scholarly journals Thiol-Affinity Immobilization of Casein-Coated Silver Nanoparticles on Polymeric Membranes for Biofouling Control

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2057 ◽  
Author(s):  
Xiaobo Dong ◽  
Halle D. Shannon ◽  
Atena Amirsoleimani ◽  
Gail M. Brion ◽  
Isabel C. Escobar
Keyword(s):  
Silver Nanoparticles ◽  
Serratia Marcescens ◽  
Antimicrobial Properties ◽  
Thiol Group ◽  
Polymeric Membranes ◽  
Step Method ◽  
Crossflow Filtration ◽  
Dead End ◽  
Affinity Immobilization ◽  
One Step

Silver nanoparticles (AgNPs) have been widely studied for the control of biofouling on polymeric membranes due to their antimicrobial properties. However, nanoparticle leaching has posed a significant impediment against their widespread use. In this study, a one-step method of chemically embedding AgNPs on cellulose acetate (CA) membranes via their affinity to thiol group chemistry was investigated. The operational efficiency of the membranes was then determined via filtration and biofouling experiments. During filtration study, the average flux values of pure CA membranes was determined to be 11 ± 2 L/(m2·hr) (LMH), while membranes embedded with AgNPs showed significant increases in flux to 18 ± 2 LMH and 25 ± 9 LMH, with increasing amounts of AgNPs added, which is likely due to the NPs acting as pore formers. Leaching studies, performed both in dead-end and crossflow filtration, showed approximately 0.16 mg/L leaching of AgNPs after the first day of filtration, but afterwards the remaining chemically-attached AgNPs did not leach. Over 97% of AgNPs remained on the membranes after seven days of crossflow leaching filtration studies. Serratia marcescens were then used as target microorganisms in biofouling studies. It was observed that membranes embedded with AgNPs effectively suppressed the growth of Serratia marcescens, and specifically, membranes with AgNPs displayed a decrease in microbial growth by 59% and 99% as the amount of AgNP increased.

scholarly journals Simple One-Step Method to Synthesize Polypyrrole-Indigo Carmine-Silver Nanocomposite

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Lara Fernandes Loguercio ◽  
Pedro Demingos ◽  
Luiza de Mattos Manica ◽  
Jordana Borges Griep ◽  
Marcos José Leite Santos ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Infrared Spectroscopy ◽  
Near Infrared ◽  
Indigo Carmine ◽  
Electrochemical Process ◽  
Conjugation Length ◽  
Step Method ◽  
Polypyrrole Films ◽  
One Step ◽  
Silver Nanocomposite

A nanocomposite of indigo carmine doped polypyrrole/silver nanoparticles was obtained by a one-step electrochemical process. The nanocomposite was characterized by scanning electron microscopy, infrared spectroscopy, ultraviolet-visible-near infrared spectroscopy, and cyclic voltammetry. The simple one-step process allowed the growth of silver nanoparticles during the polymerization of polypyrrole, resulting in films with electrochromic behavior and improved electroactivity. In addition, polypyrrole chains in the nanocomposite were found to present longer conjugation length than pristine polypyrrole films.

Antimicrobial Activity of TiO2 Coatings Prepared by Direct Thermophoretic Deposition of Flame-Synthesized Nanoparticles

MRS Advances ◽  
2016 ◽  
Vol 2 (28) ◽  
pp. 1493-1498 ◽  
Author(s):  
Gianluigi De Falco ◽  
Amalia Porta ◽  
Pasquale Del Gaudio ◽  
Mario Commodo ◽  
Patrizia Minutolo ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Protective Coatings ◽  
Colorimetric Assay ◽  
Antimicrobial Properties ◽  
Titania Nanoparticles ◽  
Rotating Disc ◽  
Step Method ◽  
One Step ◽  
Anatase Nanoparticles

ABSTRACTThis study reports the development of a one-step method for the production of antimicrobial protective coatings for aluminum surfaces with titania nanoparticles. An aerosol flame synthesis system was used to produce monodisperse, ultra-fine TiO2 nanoparticles, which were directly deposited by thermophoresis onto plates of aluminum alloy by means of a rotating disc. Fuel-lean reactor conditions were used to synthesize pure anatase nanoparticles of 3.5 nm in diameter. Substrates were mounted onto the rotating disc that repetitively passes through the flame. Convection due to the rotational motion cooled the substrates, on which particles were deposited as films by thermophoresis. Such a system allowed to obtain submicron coatings of different thickness, by varying the total time of deposition. The antimicrobial activity of TiO2 coatings was tested against the Gram positive bacterium Staphylococcus aureus. To determine the inhibition of biofilms formation, microbes were plated on TiO2 coatings and a semi-quantitative colorimetric assay was performed using crystal violet. The tests showed that the TiO2 coating obtained with tdes=10 s inhibits up to 70-80% Staphylococcus aureus biofilm formation, and the inhibition of biofilms formation was confirmed by means of Scanning Electron Microscopy observation. Also, the antimicrobial properties of the coatings was enhanced by irradiating the samples in the UV region. The results of the present work are promising for using titania films as protective coatings for applications where an antimicrobial activity is required.

Modification of Waste Leather Trimming with in Situ Generated Silver Nanoparticles by One Step Method

2021 ◽  
Vol 14 (2) ◽  
Author(s):  
Basa Ashok ◽  
Mallavarapu Umamahesh ◽  
Natarajan Hariram ◽  
Suchart Siengchin ◽  
Anumakonda Varada Rajulu
Keyword(s):  
Silver Nanoparticles ◽  
Silver Oxide ◽  
Low Cost ◽  
Step Method ◽  
Mean Size ◽  
One Step ◽  
Silver Oxide Nanoparticles ◽  
Inhibition Zones ◽  
Xrd Studies

Waste leather trimming (WLT) was modified by in situ generation of silver nanoparticles (AgNPs) and silver oxide nanoparticles (Ag2ONPs) by one step thermal assisted method. The modified WLT was analyzed by FTIR, SEM, EDS, XRD and TGA techniques and antibacterial analysis. The generated silver based nanoparticles had a mean size of 93 nm. The FTIR spectra revealed no major changes between WLT and modified WLT. The XRD studies indicated additional peaks in the diffractogram of modified WLT which belonged to AgNPs and Ag2ONPs. The unmodified WLT had four inflection temperatures at 89, 303, 454, and 785°C while these values for the modified WLT were 84, 211, 305, and 328°C indicating a slight lowering of thermal stability due to the catalytic activity of the generated silver based nanoparticles. Further, the modified WLT formed the inhibition zones against E.coli, P.aeruinosa, S.aeureus and B.lichinomonas bacteria with diameters of 33, 36, 29, and 30 mm respectively. Hence, the modified WLT can be considered as filler for making low cost antibacterial biocomposites.

scholarly journals Gamma Radiation Synthesis of Silver Nanoparticles/Chitosan composites with antimicrobial properties

2021 ◽  
Vol 57 (4) ◽  
pp. 88-95
Author(s):  
Eduard-Marius Lungulescu ◽  
Radu Setnescu ◽  
Nicoleta-Oana Nicula ◽  
Ioana Ion ◽  
Virgil Marinescu
Keyword(s):  
Silver Nanoparticles ◽  
High Stability ◽  
Antibacterial Properties ◽  
Antimicrobial Properties ◽  
Spherical Shape ◽  
Silver Ions ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
One Step ◽  
Radiochemical Synthesis

Composites of Silver nanoparticles/chitosan were obtained in aqueous solution, in-one step and eco-friendly synthesis, under ambiental conditions, using gamma irradiation. The radiochemical synthesis enabled obtaining of controlled size, monodisperse and high stability Silver nanoparticles. The obtained composites presented UV-Vis surface plasmon resonance comprised between 406-414 nm, depending on composition of the reactant system, spherical shape and narrow particle size distributions, with mean dimensions between 3-55 nm, and good antibacterial properties proven against Staphylococcus aureus and Escherichia coli. The influence of the Silver ions/chitosan ratio and of the pH of the initial solution on the final Ag Np properties is also discussed.

Effect of Dynamic Crosslinking on Mechanical Properties of PP/EPDM Blends

1993 ◽  
Vol 58 (11) ◽  
pp. 2642-2650 ◽  
Author(s):  
Zdeněk Kruliš ◽  
Ivan Fortelný ◽  
Josef Kovář
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Shear Modulus ◽  
High Impact ◽  
Necessary Condition ◽  
Step Method ◽  
Melt Mixing ◽  
One Step ◽  
High Impact Strength ◽  
Dynamic Curing

The effect of dynamic curing of PP/EPDM blends with sulfur and thiuram disulfide systems on their mechanical properties was studied. The results were interpreted using the knowledge of the formation of phase structure in the blends during their melt mixing. It was shown, that a sufficiently slow curing reaction is necessary if a high impact strength is to be obtained. Only in such case, a fine and homogeneous dispersion of elastomer can be formed, which is the necessary condition for high impact strength of the blend. Using an inhibitor of curing in the system and a one-step method of dynamic curing leads to an increase in impact strength of blends. From the comparison of shear modulus and impact strength values, it follows that, at the stiffness, the dynamically cured blends have higher impact strength than the uncured ones.

Bismuth particles imbedded degradable nanohydrogel prepared by one-step method for tumor dual-mode imaging and chemo-photothermal combined therapy

2019 ◽  
Vol 375 ◽  
pp. 122000 ◽  
Author(s):  
Yang Xuan ◽  
Xian-Lin Song ◽  
Xiao-Quan Yang ◽  
Ruo-Yun Zhang ◽  
Zi-Yu Song ◽  
...  
Keyword(s):  
Combined Therapy ◽  
Dual Mode ◽  
Step Method ◽  
One Step

scholarly journals Bio-Based Polyurethane Networks Derived from Liquefied Sawdust

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3138
Author(s):  
Kamila Gosz ◽  
Agnieszka Tercjak ◽  
Adam Olszewski ◽  
Józef Haponiuk ◽  
Łukasz Piszczyk
Keyword(s):  
Biomass Conversion ◽  
Structural Features ◽  
Mechanical Analysis ◽  
Process Efficiency ◽  
Hydroxyl Number ◽  
Step Method ◽  
One Step ◽  
Liquefaction Process ◽  
The Fourier Transform ◽  
Liquefaction Temperature

The utilization of forestry waste resources in the production of polyurethane resins is a promising green alternative to the use of unsustainable resources. Liquefaction of wood-based biomass gives polyols with properties depending on the reagents used. In this article, the liquefaction of forestry wastes, including sawdust, in solvents such as glycerol and polyethylene glycol was investigated. The liquefaction process was carried out at temperatures of 120, 150, and 170 °C. The resulting bio-polyols were analyzed for process efficiency, hydroxyl number, water content, viscosity, and structural features using the Fourier transform infrared spectroscopy (FTIR). The optimum liquefaction temperature was 150 °C and the time of 6 h. Comprehensive analysis of polyol properties shows high biomass conversion and hydroxyl number in the range of 238–815 mg KOH/g. This may indicate that bio-polyols may be used as a potential substitute for petrochemical polyols. During polyurethane synthesis, materials with more than 80 wt% of bio-polyol were obtained. The materials were obtained by a one-step method by hot-pressing for 15 min at 100 °C and a pressure of 5 MPa with an NCO:OH ratio of 1:1 and 1.2:1. Dynamical-mechanical analysis (DMA) showed a high modulus of elasticity in the range of 62–839 MPa which depends on the reaction conditions.

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