Neutron Reflectivity Investigations of Self-Assembled Conjugated Polyion Multilayers

Kellogg, G. J.; Mayes, Anne M.; Stockton, W. B.; Ferreira, Marystela; Rubner, Michael F.; Satija, Sushil K.

doi:10.1021/la960285m

Cited by 100 publications

(112 citation statements)

References 13 publications

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“…The changes in the signal should not be directly interpreted as differences in adsorbed amount, since the adsorbed starch layers penetrate/diffuse into adjacent layers, as demonstrated in the case of other polyelectrolyte systems (Decher 1997, Schmitt et al 1993, Kellogg et al 1996. This results in a film with a new refractive index increment (dn/dc) value, probably in the same range as the two components.…”

Section: Discussionmentioning

confidence: 99%

Application of polymeric multilayers of starch onto wood fibres to enhance strength properties of paper

Eriksson

Pettersson

Wågberg

2005

Nordic Pulp &Amp; Paper Research Journal

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SUMMARY:Polyelectrolyte multilayers of cationic and anionic starch have been used to enhance the strength properties of paper. All starches used in this investigation had a degree of substitution around 0.065. Optical reflectometry showed that a combination of cationic and anionic starch could form polyelectrolyte multilayers onto silicon oxide surfaces. The same combination of starches was then applied to unbeaten, bleached softwood kraft fibres to form three layers, i.e. a cationic-/anionic/cationic starch combination. The results showed a significant increase in the paper strength properties in terms of tensile index, strain at break, and Scott Bond. The adsorbed amount of starch in the sheets, determined using an enzymatic method, was found to increase with each successive starch treatment. The increased paper strength was not only due to the increase in adsorbed amount of starch; rather, the chemical composition of the starch was also important. Cationic starch with high amylose content had a more positive effect on the paper strength properties. Furthermore, it was observed that anionic starch, despite being adsorbed in large amounts, did not contribute to the increase in tensile strength or strain at break to the same extent as did cationic starch. However, the out-ofplane properties, measured as Scott Bond properties, increased with the adsorbed amount, regardless of the chemical composition of the starch used in the outermost layer.

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Section: Discussionmentioning

confidence: 99%

Application of polymeric multilayers of starch onto wood fibres to enhance strength properties of paper

Eriksson

Pettersson

Wågberg

2005

Nordic Pulp &Amp; Paper Research Journal

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“…However, Bragg peaks indicative of a well defined multilayer structure are normally not observed, neither by X-ray reflectivity 20,29,131,132,136,184,302,381) , nor by small angle neutron reflectivity 7,29,163,385) , even if the scattering contrast between polycationic and polyanionic species should be high enough. This led to the conclusion that coatings made by ESA are stratified, but do not consist of well separated, distinguishable alternating layers.…”

Section: The Structure Of Polymer Films Made By Esamentioning

confidence: 99%

Ultrathin polymer coatings by complexation of polyelectrolytes at interfaces: suitable materials, structure and properties

Bertrand

Jonas

Laschewsky³

et al. 2000

Macromol. Rapid Commun.

1,174

1,184

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A bit of historyThe key role of surfaces for many material properties as well as for many biological processes has been recognized now. Therefore, new strategies aim at the tailoring of the material's surface only -or of a thin surface layer, respectively -, while preserving the bulk properties of the underlying support. Particular emphasis has been given to the surface modification by polymers, in an attempt to extend the known versatility of polymer bulk materials to ultrathin films and coatings, and to prepare bulk-surface composite materials. The self-organization of polymers has been increasingly explored for the preparation of well-defined surfaces and interfaces in recent years, extending the use of the established methods of low molar mass compounds (for comparative reviews, see ref. 1-3)). With such techniques, polymer films are formed spontaneously on substrates, due to balanced interactions between substrate, polymer (or its precursor) and medium. Typically, very thin, often monomolecular layers are produced. Repetitive deposition steps provide a precise control over the total thickness of the coatings, in the range from a few angstroms up to the micrometer range. Moreover, the step-by-step procedures allow for a fine structuring in the third dimension. In addition to the preparation of uniform and homogeneous coatings, gratings, gradients or steps of defined height in molecular dimensions can be easily constructed.The most recent of the self-organization techniques is the alternating physisorption of oppositely charged polyelectrolytes, the so-called "layer-by-layer" method or "electrostatic self-assembly" (ESA) [3][4][5][6][7][8][9][10] . Although some early, singular studies of self-assembly by alternating adsorption of oppositely charged polyions are reported [11][12][13] , a practical method for ESA was developed Feature Article: The article presents the state-of-the-art of alternating physisorption of oppositely charged polyelectrolytes, the so-called "layer-by-layer" method or "electrostatic self-assembly" (ESA), for the preparation of thin polymer coatings. In comparison to other, more established self-organization techniques, this recent method is distinguished by its simplicity, versatility, and speed. In particular, the tendency for self-healing is unique. Emphasis is given to the role of the molecular structure of the polyelectrolytes, and to the nature of the support. Also, various parameters for the preparation of multilayer films are highlighted, which are very important due to the kinetic control of the build-up process. The structure of the resulting coatings, their quality and stability, chemical reactions in the films, and potential applications are discussed.Macromol. Rapid Commun. 21, No. 7

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“…Neutron reflectivity has been used to study the organisation of self-assembled multilayers of sulfonated polyaniline 34 and PAH 63) . Scattering contrast was achieved by a selective deuteration of bilayers blocks at varying intervals along the film.…”

Section: Conducting-polymer Multilayersmentioning

confidence: 99%

Self-assembly of mono- and multilayers of polyconjugated conducting polymers

Berlin¹,

Zotti

2000

Macromol. Rapid Commun.

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Neutron Reflectivity Investigations of Self-Assembled Conjugated Polyion Multilayers

Cited by 100 publications

References 13 publications

Application of polymeric multilayers of starch onto wood fibres to enhance strength properties of paper

Application of polymeric multilayers of starch onto wood fibres to enhance strength properties of paper

Ultrathin polymer coatings by complexation of polyelectrolytes at interfaces: suitable materials, structure and properties

Self-assembly of mono- and multilayers of polyconjugated conducting polymers

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