Effect of Charged Group Spacer Length on Hydration State in Zwitterionic Poly(sulfobetaine) Brushes
| Autor: | Atsushi Takahara, Ai Takenaka, Yuji Higaki, Norifumi L. Yamada, Tatsunori Sakamaki, Yuki Terayama, Yoshihiro Inutsuka, Keiko Higaki, Yuka Ikemoto, Taro Moriwaki |
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| Rok vydání: | 2017 |
| Předmět: |
chemistry.chemical_classification
Aqueous solution Materials science Atom-transfer radical-polymerization Infrared spectroscopy Ionic bonding 02 engineering and technology Surfaces and Interfaces 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics digestive system 01 natural sciences Dissociation (chemistry) 0104 chemical sciences Ion Contact angle Chemical engineering chemistry Polymer chemistry Electrochemistry General Materials Science 0210 nano-technology Spectroscopy Alkyl |
| Zdroj: | Langmuir. 33:8404-8412 |
| ISSN: | 1520-5827 0743-7463 |
| Popis: | Effect of alkyl chain spacer length between the charged groups (CSL) in zwitterionic poly(sulfobetaine) (PSB) brushes on the hydration state was investigated. PSB brushes with ethyl (PMAES), propyl (PMAPS), or butyl (PMABS) CSL were prepared by surface-initiated atom transfer radical polymerization on silicon wafers. Hydration states of the PSB brushes in aqueous solutions and/or humid vapor were investigated by contact angle measurement, infrared spectroscopy, AFM observation, and neutron reflectivity. The PSB brushes are swollen in humid air and deionized water due to the hydration of the charged groups leading to the reduction of hydrated PSB brushes/water interfacial free energy. The hydrated PSB brushes exhibit clear interface with low interfacial roughness due to networking of the PSB brush chains through association of the SBs. The hydrated PSB brushes produce diffusive swollen layer in the presence of NaCl because of the charge screening followed by SB dissociation by the bound ions. The ionic strength sensitivity in the hydration got more significant with increasing the CSL in SBs because of the augmentation in partial charge by charged group separation. |
| Databáze: | OpenAIRE |
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