Papers by Keyword: AgNP

Abstract: This research project produced two fabricated ultrafine conductive polymeric fibers. The first fiber was fabricated from a polymer and conductive polymer solution, and the second was fabricated from a polymer and metal nanoparticle/ nanocomposite. The resulting fibers were characterized and analyzed. For all fiber samples, the ultrafine polymeric fibers were fabricated using polyvinyl alcohol (PVA). The conductive polymer used in the first fiber sample was poly (3,4-ethylenedioxythiophene)/ polystyrene sulfonate (PEDOT/PSS). The conductive nanoparticles used in the second fiber sample were silver nanoparticles (AgNPs). The ultrafine conductive polymer fibers and the ultrafine conductive nanoparticle fibers were fabricated using an electrospining process. During the fabrication process of each fiber sample, different concentrations of either PEDOT/PSS, for fiber sample one, or AgNPs, for fiber sample two, were combined in PVA solution. Using optimal conditions, ultrafine fibers were fabricated at intervals of 5 min for the creation of random fibers, and intervals of 20 min for the creation of aligned fiber mats. The resulting fibers ranged from 0.1 μm to 0.2 μm in diameter. After characterization and analysis of the conductive ultrafine polymeric fibers, using either the PVA:PEDOT/PSS compound or the PVA:AgNPs compound, both samples produced greater conductive capacities with greater concentrations of solution. For the random fiber samples, the conductive capacity was sporadic. However, the ultrafine fiber mats (PVA:AgNPs) supported a capacity from 3.64 S/cm to 10.64 S/cm, and the PVA:PEDOT/PSS ultrafine fiber mats supported a capacity from 4.49 S/cm to 7.08 S/cm.

Abstract: Poly (vinyl alcohol)-silver nanoparticles (PVA:AgNPs), and poly (vinyl alcohol)-silver nanoparticles-poly (3, 4-ethylene dioxythiophene)/poly (styrene sulfonate) (PVA:AgNPs: PEDOT/ PSS) were generated as ultra-fine electrospun fibers using the aligned fiber mat and aligned single fiber techniques. SEM and TEM were used to confirm the morphology, diameter size, and fiber alignment of the ultra-fine fibers. A two-probe technique was utilized to assess the electrical conductivity of the ultrafine fibers. The highest conductivity of PVA:AgNPs, (10 %w/v:0.75 %w/v) with a fiber diameter of 0.152 μm, with voltage applied at 17.5 kV within a 20 min collection period in the electrospinning process, was 43.20 S/cm; whereas the highest conductivity of PVA:AgNPs: PEDOT/PSS, (10 %w/v:0.25 %w/v:0.084 %w/v), with a fiber diameter of 0.158 μm and voltage applied at 17.5 kV within a 45 min collection period in the electrospinning process, was 92.18 S/cm.

Abstract: Controlling the size of nanomaterials are attracting great interest in the research on scientific and technological applications because of their unit properties for achieving specific processes especially in biological and medical applications. Microbial assisted biosynthesis of nanoparticles is of growing potential in the area of bionanotechnology compared to chemical synthesis when dealing with medical and pharmaceutical applications. A simple and effective approach for AgNPs synthesis by Pycnoporus sanguineus was demonstrated and the effect of production mode on controlling size of AgNPs produced was studied. Culture supernatant of Pycnoporus sanguineus was used to synthesis AgNPs of nanosize. One factor at a time (OFAT) method was employed to perform optimization on process parameter such as inoculum size and AgNO₃ concentration. The morphology, uniformity and concentration of AgNPs were investigated using dynamic light scattering (DLS) zetasizer and atomic absorption spectroscopy. It was observed that increase in inoculum size leads to decrease in size of AgNPs and increase of AgNPs concentration. Hence, it can be deduced that optimizing the bioprocess parameters led to superior control of AgNPs size.

Abstract: An Ag nanoparticle included Glassy carbon (GC)/poly [3, 4-ethylenedioxythiophene] (PEDOT) modified electrode was organized by a straightforward electrochemical method without using any stabilizer or reducing agent. The obtained working electrodes showed a high conductivity when compared to the bare electrode. It also shows superior ability of electrochemically sensing towards the electroreduction of H2O2 with no need for an enzyme or mediator immobilized in the electrode. Under optimum condition the detection limit using chronoamperometry response was estimated to be 0.61 M based on the criterion of signal-to-noise ratio of 3 (S/N of 3).