Reflective and electrically conductive palladium surface‐metallized polyimide nanocomposite membranes

Abstract

ligand on the reductive metallization of BTDA/4,4 0 -ODA were also examined for the PdCl 2 (SMe 2 ) 2 , PdBr 2 (SMe 2 ) 2 , and Pd(CF 3 COO) 2 complexes. The hybrid films were characterized by specular and diffuse reflectivity and by conductivity measurement. Maximum specular reflectivity was in the range of 35%-55%, and conductivity was in the range of 1-10 O/square. Scanning electron microscopy and transmission electron microscopy revealed that the initial Pd metal particles formed within the films were in the 3-8 nm range in size. These particles increased in size with irregular shapes at the surface as the metallic exterior emerged. A fraction of the nanometer-sized Pd particles remained uniformly distributed throughout the bulk of the film. The mechanism for the formation of a metallic surface required selective oxidative degradation of the polyimide at the polyimide-air interface.

Metallopolymer Capacitor in “One Pot” by Self-Directed UV-Assisted Process

“…Southward and Stoakley reported the observation of such migration of silver in thermally cured polyimides, and it seemed there was still no explanation as to why and how it happens . However, in their papers on Pd metalized polymer surfaces, they argue that the development of a metalized film surface from atom/cluster migration to the surface within an organic macromolecular matrix is unexpected because metal atoms and nanoclusters produced in the thermal cycle must remain within the bulk of the polymer , . That is, the high surface free energy of metal particles relative to organic materials (about 10:1) thermodynamically precludes a metal surface developing via atom/cluster migration from the bulk to the surface of the polymer film.…”

Palladium: a future key player in the nanomedical field?

“…Palladium nanostructures have gained interest in the last decade in a number of applications including catalysis (e.g. : hydrogenation, C-C bond formation and oxidation, for the manufacture of pharmaceuticals, the processing of environmental pollutants or automotive emission control), [10][11][12][13] composition of electrical equipment, 14,15 or as sensors for the detection of various analytes. [16][17][18][19] In medicine, palladium is nowadays commonly used in dental appliances 20 and 103 Pd needles are used in the clinic for prostate cancer 21 and choroidal melanoma brachytherapy.…”

Hybrid films of polyetherimide containingin situgrown Ag, Pd, and AgPd alloy nanoparticles: Synthesis route, morphology, and gas transport properties

“…The metal nanoclusters are then formed via a reduction process directly within the polymer film, thus in a solid medium that limits aggregation phenomena. Depending on the polymer/metal precursor system, different ways can be used to obtain the metal ion reduction . The most common way consists in swelling the precursor film in a solvent and then using an external reducing agent such as sodium borohydride, which has to diffuse through the polymer continuous phase to reduce the metal precursor .…”

“…Although efficient, this route can not be considered as environmentally friendly. Thermal annealing has also been reported as an efficient way to obtain polymer embedded metal nanoparticles for some systems . This route has been extensively used to form silver nanoparticles within polymer films and different morphologies, that is, from a homogeneous dispersion of metal nanoparticles to the formation of a metal rich surface layer, have also been achieved .…”

“…This route has been extensively used to form silver nanoparticles within polymer films and different morphologies, that is, from a homogeneous dispersion of metal nanoparticles to the formation of a metal rich surface layer, have also been achieved . The efficiency of this simple and environmentally friendly route to form Pd nanoclusters in thermally stable polymers has been recently demonstrated . The Pd nanoparticles formed by this way, as those obtained from classical reduction processes, have been shown to display specific behaviour toward hydrogen permeation properties due to a high hydrogen entrapment capacity .…”