Hydrogen-bonded layer-by-layer films of block copolymer micelles with pH-responsive cores

Erel Göktepe, İrem
Zhuk, Aliaksandr
Sukhishvili, Svetlana A.
We report on construction of hydrogen-bonded monolayers and multilayers of micelles of the poly(2-(diethylamino)ethyl methacrylate)-block-poly(N-isopropyl acrylamide) (PDEA-b-PNIPAM) with PNIPAM-corona and polybasic PDEA cores. Films were constructed at pH 7.5 and 25 degrees C to assure the deposition of PDEA-b-PNIPAM in the micellar form. When monolayers of block copolymer micelles (BCMs) were exposed to moderately acidic pH values, micellar cores dissolved, while PDEA-b-PNIPAM remained adsorbed at the surface as unimers. In contrast to reversible micellization of PDEA-b-PNIPAM in solution, micelle-to-unimer transition was irreversible at the surface. Adsorption of a layer of tannic acid (TA) or polyethacrylic acid (PEAA) on top of BCM monolayers inhibited pH-triggered morphological changes within adsorbed BCMs. By taking advantage of the high pK(a) values of TA and PEAA, we were also able to construct multilayers of PDEA-b-PNIPAM micelles through hydrogen bonding interactions between micellar PNIPAM coronas and TA or PEAA. Similar to BCM monolayers coated with TA or PEAA, dissolution of BCMs was also inhibited when incorporated within hydrogen-bonded multilayers. Such inhibition of dissolution is due to enhanced hydrogen bonding interactions between coronal PNIPAM chains and protonated TA molecules or PEAA chains at decreasing pH values restricting the pH-induced conformational changes of the micellar core chains within the adsorbed layer. Films of responsive BCMs are attractive coatings for controlled delivery of functional molecules from surfaces due to a combination of stimuli-response properties with the relatively high loading capacity for functional molecules.


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Erel Göktepe, İrem; Tuncer, Cansel; Butun, Vural; Demirel, A. Levent (2012-01-01)
We report the fabrication of hydrogen-bonded multilayers of micelles of a dually responsive, dicationic block copolymer, poly[2-(N-morpholino)ethyl methacrylate-block-2-(diisopropylamino)ethyl methacrylate] (PMEMA-b-PDPA). By taking advantage of the difference in the hydrophilicity of PMEMA and PDPA blocks, micelles with a PMEMA-corona and a PDPA-core were obtained above pH 6.5 and were assembled layer-by-layer at the surface with tannic acid (TA) at pH 7.4 through hydrogen bonding interactions between morp...
Transition metal-doped janus monolayer SMoSe with excellent thermal spin filter and spin Seebeck effect
Ding, Guangqian; Wei, Mian; Surucu, Gokhan; Liang, Zhengyong; Wang, Xiaotian (Elsevier BV, 2019-10-15)
Motivated by the recent experimental synthesis of the novel janus monolayer SMoSe, we propose the design of spin caloritronic material based on transition metal-doped SMoSe monolayer. Using density functional theory combined with the non-equilibrium Green's function method, we show that a perfect thermal spin filter and a negative differential thermoelectric resistance are obtained in Fe-doped SMoSe janus monolayer. For Cr-doped SMoSe janus monolayer on the other hand, the thermal induced spin-up and spin-d...
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There is a growing trend of characterizing coal and coal wastes in order to study the effect of clays present in them during coal washing, Coarse wastes from the Zonguldak Coal Washery, Turkey, were characterized and found to contain kaolinite, illite, and chlorite, These three clays, obtained in almost pure form from various locations in Turkey, have been subjected to X-ray diffraction (XRD) analysis to assess their purity and zeta potential measurements in order to evaluate their properties in terms of th...
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Designing a cost-effective catalyst with high activity and stability for hydrogen evolution reaction (2H(+) + 2e(-) -> H-2) is a big challenge due to increasing demand for energy. Herein, we report the electrocatalytic activity of glassy carbon electrodes with group 4 metal oxides (TiO2, ZrO2, HfO2) supported ruthenium(0) nanoparticles in hydrogen evolution reaction. Electrochemical activity of modified electrodes is investigated by recording linear sweep voltammograms in 0.5 M H2SO4 solution. The results o...
Citation Formats
İ. Erel Göktepe, A. Zhuk, and S. A. Sukhishvili, “Hydrogen-bonded layer-by-layer films of block copolymer micelles with pH-responsive cores,” JOURNAL OF COLLOID AND INTERFACE SCIENCE, pp. 61–69, 2011, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/41191.