Structure-property relationships in Langmuir-Blodgett films of Zwitterionic D-π-A adducts of TCNQ

ABSTRACTThe fabrication, structure and electrical properties of new electrically conductive Langmuir-Blodgett (LB) films of polyaniline and polypyrrole have been investigated. Polyaniline in its emeraldine-base form was mixed with stearic acid (PAN-B/SA) to produce stable films at the air-water interface (5/1 or 10/1 mole ratio of PAN-B/SA). These films were then transferred into multilayer films which were found to exhibit conductivities of about 1 S/cm upon doping with hydrochloric acid. The alkyl chains of the stearic acid molecules were found to be distributed randomly throughout the LB film thereby exerting a minimal influence on the electrical properties of the polyaniline phase. In addition to this mixed monolayer approach, a novel method of fabricating highly conductive polypyrrole LB films has been developed. This method is based on the sequential exposure of ferric stéarate LB films to hydrogen chloride (HC1) gas and pyrrole vapor. Each of these two solid state reactions was found to impart dramatic chemical and structural changes to the film. Polypyrrole LB films with conductivities as high as 5 S/cm were produced via this process. The electrical and optical properties of films made by both techniques were examined in order to elucidate their structure/property relationships.

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A Comparative Study of the Structure/Property Relationships of Langmuir-Blodgett and Spin-Cast Films of an Amphiphilic, Regioregular Polythiophene Polymer

MRS Proceedings ◽

10.1557/proc-0949-c02-07 ◽

2006 ◽

Vol 949 ◽

Author(s):

Jusroop Mattu ◽

Thomas Johansson ◽

Steven Holdcroft ◽

Gary W. Leach

Keyword(s):

Thin Films ◽

Comparative Study ◽

Conjugated Polymer ◽

Structure Property ◽

Materials Properties ◽

Langmuir Blodgett ◽

Thermal Reactivity ◽

Structure Property Relationships ◽

Structural Conformation ◽

Cast Films

ABSTRACTThe effects of structural conformation and order on materials properties and reactivity in thin films of an amphiphilic, regioregular polythiophene π-conjugated polymer (πCP) derivative are presented. Thin films deposited by the Langmuir Blodgett technique provide highly ordered anisotropic films compared to those deposited by spin cast methods. Large differences in both the thermal reactivity and physical properties of the films are observed.

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Structure-property relationships of PE/PP sandwiched films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100126998 ◽

1987 ◽

Vol 45 ◽

pp. 454-455

Author(s):

J. Petermann ◽

G. Broza ◽

U. Rieck ◽

A. Jaballah ◽

A. Kawaguchi

Keyword(s):

Mechanical Tests ◽

Polymer Materials ◽

Ionic Crystals ◽

Structure Property ◽

Polymer Systems ◽

Structure Property Relationships ◽

Oriented Films ◽

Materials Used ◽

Polymer Laminates ◽

Heated Glass

Oriented overgrowth of polymer materials onto ionic crystals is well known and recently it was demonstrated that this epitaxial crystallisation can also occur in polymer/polymer systems, under certain conditions. The morphologies and the resulting physical properties of such systems will be presented, especially the influence of epitaxial interfaces on the adhesion of polymer laminates and the mechanical properties of epitaxially crystallized sandwiched layers.Materials used were polyethylene, PE, Lupolen 6021 DX (HDPE) and 1810 D (LDPE) from BASF AG; polypropylene, PP, (PPN) provided by Höchst AG and polybutene-1, PB-1, Vestolen BT from Chemische Werke Hüls. Thin oriented films were prepared according to the method of Petermann and Gohil, by winding up two different polymer films from two separately heated glass-plates simultaneously with the help of a motor driven cylinder. One double layer was used for TEM investigations, while about 1000 sandwiched layers were taken for mechanical tests.

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Approaches for TEM imaging of cavitation in toughened nylon

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100153737 ◽

1989 ◽

Vol 47 ◽

pp. 352-353

Author(s):

Barbara A. Wood

Keyword(s):

Morphological Characteristics ◽

Structure Property ◽

Polymer Systems ◽

Selective Staining ◽

Structure Property Relationships ◽

Rubber Toughened ◽

Shear Yield ◽

Controversial Topic ◽

Selection Of ◽

Diamond Knife

A controversial topic in the study of structure-property relationships of toughened polymer systems is the internal cavitation of toughener particles resulting from damage on impact or tensile deformation.Detailed observations of the influence of morphological characteristics such as particle size distribution on deformation mechanisms such as shear yield and cavitation could provide valuable guidance for selection of processing conditions, but TEM observation of damaged zones presents some experimental difficulties.Previously published TEM images of impact fractured toughened nylon show holes but contrast between matrix and toughener is lacking; other systems investigated have clearly shown cavitated impact modifier particles. In rubber toughened nylon, the physical characteristics of cavitated material differ from undamaged material to the extent that sectioning of heavily damaged regions by cryoultramicrotomy with a diamond knife results in sections of greater than optimum thickness (Figure 1). The detailed morphology is obscured despite selective staining of the rubber phase using the ruthenium trichloride route to ruthenium tetroxide.

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