期刊名稱Langmuir
出版年份2013
月份9
日期1
卷號29
期次35
出版社AMER CHEMICAL SOC
頁次11038 - 11045
國際標準期刊號0743-7463
電子國際標準期刊號1520-5827
語言英式英語
Web of Science 學科類別Chemistry; Chemistry, Multidisciplinary; CHEMISTRY, MULTIDISCIPLINARY; Chemistry, Physical; CHEMISTRY, PHYSICAL; Materials Science; Materials Science, Multidisciplinary; MATERIALS SCIENCE, MULTIDISCIPLINARY

上次更新時間 2020-24-10 於 02:20