Novel Photoactive Polymeric Multilayer Films Formed via Electrostatic Self‐Assembly

Zapotoczny, Szczepan; Golonka, Monika; Nowakowska, Maria

doi:10.1002/marc.200500171

Cited by 30 publications

(28 citation statements)

References 27 publications

(20 reference statements)

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“…In addition, vinyl monomers with a naphthyl group in their side chains are copolymerizable with other vinyl monomers, giving various properties described above to copolymers. In fact, a poly(2‐vinylnaphthalene) segment was introduced as a film‐forming segment into block copolymers with ionic segments28,29…”

Section: Introductionmentioning

confidence: 99%

Living cationic polymerization of vinyl ethers with a naphthyl group: Decisive effect of the substituted position on naphthalene ring

Shinke

Kanazawa

Kanaoka

et al. 2012

J. Polym. Sci. A Polym. Chem.

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Living cationic polymerization of a vinyl ether with a naphthyl group [2‐(2‐naphthoxy)ethyl vinyl ether, βNpOVE] was achieved using base‐assisting initiating systems with a Lewis acid. The Et1.5AlCl1.5/1,4‐dioxane or ethyl acetate system induced the living cationic polymerization of βNpOVE in toluene at 0 °C. The living nature of this reaction was confirmed by a monomer addition experiment, followed by 1H NMR and matrix‐assisted laser desorption ionization time‐of‐flight mass spectrometry (MALDI‐TOF‐MS) analyses. In contrast, the polymerization of αNpOVE was not fully controlled; under similar conditions, it produced polymers with broad molecular weight distributions. The 1H NMR and MALDI‐TOF‐MS spectra of the resultant poly(αNpOVE) revealed that the products had undesirable structures derived from Friedel–Crafts alkylation. The higher reactivity of αNpOVE in electrophilic substitution reactions, such as the Friedel–Crafts reaction, was attributable to the greater electron density of the naphthyl ring, which was calculated based on frontier orbital theory. The naphthyl groups significantly affected the properties of the resultant polymer. For example, the glass transition temperatures (Tg) of poly(NpOVE)s are higher by approximately 40 °C than that of poly(2‐phenoxyethyl vinyl ether). © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012

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Section: Introductionmentioning

confidence: 99%

Living cationic polymerization of vinyl ethers with a naphthyl group: Decisive effect of the substituted position on naphthalene ring

Shinke

Kanazawa

Kanaoka

et al. 2012

J. Polym. Sci. A Polym. Chem.

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“…The reaction is given some time to complete, the substrate is washed extensively, and then the next layering step is carried out. 7 –28 Unfortunately, limitations of many of these present LBL self-assembly processes provide considerable incentive to continue the development of better paradigms for LBL nanofabrication, heterogeneous integration, and in particular, the automation of these processes.…”

Section: Introductionmentioning

confidence: 99%

Automated Combinatorial Process for Nanofabrication of Structures Using Bioderivatized Nanoparticles

Dehlinger

Sullivan

Esener

et al. 2007

JALA: Journal of the Association for Laboratory Automation

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A fully automated electronic microarray control system (Nanochip 400 System) was used to carry out a combinatorial process to determine optimal conditions for fabricating higher order three-dimensional nanoparticle structures. Structures with up to 40 layers of bioderivatized nanoparticles were fabricated on a 400test site CMOS microarray using the automated Nanochip 400 System. Reconfigurable electric fields produced on the surface of the CMOS microarray device actively transport, concentrate, and promote binding of 40 nm biotin-and streptavidin-derivatized nanoparticles to selected test sites on the microarray surface. The overall fabrication process including nanoparticle reagent delivery to the microarray device, electronic control of the CMOS microarray and the optical/fluorescent detection, and monitoring of nanoparticle layering are entirely controlled by the Nanochip 400 System. The automated nanoparticle layering process takes about 2 minutes per layer, with 10e20 seconds required for the electronic addressing and binding of nanoparticles, and roughly 60 seconds for washing. The addressing and building process is monitored by changes in fluorescence intensity as each nanoparticle layer is deposited. The final multilayered 3D structures are about 2 mm in thickness and 55 mm in diameter. Multilayer nanoparticle structures and control sites on the microarray were verified by SEM analysis.

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“…Absorbance at 225 nm is most likely related to the characteristic wavelength of 228 nm for the sodium styrene sulfonate mers. [20] Since PDDA is almost transparent in the UV-vis spectral range, the increase in absorbance was attributed to the adsorption of PSS on the previously deposited PDDA layer. The inset graph of Figure 2a shows the absorbance at 225 nm as a function of the number of PDDA-PSS bilayers, which increased linearly with the number of LbL self-assembled PDDA-PSS bilayers.…”

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confidence: 99%

“…The process leads to the formation of a final multilayer structure that is stabilized primarily by strong electrostatic forces. The simplicity and efficiency of this technique has resulted in a wide range of applications of multilayer films for sensors, [18] nonlinear optics, [19] photoactive films, [20] drug delivery, [21,22] and selectivearea patterning. [23] Recently, Farhat and Hammond reported…”

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confidence: 99%

Layer‐by‐Layer Self‐Assembly of Composite Polyelectrolyte–Nafion Membranes for Direct Methanol Fuel Cells

2006

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Perfluorosulfonic polymers such as Nafion are the most common membrane electrolytes used in polymer electrolyte and direct methanol fuel cells (PEFCs and DMFCs) owing to their high proton conductivity and good chemical and thermal stability. However, methanol readily migrates from the anode, through the Nafion membrane, to the cathode, reducing the open-circuit potential (OCP) by as much as 0.15-0.2 V and poisoning the electrocatalysts at the cathode.[1] Methanol crossover seriously retards the technological development of DMFCs. Thus, there has been extensive research activity in the modification of Nafion-based membranes to reduce the methanol crossover through, for example, the in situ polymerization of Nafion with poly(1-methylpyrrole), [2] and the development of composite membranes such as Nafion-silica, [3,4] Nafion-zirconium phosphate, [5] Nafion-cesium ions, [6] and Nafion-poly(furfuryl alcohol) nanocomposite membranes.[7]The modification of Nafion membranes reduces the methanol crossover and, in general, improves the performance of DMFCs. To achieve significant reduction in the methanol permeability, the oxide content has to be high (e.g., 20 wt % silica in the case of the Nafion-silica composite [3] ). This, in turn, reduces the proton conductivity and the mechanical properties are also seriously affected owing to the significant alteration of the membrane microstructure. Sandwiching a Pd thin film between Nafion membranes, [8] depositing a Pd and/or Pd-Cu alloy thin film on the surface of a Nafion membrane, [9][10][11] or depositing Pd nanoparticles through ion exchange followed by chemical reduction, [12] have been shown to reduce the methanol crossover. Unfortunately, the Pd thin film increased the overall cell resistance. The dispersed Pd particles in the membrane altered its microstructure, resulting in reduced cell performance and stability. Various multilayer membrane structures have also been investigated with the aim of suppressing methanol crossover. Yang and Manthiram studied the methanol crossover and conductivity of Nafion membranes with a thin barrier layer of sulfonated poly(ether ether ketone) (SPEEK).[13] Si et al. developed trilayer membranes composed of one central methanol barrier layer and two conductive layers to suppress the methanol crossover. [14] Casting non-conductive polymers such as poly(vinyl alcohol) (PVA) onto Nafion membranes can also reduce the methanol crossover. [15] However, in all these cases, the proton conductivity also decreased significantly due to the addition of a relatively thick barrier layer. The sequential adsorption of oppositely charged polyelectrolytes by layer-by-layer (LbL) self-assembly is an efficient method for obtaining multilayer thin films. This technique has progressed significantly since the pioneering work by Decher et al. [16,17] In this technique, two oppositely charged polyelectrolytes dissolved in aqueous solution are alternately deposited on a support surface by means of electrostatic attraction. After each dipping cycle, the surface cha...

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Novel Photoactive Polymeric Multilayer Films Formed via Electrostatic Self‐Assembly

Cited by 30 publications

References 27 publications

Living cationic polymerization of vinyl ethers with a naphthyl group: Decisive effect of the substituted position on naphthalene ring

Living cationic polymerization of vinyl ethers with a naphthyl group: Decisive effect of the substituted position on naphthalene ring

Automated Combinatorial Process for Nanofabrication of Structures Using Bioderivatized Nanoparticles

Layer‐by‐Layer Self‐Assembly of Composite Polyelectrolyte–Nafion Membranes for Direct Methanol Fuel Cells

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