Investigating the link between a layer thickness and surface relief depth in an azo poly(ether imide).

Surface relief grating formation in photo-responsive azo polymers under irradiation is a long-ago-found phenomenon, but all the factors governing its efficiency are still not fully recognized. Here, we report on the enormous impact of the polymer thickness on the possibility of fabrication of extremely high-amplitude surface deformations. We performed prolonged holographic recordings on the layers of the same azobenzene poly(ether imide), which had substantially different optical transmittances at the recording wavelength and revealed that the depths of the inscribed relief structures increased with the polymer thickness from a nondetectable value up to almost 2 µm, unaffected by the presence of a polymer-glass substrate interface in either sample.

A New Approach for Sensitive Characterization of Semiconductor Laser Beams Using Metal-Semiconductor Thermocouples.

This paper presents the results of beam investigations on semiconductor IR lasers using novel detectors based on thermocouples. The work covers the design, the fabrication of detectors, and the experimental validation of their sensitivity to IR radiation. The principle of operation of the manufactured detectors is based on the Seebeck effect (the temperature difference between hot and cold junctions induced voltage appearance).

Surface Relief Modulated Grating in Azo Polymer-From the Tailoring of Diffraction Order to Reshaping of a Laser Beam.

Among light-responsive materials for photonics, azo polymers occupy an important position due to their optical response and the related concepts of consecutive applications. However, scientific insight is still needed to understand the effects of irradiation on the modification of the azo polymer structure and the effect of this modification on incoming probing light. In this work, we report on a surface relief grating with a maximum depth of a record-high value of 1.

Sensitive Metal-Semiconductor Nanothermocouple Fabricated by FIB to Investigate Laser Beams with Nanometer Spatial Resolution.

The focused ion beam (FIB) technique was used to fabricate a nanothermocouple (with a 90 nm wide nanojunction) based on a metal-semiconductor (Pt-Si) structure, which showed a sensitivity up to 10 times larger (with Seebeck coefficient up to 140 µV/K) than typical metal-metal nanothermocouples. In contrast to the fabrication of nanothermocouples which requires a high-tech semiconductor manufacturing line with sophisticated fabrication techniques, environment, and advanced equipment, FIB systems are available in many research laboratories without the need for a high-tech environment, and the described processing is performed relatively quickly by a single operator. The linear response of the manufactured nanothermocouple enabled sensitive measurements even with small changes of temperature when heated with a stream of hot air.

Active calibration reference of minimized height for characterization of scanning thermal microscopy systems.

In this paper we describe the design, technology and application of a test and reference sample for calibration and characterization of scanning thermal microscopy (SThM) probes and systems. In our solution temperature field in thin film structure, which is being contacted with the thermal tip is controlled in the traceable manner. The developed technology, integrating plasma etching of Pt and chemical-mechanical planarization (CMP) processing, enabled manufacturing a nanosize 100 nm thick Pt resistor on SiO with topography profile below 10 nm.

Physico-Chemical and Light-Induced Properties of Quinoline Azo-dyes Polymers.

We present investigation of optical and photochromic properties as well as of surface quality of thin films of novel methacrylic polymers with 8-hydroxyquinoline azo-dyes in side-chain. Additionally, thermal stability of polymer powders was examined and their glass transition temperature was determined. Optical properties (extinction coefficient and refractive index) were determined by spectroscopic ellipsometry (SE) combined with absorbance measurements.

Mechanical and Physicochemical Properties of Newly Formed ZnO-PMMA Nanocomposites for Denture Bases.

Aim: The aim of this study was to investigate the selected properties of zinc oxide- polymethyl methacrylate (ZnO-PMMA) nanocomposites that can influence the microorganism deposition on their surface.

Materials And Methods: Non-commercial ZnO-NPs were prepared, characterized and used for the preparation of PMMA nanocomposite. Roughness, absorbability, contact angle and hardness of this new nanomaterial were evaluated.

Preparation and characterization of ZnO-PMMA resin nanocomposites for denture bases.

Purpose: The aim of the paper was to investigate the antifungal activity of zinc oxide nanoparticles (ZnONPs) against Candida albicans. Some attempts have been made to find out the best way to introduce ZnONPs into polymethyl methacrylate (PMMA) resin material and to determine some parameters of a newly formed composite.

Material And Methods: Zinc oxide nanoparticles were manufactured and their basic physical parameters were determined (average particle size, density, specific surface area).

Oxygen plasma surface modification augments poly(L-lactide-co-glycolide) cytocompatibility toward osteoblasts and minimizes immune activation of macrophages.

Here, we report on modification of one of the model biomedical polymers, poly L-lactide-co-glycolide (PLGA; 85:15), by reactive ion etching (RIE) oxygen plasma treatment. PLGA's major disadvantage is high hydrophobicity which restrains binding of cell-adhesive proteins and host cells. In the current approach, we aimed to answer two questions: (1) will only short (10 s) and moderate (20-200 mTorr, 45-90 W) RIE oxygen plasma treatment, leading to decrease of water contact angle by only up to 10°, sufficiently improve PLGA adherence to cells, and (2) how will this affect osteoblasts and activation of the immune system? All obtained modified PLGAs had improved hydrophilicity but unaltered roughness (as revealed by water contact angle measurements, X-ray photoelectron spectroscopy, and atomic force microscopy) resulting in significantly improved adhesion of osteoblasts (MG-63) and their low activation.