Comparative Study on Structural Differences in Monosaccharide Layers Using PLD and PED Techniques.

To demonstrate the feasibility of obtaining low-molecular-weight organic films (below 200 Da) using non-solvent PVD processes, glucose layers were produced via pulsed laser deposition (PLD) and pulsed electron beam deposition (PED) methods. Glucose was chosen due to its fundamental role in various biological processes, and because this low-molecular-weight compound is a solid at room temperature, which is required for both techniques. The physical and chemical structures of the deposited glucose layers were characterized by optical, scanning electron, and atomic force microscopy, as well as by X-ray diffraction, X-ray photoelectron, and infrared spectroscopy.

Rubber-like PTFE Thin Coatings Deposited by Pulsed Electron Beam Deposition (PED) Method.

PTFE coatings were manufactured using the pulsed electron beam deposition (PED) technique and deposited on Si substrates. The deposition was carried out at constant parameters: temperature 24 °C, discharge voltages 12 kV, and 5000 electron pulses with a pulse frequency of 5 Hz. Nitrogen was used as the background gas.

Influence of Chemical Composition on Structure and Mechanical Properties of Vacuum-Carburized Low-Alloy Steels.

This study presents research results concerning the vacuum carburizing of four steel grades, specifically conforming to European standards 1.7243, 1.6587, 1.

Towards Understanding the Chemical Structure Modification of EVA Copolymer upon MAPLE Processing of Thin Films.

A series of coatings from poly(ethylene--vinyl acetate) (EVA) were obtained using the matrix-assisted pulsed laser evaporation (MAPLE) technique. By changing the process parameters, i.e.

Laser Direct Writing via Two-Photon Polymerization of 3D Hierarchical Structures with Cells-Antiadhesive Properties.

We report the design and fabrication by laser direct writing via two photons polymerization of innovative hierarchical structures with cell-repellency capability. The structures were designed in the shape of "mushrooms", consisting of an underside (mushroom's leg) acting as a support structure and a top side (mushroom's hat) decorated with micro- and nanostructures. A ripple-like pattern was created on top of the mushrooms, over length scales ranging from several µm (microstructured mushroom-like pillars, MMP) to tens of nm (nanostructured mushroom-like pillars, NMP).

Hierarchical multi-layered scaffolds based on electrofluidodynamic processes for tissue engineering.

The aim of this study was to obtain hierarchical scaffolds combining 3D printing and two electrofluidodynamic methods. The multi-layered scaffold is composed by 3D printed struts, electrospun fibers obtained from poly(-caprolactone) and electrosprayed spheres produced from hydrophobically modified chitosan, namely chitosan grafted with linoleic acid (CHLA). Since CHLA has been used for the first time in the electrospraying (electro dynamic spraying, EDS) process, the formation of spheres needed an optimization process.

Antibacterial Activity of ,-Acylated Chitosan Derivative.

The antibacterial activity of ,-acylated chitosan derivative with linoleic acid (CH_LA) was tested by disc and well diffusion, agar impregnation and microdilution methods against , and strains. Hydrophobically modified chitosan (HMC) was expected to exhibit enhanced antibacterial activity and specific mucin interactions. Although diffusion tests have not indicated the antibacterial potential of chitosan (CH) or CH_LA, the results of the microdilution method demonstrated that tested polymers significantly reduced the amount of living bacteria cells in different concentrations depending on the microorganism.

XPS and FTIR Studies of Polytetrafluoroethylene Thin Films Obtained by Physical Methods.

Two methods-attenuated total reflection Fourier infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS)-have been used to analyze the chemical structure of polytetrafluorethylene (PTFE) thin coatings deposited by pulsed laser (PLD) and pulsed electron beam (PED) ablations. The volume of the analyzed materials is significantly different in these techniques which can be of great importance in the characterization of highly heterogeneous thin films. Optical microscopy, atomic force microscopy (AFM) and scanning electron microscopy (SEM) have been additionally used to examine the coating surface morphology.

Biofunctional catheter coatings based on chitosan-fatty acids derivatives.

Multifunctional and biofunctional coatings for medical devices are an attractive strategy towards tailoring the interactions of the device with the body, thereby influencing the host response, and the susceptibility to microbial colonization. Here we describe the development of a coating process to yield amphiphilic, lubricious coatings, resistant to bacterial colonization, based on chitosan. Chitosan-fatty acid derivatives were obtained by simultaneous N,O-acylation of chitosan with either linoleic, α-linolenic, or dilinoleic acid.

Chemical Structure of EVA Films Obtained by Pulsed Electron Beam and Pulse Laser Ablation.

Poly(ethylene--vinyl acetate) (EVA) films were deposited for the first time using physical methods. The chemical structure of the films obtained using two techniques, pulsed electron beam deposition (PED) and pulsed laser deposition (PLD), was studied by attenuated total reflection Fourier infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS). Whilst significant molecular degradation of the EVA films was observed for the PLD method, the original macromolecular structure was only partially degraded when the PED technique was used, emphasizing the superiority of the PED method over PLD for structurally complex polymers such as EVA.

The Importance of Reaction Conditions on the Chemical Structure of ,-Acylated Chitosan Derivatives.

The structure of acylated chitosan derivatives strongly determines the properties of obtained products, influencing their hydrodynamic properties and thereby their solubility or self-assembly susceptibility. In the present work, the significance of slight changes in acylation conditions on the structure and properties of the products is discussed. A series of chitosan-acylated derivatives was synthesized by varying reaction conditions in a two-step process.

Modification of bacterial cellulose through exposure to the rotating magnetic field.

The aim of the study was to assess the influence of rotating magnetic field (RMF) on production rate and quality parameters of bacterial cellulose synthetized by Glucanacetobacter xylinus. Bacterial cultures were exposed to RMF (frequency f=50Hz, magnetic induction B=34mT) for 72h at 28°C. The study revealed that cellulose obtained under RMF influence displayed higher water absorption, lower density and less interassociated microfibrils comparing to unexposed control.