Layer-by-layer films of block copolymer micelles with cores exhibiting upper critical solution temperature behaviour

Ustoglu, Cansu
Çağlı, Eda
Erel Göktepe, İrem
We report on preparation of block copolymer micelles with cores exhibiting upper critical solution temperature (UCST) behavior in the range of 40-45 degrees C at pH 7.5 and incorporation of such micelles into layer-by-layer (LbL) films to obtain UCST-type milltilayer films. Pyridine units of poly(2-vinylpyridine-b-ethylene oxide) (P2VP-b-PEO) were partially quaternized and its self-assembly into micellar aggregates was achieved in the presence of potassium hexacyanoferrate (K3Fe(CN)(6)p) at pH 7.5 at either 25 degrees C or 37.5 degrees C. The cores of the resulting (QP2VP + [Fe(CN)(6)](3-))-b-PEO micelles exhibited UCST-type behavior at pH 7.5 and the critical temperature varied in the range of 40-45 degrees C depending on the micellization temperature and amount of K3Fe(CN)(6). Our results showed that micellization temperature and K3Fe(CN)(6) concentration were highly critical on the UCST of the micellar cores. In case of (QP2VP + [Fe(CN)6]3-)-b-PEO micelles prepared at 25 degrees C, increasing K3Fe(CN)(6) concentration during micellization suppressed UCST behavior within a temperature range of 25-50 degrees C. In contrast, increasing K3Fe(CN)(6) concentration induced only small shifts in UCST when (QP2VP + [Fe(CN)(6)l(3-))-b-PEO micelles were produced at 37.5 degrees C. Moreover, we showed that (QP2VP + [Fe(CN)(6)](3-))-b-PEO micelles could be incorporated into LbL films using Tannic Add (TA) at pH 7.5. Multilayers which partially disintegrate near above 40 degrees C could be assembled by controlling micellization temperature and film deposition temperature. This study contributes to fundamental understanding of salt -induced micellization and structure-property relationship in hydrogen -bonded LbL films.


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Bis(4-bromo-2,6-dichlorophenoxo) ethylenediamine copper(II) complex has been polymerized using electro-initiation by constant potential electrolysis, in dimethylformamide-tetrabutylammonium fluoroborate solvent-supporting electrolyte couple, at room temperature under air or N2. The process leads to low molecular weight (5.6 x 10(3)) linear poly(dichlorophenylene oxide). The structures of the polymers were determined by H-1-NMR and C-13-NMR. The kinetics of the polymerization were followed by in situ cycl...
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We report the surface modification of chitosan/poly(ethylene glycol) (chitosan/PEG) hydrogel materials via layer-by-layer (LbL) technique using stimuli-responsive polymers. Water-soluble complexes of Tannic Acid (TA) and a broad-spectrum antibiotic, Ciprofloxacin (Cipro) were prepared and co-assembled at the surface of Chitosan/PEG hydrogels with poly(N-vinyl caprolactam) (PVCL). Compared to the bare hydrogels, the surface spreading and proliferation of human fibroblasts were significantly enhanced on preca...
KUCUKYAVUZ, Z; ALYURUK, K; AHMAD, AM (Elsevier BV, 1991-01-01)
Dipole moments of poly(propylene oxide) (PPO) samples with different tacticities were determined from dielectric constant and refractive index increment measurements, which were performed on dilute toluene and isooctane solutions. In contrast to previous reports, both refractive index increments and the dipole moment ratios showed a marked dependence on the tacticities of the samples. The dipole moment ratios of isotactic samples were greater than unity and decreased with increasing sequence concentration...
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Hydrogen-Bonded Hybrid Multilayers: Film Architecture Controls Release of Macromolecules
Erel Göktepe, İrem (American Chemical Society (ACS), 2008-11-25)
We report on the construction of purely hydrogen-bonded hybrid polymer multilayers, which are composed of polymer pairs with low- and high- pH stability, and show that the critical pH value of film deconstruction, fraction of components released, and the rate of film dissolution can be tuned in a wide pH range from 3 to 9.5 by varying film composition and architecture. The film building blocks were poly(N-vinylcaprolactam) (PVCL)/poly(L-aspartic acid) (PLAA) bilayers as pairs of hydrogen-bonded polymers wit...
Citation Formats
C. Ustoglu, E. Çağlı, and İ. Erel Göktepe, “Layer-by-layer films of block copolymer micelles with cores exhibiting upper critical solution temperature behaviour,” EUROPEAN POLYMER JOURNAL, pp. 278–294, 2017, Accessed: 00, 2020. [Online]. Available: