Katzur, Verena and Eichler, Mirjam and Deigele, Erika and Stage, Christiane and Karageorgiev, Peter and Geis-Gerstorfer, Juergen and Schmalz, Gottfried and Ruhl, Stefan and Rupp, Frank and Mueller, Rainer (2012) Surface-immobilized PAMAM-dendrimers modified with cationic or anionic terminal functions: Physicochemical surface properties and conformational changes after application of liquid interface stress. JOURNAL OF COLLOID AND INTERFACE SCIENCE, 366 (1). pp. 179-190. ISSN 0021-9797,
Full text not available from this repository. (Request a copy)Abstract
Functionalization of surfaces with highly branched dendrimer molecules has gained attractiveness for various applications because the number of functional groups exceeds those of surfaces functionalized with self-assembled monolayers. So far, little is known about the physicochemical properties of dendrimer functionalized surfaces, especially if the flexibility of dendrimer structure remains after covalent immobilization. Therefore, the purpose of this study was to covalently immobilize polyamidoamine (PAMAM) dendrimer molecules exhibiting terminal amine and carboxyl groups to silicon model surfaces and to explore their properties and structure at the solid-air and solid-liquid interface. Our results show that the surface free energy is higher for PAMAM coatings than for analogously terminated SAMs and also higher for carboxyl than amine functionalized coatings. Furthermore, several findings suggest that conformational freedom of the dendrimers was preserved after surface immobilization. Wet compared to dry PAMAM-NH(2) surfaces show reduced hydrophilicity and increased contact angle hysteresis, whereas PAMAM-COOH surfaces become more hydrophilic and showed decreased hysteresis. Streaming current measurements showed an unexpected behavior for PAMAM-COOH surfaces in that they reveal a net positive surface charge over a wide pH range in spite of the carboxylated periphery. All of these results indicate a certain degree of masking, burrowing, back-folding and unfolding of functional groups upon environmental changes. (C) 2011 Elsevier Inc. All rights reserved.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | SELF-ASSEMBLED MONOLAYERS; CONTACT-ANGLE HYSTERESIS; POLY(AMIDOAMINE) DENDRIMERS; BINDING CONSTANTS; CALCIUM-PHOSPHATE; SILICA SURFACES; MODEL SURFACES; FREE-ENERGY; ADHESION; GROWTH; Polyamidoamine dendrimer; Self-assembled monolayer; Streaming potential; Dynamic contact angle; Surface free energy; Sum frequency spectroscopy |
| Subjects: | 500 Science > 540 Chemistry & allied sciences 600 Technology > 610 Medical sciences Medicine |
| Divisions: | Medicine > Lehrstuhl für Zahnerhaltung und Parodontologie Chemistry and Pharmacy > Institut für Physikalische und Theoretische Chemie > Chair of Chemistry VI - Physical Chemistry (Solution Chemistry) > PD Dr. Rainer Müller |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 20 May 2020 09:45 |
| Last Modified: | 20 May 2020 09:45 |
| URI: | https://pred.uni-regensburg.de/id/eprint/19368 |
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