POSTER SESSION B

Nanofibers represent an emerging material for filtration. They can be fabricated and collected randomly and transformed into a membrane or fibrous textile. Flexible nanofibers production technologies allowing to process variety of polymeric raw materials with many process parameters in cost effective manner are needed for the filter manufacturing. Nanofibrous membranes enable separation of bacteria, particles and also molecular filtration of risk compounds. Polyhydroxyalkanoates (PHA), namely polyhydroxybutyrate is microbial polymer produced biotechnologically by some bacteria. This polymer is very suitable for water filtration because of its hydrophobic character, water insolubility and full biodegradability. This work is focused on preparation and testing of modified PHA-based filters for water filtration and decontamination. Fibers were prepared by electrospinning and spin-coating techniques. PHA fibrous material was tested as high-volume microfibrous and nanofibrous filter membrane. Several bacterial strains were filtered in model conditions and separation capacity of PHA membranes was evaluated. It can be summarized that PHA-based polymers are quite suitable for removing of both gramnegative and grampositive strains as well as yeasts. Further advantage of PHA based material is that after use the filter with separated microbial cells and other impurities can be composting. Under composting conditions the fibrous material can be fully biodegraded during several days or weeks.
ACKNOWLEDGEMENTS:
This work was supported by project “Materials Research Centre – Sustainability and Development” No. LO1211 (Ministry of Education, Youth and Sport of the Czech Republic).

An agricultural soil in region of Czech Republic and Austria is continuously losing its natural ability to retain water in its structure. Most of the water which comes from rains just goes through the soil into the groundwater and agricultural lands suffer by the lack of humidity. One of the reasons of this strange soil behaviour is caused by decreasing amount of soil organic matter. Solution of this problem can be found in application of superabsorbent polymers enriched by addition of active substance based on humic acids. This system of controlled released preparation is able to retain more water in the ground together with a sustainable supply of humic acids which are important part of organic soil matter. Rheological properties of superabsorbent polymers samples enriched by humic acids were determined to prove if they are able to resist certain mechanical mechanical stress which they will have to hold out after the agricultural application.

Carbon nanotubes (CNTs) are in recognition of scientific community for almost 25 years. They are known for their unique physicochemical and electronic properties. During these years, methods of their production and characterization vastly improved and many new applications were developed in almost every aspect of our daily lives.
This work is focused on verification of the possibility to use sorbents based on nanocarbon to remove drug residues from wastewater, specifically sorbents based on multiwalled CNTs. In this work, commercially available carbon nanotubes Nanocyl 7000 (NC7000) in its original raw and oxidized form have been used. Surface of the pristine CNTs is strictly hydrophobic and due to this fact a surface modification (by oxidation using NaOCl) was made. The surface became more polar and more suitable for interactions with ibuprofen and diclofenac, which have polar functional groups in their structure. Sorption properties of both materials for ibuprofen and diclofenac was observed and evaluated in model aqueous solutions. The materials were characterized by SEM, FTIR, XRD methods to study changes in surface structures. The results obtained showed that carbon nanotubes are suitable adsorbents for drug removal with high efficiency, the modified ones were better than pristine.
ACKNOWLEDGEMENTS:
This work was funded by the MSMT project SP2015/55 and the European Regional Development. Fund in the IT4Innovations Centre of Excellence (CZ.1.05/1.1.00/02.0070).

In the presented work, new composite nanomaterials, based on graphene oxide and styrene, have been developed for the retention purpose. Sr-85 and Cs-137 represent two of the main fission products being present in radioactive wastes from nuclear power cycle.
The graphene oxide samples were prepared, using natural graphite using high intensity cavitation field in a pressurized (6 bar) batch-ultrasonic reactor. Graphene oxide polystyrene composite was synthesized using direct emulsion polymerization of styrene in the presence of graphene oxide at 90 °C.
The basic method used for the evaluation of nanomaterial retention properties was batch sorption methodology, based on contact of solid material with tracer solution under defined boundary conditions (solid/solution ratio, time, solution composition as pH and ionic strength).
ACKNOWLEDGEMENTS:
We thank for the support from Ministry of the Interior of the Czech Republic (Project No. VG20132015132).

Membrane biofouling limits widespread using of membrane technology in different fields. Several ways how to restrict this negative effect and achieve improving in long-term membrane filtration performances have been tested so far. Membrane modification by silver in the nanometre size-range can be a promising option for achieving high and long-term membrane permeabilities as well as antimicrobial features.
Commercially available ultrafiltration membrane NADIR® UP 150 (commonly used for wastewater treatment) was modified by nanosilver. Modification methods were based on i) diffusion of silver together with its subsequent reduction, and ii) silver-doped nanofibers. Changes in permeabilities, antimicrobial properties, silver leaching and contact angles of modified membranes were examined.
While the membrane modified by diffusion method revealed higher permeabilities with demineralized water as well as diluted activated sludge, membrane modified through silver-doped nanofibers showed lower permeabilities, when comparing to unmodified one. The results of filtration tests well corresponded with contact angles which showed higher hydrophilic character of membranes modified through diffusion method. Both modified membranes also exhibited strong antimicrobial features and low silver leaching over time.

A template-free solid-state synthesis of morphologically controlled and highly organized iron(III) oxide micro-mesoporous Fenton catalysts is demonstrated. The flower-like 3D nanoassembly of hematite nanoparticles (5-7 nm) exhibits the highest rate constant reported to date for the decomposition of H2O2 (1.43 × 10-1 min–1) with superior efficiency for degradation of aromatic (phenol, benzene, ethylbenzene) and chlorinated (trichloroethylene) pollutants in contaminated water. The morphological arrangement of nanoparticles apparently represents the key variable in heterogeneous Fenton-type catalysis.

This paper deals with testing of a nanofibrous filter by submicron monodisperse polystyrene particles of several sizes. The nanofibrous filtration textiles are non-woven materials and they are made by the electro-spinning technology. They are composed of individual fibers which occur in an unorganized way. This structure is not uniform as a sieve, but it includes places with higher and lower fiber density. In this article, the filtration efficiency is measured on the basis of a visualization of filtration process. A laser sheet is aimed to the place where a filter mounted is. A digital camera records the flow in the laser sheet and by an image analysis the local filtration efficiency is calculated. The experiments were carried out on the water filtration setup including a filtration chamber with an optical access. The bubble point test is used for a determination of maximum, medium and minimum pore size of a filtration textile. The information about pores is compared to the local filtration efficiency of a nanofibrous textile tested by submicron monodisperse particles.

According to the unique method, SiO2-Cd2SiO4@CdS composite was modified by Co2+ and Ni2+ ions. Properties, composition and structure of the composite obtained were investigated. Photocatalytic properties of the materials obtained were studied during the decomposition of Nile Blue in aqueous solution under visible light irradiation (> 390 nm). It is shown that the doped samples exhibit better photocatalytic activity than non-doped (an increase in degradation rate of 15%). At the same time the composite shows good resistance to photocorrosion that is distinctive for SiO2-Cd2SiO4@CdS system.
ACKNOWLEDGEMENTS:
This study was supported by the State Assignment # 2014/223 of the Ministry of Education and Science of the Russian Federation (Project # 1766).

Pipeline corrosion, especially in regions with a harsh climate such as Ural or Siberia in Russia, is a significant problem for oil and gas transport infrastructure. Disastrous destruction of pipelines can be prevented if the corrosion is detected early by non-destructive testing (NDT) methods. There are a lot of NDT methods available for corrosion monitoring, but they suffer from drawbacks. For example, they are not applicable for rough surfaces, their contrast ability is low and a size-selective contrasting of nano-sized corrosion defects is unavailable.
We have developed a modified penetrant method in which a visual inspection is replaced by a mapping of nanocracks contrasted by the penetrant – photoluminescent metal nanoparticles. Nanoparticles fill in nanocracks that are wider than the nanoparticles diameter. After that the nanoparticles can be detected by femtosecond laser-induced photoluminescence and second harmonic generation, thus enabling size-selective contrasting of surface defects.
This method allows selectively contrasting of nanocracks with a different width by changing size of nanoparticles. Furthermore, it is possible to distinguish deep cracks from shallow surface defects. Preliminary results suggest to be applicable for testing of other high-loaded materials such as outer skin of aircraft or spacecraft.
ACKNOWLEDGEMENTS:
This work was supported by Ministry of Education and Science of the Russian Federation (target funding, project 1256).

Nano-sized iron oxide particles such as maghemite γ-Fe2O3, hematite α-Fe2O3 and magnetite Fe3O4 are well known for their multiple applications such as; medicine, catalysis, sensors, memory devices and electronics. In photocatalytic properties, these particles play important role as holder for photocatalytic compounds, such as co-dopped TiO2. In order to maintain high surface area of such photocatalytic compounds and to get easy and economic process of restoring photocatalysts from the cleaning system utilizing their magnetic behaviour, these particles are used for also preparing
core-shell catalysts. In present study, the nanosized iron oxide particles are synthetized by precipitation of Mohric salt (NH4)2Fe(SO4)2·6H2O with sodium hydroxide solution and later in the process they are coated with nanosized TiO2. XRD, SEM and pH measurements are used in this study.

Nowadays production of parallel structured nanofibers is widely evolving and is gaining popularity in various fields. This research is about the development of a modified device for production nanofibers yarns that would be capable of ensuring production of high quality oriented nanofibers. The main requirement to the device is to simplify the production of homogeneous nanofibers layers and also to allow the user to change settings to conduct experimentation. This article describes design process of the device in accordance with the technological requirements, its construction and prototyping. The article also includes an overview of the main disadvantages of existing device and describes the advantages of the modified device. The main feature of the developed device is the precise control of the rotational speed of the collecting element. This is done in order to make the collecting fibers process in strictly parallel form. Also important is modification of collecting element that allows you to change the parameters of the nanofibers collection process. Using this device it will be able to test new materials for the production of nanofibers. The device has been already tested with several materials and we have got positive results.

Carbon dioxide contributes largely to the global climate change because it is one of the main greenhouse gases that are presented in the atmosphere. Due to this fact, CO2 is more and more attracted by the researchers. Especially, transformation of CO2 into the useful fuels and other chemicals was widely studied in recent years. However, it is well known that CO2 is very stable and inert, thus, it is very hard to transform CO2 from the thermodynamics point of view.
In this work, a new gas phase photoreduction system was designed to convert CO2 into useful products. The optimal conditions (such as humidity, ratio of CO2/Helium and the placement of powder photocatalyst) for CO2 photocatalytic conversion were systematic investigated with the commercial photocatalyst TiO2 Evonik P25 in the homemade gas phase reactor. Methane and hydrogen were observed as the main products. Also carbon monoxide was detected.
The photoreduction efficiency was decreased with increasing dilution of CO2 by Helium. The humidity has the key role for the CO2 photocatalytic reduction, the best value of humidity was about 51.8% leading to the highest yields of products. In addition, the conversion was also influenced by the placement of photocatalyst, the perfectly dispread sample showed higher conversion than that of gathered one.

Three different ordered mesoporous silica materials, such as MCM-41, Al containing MCM-41 (mass ratio Si/Al = 10) and SBA-15, were prepared. In a next step, cobalt (5-8 wt%), as an active metal for redox reactions, was introduced by the impregnation. The prepared catalysts were characterized by AAS, EDX, N2 physisorption, XRD, DR UV-Vis spectroscopy, Raman spectroscopy, TPR-H2 and their catalytic properties were evaluated in the redox reactions of N2O decomposition and reduction. The catalysts showed poor activity in N2O decomposition while the use of reducing agent (carbon monoxide) increased the catalytic activity (XN2O at 450 °C) which was in the order: SBA+Co (33 %) > Al-MCM+Co (27 %) > MCM+Co (17 %). The Co-impregnated catalysts differed in the presence of aluminum, textural properties, the coordination and oxidation state of cobalt, the presence of cobalt spinel phase and reducibility of catalysts. The correlation of these properties with their catalytic activities is further discussed.
ACKNOWLEDGEMENTS:
The presented work was financially supported by Grant Agency of the Czech Republic (project no. P106/14-13750S), by Ministry of Education, Youth and Sports of the Czech Republic in the “National Feasibility Program I” (project no. LO1208 “Theoretical Aspects of Energetic Treatment of Waste and Environment Protection against Negative Impacts”) and the project of specific research of VSB-TU Ostrava (no. SP2015/125).

Water pollution problems have been an important issue correlated negatively with the health and the environment. One of the most important materials, used in water purification processes like photocatalysis, is titanium dioxide (TiO2), which is widely used due to its high photocatalytic activity, nontoxicity and low price. Fly ash, a waste material produced in large quantities in coal burning power plants or steel mills, can be used as an effective catalyst carrier and enables easier separation of a catalyst after process.
This study involves preparation of fly ash/TiO2 photocatalytic nanocomposites for photocatalytic treatment of a wastewater contaminated with azo dye Reactive Red 45 (RR45). Nanocomposites were obtained by preparation route which primarily included fly ash modification by hydrochloric acid (HCl) in order to get higher specific surface of fly ash. Then followed the synthesis of TiO2 from tetrabutyl titanate in a presence of fly ash, which resulted in a preparation of fly ash/TiO2 nanocomposites. The content of fly ash in the nanocomposite samples was from 16 to 20 %. Some samples were prepared with addition of small amount of commercial TiO2 P25 Degussa (1-3 %).
Prepared fly ash/TiO2 nanocomposites were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The photocatalytic efficiency of prepared samples was studied as a decomposition of RR 45 dye, which was monitored by UV-VIS spectroscopy as a change in absorbance of characteristic wavelength at 542 nm.
Results show good photocatalytic efficiency of all fly ash/TiO2 nanocomposite samples, especially for the sample FA4/20-TiB-1.

Hydrogenated TiO2 (H-TiO2) with distinct physical and chemical properties are controlledly synthesized through a hydrogen (H2) plasma treatment, which exhibit excellent performance in application for lithium ion batteries, photocatalysis, and photothermal conversion. Moreover, the microstructure of H-TiO2, and their effect on the application performance of H-TiO2 are comprehensively investigated.
Firstly, hydrogenated anatase TiO2 nanoparticles with significantly improved fast lithlium storage performance are synthesized through a high-temperature H2 plasma treatment. Systematic electrochemical analysis revealed that the improved rate capability of H-TiO2 results from the enhanced contribution of pseudocapacitive lithium storage on the particle surface.
Secondly, H-TiO2 with different hydrogenation degrees are rapidly synthesized through high-power H2 plasma treatment. The slightly hydrogenated TiO2 (s-H-TiO2) with the original white color exhibit enhanced photoactivity compared with the pristine TiO2; while the grey or black H-TiO2 with higher hydrogenation degrees (h-H-TiO2) display much worse catalytic performances. Further investigations reveal that the higher ratio of trapped holes (O- centers) and lower recombination rates induced by the increasing of surface defects might be the critical factors for the high activity of s-H-TiO2; on the contrary, h-H-TiO2 possess high concentrations of bulk defects, leading to the significantly decreased amount of O- centers and enhanced non-radiative recombination, which strongly inhibit their photoactivity.
Thirdly, hydrogenated black TiO2 with large infrared absorption and dramatically enhanced non-radiative recombination, is explored as photothermal agent for cancer photothermal therapy. The results demonstrated H-TiO2 is of low toxicity, and exhibite high photothermal conversion efficiency of 40.8%, which can effectively kill cancer cellls under infrared irradiatation.

Screen printed contacts are often used in solar cell production due to its simplicity, process speed and price. Contacts created by printing of conductive paste ale fired in a furnace at high temperatures which are necessary to open an antireflection and passivation layer and to support the reactions during firing.
In this experiment the investigation of the influence of sintering condition during the screen printed contacts formation is presented. The experiment was focused on measuring of resistance changes during firing processes with different conditions – temperature profile, and oxygen content in process gas. The evolution of the line resistance of a printed paste was measured simultaneously with the temperature. A rapid thermal processing furnace modified for in-situ resistance measurement was used.
For experiment were used 6 inch N-type mono-Si substrates after saw damage removal and alkaline texturing. The emitter was created by diffusion using BBr3 with resulting sheet resistance around 75 Ω/sq. A 70 nm thick dielectric layer of SiO2-SiNX was deposited as a passivation and antireflection layer. The testing structure was created by 4 mm × 1mm printed spots at 50 mm distance. The in-situ resistance measurements of two pastes from different producers were evaluated between 400 °C and 800 °C.
The resistance was alternating between conductive state and insulating state during firing. The length of the first insulating state is connected with the burning through the passivation layer.

Nowadays, the rapid development of civilization entails an increase in energy consumption. The content of the work is in the main stream of the research for new proton conducting materials exhibiting high electrical conductivity and temperature operating range above 100 OC (anhydrous condition), which can be used as solid electrolyte membranes in fuel cells or batteries.
The origin of the electrical conductivity and its percolation nature has been studied in new materials consist of microcrystalline cellulose (Cell) as the polymer matrix functionalized with different concentration of imidazole (Im) as a dopant. Under anhydrous conditions the composite with the highest content of Im (5Cell-Im) exhibits electrical conductivity of about 2 × 10-4 S/m at 160 OC. The Nyquist plots of 5Cell-Im are asymmetric in the temperature range from 60 OC to 150 OC and can be fitted with two semicircles. Because imidazole molecules are only present at the surface of the microcrystalline cellulose grains, the origin of the two semi-circles can be explained by the existence of conduction derived from the imidazole layers at the grain surface and the contacts between the grains, respectively.
The percolation model of conductivity was used to simulate the behavior of conductivity as a function of the imidazole concentration. This model allows to show the percolation nature of the electrical conductivity and the phase transition from an ionic non-conducting to the conducting one has been identified for the first time in the Cell-Im composite. Also, the manner in which the clusters of heterocycles are dispersed in the system was recognized as not being randomly, probably they are flocculated into some separated regions.

Temperature dependent of dark current measurement is an efficient way to verify the quality of an infrared detector. Low dark current density values are needed for high performance detector applications. Identification of dominant current mechanism in each operating temperature with extracted their minority carrier lifetimes are highly important for understanding of carrier transport and improve the detector performance. Here we present electrical as well as optical performance of InAs/AlSb/GaSb based type-II SL N-structure photodiodes
Current density-voltage (J-V) characteristics of InAs/AlSb/GaSb based type-II SL N-structure photodiodes are measured as a function of temperature (78-271K). The J-V curves are fitted by using Shockley Formula in order to identify the dominant dark current mechanizm in each operating temperature range. Minority carrier lifetimes are extracted from temperature dependence of current density (J-1000/T) curve quantatively [3].
Temperature dependence of J–V characteristics is also analysed in InAs/AlSb/GaSb based T2SL N-structure. Deduced from J–V curve-fitting, minority carrier lifetimes have been estimated in the temperature range 87–215 K. At 87K and under -0.1V bias voltage, the dark current density is measured as 9.29x 10-8 A/cm2 and corresponding dynamic resistance area product (RA) is determined as 6.43x105Ωcm2. In the temperature range 271–125 K, the dark current density reveals diffusion-limited behavior (Arrhenius type) with electron lifetime values between 1ns and 15ns. In the lower temperature range (125–87 K), the dominant mechanism starts to become generation recombination (GR) with GR lifetimes varies between 16-20ns.

TiO2 nanotubes are highly promising for application in various fields. Many publications are concerned with nanotubes prepared by the anodization of titanium foil. This work presents TiO2 nanotube arrays fabricated by the anodic oxidation of thin titanium layer. Titanium layer is sputter-deposited on silicon wafer with thermal SiO2 layer. Nanotubes were prepared in organic electrolyte containing water and different amounts of ammonium fluoride. The influence of different amount of ammonium fluoride is observed by scanning electron microscopy (SEM). Removing initial oxide barrier layer plays a significant role in successful preparation of nanotubes. Under optimized conditions, i.e. a good balance between oxidation and etching during anodization, nanotube arrays with uniform configuration are obtained.
ACKNOWLEDGEMENTS:
The research was supported by project no. FEKT-S-14-2300 A new types of electronic circuits and sensors for specific applications.

High-voltage nanoporous anodic films grown on aluminium in certain organic electrolytes are of increasing interest for potential applications as nanotemplates to electrical capacitors and, more generally, as models for investigating self-organized growth of anodic oxides at the frontier conditions. The major difficulty associated with this technology is that the process of pore nucleation and growth over a large-area aluminium substrate needs optimization and adaptation to the specific technological conditions applied to aluminium substrates as the surface finishing pre-treatments.
In this work we have studied the impact of important pre-treatment technologies for Al foils, such as high temperature annealing and electrochemical polishing, on the pore nucleation and growth during galvanostatic formation of nanoporous anodic alumina templates in aqueous solutions of citric acid.
It was revealed that the self-organized pore nucleation and growth is strictly dependent upon the anodizing setup, anodizing variables, surface morphology and crystalline structure of aluminium foils, which are additionally affected by the conditions of vacuum annealing and electropolishing pre-treatments. The findings are useful for growing well-ordered, individual or grouped alumina nanopores, without external techniques, for non-lithographic formation of metal and metal-oxide nanostructures for advanced capacitor application.
ACKNOWLEDGEMENTS:
This research was supported in part by GA ČR grant no. 14-29531S and by CEITEC project STI-J-15-2886.

The paper focuses on the problematic of coaxial electrospinning with a wire spinning electrode. Despite of wide usage of wire spinner in the industrial sector, only basic research has been made in the field of possible coaxial technology application. In the paper, the new concept of the wire spinner, reflecting the polymeric two-layer formation, is introduced. The design is supported by electrostatic analysis of the problem using FEM method. The manufactured testing device was experimentally verified and the results were evaluated. The electrospinning process stability and the final product were analysed and the potential of the application was discussed.

That article is focused on the biocidal effect of nanofiber textiles based PVA enriched by agents with potential (copper, diamond and commercial biocide) to limit the growth of consortium consists of algae and bacteria. Model organisms were obtained from the surface of building facade in Brno in Czech Republic. These organisms are common in the Central Europe. It was proved the basic PVA (solution and nanofiber textiles) has not any effect against the growth. And the addition causes the inhibition the growth of consortium. There is a comparison of effect of liquid polymer solution dopped by biocides and nanofiber textiles based on that polymer solution. Higher efficiency showed liquid polymer solution than nanofiber textiles. The biocidal effect of nanofiber textile depends on leaching active substance from the matrix. The leaching properties are given by the way of stabilization process and type of nanofiber textile.

Solid phase microextraction (SPME) has been established as a convenient method of sample preparation in organic analytical chemistry since its introduction by Pawliszyn in 1989. Recently, there are reported first attempts on the preparation of SPME sorbents by electrospun nanofibres, in contrast to routinely applied sol-gel techniques. The intention of using electrospun fibres geometry is to enhance the sorbent sensitivity and capacity. In this work, polyetherimide (PEI) electrospun nanofibres were prepared from PEI 15 % solution in DMF/THF 1:1 using a needle electrospinner and SPME steel core as electrode under 10 kV following the work of Bagheri at all, 2013. Adhesion between steel core and polymeric coating was optimized to obtain thermally stable PEI/PDMS SPME fibre assembly. Final laboratory-made SPME fibres were characterized by SEM and TGA and their analytical performance (in determination of phthalate esters and hexachlorocyclohexanes by headspace-SPME GC/MS) was compared with commercially available SPME fibres. This work was supported by National Programme for Sustainability I (CZ. 1.07/2.3.00/30.0024).

Today, many scientists deal with the research of properties of nanofiber textiles. Properties of textiles depends on theirs unique structure and therefore it is necessary to know how exactly structure of the fabric looks like. Nowadays, there are a few macroscopic models, but they are inaccurate. It was the main motivation of this research.
For our study we have chosen nanotextiles made of two polymers PVDF (polyvinylidene fluoride) and PUR (polyurethane). The nanotextiles were produced at Czech Technical University in Liberec by NS 4S1000U device using Nanospider technology.
In this research, the fabrics were mapped in two ways using an electron scanning microscope Tescan Maia 3. In the first experiment the surface structure of the sample was analysed. Photos created by SEM were analysed using program Atlas and a bitmap graphics editor GIMP 2. Here we determined the initial parameters for the creating a digital 2D model of a single layer (fibre distribution, the radius of the fibre, pore size and curvature of the fibres). In the second experiment cross sections of nanofiber textiles were made and from it the inner structure was determined. The cross section looks almost exactly like the surface of the textile. Finally, we calculated the total number of 2D layers from the whole thickness of sample and it is a key piece of information for future creating a 3D model of the fabric.

In this context, nanofibres that have improved properties compared to conventional materials are widely used. Titanium dioxide TiO2 nanofibres are mainly used for many applications, which are characterized by their crystalline structure. Nanofibres are produced based on the principle of electrospinning with subsequent calcination of the spinning material. Titanium dioxide possesses antibacterial functions by its photocatalytic properties which can destroy bacteria or suppress their reproduction. We have recently developed an innovative TiO2 polymer surfaces. The results showed the bacterial activity in the vicinity of these surfaces during influence of UV light.

Nanomaterials change our life. Every day they find applications in new branches of technology. At the same time, some branches of technology, like civil engineering, are rather conservative and do not accept new approaches lightly. Nanotextiles exhibit a number of qualities that make them a promising material for civil engineering applications. They can potentially play a role of filters, protective layers, armature and others. Properties of the nanotextiles can be significantly influenced by parameters of technological process. Pure experimental search of the optimal technological parameters to achieve the desired properties of the final material can be very tedious. Thus, a theoretical dependence of the properties of the nanotextile on parameters of the technological process must be established. Two independent tasks must be solved for this: the dependence of nanotextile structure on technological parameters, and determination of physical, chemical or biological properties of a nanotextile of a given structure. In this paper we discuss steps necessary for the solution of the second task.
Nanotextile is a material with extremely large porosity, which makes standard macroscopic models for the description of its properties inappropriate. Thus, any successful model must be based on the specific structure of the nanotextile. After the structure is known the next step is to understand all important interactions between nanofibers and the environment. The set of such interactions depend on the problem under consideration. Finally, the properties of the material should be determined as a numerical solution of the corresponding 3D model.

The paper deals with verifications of the mathematical model electrospinning devices. The model is able to simulate the electrostatic field strength and voltage with using the finite element method. The simulation could be used mainly in the design of the spinning device for electrostatic spinning process. Boundary conditions introduced into the mathematical model were obtained by using the experiments on the functional model. The experiment was based on the theory of the critical field strength presented by Taylor in 1969. Thanks the FEM analysis was found the value of the critical field strength and the place where the critical field strength appears on the polymer droplet. The analysis results were compared with analytical calculation presented by professor Lukáš in 2008. The presented mathematical model can facilitated development of the electrospinning machines. The model could be used for optimal design of the spinning electrodes as well as the design of the whole electrospinning apparatus. Moreover, the model might be apply to the setting up of optimal technological parameters for producing modern nonwoven textile products.

The work aims to explain and demonstrate the possibility of preparing nanofibers with specific magnetic properties.
Described is the preparation of ferrite nanoparticles and magnetic nanofibers by using appropriate methods. Emphasis is placed on preparing quality spinning solution, the choice of effective methods of spinning and thorough characterization of the products obtained. They also described the preparation of magnetic nanofibers with a very high content of solid ferrite particles in a polymer matrix.
Achieved results show interesting magnetic properties of nanomaterials that are applicable in various fields including medicine and industry.

For many of applications is very important the input processing of vermiculite particles. The vermiculite particles are normally carried out in energy intensive grinding mills such as planetary mill, oscillating mill and jet mill. Short-time grinding of vermiculite particles requires to the particle size reduction. But extended grinding lead to an intense structural degradation of the lamellar shape, lateral size and particle thickness reduction and progressive amorphization accompanied with formation of hard agglomerates. The changes of the structure and vermiculite particle size has an influence on the properties of new nanocomposite materials used in the chemical industry.
The natural vermiculite particles from Brazil were grinding in jet and ball mills. The shape of vermiculite particles has been studied using scanning electron microscopy (SEM) and atomic force microscopy (AFM). The particles size (PS) changes were characterized by the median particle size, volume-weighted mean diameter, mode diameter and span value.
ACKNOWLEDGEMENTS:
This work was supported by the project No. SP2015/18 - Functional gradient nanostructured materials and CZ.1.05/1.1.00/02.0070 - IT for Innovations Centre of Excellence project.

The development of new packaging plastics contributes significantly to the preservation of packed food quality. Especially important is polymer active packaging in which addition of active ingredients targets to improve one or more properties such as water vapour and oxygen permeability. Food packaging, except good barrier, needs to have good thermal and mechanical properties because it has to be flexible and endure higher temperatures, like during sterilization.
Low density polyethylene is a classic material used for food packaging due to numerous advantages it has, but low barrier property is its main weakness. To improve permeability properties, mechanical properties and thermal stability double layer polyethylene/polycaprolactone (PE/PCL) films were prepared with the addition of nanoparticles of zinc oxide (ZnO) and aluminium oxide (Al2O3) in PCL layer.
For the studied samples water vapour permeability, thermal stability and mechanical properties were determined
The results showed that addition of both nanoparticles significantly improves mechanical properties when compared to pure PE but samples with Al2O3 have much higher values of tensile properties. Water vapour permeability is decreased when nanoparticles are added but different behaviour is observed. For samples with ZnO permeability decreases at higher loading of nanoparticles while on the other hand, the lowest value for samples with Al2O3 is at the lowest loading and increase of loading causes increase in permeability. Thermogravimetric analysis was used to evaluate thermal stability and it showed that samples with nanoparticles had around 10 °C higher onset of degradation and maximum degradation rate temperature compared to PE.

Refractories play an important role in metallurgical, glassmaking and ceramic industries, where they are formed into a variety of shapes to line the interiors of furnaces or kilns or other devices for processing the materials at high temperatures. Many of the scientific and technological inventions and developments would not have been possible without refractory materials. The performance of refractories greatly depends on the selection of raw materials. In this study, raw amorphous magnesite and γ- Al2O3 nanopowders were used as starting materials for preparation of periclase-magnesium aluminate spinel ceramics. Magnesite was annealed at a temperature of 800°C with an exposure of 2 hours. A nanosized γ - Al2O3 powder was obtained by hydrothermal method. The resulting caustic magnesite and seven volume percent of γ - Al2O3 nanopowders were mixed and milled in a ball mill during 30 min. Specimens of periclase-magnesium aluminate spinel ceramics were compacted by a bi-directional axial compression and sintered at 1500°C with an exposure 2 hours at the maximum temperature. The microstructure and mechanical properties of the ceramics were evaluated. Dense periclase-magnesium aluminate spinel ceramics with density of 3.3 g/cm3 and compressive strength of more than 300 MPa were obtained. The evaluation of the results is the basis for the industry design of magnesia spinel refractories for new advanced applications.

High density polyethylene (HDPE) is often used industrial polymer because of its good mechanical properties such as high flexibility, tensile strength, high chemical resistance, easy processing and low price. Low surface energy of HDPE causes its low adhesion to printings, coatings and adhesives, which limits its industrial use. The aim of this work is to improve wettability of HDPE surface while bulk properties are kept. Atmospheric Diffuse Coplanar Surface Barrier Discharge (DCSBD) operated at frequency 50 kHz in an ambient air was used. The main advantages of this plasma source are the possibility to operate it at atmospheric pressure, high power density and its good applicability in in-line processes. Surface properties of the samples were analyzed via sessile drop contact angle measurement and calculation of surface energy and its acido-basic and Lifshitz-van der Waals components using Owens, Wendt, Rabel and Kaelble model (OWRK).
Exposure time was 1.5 – 20 sec and distances between samples and electrode were 0.1, 0.2 and 0.3 mm. Obtained results show that the surface energy of treated HDPE depends not only on the exposition time but also on the distance between the sample and the electrode.
The best results were obtained for 10 sec treatment at the lowest distance between the sample and the electrode. Surface energy increased up to mJ/m2 compared with 38 mJ/m2 of untreated HDPE.
Aging test proved only a week decrease in surface energy in the first 720 min after the treatment.
ACKNOWLEDGEMENTS:
This work was supported by The project CEPLANT created at the MU in the Operational Programme Research and Development for Innovation, Reg No. CZ.1.05/2.1.00/03.0086.

Plasma treatments were used to modify surface properties of polyethylene terephthalate (PET) and glass micro fibers, to improve their wettability. PET fibers, having diameter of 400 µm, and glass fibers (ø14 µm) were exposed to low pressure oxygen plasma. A direct horizontal optical method was used for contact angle measurements on fiber surfaces submerged into distilled water. Surface morphology changes before and after treatment were characterized by scanning electron microscopy. Finally, cement paste specimens reinforced with PET and lime-based mortars reinforced with glass fibers were made and after 28 days of mixture curing tested by four-point bending tests. Contact angles measured on treated fibers were less about 60 (PET fibers) and 25 (glass fibers) percent in comparison with untreated fibers. SEM pictures showed the significant surface damages on PET fibers and minor damages on glass fibers. Both four-point tested samples reinforced with treated fibers exhibited the maximum bending strength loss about to 10 to 20 percent compared to samples with untreated reinforcement. The samples reinforced with untreated fibers exhibited the deflection-softening, while the samples with plasma treated fibers deflection-hardening.

Increase of surface wettability on glass was observed after atmospheric pressure plasma treatment using two different plasma sources. First used plasma source was Diffuse coplanar surface barrier discharge (DCSBD) and second was commercial gliding arc. Standard microscopic cover glasses were used as a substrate. Examined parameters were water contact angle, aging effect of plasma treatment, and surface roughness. Different exposure times (10 s, 20 s) of plasma treatment were examined. The influence of plasma treatment on surface roughness was investigated. Aging effect of plasma treatment was faster on glass treated with gliding arc, than on glass treated with DCSBD. Therefore DCSBD is a more suitable device for plasma treatment of glass than gliding arc.

The sintering of plasma pre-treated alumina sub-micron powders results in finer microstructure of final ceramics. This highly interesting and potentially useful result motivates us to study the microscopic changes on plasma treated alumina powders. In this paper we present the study of luminescence produced by thermally stimulated plasma treated alumina powders, to extend the portfolio of standard surface diagnostic tools specializing primarily at chemical and topological changes. We found that luminescence signal is exceedingly sensitive to plasma treatment. The comprehensive set of experiments implies that the emitted light is produced chiefly by the process of thermoluminescence. Hence the emitted light is the direct consequence of plasma assisted electron trapping in the material, rather than the outcome of chemical reactions.

Vermiculite is a well-known material from the group of the phyllosilicates nowadays used for nanostructured sorbent preparation. In their organically modified forms they are known to be very efficient sorbents of organic compounds, especially polycyclic aromatic compounds, from aqueous solutions. There is a large amount of research in the topic of organically modified vermiculites and their properties. One of ours previous studies revealed almost 100% efficiency in column sorption of benzene, dichlorbenzene, toluene, naphthalene and others from highly polluted waste water. But there are only few studies about their treatment after utilization. Thus, the goal of this work is to propose ways of disposing them after their application.
The thermal treatment in high temperatures is one of the options. The goal of this study is to determine vermiculite structural changes after thermal process which can show if there is a possibility of its reuse or if the burned out material could be used in another application. In the thermal process various temperature influences were studied. Only a partial removal of organic compounds occurred in temperature of 300 °C. After exposing sample to the temperature 1100 °C a new ceramic material was made which showed different properties comparing original vermiculite. The prepared and tested samples were investigated using X-ray diffraction (XRD) method, Fourier transform infrared (FTIR) spectrometry, total organic carbon content (TOC), scanning electron microscopy (SEM).
ACKNOWLEDGEMENTS:
This work was funded by the MSMT project SP2015/55 and the European Regional Development. Fund in the IT4Innovations Centre of Excellence (CZ.1.05/1.1.00/02.0070).

Understanding of the machining process fluids (types, compositions, operational conditions, lubricating and cleaning effect) is significant when maximize the machining process efficiency (reduce the heat generation, improve the surface roughness, stabilize the machining process, increase the operating life). Contamination by bacteria (or even fungi) is the weak point of these liquids. The uninhibited growth of bacteria may lead to poor lubricating properties of fluids, higher material oxidization; moreover the presence of endotoxin at the shop floor atmosphere is the consequence of bacterial activity. Thus, biocides chemicals are added to process fluids in order to prevent the bacterial growth. The biocides maintain the efficiency of process fluids however they are injurious to the operators (potential carcinogenic compound). Natural nanoadditives are one of modern possibilities how to increase the biocidal effects. Nanoadditives added to the process fluids have positive impact on the machining process behavior, there is a reducing of the friction coefficient resulting in a reduction of wear of the cutting tool; as well as the nanoadditives enhances the bactericidal effect (reduce bacterial respiratory rates and viability).

The article is focused on comparison of inhibition effect of two types of silver nanoparticles and silver ions on mold growth on surfaces of building materials. Nanoparticles of silver are product of different producers prepared by different way (e. g. chemical to mechanical). We used typical mold mixture of commonly occurring fungal species in middle Europe especially in the middle of Czech Republic including Trichoderma, Penicillium, Alternaria, Paecilomyces. They were isolated from samples taken in the air exposition. But the molds used in experiment were received from a Czech Collection of Microorganisms (CCM). It is not proved that type of biodeteriogens in the air correlates with isolated species on buildings facades. Tested building materials were gypsum and wooden based. Presented results show that protection against mold by silver nanoparticles and ions is not universally applicable protection for all tested materials.

Our research is focused on foliar fertilizers and their impacts on plant behaviour. These experiments are realized in agarose hydrogels (blank agarose hydrogels and agarose hydrogel with addition of potassium lignohumate). These materials were explored basic physical chemical instrumentations (rheology, scanning electron microscopy, mercury intrusion porosimetry and stereomicroscopy). Mentioned methods are able to characterize behaviour of hydrogels. Rheology enables to determine the mechanical properties of hydrogels. Hydrogel materials must be modified for some trials, otherwise it wouldn’t possible to measure it. lyophilisation was used for modification of hydrogel, because for aforementioned instruments are dry hydrogels (xerogels) more appropriate. Scanning electron microscopy and stereomicroscopy were used to determine the surface of hydrogels. Mercury intrusion porosimetry was used for determination of hydrogels pores for both types. It was considered, from obtained experimental data, if this material doesn’t significantly affect the diffusion processes.

The permeability and barrier properties of various solutes were studied through nanoporous alumina membranes by diffusion cell technique. Fabricated membranes were characterized by basic physic-chemical methods. The accurate thickness and roughness was determined by profilometry, the distribution of pores and pore size was detected by mercury intrusion porosimetry, textural properties were studied by scanning electron microscopy and specific surface area by BET analysis. The specific permeability was compared by determination of fundamental diffusion parameters such as diffusion flux and break-through time (lag time).
Results show, that the penetration ability and other important parameters such as thickness and the distribution of pores are strongly dependent on experimental setup within preparation of nanoporous alumina membranes. The most important parameters which influenced the final properties of membranes are time of anodization, type of electrolyte, applied voltage and current density.

Nanoporous alumina membrane is useful material for development of electrochemical sensors including filtration, molecule sorting and subsequent detection. Big advantage of alumina is possibility to reliably control size of nanopores and membrane thickness. For sensorial utilization, it is necessary to know diffusion properties of membranes and their permeability of various substances. Therefore, membranes with different pore diameter and thickness were prepared by two step anodization and modified by deposition of gold layers which serve as electrodes. Thereafter, their influence on changes of electrochemical impedance spectra was studied and compared in dependency on membrane morphology.

Usage of plant source-based stiff fillers as reinforcement material in polymer composites have attracted significant interests of researchers during last few decades. The crystalline parts of the
semicrystalline cellulose chains represents the most highly potential biobased reinforcing agents for polymers. This paper covers the extraction of cellulose nanocrystals (CNC) from commercial microcrystalline cellulose (MCC) and their polylactic acid (PLA) nanocomposite films preparation by solvent casting. The nucleation effect of CNC on PLA matrix crystallization were investigated. The production of biodegradable nanocomposites based on cellulosic biomass waste suggests the possibility of using these new bio-nanocomposites in industrial and environmental friendly applications.

Basic component of impregnating liquid is the methyl-silicon resin. By using a suitable solvent (e.g. xylene) and water was formed an aqueous emulsion. Thus prepared emulsion had to be further thickened to increase the viscosity of the resulting solution.
The silicone component can be via a carrier solvent of water and residual solvent highly efficiently transported deep into the structure of the material .
To increase the utility properties (hydrophobic and antisoiling) of the emulsion were part of the emulsion also nanoparticles. The protective layer is developed on the basis of nanotechnology. Thanks to the nanometric dimensions (10 - 30nm) nanoparticles can penetrate into the porous structure of the substrate.
Thus prepared impregnating emulsion was applied onto the various substrates e.g. polycarbonate, autolack or geopolymer material.
The treated samples were further tested for the changes in contact angles (change in hydrophobic properties), the abrasion resistance by means of the tribological tests and resistance to the elevated temperatures.

Attachment of organic molecules is usually accomplished through the thiol functionality, but it would be desirable to have alternatives. Herein we would like to report preparation of gold nanoparticles with diameter of a few nanometers and their modification by alkyl chains. Such functionalization was achieved by direct attachment of organic moieties present in organo-tin compounds. The modified nanoparticles are expected to be more stable than the thiolated ones thus providing broader field of use in the catalysis of chemical reactions.

This research paper describes a feasibility study regarding the use of inkjet printing for designing a flexible microstrip antenna. Our prototype antenna is printed, using a specially prepared ink based on silver nanoparticles with diameter ranging from 50 to 200 nm, on a plastic substrate PET (Polyethylene terephthalate). Nanoparticles and flexible PET substrate are used to achieve very advanced parameters in four frequency bands of 1.4 GHz, 3.1 GHz, 5.1 GHz and 6 GHz. These properties could be confirmed in our measurements.
Multiband antennas of this type may find use in many portable devices like cell phones, where it would be possible to implement the antenna on the cover in the form of printing, thus yielding important benefits with respect to size and weight. The inkjet printing technology onto flexible polymer substrates serves another wide range of applications, namely those with high demands on flexibility, like for instance wearable technologies.

The paper describe an influence of rice husk particles as a filler in a common epoxy resin from the point of view mechanical properties with the accent on effect of silicon dioxide nanoparticles. The utilised filler has a diameter in range from 1 to 100 micron. Rice husk particles are natural composite system composed from organic matrix (cellulose, hemicellulose, lignin) reinforced with amorphous silicon dioxide nanoparticles. This typical composition provides specific parameters of rice husks like strength, hardness and mechanical barrier to surrounding environment. The optimised composition of designed composite system was 10 g of rice husk particles added to 1 kg of epoxy resin ChS - Epoxy 520. Rice husk particles in epoxy resin composite system express an excellent adhesion. The system was evaluated from the point of view parameters like strength, Young modulus, hardness and density. All these parameters show analogous value of the parameters like unfilled epoxy resin. The coefficient of friction shows lower value in case of optimised composition (1 dsk) in compare to unfilled epoxy resin. The wear rate (the weight loss of the samples) after adding the filler was increased at 75%. Optimised sample composition was tested to water absorption that was same as in unfilled epoxy resin although the organic particles were present in this epoxy system. The wear rate was positively influenced with presence of rice husk filler in case that other filler like pigments were added to epoxy matrix. The described system has a potential to be used in building industry.

Following up on a previous research, the aim of the work is to further investigate the possibility of using rare earth elements compounds in polymer matrix for ionizing radiation attenuation. Having proven the effectivity, the focus is primarily on the proper preparation and characterization of the materials and the effect on the stability of polymer solution and it's suitability for needleless electrospinning. The investigated materials in this case were the oxides of lanthanum, cerium, praseodymium, neodymium, gadolinium, holmium, erbium, thulium and lutetium. The methods of characterisation used were solution conductivity measurement, x-ray fluorescence analysis, scanning electron microscopy, energy-dispersive x-ray spectroscopy and sedimentation time measurement in combination with Tyndall's effect.

Presented work is focused on possibilities of preparation of cosmetic emulsion with added liposome particles. Beta carotene, tocoferol, vitamin C and catechin as representative of natural antioxidants and UV filters were encapsulated into liposomes using several types of techniques.
Sedimentation stability of emulsions was analyzed by analytical ultracentrifugation. The efficiency of encapsulation was evaluated by HPLC/UV-VIS and spectrophotometrical methods. Size of prepared particles was determined by dynamic light scattering and stability of particles was determined using zeta potential. Moreover, long-term stability of particles in cosmetic emulsions was studied too. To analyse sun protection factor (SPF) spectrophotometry was used.
In this work it was found that prepared oil-in-water emulsions enriched by liposome particles are physically stable and can be used in sunscreen preparations. All of actives were encapsulated with high efficiency a and prepared particles exhibited excellent stability. It was found, that neither type of particle or encapsulated substance does not significantly affect the sedimentation stability of emulsions.

Nanotechnology represents the future of materials with unique properties enabling construction of new devices with properties which are not obtainable with macroscopic materials. Nowadays many nanomaterials are studied in scientific laboratories but only several of them have spread to the common life of people. Silver nanoparticles are one of these nanomaterials mainly thanks to their excellent antimicrobial activity. They are used for antimicrobial treatment of fabrics, in cosmetic products and also in materials for human or veterinary medicine.
The modern packaging materials have a multifunctional properties which are adjusted on demand of particular utilization of package in commercial practice. The serious problem in commercial practice represents microbial contamination of outer part of package during manipulation with goods during their distribution. Therefore, development of packaging materials with antimicrobial properties represents a current problem of packaging technology. Silver nanoparticles can be used to solve this problem in packaging technology. However, typical packaging materials are non-polar polymers as polyethylene or polypropylene and combination of these polymers with silver nanoparticles represents complex technological problem. We have developed the highly concentrated and well stabilized dispersion of silver nanoparticles which can be used for modification of low-density polyethylene polymer (LDPE) to obtain antimicrobial activity of the resulting composite material. This way modified LDPE polymer can be used for production of packaging materials with excellent antimicrobial properties.
ACKNOWLEDGEMENTS:
This research was supported by the project TA03010799 of the Technology Agency of the Czech Republic, and by Internal Grant of Palacky University in Olomouc (IGA_PrF_2015_022).

One way of plastic processing, which can produce long products with significant changes of the microstructure is the cross rolling. However, deformation and motion path of the metal is very heterogeneous across the section of the rolled piece. This paper presents the finite element modeling of hot cross rolling of steel in the software package DEFORM-3D features implemented and studied the stress-strain state. An experimental study of the effect of the cross rolling on a three-roll mill on the microstructure of structural alloy steel and stainless steel AISI321 in different zones of the bar. Analysis of microsections made after rolling with high total stretch and the final pass temperature 700ᴼC, shows the formation of equiaxial ultrafinegrain structure on the periphery of an elongated rod and "rolling" texture in the central zone. The resulting microstructure corresponds to that obtained in models of stress-strain state.

In this work, we used atmospheric pressure plasma in ambient air generated by diffuse coplanar surface barrier discharge [1] to treat polypropylene non-woven textiles in order to increase their surface energy prior deposition of poly(L-lactide) nanoparticles containing antimicrobial agent octenidine, that can be released when nanoparticles are in contact with bacteria. Untreated textiles showed poor surface properties and distribution of particles was uneven and remained on the textile surface. Short plasma treatment time led to fast hydrophilization of the textiles and penetration of particles into textile volume. This work is mainly focus on the advantages of atmospheric plasma treatment technology, while antibacterial particles are described in our previous work [2]. We have investigated plasma treatment efficiency by means of strike-through-time measurements and linked these findings with XPS data of untreated and plasma treated surfaces. SEM showed that distribution of particles formed a crust on the untreated non-woven textiles surface, whereas plasma treatment textiles showed particles distributed evenly in the volume of treated material. Plasma had no damage influence on textiles which consist of thin fibres. We have demonstrated that the plasma system can be also integrated within roll-to-roll line and nanoparticles can be delivered on the textiles using ink jet printing.
REFERENCES:
[1] T. Homola, J. Matoušek, M. Kormunda, L. Y. L. Wu, M. Černák, Plasma Chemistry and Plasma Processing 33 (2013) 881.
[2] T. Ivanova, et al., Attachment of Poly(L-lactide) Nanoparticles to Plasma Treated Non-Woven Polymer Fabrics Using Inkjet Printing, Macromolecular Bioscience 15 (2015) 1274-1282