Catalytic Sol Assisted Dense Pd/γ-Al2O3 Membrane using Modified Electroless Plating: Effect of Process on Surface Morphology

2016 ◽  
Vol 12 (2) ◽  
Author(s):  
Richa Sharma ◽  
Amit Kumar ◽  
Rajesh K. Upadhyay

Abstract Palladium membranes are considered ideal for high purity hydrogen separation owing to their infinite selectivity to hydrogen. The key to such selectivity depends on the dense surface of the membrane that suggests absolute non-porous surface morphology. However, preparation of dense palladium membranes irrespective of any deposition technique leads to pit formation which makes synthesis of dense palladium membrane challenging. The current study illustrates the application of electroless plating assisted with novel catalytic sol pre-coating to prepare dense Pd membranes. The surface characterization using field emission scanning electron microscope (FESEM) and atomic force microscopy (AFM) were performed to identify the gaps between dip coating and electroless plating. It was observed that with the use of a dip coated catalytic sol, thinner and well dispersed Pd deposits could be prepared. The porosity of deposited Pd layers does not affect the essential densification property as sol surface underneath dispersed Pd remains dense.

2017 ◽  
Vol 68 (11) ◽  
pp. 2700-2703 ◽  
Author(s):  
Kamel Earar ◽  
Vasile Iulian Antoniac ◽  
Sorana Baciu ◽  
Simion Bran ◽  
Florin Onisor ◽  
...  

This study examined and compared surface of human dentine after acidic etching with hydrogen peroxide, phosphoric acid liquid and gel. Surface demineralization of dentin is necessary for a strong bond of adhesive at dental surface. Split human teeth were used. After application of mentioned substances at dentin level measures of the contact angle and surface morphology were employed. Surface morphology was analyzed with the help of scanning electron microscopy and atomic force microscopy. Liquid phosphoric acid yielded highest demineralization showing better hydrophobicity than the rest, thus having more contact surface. Surface roughness are less evident and formed surface micropores of 4 �m remained open after wash and air dry providing better adhesive canalicular penetration and subsequent bond.


1992 ◽  
Author(s):  
Mark R. Kozlowski ◽  
Michael C. Staggs ◽  
Mehdi Balooch ◽  
Robert J. Tench ◽  
Wigbert J. Siekhaus

1999 ◽  
Vol 200 (3-4) ◽  
pp. 348-352 ◽  
Author(s):  
R.S Qhalid Fareed ◽  
S Tottori ◽  
K Nishino ◽  
S Sakai

1999 ◽  
Vol 594 ◽  
Author(s):  
M. E. Ware ◽  
R. J. Nemanich

AbstractThis study explores stress relaxation of epitaxial SiGe layers grown on Si substrates with unique orientations. The crystallographic orientations of the Si substrates used were off-axis from the (001) plane towards the (111) plane by angles, θ = 0, 10, and 22 degrees. We have grown 100nm thick Si(1−x) Ge(x) epitaxial layers with x=0.3 on the Si substrates to examine the relaxation process. The as-deposited films are metastable to the formation of strain relaxing misfit dislocations, and thermal annealing is used to obtain highly relaxed films for comparison. Raman spectroscopy has been used to measure the strain relaxation, and atomic force microscopy has been used to explore the development of surface morphology. The Raman scattering indicated that the strain in the as-deposited films is dependent on the substrate orientation with strained layers grown on Si with 0 and 22 degree orientations while highly relaxed films were grown on the 10 degree substrate. The surface morphology also differed for the substrate orientations. The 10 degree surface is relatively smooth with hut shaped structures oriented at predicted angles relative to the step edges.


1995 ◽  
Vol 413 ◽  
Author(s):  
V. Shivshankar ◽  
C. Sung ◽  
J. Kumar ◽  
S. K. Tripathy ◽  
D. J. Sandman

ABSTRACTWe have studied the surface morphology of free standing single crystals of thermochromic polydiacetylenes (PDAs), namely, ETCD and IPUDO (respectively, the ethyl and isopropyl urethanes of 5,7-dodecadiyn-1,12-diol), by Atomic Force Microscopy (AFM) under ambient conditions. Micron scale as well as molecularly resolved images were obtained. The micron scale images indicate a variable surface, and the molecularly resolved images show a well defined 2-D lattice that is interpreted in terms of molecular models and known crystallographic data. Thereby information about surface morphology, which is crucial to potential optical device or chromic sensor performance is available. We also report the observation of a “macroscopic shattering” of the IPUDO monomer crystal during in-situ UV polymerization studies.


2006 ◽  
Vol 20 (02) ◽  
pp. 217-231 ◽  
Author(s):  
MUHAMMAD MAQBOOL ◽  
TAHIRZEB KHAN

Thin films of pure silver were deposited on glass substrate by thermal evaporation process at room temperature. Surface characterization of the films was performed using X-ray diffraction (XRD) and atomic force microscopy (AFM). Thickness of the films varied between 20 nm and 72.8 nm. XRD analysis provided a sharp peak at 38.75° from silver. These results indicated that the films deposited on glass substrates at room temperature are crystalline. Three-dimension and top view pictures of the films were obtained by AFM to study the grain size and its dependency on various factors. Average grain size increased with the thickness of the deposited films. A minimum grain size of 8 nm was obtained for 20 nm thick films, reaching 41.9 nm when the film size reaches 60 nm. Grain size was calculated from the information provided by the XRD spectrum and averaging method. We could not find any sequential variation in the grain size with the growth rate.


2004 ◽  
Vol 11 (03) ◽  
pp. 265-269
Author(s):  
O. P. SINHA ◽  
P. C. SRIVASTAVA ◽  
V. GANESAN

The p-silicon surfaces have been irradiated with ~ 100 MeV Si 7+ions to a fluence of 2.2×1013 ions cm -2, and surface morphology has been studied with atomic force microscopy (AFM). Interesting features of cracks of ~ 47 nm in depth and ~ 103 nm in width on the irradiated surfaces have been observed. The observed features seemed to have been caused by the irradiation-induced stress in the irradiated regions of the target surface.


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