| 1. |
- Claesson, Per M., et al.
(author)
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Interfacial properties of bottle-brush polyelectrolytes
- 2007
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In: PROCEEDINGS OF BALTIC POLYMER SYMPOSIUM 2007. - Vilnius : VILNIUS UNIV.. - 9789955331506 ; , s. 77-81
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Conference paper (peer-reviewed)abstract
- This article is focused on interfacial properties of bottle brush polyelectrolytes, where side-chains are attached along a polymer backbone. This class of polymer has been much less studied than block copolymers, which is particularly true for bottle brush polyelectrolytes with a high graft density. We have explored how the graft density and charge density of such polymers affect surface properties, as well as some bulk properties. The adsorption of this class of polymer onto negatively charged silica and mica surfaces has been determined. On mica adsorption is driven by electrostatic forces whereas on silica both electrostatic forces and interactions between silica and ethylene oxide chains drive the adsorption. On silica the adsorbed amount is very sensitive to solution ionic strength and pH. We also report on surface interactions and frictional forces obtained between surfaces coated with bottle brush polyelectrolytes.
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| 2. |
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| 3. |
- Bastardo Zambrano, Luis Alejandro, et al.
(author)
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Soluble complexes in aqueous mixtures of low charge density comb polyelectrolyte and oppositely charged surfactant probed by scattering and NMR
- 2007
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In: Journal of Colloid and Interface Science. - : Elsevier BV. - 0021-9797 .- 1095-7103. ; 312, s. 21-33
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Journal article (peer-reviewed)abstract
- A low charge density polyelectrolyte with a high graft density of 45 units long poly(ethylene oxide) side-chains has been synthesized. In this comb polymer, denoted PEO45 MEMA:METAC-2, 2 mol% of the repeating methacrylate units in the polymer backbone carry a permanent positive charge and the remaining 98 mol% a 45 unit long PEO side-chain. Here we describe the solution conformation of this polymer and its association with an anionic surfactant, sodium dodecylsulfate, SDS. It will be shown that the polymer can be viewed as a stiff rod with a cross-section radius of gyration of 29 Å. The cross section of the rod contracts with increasing temperature due to decreased solvency of the PEO side-chains. The anionic surfactant associates to a significant degree with PEO45 MEMA:METAC-2 to form soluble complexes at all stoichiometries. A cooperative association is observed as the free SDS concentration approaches 7 mM. At saturation the number of SDS molecules associated with the polymer amounts to 10 for each PEO side-chain. Two distinct populations of associated surfactants are observed, one is suggested to be molecularly distributed over the comb polymer and the other constitutes small micellar-like structures at the periphery of the aggregate. These conclusions are reached based on results from small-angle neutron scattering, static light scattering, NMR, and surface tension measurements.
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| 4. |
- Dedinaite, Andra, et al.
(author)
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Solution properties of bottle-brush polyelectrolytes
- 2007
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In: PROCEEDINGS OF BALTIC POLYMER SYMPOSIUM 2007. - 9789955331506 ; , s. 112-116
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Conference paper (peer-reviewed)abstract
- Aqueous solution properties of bottle brush polyelectrolytes, where side-chains are attached to a polymer backbone, have been studied. The side chains consist of 45 units long poly(ethylene oxide) groups and the backbone is of the methacrylate type. Small-angle X-ray scattering (SAXS) was used to elucidate the solution conformation of this class of polymer and how it is affected by the side chain density and charge density. The effect of temperature on the solution conformation, and in particular the side chain extension, has also been quantified. At higher concentrations the interactions between the polymer chains in solution affects the scattering, and it is shown that this interaction is well described by a model originally developed for wormlike micelles.
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