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Ravindra Uppaluri - One of the best experts on this subject based on the ideXlab platform.
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optimal Electroless Plating rate enhancement techniques for the fabrication of low cost dense nickel ceramic composite membranes
Ceramics International, 2014Co-Authors: Amrita Agarwal, Murali Pujari, Ravindra Uppaluri, Anil VermaAbstract:Abstract Addressing combinatorial Plating characteristics for dense metal ceramic composite membranes, this article attempts to identify the most suitable Electroless Plating rate enhancement technique. The support morphology considered for this work corresponds to low combinations of pore size and porosity. Cases considered for comparative assessment include conventional Electroless Plating (CEP), surfactant induced Electroless Plating (SIEP) and sonication induced Electroless Plating (SOEP). BET, FTIR, XRD, FESEM and nitrogen permeation techniques were employed for surface and physical characterization. It was observed that with SIEP the average metal film thickness was about 18.3 μm and with SOEP it was 24.6 μm. Correspondingly it was also observed that for SIEP baths the ratio of percent pore densification (PPD) to metal film thickness (δ) i.e. PPD/δ varied from 11.2 to 5.35 and for SOEP baths PPD/δ varied from 3.5 to 4.7 for 8–24 h of sequential Plating. Thereby, it was inferred that SIEP possessed maximum potential towards dense metal ceramic composite membrane fabrication for the realization of maximum PPD with minimal metal film thickness.
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effect of surface roughness and mass transfer enhancement on the performance characteristics of nickel hypophosphite Electroless Plating baths for metal ceramic composite membrane fabrication
Chemical Engineering Research & Design, 2011Co-Authors: Vijaya Kumar Bulasara, Oruganti Chandrashekar, Ravindra UppaluriAbstract:Abstract Mass transfer enhanced Electroless Plating is a relatively new concept in the field of metal–ceramic composite membrane fabrication. In this article, we present the effect of substrate surface roughness along with various mass transfer enhancement techniques such as solution stirring, membrane stirring and sonication on metal conversion, Plating efficiency, thickness, and percent pore densification using Electroless Plating of nickel on a porous disk shaped ceramic support with a nominal pore size of 700 nm. The Plating characteristics were investigated for three different roughness values, stirrer speeds (0–300 rpm) and a loading ratio (defined as membrane area per unit volume of Plating solution) value of 196 cm 2 /L. It was evaluated that stirring as well as sonication had a profound effect on sodium hypophosphite based Electroless nickel baths. This led to a reduction in average membrane pore size by 100 nm for stirring and 130 nm for sonication when compared to the base case. Surface roughness was observed to influence the metal deposition characteristics for base case without mass transfer enhancement. Sonication, irrespective of surface roughness, provided the maximum values of selective conversion, densification and membrane thickness along with acceptable values of Plating efficiency.
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combinatorial performance characteristics of agitated nickel hypophosphite Electroless Plating baths
Journal of Materials Processing Technology, 2011Co-Authors: Vijaya Kumar Bulasara, Harjyoti Thakuria, Ravindra Uppaluri, Mihir Kumar PurkaitAbstract:Abstract In this article, we present the combinatorial performance characteristics of agitated sodium hypophosphite Electroless Plating baths. Various performance characteristics assessed include bath conversion, Plating efficiency, selective conversion, metal film thickness, average pore size, effective porosity and percent pore densification (PPD). Bath agitation was brought forward by rotating a symmetric disk shaped porous ceramic substrate with a nominal pore size of 275 nm. The Plating characteristics were investigated for wide range of nickel solution concentrations (0.04–0.16 mol/L), stirrer speed (0–200 rpm) and for two different loading ratios (defined as substrate surface area per unit volume of Plating solution) values (196 and 393 cm2/L). It was evaluated that stirring had a profound effect on sodium hypophosphite based Electroless nickel baths, which are characterized with lower conversions (10–39%) and higher Plating efficiencies (62–99%) without stirring phenomena. The stirred Plating baths provided about 20–56% excess nickel Plating rate when compared to the baths without stirring. This lead to a reduction in average membrane pore size by 20–42 nm and an enhancement in percent pore densification values by about 2–7%. Further, higher concentrations as high as 0.16 mol/L have been found to be detrimental to reduce the metal Plating efficiency to lower values (42%). Observed data trends confirm upon the urgent need to identify suitable mass transfer enhancement techniques that target enhancement in selective conversion while providing good values of Plating efficiency and PPD.
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manufacture of nickel ceramic composite membranes in agitated Electroless Plating baths
Materials and Manufacturing Processes, 2011Co-Authors: Vijaya Kumar Bulasara, Ravindra Uppaluri, Mihir Kumar PurkaitAbstract:Nickel hydrazine Electroless Plating baths with membrane stirring as a mass transfer enhancement is considered to evaluate the membrane morphological dependence on metal solution concentration, loading ratio (membrane area per unit volume of Plating solution), and stirrer speed. Inexpensive sintered ceramic supports with an average pore size of 275 nm were used for all experimental investigations. Other parametric investigations include conversion and Plating efficiency. It was observed that the loading ratio significantly influenced metal film thickness but not the nominal pore size of the membranes. On the other hand, effect of stirrer speed is significant for solutions with 0.04 mol/L metal solution concentrations, moderate for solutions with 0.08 mol/L solution concentration, and insignificant for 0.16 mol/L concentration. Based on several experimental investigations, it is inferred that the optimal choice of the agitated Plating process are 0.08 mol/L initial nickel solution concentration, 393 cm2/L ...
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effect of process parameters on Electroless Plating and nickel ceramic composite membrane characteristics
Desalination, 2011Co-Authors: Vijaya Kumar Bulasara, Harjyoti Thakuria, Ravindra Uppaluri, Mihir Kumar PurkaitAbstract:Abstract In this article we address the process perspective of Electroless Plating technique to fabricate nickel-ceramic composite membranes. In this work, we also report an inexpensive ceramic membrane precursor formulation which upon sintering process yielded a membrane support with an average pore size of 275 nm. Subsequently, membranes were subjected to Electroless Plating for wide choice of nickel solution concentration (0.04–0.16 mol/L) and loading ratio (defined as membrane area per unit Plating solution volume) values (196–393 cm2/L). Various parameters evaluated to relate upon Plating and membrane characteristics are conversion, Plating efficiency and inefficiency, metal layer thickness and average nickel-ceramic membrane pore size. In general it was observed that sodium hypophosphite based Electroless nickel baths provided lower conversion (10–40%) and moderately higher efficiencies (90–60%). However, the effect of loading ratio on efficiency was found to be insignificant. On the other hand, membrane densification was observed to vary between 78–90% to yield a surface pore size reduction from 275 nm to 128–90 nm. Retail cost based analysis further indicates the non-linear dependencies of both chemicals cost and metal layer thickness with respect to the percent pore densification values.
Vijaya Kumar Bulasara - One of the best experts on this subject based on the ideXlab platform.
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effect of surface roughness and mass transfer enhancement on the performance characteristics of nickel hypophosphite Electroless Plating baths for metal ceramic composite membrane fabrication
Chemical Engineering Research & Design, 2011Co-Authors: Vijaya Kumar Bulasara, Oruganti Chandrashekar, Ravindra UppaluriAbstract:Abstract Mass transfer enhanced Electroless Plating is a relatively new concept in the field of metal–ceramic composite membrane fabrication. In this article, we present the effect of substrate surface roughness along with various mass transfer enhancement techniques such as solution stirring, membrane stirring and sonication on metal conversion, Plating efficiency, thickness, and percent pore densification using Electroless Plating of nickel on a porous disk shaped ceramic support with a nominal pore size of 700 nm. The Plating characteristics were investigated for three different roughness values, stirrer speeds (0–300 rpm) and a loading ratio (defined as membrane area per unit volume of Plating solution) value of 196 cm 2 /L. It was evaluated that stirring as well as sonication had a profound effect on sodium hypophosphite based Electroless nickel baths. This led to a reduction in average membrane pore size by 100 nm for stirring and 130 nm for sonication when compared to the base case. Surface roughness was observed to influence the metal deposition characteristics for base case without mass transfer enhancement. Sonication, irrespective of surface roughness, provided the maximum values of selective conversion, densification and membrane thickness along with acceptable values of Plating efficiency.
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combinatorial performance characteristics of agitated nickel hypophosphite Electroless Plating baths
Journal of Materials Processing Technology, 2011Co-Authors: Vijaya Kumar Bulasara, Harjyoti Thakuria, Ravindra Uppaluri, Mihir Kumar PurkaitAbstract:Abstract In this article, we present the combinatorial performance characteristics of agitated sodium hypophosphite Electroless Plating baths. Various performance characteristics assessed include bath conversion, Plating efficiency, selective conversion, metal film thickness, average pore size, effective porosity and percent pore densification (PPD). Bath agitation was brought forward by rotating a symmetric disk shaped porous ceramic substrate with a nominal pore size of 275 nm. The Plating characteristics were investigated for wide range of nickel solution concentrations (0.04–0.16 mol/L), stirrer speed (0–200 rpm) and for two different loading ratios (defined as substrate surface area per unit volume of Plating solution) values (196 and 393 cm2/L). It was evaluated that stirring had a profound effect on sodium hypophosphite based Electroless nickel baths, which are characterized with lower conversions (10–39%) and higher Plating efficiencies (62–99%) without stirring phenomena. The stirred Plating baths provided about 20–56% excess nickel Plating rate when compared to the baths without stirring. This lead to a reduction in average membrane pore size by 20–42 nm and an enhancement in percent pore densification values by about 2–7%. Further, higher concentrations as high as 0.16 mol/L have been found to be detrimental to reduce the metal Plating efficiency to lower values (42%). Observed data trends confirm upon the urgent need to identify suitable mass transfer enhancement techniques that target enhancement in selective conversion while providing good values of Plating efficiency and PPD.
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manufacture of nickel ceramic composite membranes in agitated Electroless Plating baths
Materials and Manufacturing Processes, 2011Co-Authors: Vijaya Kumar Bulasara, Ravindra Uppaluri, Mihir Kumar PurkaitAbstract:Nickel hydrazine Electroless Plating baths with membrane stirring as a mass transfer enhancement is considered to evaluate the membrane morphological dependence on metal solution concentration, loading ratio (membrane area per unit volume of Plating solution), and stirrer speed. Inexpensive sintered ceramic supports with an average pore size of 275 nm were used for all experimental investigations. Other parametric investigations include conversion and Plating efficiency. It was observed that the loading ratio significantly influenced metal film thickness but not the nominal pore size of the membranes. On the other hand, effect of stirrer speed is significant for solutions with 0.04 mol/L metal solution concentrations, moderate for solutions with 0.08 mol/L solution concentration, and insignificant for 0.16 mol/L concentration. Based on several experimental investigations, it is inferred that the optimal choice of the agitated Plating process are 0.08 mol/L initial nickel solution concentration, 393 cm2/L ...
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effect of process parameters on Electroless Plating and nickel ceramic composite membrane characteristics
Desalination, 2011Co-Authors: Vijaya Kumar Bulasara, Harjyoti Thakuria, Ravindra Uppaluri, Mihir Kumar PurkaitAbstract:Abstract In this article we address the process perspective of Electroless Plating technique to fabricate nickel-ceramic composite membranes. In this work, we also report an inexpensive ceramic membrane precursor formulation which upon sintering process yielded a membrane support with an average pore size of 275 nm. Subsequently, membranes were subjected to Electroless Plating for wide choice of nickel solution concentration (0.04–0.16 mol/L) and loading ratio (defined as membrane area per unit Plating solution volume) values (196–393 cm2/L). Various parameters evaluated to relate upon Plating and membrane characteristics are conversion, Plating efficiency and inefficiency, metal layer thickness and average nickel-ceramic membrane pore size. In general it was observed that sodium hypophosphite based Electroless nickel baths provided lower conversion (10–40%) and moderately higher efficiencies (90–60%). However, the effect of loading ratio on efficiency was found to be insignificant. On the other hand, membrane densification was observed to vary between 78–90% to yield a surface pore size reduction from 275 nm to 128–90 nm. Retail cost based analysis further indicates the non-linear dependencies of both chemicals cost and metal layer thickness with respect to the percent pore densification values.
Mihir Kumar Purkait - One of the best experts on this subject based on the ideXlab platform.
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combinatorial performance characteristics of agitated nickel hypophosphite Electroless Plating baths
Journal of Materials Processing Technology, 2011Co-Authors: Vijaya Kumar Bulasara, Harjyoti Thakuria, Ravindra Uppaluri, Mihir Kumar PurkaitAbstract:Abstract In this article, we present the combinatorial performance characteristics of agitated sodium hypophosphite Electroless Plating baths. Various performance characteristics assessed include bath conversion, Plating efficiency, selective conversion, metal film thickness, average pore size, effective porosity and percent pore densification (PPD). Bath agitation was brought forward by rotating a symmetric disk shaped porous ceramic substrate with a nominal pore size of 275 nm. The Plating characteristics were investigated for wide range of nickel solution concentrations (0.04–0.16 mol/L), stirrer speed (0–200 rpm) and for two different loading ratios (defined as substrate surface area per unit volume of Plating solution) values (196 and 393 cm2/L). It was evaluated that stirring had a profound effect on sodium hypophosphite based Electroless nickel baths, which are characterized with lower conversions (10–39%) and higher Plating efficiencies (62–99%) without stirring phenomena. The stirred Plating baths provided about 20–56% excess nickel Plating rate when compared to the baths without stirring. This lead to a reduction in average membrane pore size by 20–42 nm and an enhancement in percent pore densification values by about 2–7%. Further, higher concentrations as high as 0.16 mol/L have been found to be detrimental to reduce the metal Plating efficiency to lower values (42%). Observed data trends confirm upon the urgent need to identify suitable mass transfer enhancement techniques that target enhancement in selective conversion while providing good values of Plating efficiency and PPD.
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manufacture of nickel ceramic composite membranes in agitated Electroless Plating baths
Materials and Manufacturing Processes, 2011Co-Authors: Vijaya Kumar Bulasara, Ravindra Uppaluri, Mihir Kumar PurkaitAbstract:Nickel hydrazine Electroless Plating baths with membrane stirring as a mass transfer enhancement is considered to evaluate the membrane morphological dependence on metal solution concentration, loading ratio (membrane area per unit volume of Plating solution), and stirrer speed. Inexpensive sintered ceramic supports with an average pore size of 275 nm were used for all experimental investigations. Other parametric investigations include conversion and Plating efficiency. It was observed that the loading ratio significantly influenced metal film thickness but not the nominal pore size of the membranes. On the other hand, effect of stirrer speed is significant for solutions with 0.04 mol/L metal solution concentrations, moderate for solutions with 0.08 mol/L solution concentration, and insignificant for 0.16 mol/L concentration. Based on several experimental investigations, it is inferred that the optimal choice of the agitated Plating process are 0.08 mol/L initial nickel solution concentration, 393 cm2/L ...
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effect of process parameters on Electroless Plating and nickel ceramic composite membrane characteristics
Desalination, 2011Co-Authors: Vijaya Kumar Bulasara, Harjyoti Thakuria, Ravindra Uppaluri, Mihir Kumar PurkaitAbstract:Abstract In this article we address the process perspective of Electroless Plating technique to fabricate nickel-ceramic composite membranes. In this work, we also report an inexpensive ceramic membrane precursor formulation which upon sintering process yielded a membrane support with an average pore size of 275 nm. Subsequently, membranes were subjected to Electroless Plating for wide choice of nickel solution concentration (0.04–0.16 mol/L) and loading ratio (defined as membrane area per unit Plating solution volume) values (196–393 cm2/L). Various parameters evaluated to relate upon Plating and membrane characteristics are conversion, Plating efficiency and inefficiency, metal layer thickness and average nickel-ceramic membrane pore size. In general it was observed that sodium hypophosphite based Electroless nickel baths provided lower conversion (10–40%) and moderately higher efficiencies (90–60%). However, the effect of loading ratio on efficiency was found to be insignificant. On the other hand, membrane densification was observed to vary between 78–90% to yield a surface pore size reduction from 275 nm to 128–90 nm. Retail cost based analysis further indicates the non-linear dependencies of both chemicals cost and metal layer thickness with respect to the percent pore densification values.
Harjyoti Thakuria - One of the best experts on this subject based on the ideXlab platform.
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combinatorial performance characteristics of agitated nickel hypophosphite Electroless Plating baths
Journal of Materials Processing Technology, 2011Co-Authors: Vijaya Kumar Bulasara, Harjyoti Thakuria, Ravindra Uppaluri, Mihir Kumar PurkaitAbstract:Abstract In this article, we present the combinatorial performance characteristics of agitated sodium hypophosphite Electroless Plating baths. Various performance characteristics assessed include bath conversion, Plating efficiency, selective conversion, metal film thickness, average pore size, effective porosity and percent pore densification (PPD). Bath agitation was brought forward by rotating a symmetric disk shaped porous ceramic substrate with a nominal pore size of 275 nm. The Plating characteristics were investigated for wide range of nickel solution concentrations (0.04–0.16 mol/L), stirrer speed (0–200 rpm) and for two different loading ratios (defined as substrate surface area per unit volume of Plating solution) values (196 and 393 cm2/L). It was evaluated that stirring had a profound effect on sodium hypophosphite based Electroless nickel baths, which are characterized with lower conversions (10–39%) and higher Plating efficiencies (62–99%) without stirring phenomena. The stirred Plating baths provided about 20–56% excess nickel Plating rate when compared to the baths without stirring. This lead to a reduction in average membrane pore size by 20–42 nm and an enhancement in percent pore densification values by about 2–7%. Further, higher concentrations as high as 0.16 mol/L have been found to be detrimental to reduce the metal Plating efficiency to lower values (42%). Observed data trends confirm upon the urgent need to identify suitable mass transfer enhancement techniques that target enhancement in selective conversion while providing good values of Plating efficiency and PPD.
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effect of process parameters on Electroless Plating and nickel ceramic composite membrane characteristics
Desalination, 2011Co-Authors: Vijaya Kumar Bulasara, Harjyoti Thakuria, Ravindra Uppaluri, Mihir Kumar PurkaitAbstract:Abstract In this article we address the process perspective of Electroless Plating technique to fabricate nickel-ceramic composite membranes. In this work, we also report an inexpensive ceramic membrane precursor formulation which upon sintering process yielded a membrane support with an average pore size of 275 nm. Subsequently, membranes were subjected to Electroless Plating for wide choice of nickel solution concentration (0.04–0.16 mol/L) and loading ratio (defined as membrane area per unit Plating solution volume) values (196–393 cm2/L). Various parameters evaluated to relate upon Plating and membrane characteristics are conversion, Plating efficiency and inefficiency, metal layer thickness and average nickel-ceramic membrane pore size. In general it was observed that sodium hypophosphite based Electroless nickel baths provided lower conversion (10–40%) and moderately higher efficiencies (90–60%). However, the effect of loading ratio on efficiency was found to be insignificant. On the other hand, membrane densification was observed to vary between 78–90% to yield a surface pore size reduction from 275 nm to 128–90 nm. Retail cost based analysis further indicates the non-linear dependencies of both chemicals cost and metal layer thickness with respect to the percent pore densification values.
Serge Kaliaguine - One of the best experts on this subject based on the ideXlab platform.
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simultaneous deposition of pd and ag on porous stainless steel by Electroless Plating
Journal of Membrane Science, 1993Co-Authors: J Shu, Bernard P. A. Grandjean, E Ghali, Serge KaliaguineAbstract:Abstract This work investigates the codeposition behavior of palladium and silver on porous stainless steel by means of Electroless Plating. Although palladium and silver can be deposited independently to a considerable thickness, simultaneous deposition of palladium and silver is passivated by the preferential deposition of silver in an Electroless bath containing EDTA as a complexing agent. After effective activation of the substrate by Pd predeposition, Pd and Ag can be successfully codeposited. A combination of XRD and EDX analyses reveals that codeposited Pd and Ag are in separate phases and that small amounts of an amorphous palladium rich phase are also present in the deposited material. Thus a codeposition mechanism of Pd and Ag is proposed. Thermal treatment of as-deposited Pd-Ag films in H 2 atmosphere provides composite Pd-Ag alloy membranes on the porous stainless steel substrate.