Oleksandr Trotsenko

• MS
• PhD Student at University of Georgia

Reactive spinning of nano- and microfibers that involves very fast chemical reactions and ion exchange is a challenge for the common methods for nanofiber formation. Herein, we introduce the reactive magnetospinning method. This procedure is based on the magnetic-field-directed collision of ferrofluid droplets with liquid droplets that contain comp...

Magnetic field imaging in living specimens with magnetic nanoparticles as contrasting agents has attracted significant interest in the rapidly developing field of nanomedicine. Developments in this field have also stimulated research into the synthesis and design of functionalized magnetic nanoparticles that find applications in broader areas of ma...

Superparamagnetic nanoparticles have a wide range of applications in materials science and biomedicine, because of their unique response and manipulability under magnetic fields. On page 3761, S. Minko and co-workers review the synthesis of functionalized magnetic nanoparticles, and discuss the various approaches for manipulation and assembly in un...

Optimizing Nafion loading and surface distribution of Nafion in the fuel cell electrode is critical for the fuel cell performance for minimizing ohmic and mass transport overpotentials. An atomic force microscopy method is used here for a qualitative and a quantitative discrimination between the ionomer and Pt in the fuel cell electrode. This work...

Reactive spinning of nano- and microfibers that involves very fast chemical reactions and ion exchange is a challenge for the common methods for nanofiber formation. Herein, we introduce the reactive magnetospinning method. This procedure is based on the magnetic-field-directed collision of ferrofluid droplets with liquid droplets that contain comp...

Reactive spinning of nano- and microfibers that involves very fast chemical reactions and ion exchange is a challenge for the common methods for nanofiber formation. Herein, we introduce the reactive magnetospinning method. This procedure is based on the magnetic-field-directed collision of ferrofluid droplets with liquid droplets that contain comp...

Robust, simple, and scalable touch- and brush-spinning methods for drawing of nanofibers, core-shell nanofibers, and their aligned 2D and 3D meshes using polymer solutions and melts are discussed.

A colloidal AFM-based method was used to understand the role of diallyldimethyl ammonium chloride (DADMAC) molecules in non-Prestonian silicon dioxide removal obtained using ceria-based slurries. A series of force-distance measurements between silicon dioxide films, polyurethane IC1000 polishing pad and ceria abrasives in liquid media with and with...

Nano and microfibers were prepared by spinning a colloidal dispersion of the stabilized magnetic nanoparticles, known as a ferrofluid, in an external magnetic field. During this process, the polymeric nano and microfibers with the average diameters of 0.05–20 µm were drawn in a magnetic field created by a permanent magnet. This technique provides a...

Reactive spinning of nano- and microfibers that involves very fast chemical reactions and ion exchange is a challenge for the common methods for nanofiber formation. Herein, we introduce the reactive magnetospinning method. This procedure is based on the magnetic-field-directed collision of ferrofluid droplets with liquid droplets that contain comp...

Magnetic field assisted assembly is used to fabricate aligned single nanowire mesh-like nanostructured films. Inhomogeneous magnetic field is applied to translocate high aspect ratio silver nanowires from suspensions to the surface of solid supports. The tangential component of the magnetic field vector is rotated in two consecutive steps to arrang...

A method for the generation of remotely reconfigurable anisotropic coatings is developed. To form these coatings, locking magnetic nanoparticles (LMNPs) made of a superparamagnetic core and a two-component polymer shell are employed. Two different polymers form phase-separated coaxial shells. The outer shell provides repulsive interactions between...

Optimized conditions for imaging and spectroscopic/elemental mapping of thin perfluorosulfonic acid (PFSA) ionomer layers in fuel cell electrodes by scanning transmission electron microscopy (STEM) have been investigated. The proper conditions were first identified using model systems of either Nation ionomer-coated nanostructured thin film catalys...

The enzymogel nanoparticle made of a magnetic core and polymer brush shell demonstrates a novel type of remote controlled phase-boundary biocatalysis that involves remotely directed binding to and engulfing insoluble substrates, high mobility, and stability of the catalytic centers. The mobile enzymes reside in the polymer brush scaffold and shuttl...

Chemical cross-linking was used to prepare DNA nanostructures with enhanced thermal stability. These thermostable DNA nanostructures were then utilized as modular primers in polymerase chain reaction (PCR; see picture), thus enabling the production of multifunctionalized and branched PCR products for multiplexed detection and hydrogel formation.

Conformations of cationic polyelectrolytes (PEs), a weak poly(2-vinylpyridine) (P2VP) and a strong poly(N-methyl-2-vinylpyridinium iodide) (qP2VP), adsorbed on mica from saline solutions in the presence of counterions of different valences are studied using in situ atomic force microscopy (AFM). Quantitative characteristics of chain conformations a...

This work provides direct experimental verification (on the level of single molecules) for the behavior of hydrophobic polyelectrolyte chains adsorbed at a solid-liquid interface in the full range of possible salt concentrations: (a) in a dilute salt solution, PE chains possess an extended coil conformation visualized as adsorbed 2D-equilibrated co...

In this article, we compare structures of protonated poly(2-vinylpyridine) globules (2D compact coils on the surface) adsorbed on the mica surface from aqueous solution when the shrinking is brought about either by discharging the molecules at an elevated pH or by adding monovalent and polyvalent salts. We study the structure of the PE coils using...

The poly(4-vinyl pyridine) (P4VP)-brush-modified indium tin oxide (ITO) electrode was used to switch reversibly the interfacial activity by the electrochemical signal. The application of an external potential (-0.85 V vs Ag|AgCl|KCl, 3M) that electrochemically reduced O(2) resulted in the concomitant consumption of hydrogen ions at the electrode in...