scholarly journals Synthesis of Copper Nanoparticles on Cellulosic Fabrics and Evaluation of their Multifunctional Performances

2021 ◽  
Author(s):  
Veerender Sharma ◽  
Santanu Basak ◽  
Wazed Ali
Keyword(s):  
Cotton Fabric ◽  
Copper Nanoparticles ◽  
Localized Surface Plasmon ◽  
High Catalytic Activity ◽  
Physico Chemical ◽  
Washing Durability ◽  
Solution Route ◽  
Uv Visible ◽  
Cellulose Materials ◽  
Very High

Abstract Two different kinds of copper nanoparticles (CuNPs) (brown colour and greenish colour) were synthesised by using simple solution route and applied on cotton by exhaust method to achieve multidimensional functionalization on one of the most popular cellulose materials e.g., cotton fabric. The synthesised CuNPs imparted different colours to cotton textile due to different conditions of synthesis and localized surface plasmon resonance. Physico-chemical characterizations of the synthesized nanoparticles were performed by using scanning electron microscope (SEM) and EDX analysis whereas the optical properties of the nanoparticles were studied using UV-visible spectroscopy. The prepared CuNPs of both the types demonstrated very good antimicrobial activity up to 97%. In addition, cotton fabric treated with CuNPs showed very high catalytic activity for reduction of 4-nitroaniline in presence of sodium borohydride to phenylene diamine. Washing durability and rubbing fastness of the treated fabric have also been measured by following standard testing methods and found to be very good with a rating 4.

Interior vs. Exterior Incorporation of Silver Nanoparticles in Cotton Fiber and Washing Durability

2021 ◽  
Vol 8 (6) ◽  
pp. 1-12
Author(s):  
Sunghyun Nam ◽  
Sonia E. Chavez ◽  
Matthew B. Hillyer ◽  
Brian D. Condon ◽  
Hongqing Shen ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Cotton Fabric ◽  
Cotton Fiber ◽  
Detergent Solution ◽  
Ag Nps ◽  
Antibacterial Performance ◽  
The Poor ◽  
Washing Durability ◽  
Textile Products

The popular use of silver nanoparticles (Ag NPs) in commercial textile products that inhibit odor- and/or infection-causing bacteria has continuously raised concerns about their washing durability. The poor durability not only deteriorates the antibacterial performance, but also results in unwanted leaching of NPs into washing solutions. In this study, we showed how the incorporation location of Ag NPs—interior vs. exterior of cotton fiber—governs their durability against consecutive simulated home launderings. The superior washing durability of interior NPs was confirmed. The Ag losses after 50 laundering cycles for interior and exterior systems were 16% and 63% in water and 24% and 78% in detergent solution, respectively. The cotton fabric containing interior NPs predominantly released ionic Ag, whereas the fabric containing exterior NPs released particulate Ag.

scholarly journals Molecular weight control in organochromium olefin polymerization catalysis by hemilabile ligand–metal interactions

2016 ◽  
Vol 12 ◽  
pp. 1372-1379 ◽  
Author(s):  
Stefan Mark ◽  
Hubert Wadepohl ◽  
Markus Enders
Keyword(s):  
Ethylene Polymerization ◽  
Weight Control ◽  
Transfer Reactions ◽  
High Catalytic Activity ◽  
Co Catalyst ◽  
Metal Centers ◽  
Molecular Weights ◽  
Metal Interactions ◽  
Polymerization Catalysis ◽  
Very High

A series of Cr(III) complexes based on quinoline-cyclopentadienyl ligands with additional hemilabile side arms were prepared and used as single-site catalyst precursors for ethylene polymerization. The additional donor functions interact with the metal centers only after activation with the co-catalyst. Evidence for this comes from DFT-calculations and from the differing behavior of the complexes in ethylene polymerization. All complexes investigated show very high catalytic activity and the additional side arm minimizes chain-transfer reactions, leading to increase of molecular weights of the resulting polymers.

Expression of bacterial Rubisco genes in Escherichia coli

1986 ◽  
Vol 313 (1162) ◽  
pp. 433-445 ◽  
Keyword(s):  
Escherichia Coli ◽  
Rhodospirillum Rubrum ◽  
Active Form ◽  
Amino Acid Residues ◽  
Structural Genes ◽  
Physico Chemical ◽  
Chemical Studies ◽  
The Individual ◽  
Very High

The structural genes for three forms of Rubisco have been isolated from bacteria and introduced into various plasmids. Apart from details of the sequences which have been obtained from these constructs, they are now being exploited for mutagenesis to determine the identity and specific function of the individual amino acid residues that compose the active site. These methods have been applied to a plasmid that contains the structural gene for the simplest form of Rubisco from Rhodospirillum rubrum to obtain mutant enzymes with altered activity. The construct pRR2119 is also expressed to very high levels in Escherichia coli and enough recombinant protein of both the wild-type and m utant enzymes can be obtained for detailed physico-chemical studies. Other vectors have now been constructed, containing the genes of prokaryotic Rubisco that assemble into an active form I enzyme. The levels of expression are acceptable and the product is similar to the authentic enzyme. These constructs are now being used for mutagenesis in vitro to attempt to alter the relative rates of the oxygenase and carboxylase activities.

Optical Modeling of Gold nanoparticles (Au NP) for efficiency improvement of a-Si:H photovoltaic cells

2014 ◽  
Vol 1671 ◽  
Author(s):  
Peiqing Yu ◽  
Jean-Philippe Blondeau ◽  
Caroline Andreazza ◽  
Esidor Ntsoenzok ◽  
Julien Roussel ◽  
...  
Keyword(s):  
Annealing Temperature ◽  
Surface Coverage ◽  
Thermal Evaporation ◽  
Active Material ◽  
Optical Path Length ◽  
Localized Surface Plasmon ◽  
Optical Modeling ◽  
Mean Size ◽  
Refractive Medium ◽  
Uv Visible

ABSTRACTThe efficiency of thin-film solar cells using a-Si:H is limited by the decrease in a-Si:H layer optical path length and its poor light absorption at red and NIR wavelengths. Metal NP such as Au have been shown to increase the absorption in the active material and then cell performances, by exhibiting localized surface plasmon (LSP) resonances. Our work’s goal is to understand NP influence in such cells, to perform an optimal structure by increasing the amount of light absorbed within the cell using NP scattering and luminescence. Modeling based on Mie theory is first carried out using bulk Palik data for Au spheres with various diameters and refractive medium indexes. Using modeling parameters, Au layers were deposited on glass and SnO2 substrates respectively by thermal evaporation in vacuum and sputtering, followed by thermal annealing (200 ∼ 500°C) in order to promote the NP growth. MEB pictures show quasispherical Au NP shape with a mean size of 150nm. This diameter range switches extinction of NP in scattering regime. Annealing temperature (T) strongly affects the NP morphology. Surface coverage decreases and sphericity appears to increase with T. UV-Visible spectroscopy displays distinct LSP resonances around 600nm after annealing with a red shift while T increases.

scholarly journals Silver-Nanoparticles Embedded Pyridine-Cholesterol Xerogels as Highly Efficient Catalysts for 4-nitrophenol Reduction

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1486
Author(s):  
Ganesh Shimoga ◽  
Eun-Jae Shin ◽  
Sang-Youn Kim
Keyword(s):  
Silver Nanoparticles ◽  
Trisodium Citrate ◽  
Environmentally Benign ◽  
X Ray Diffraction ◽  
Physico Chemical ◽  
Efficient Reduction ◽  
Nitrophenol Reduction ◽  
Uv Visible ◽  
Average Size

Two xerogels made of 4-pyridyl cholesterol (PC) and silver-nanocomposites (SNCs) thereof have been studied for their efficient reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) in the presence of aqueous sodium borohydride. Since in-situ silver doping will be effective in ethanol and acetone solvents with a PC gelator, two silver-loaded PC xerogels were prepared and successive SNCs were achieved by using an environmentally benign trisodium citrate dehydrate reducing agent. The formed PC xerogels and their SNCs were comprehensively investigated using different physico-chemical techniques, such as field emission scanning electron microscopy (FE-SEM), Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), powdered X-ray diffraction (XRD) and UV-Visible spectroscopy (UV-Vis). The FE-SEM results confirm that the shape of xerogel-covered silver nanoparticles (SNPs) are roughly spherical, with an average size in the range of 30–80 nm. Thermal degradation studies were analyzed via the sensitive graphical Broido’s method using a TGA technique. Both SNC-PC (SNC-PC-X1 and SNC-PC-X2) xerogels showed remarkable catalytic performances, with recyclable conversion efficiency of around 82% after the fourth consecutive run. The apparent rate constant (kapp) of SNC-PC-X1 and SNC-PC-X2 were found to be 6.120 × 10-3 sec-1 and 3.758 × 10-3 sec-1, respectively, at an ambient temperature.

scholarly journals Spectral Studies and Antibacterial Activity of Vanadium(III) Complexes of Heterocyclic Hydrazones

2020 ◽  
Vol 32 (5) ◽  
pp. 1059-1063
Author(s):  
D. Kasimbi ◽  
K. Hussain Reddy ◽  
N. Devanna
Keyword(s):  
Analytical Techniques ◽  
Spectral Studies ◽  
Bacterial Strains ◽  
Gram Positive ◽  
Tridentate Ligands ◽  
Structure Comparison ◽  
Gram Negative ◽  
E Coli ◽  
Physico Chemical ◽  
Uv Visible

Vanadium(III) complexes having the composition VLCl3 [where L = 2-acetylpyridine acetoylhydrazone (APAH), 2-acetylpyridine benzoylhydrazone (APBH), 2-acetylthiophene acetoylhydrazone (ATAH) and 2-acetylthiophene benzoylhydrazone (ATBH)] have been investigated using physico-chemical and analytical techniques. Molar conductivity data suggested that the complexes are neutral. Structures of all the vanadium(III) complexes are determined based on infrared and UV-visible spectral data. Electronic spectra of vanadium(III) complexes show three peaks suggesting octahedral structure. Comparison of vibrational spectra of hydrazones and complexes suggest that the hydrazones act as neutral tridentate ligands. The ligands and their vanadium derivatives are screened for their bacteria destroying activity against pathogenic bacterial strains viz. Gram-negative E. coli, Gram-positive Bacillus, Gram-positive Staphylococcus aureus and Gram-negative P. aureoginosa. Bacteria destroying activities of present complexes are comparable to the activity of the streptomycin. Complexes show more activity than their respective ligands in the case of Gram-positive Bacillus and Gram-negative P. aureoginosa.

Quantitation and Adsorption of Glyphosate Using Various Treated Clay

2017 ◽  
Vol 231 (11-12) ◽  
Author(s):  
Rodrigo Mattos ◽  
Sabir Khan ◽  
Sajjad Hussain ◽  
José de Alencar Simoni
Keyword(s):  
Low Cost ◽  
Chemical Characterization ◽  
Adsorption Capacities ◽  
Physico Chemical ◽  
As Adsorption ◽  
Uv Visible

AbstractThe objective of this work is to develop a low-cost, alternative UV-visible Spectrophotometer method using ninhydrin to the current chromatography techniques (GC and HPLC), which is usually use for the quantitation of glyphosate. The physico-chemical characterization, such as adsorption capacities, effect of time and temperature has been studied. The reaction between the ninhydrin and compounds that present NH

Natural mixture of silica and smectite as a new clayey material for industrial applications

Clay Minerals ◽  
2009 ◽  
Vol 44 (4) ◽  
pp. 525-537 ◽  
Author(s):  
U. Sohling ◽  
F. Ruf ◽  
K. Schurz ◽  
K. Emmerich ◽  
A. Steudel ◽  
...  
Keyword(s):  
Protein Separation ◽  
Amorphous Material ◽  
Chemical Properties ◽  
Industrial Applications ◽  
High Porosity ◽  
Clayey Material ◽  
Physico Chemical ◽  
Natural Mixture ◽  
Biodiesel Purification ◽  
Very High

AbstractThe main physico-chemical properties of a new smectitic clay containing large amounts of amorphous material are reviewed and potential industrial applications of this type of clay are discussed. Due to a 34% amorphous material content (natural silica gel), the investigated clay has very high porosity and can be used as it is or in acid-impregnated form for oil bleaching or phosphate reduction in edible oil. In the field of biodiesel purification, the new clay can be used to remove, in particular, mono-, diglycerides and glycerol. The natural silica-smectite mixture is also suitable as a carrier for liquid ingredients, for example in animal feeds, and might serve as a partial or complete substitute for synthetic precipitated silicas. In the field of bioseparation processes, the clay can be used as an adsorbent for protein separation by means of cation exchange. Due to the suppressed swelling (compared with smectite alone), it can be packed in columns which can be regenerated.

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