Copper(0) Nanoparticles Supported on Silica-Coated Cobalt Ferrite Magnetic Particles: Cost Effective Catalyst in the Hydrolysis of Ammonia-Borane with an Exceptional Reusability Performance

2012 ◽  
Vol 4 (8) ◽  
pp. 3866-3873 ◽  
Author(s):  
Murat Kaya ◽  
Mehmet Zahmakiran ◽  
Saim Özkar ◽  
Mürvet Volkan
Keyword(s):  
Magnetic Particles ◽  
Cobalt Ferrite ◽  
Cost Effective ◽  
Ammonia Borane ◽  
Effective Catalyst ◽  
Hydrolysis Of

DISPERSION OF COBALT FERRITE FUNCTIONALIZED GRAPHENE NANOPLATELETS IN PLA FOR EMI SHIELDING APPLICATIONS

2021 ◽  
Author(s):  
KANAT ANURAKPARADORN ◽  
ALAN TAUB ◽  
ERIC MICHIELSSEN
Keyword(s):  
Functional Groups ◽  
Electromagnetic Interference ◽  
High Speed ◽  
Magnetic Particles ◽  
Cobalt Ferrite ◽  
Reduction Process ◽  
Cost Effective ◽  
Graphene Nanoplatelets ◽  
Angle Of Incidence ◽  
Emi Shielding

The proliferation of wireless technology calls for the development of cost-effective Electromagnetic Interference (EMI) shielding materials that reduce the susceptibility of high-speed electronic circuits to undesired incoming radiation. Ideally, such materials offer protection over wide frequency ranges and are insensitive to the polarization or angle of incidence of the impinging fields. Here, next-generation EMI shielding materials composed of polymer composites with conductive and magnetic fillers are introduced. It is shown that careful control of the concentration and dispersion of the polymers’ conductive and magnetic constituents permits tuning of the composites’ intrinsic electrical and magnetic properties. The resulting EMI shields are lightweight, cheap and offer greater protection than traditional metal gaskets and foams. In this work, cobalt ferrite magnetic nanoparticles (CoFe2O4) decorated on graphene-based material were dispersed in polylactic acid (PLA) matrix for high EM absorption level in X-band (8-12 GHz). The decoration of the magnetic particles was performed on the as-prepared conductive graphene nanoplatelets (GNP) and reduced graphene oxide (rGO). GNP composites exhibited higher DC conductivity, and permittivity than rGO composites. This is attributed to issues associated with the reduction process, including a lack of conductivity due to the insulated oxygen functional groups and the reduction in the lateral size. Compared with rGOs, the lack of out-plane functional groups causes the cobalt ferrite nanoparticles to agglomerate and not cover the entire surface of the GNPs. These morphological differences improve the magnetization and EM absorption of the composite system. The compatibilizer (pyrene-PLA-OH) was added to the composites to enhance dispersion of the GNPs in the polymer matrix which benefits in higher absorption of the shield. The influence of the compatibilizer on parameter, the reflection loss (RL) of the composite were determined from the characterized intrinsic properties

scholarly journals Construction of cost-effective bimetallic nanoparticles on titanium carbides as a superb catalyst for promoting hydrolysis of ammonia borane

RSC Advances ◽  
2018 ◽  
Vol 8 (2) ◽  
pp. 843-847 ◽  
Author(s):  
Zhangwei Guo ◽  
Tong Liu ◽  
Qingtao Wang ◽  
Guanhui Gao
Keyword(s):  
Chemical Method ◽  
Bimetallic Nanoparticles ◽  
Cost Effective ◽  
Ammonia Borane ◽  
Wet Chemical Method ◽  
One Step ◽  
Wet Chemical ◽  
Titanium Carbides ◽  
Hydrolysis Of

Bimetallic cost-effective CoNi nanoparticles are supported on MXene by a simple one-step wet-chemical method. The Co0.7Ni0.3/MXene shows the best performance toward catalyzing AB decomposition with TOF of 87.6 molH2molcat−1min−1at 50 °C.

scholarly journals Preparation of Magnetic Cross-Linked Amyloglucosidase Aggregates: Solving Some Activity Problems

Catalysts ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 496 ◽  
Author(s):  
Murilo Amaral-Fonseca ◽  
Willian Kopp ◽  
Raquel Giordano ◽  
Roberto Fernández-Lafuente ◽  
Paulo Tardioli
Keyword(s):  
Magnetic Particles ◽  
Cost Effective ◽  
Soluble Enzyme ◽  
Amino Groups ◽  
Effective Technique ◽  
Volumetric Activity ◽  
Dextrose Equivalent ◽  
Cost Effective Technique ◽  
Improved Stability ◽  
Hydrolysis Of

The preparation of Cross-Linked Enzyme Aggregates (CLEAs) is a simple and cost-effective technique capable of generating insoluble biocatalysts with high volumetric activity and improved stability. The standard CLEA preparation consists of the aggregation of the enzyme and its further crosslinking, usually with glutaraldehyde. However, some enzymes have too low a content of surface lysine groups to permit effective crosslinking with glutaraldehyde, requiring co-aggregation with feeders rich in amino groups to aid the formation of CLEAs. The co-aggregation with magnetic particles makes their handling easier. In this work, CLEAs of a commercial amyloglucosidase (AMG) produced by Aspergillus niger were prepared by co-aggregation in the presence of polyethyleneimine (PEI) or starch with aminated magnetic nanoparticles (MNPs) or bovine serum albumin (BSA). First, CLEAs were prepared only with MNPs at different glutaraldehyde concentrations, yielding a recovered activity of around 20%. The addition of starch during the precipitation and crosslinking steps nearly doubled the recovered activity. Similar recovered activity (around 40%) was achieved when changing starch by PEI. Moreover, under the same conditions, AMG co-aggregated with BSA was also synthesized, yielding CLEAs with very similar recovered activity. Both CLEAs (co-aggregated with MNPs or BSA) were four times more stable than the soluble enzyme. These CLEAs were evaluated in the hydrolysis of starch at typical industrial conditions, achieving more than 95% starch-to-glucose conversion, measured as Dextrose Equivalent (DE). Moreover, both CLEAS could be reused for five cycles, maintaining a DE of around 90%. Although both CLEAs had good properties, magnetic CLEAs could be more attractive for industrial purposes because of their easy separation by an external magnetic field, avoiding the formation of clusters during the filtration or centrifugation recovery methods usually used.

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