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Electroless Plating (electroless + plating)

Distribution by Scientific Domains

Polymers and Materials Science	50%

Selected Abstracts

Preparation and thermal properties of zirconium tungstate/copper composites

MATERIALWISSENSCHAFT UND WERKSTOFFTECHNIK, Issue 9 2008
X. Yan
Metall-Matrix-Verbundwerkstoffe; thermische Eigenschaften; Pulver Prozess Abstract ZrW2O8/Cu composites were prepared by the powder metallurgy method. Electroless plating was used to deposit copper on ZrW2O8 powder before sintering. The thermal expansion and thermal conductivity of composites were measured in the temperature range from 25 oC to 200 oC and compared with those predicted from various theoretical models. The results show that the coefficient of thermal expansion of ZrW2O8/ Cu composites with a different volume fraction of ZrW2O8 is greater than the theoretically calculated value. The thermal conductivities of ZrW2O8/ Cu composites increase with a higher copper content and decrease upon elevated temperature. The thermal conductivity of composites with a different volume fraction of ZrW2O8 is lower than the theoretically calculated value. Fertigungsverfahren und thermische Eigenschaften von Zirkonium Wolfram/Kupfer Verbundwerkstoffen No Abstract [source]

Tubular and Twisted Ni,P Fibers Molded from Morphology-Tunable and Recyclable Organic Templates of Hydrogen-Bonded Supramolecular Assemblages,

ADVANCED MATERIALS, Issue 2 2005
M. Nakagawa
Morphology-controlled nickel, phosphorus hollow microfibers (see Figure) have been fabricated by electroless plating using hydrogen-bonded fibrous molecular aggregates as novel morphology-tunable and recyclable templates. The inner diameter and the tubular morphology are tunable by simply varying the amphoteric azopyridine carboxylic acids forming the fibrous molecular aggregates. [source]

Effect of metal-support interface on hydrogen permeation through palladium membranes

AICHE JOURNAL, Issue 3 2009
Ke Zhang
Abstract Thin palladium membranes of different thicknesses were prepared on sol-gel derived mesoporous ,-alumina/,-alumina and yttria-stabilized zirconia/,-alumina supports by a method combining sputter deposition and electroless plating. The effect of metal-support interface on hydrogen transport permeation properties was investigated by comparing hydrogen permeation data for these membranes measured under different conditions. Hydrogen permeation fluxes for the Pd/,-Al2O3/,-Al2O3 membranes are significantly smaller than those for the Pd/YSZ/,-Al2O3 membranes under similar conditions. As the palladium membrane thickness increases, the difference in permeation fluxes between these two groups of membranes decreases and the pressure exponent for permeation flux approaches 0.5 from 1. Analysis of the permeation data with a permeation model shows that both groups of membranes have similar hydrogen permeability for bulk diffusion, but the Pd/,-Al2O3/,-Al2O3 membranes exhibit a much lower surface reaction rate constant with higher activation energy, due possibly to the formation of Pd-Al alloy, than the Pd/YSZ/,-Al2O3 membranes. © 2009 American Institute of Chemical Engineers AIChE J, 2009 [source]

Pd membranes formed by electroless plating with osmosis: H2 permeation studies

AICHE JOURNAL, Issue 2 2002
Razima S. Souleimanova
The synthesis of fully dense Pd-Vycor glass composite membranes by electroless plating with or without osmosis is reported. Use of osmotic flux allows one to rapidly form thin (a few microns), fully dense palladium films, which have submicron size microstructure. These features significantly enhance hydrogen permeability as compared to the conventional method. By accounting for resistance of the porous support, it is confirmed that for membranes prepared by the same technique, with gradually changing microstructural characteristics, those with smaller palladium crystallites exhibit larger hydrogen flux. Pd-stainless steel composite membranes were also prepared using electroless plating, either with or without osmosis. Membranes synthesized using osmosis exhibit superior thermal stability. [source]

The electrical behavior of thermosetting polymer composites containing metal plated ceramic filler

POLYMER COMPOSITES, Issue 1 2005
Hedva Bar
This paper describes the electrical behavior of a thermosetting system, based on epoxy resin, containing metal plated fillers. Ceramic fillers such as chopped glass fibers and mica flakes were coated with copper by electroless plating and incorporated into an epoxy resin based on di-glycidyl ether of bisphenol A (DGEBA) with tri-ethylenetetramine (TETA) curing agent. The percolation threshold in these systems is obtained at very low copper contents of 0.11,0.44 vol%. The epoxy/copper coated mica system is characterized by an extremely large positive temperature coefficient (PTC) effect, which is not followed by a negative temperature coefficient (NTC) effect. Increasing the copper coated mica concentration raises the PTC temperature of the first temperature cycle, and exposing the material to continuous heating-cooling cycles results in a decrease in the PTC temperature and an increase of its room temperature resistivity. Inverse relations were found between the coefficient of thermal expansion and the PTC temperature. Accordingly, the mechanism governing the PTC effect in the epoxy/copper coated mica composite is based on a larger thermal expansion coefficient of the matrix compared with the ceramic filler. POLYM. COMPOS., 26:12,19, 2005. © 2004 Society of Plastics Engineers. [source]