Wyniki wyszukiwania - BazTech

1

Polylactide-based composite materials for 3D printing and medical applications - the effect of basalt and silicon dioxide addition

Pyza Maciej, Brzezińska Natalia, Kulińska Karolina, Gabor Jadwiga, Barylski Adrian, Aniołek Krzysztof, Garczyk-Mundała Żaneta, Adebesin Kayode, Swinarew Andrzej

Engineering of Biomaterials

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2022

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vol. 25, no. 166

29--39

EN

Polymers are compounds that play a key role in the development of many fields of science, including emergency medicine. Currently, there are increasing requirements for biomedical polymers in terms of producing lighter and more ecological equipment. To meet these requirements, a composite material was developed: polylactide (PLA) with the addition of modifiers - basalt and silicon dioxide (SiO2). PLA was chosen as a biodegradable polymer that naturally decomposes in the environment. This is very important, regarding a large number of single-use materials made of microplastics polluting the environment. The samples were made by additive 3D printing and then immersed in swimming pool water, chlorine solution, and distilled water. FTIR analysis showed the influence of the environment on the intensity and shift of PLA absorption bands. Microscopic analysis provided information on surface morphology, roughness, and potential defects. Tribological and micromechanical tests showed that the additions of basalt and silica to the PLA material influenced the morphological structure and the average area of the wear trace, volumetric wear, and average coefficient of friction. In the presence of chlorine solution, distilled water, and pool water under real conditions, the SiO2 addition made the PLA material more resistant to abrasion, as compared to the basalt addition. However, additives did not significantly affect the PLA material hardness, and the samples with basalt turned out to be more resistant to deformation.

2

Enhancement of color quality and luminous flux for remote-phosphor LEDs with red-emitting CaMgSi2O6:Eu2+,Mn2+

Luo Guo-Feng, Loan Nguyen Thi Phuong, Tho Van Le, Anh Nguyen Doan Quoc, Lee Hsiao-Yi

Materials Science Poland

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2020

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Vol. 38, No. 3

409--415

EN

SiO2 particles and red-emitting CaMgSi2O6:Eu2+,Mn2+ phosphor have been added into a yellow phosphor compound YAG:Ce3+ to enhance the optical efficiency of white light LEDs whose average correlated color temperature (CCT) is in the range of 5600 K ÷ 8500 K. It was observed that altering CaMgSi2O6:Eu2+,Mn2+ concentration from 2 % to 30 % while maintaining 5 % of the SiO2 strongly influenced the color rendering index (CRI), color quality scale (CQS), and lumen efficiency of the compound. Besides, through the application of Monte Carlo simulation and Mie-scattering theory, it was possible to improve the optical properties by CaMgSi2O6:Eu2+,Mn2+ and SiO2 addition. The results provided a practical approach to achieve higher luminous efficiency and better color uniformity in remote-phosphor white LEDs (RP-WLEDs).

3

Synthesis and characterization of binary and ternary nanocomposites based on TiO2, SiO2 and ZnO with PVA based template-free gel combustion method

Fakoori Elham, Karami Hassan, Nezhadali Azizollah

Materials Science Poland

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2019

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Vol. 37, No. 3

426--436

EN

Binary and ternary nanocomposites based on TiO2, SiO2 and ZnO were synthesized by PVA-based template-free gel combustion method. The morphology and the particles sizes of the synthesized samples depended on some parameters including the initial concentrations of metal salts and PVA amount in the sol, solvent composition and solution pH. Effects of these parameters were investigated and optimized by using the Taguchi method. In the experimental design, the Taguchi L25 array was used to investigate six factors at five levels. The samples were characterized by dynamic light scattering (DLS), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET) specific surface areas, scanning electron microscopy (SEM). The obtained results showed that the present method can be used to synthesize TiO2/SiO2/ZnO ternary nanocomposite with an effective surface area of 0.3 m2 · g−1 and ZnO/TiO2, TiO2/SiO2, ZnO/SiO2 binary nanocomposites with an effective surface area of 234 m2 · g-1, 6 m2 · g-1 and 0.5 m2 · g-1, respectively. The ZnO/TiO2 nanocomposite which was synthesized under the following experimental conditions: 2.5 wt.% Zn salt, 2.5 wt.% Ti salt, 2.0 wt.% PVA, pH = 1 and ethanol:water ratio 30:70 was selected by the Taguchi method as an optimum sample with the smallest particles (average diameter = 50 nm).

4

Improving color uniformity and color rending index of remote-phosphor packaging white LEDs by co-doping SiO2 and Sr2Si5N8:Eu2+ particles

Minh T. H. Q., Nhan N. H. K., Anh N. D. Q., Nam T. T., Lee H.-Y.

Materials Science Poland

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2018

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Vol. 36, No. 3

370--374

EN

Based on some advantageous properties, such as fast response time, environment friendliness, small size, long lifetime, and high efficiency, white LEDs are increasingly used in common illumination applications. In this research, by co-doping of redemitting Sr2Si5N8:Eu2+ phosphor and adding SiO2 particles to yellow-emitting YAG:Ce phosphor compounds, a new approach for improving color uniformity and color rending index of remote-phosphor structure white LEDs is proposed and demonstrated. The obtained results clearly indicate that the color rendering index (CRI) and color uniformity (DCCT) significantly depend on Sr2Si5N8:Eu2+ concentration. The results provide a potential practical solution for manufacturing remote-phosphor white LEDs (RP-WLEDs) in the near future.

5

Solid State Synthesized YVO4:Dy3+/ SiO2 Composites: Microstructures and Optical Characteristics

Rafiaei S. M.

Archives of Metallurgy and Materials

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2018

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Vol. 63, iss. 1

199--202

EN

In this paper YVO4:Dy3+ was synthesized via solid state method at 1100°C and effects of different quantities of SiO2 particles on microstructure and photoluminescence properties were investigated in details. To study the microstructure and properties of these composites XRD, SEM, TEM, HRTEM, XPS and PL equipments were employed. It was found that via addition of SiO2 particles to YVO4:Dy3+ phosphors, strong bonding is made between SiO2 particles and phosphors. Furthermore, based on stronger electronegativity of Si 2p element compared to Y 3d and V 2p elements, increase of SiO2 causes the increase of binding energy. Moreover, this research showed that the addition of 10 wt% SiO2 particles to YVO4:Dy3+ material enhances the excitation and emission luminescence properties, significantly. Further increase of SiO2 particles results in suppress of emission intensity.

6

Preparation and investigations of electrical and optical properties of thin composite layers PAN/SiO2, TiO2 and Bi2O3

Matysiak W., Jarka P., Tański T.

Archives of Materials Science and Engineering

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2018

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Vol. 91, nr 1

15--22

EN

Purpose: The aim of this study was to present the influence of mass concentration of the reinforcement phase on the structure and optical properties of the obtained composite thin films with a polymer matrix reinforced by SiO2, TiO2 and Bi2O3 nanoparticles, produced by the spin-coating method. Design/methodology/approach: To produce composite materials, 10% wt. polymer solutions of polyacrylonitrile (PAN) and N, N - Dimethyloformamide (DMF) were used, containing nanoparticles with a mass concentration ratio of, sequentially: 0, 4, 8, 12%. The morphology, structure and chemical composition of the obtained thin films were determined on the basis of surface topography images, taken using atomic force microscopy (AFM) and a scanning electron microscope (SEM) with EDX and QBSD spectrometers. In order to analyse the optical properties, UV-Visible spectroscopy (UV-Vis) was used. The width of the band gap was determined on the basis of the absorption spectra of radiation (UV-Vis). Findings: The carried out morphology and surface structure research showed that with increasing mass increased porosity of the produced coating surface was observed. In addition, the greater the diameter of the applied ceramic nanoparticles, the more noticeable this effect was. The analysis of the optical properties of the obtained nanomaterials, carried out based on the registered spectra in absorption function of the wavelength, revealed a strong absorption of this type of layers under ultraviolet radiation. Research limitations/implications: The nanostructured materials as components provides nanocomposite optical properties, such as absorption and width of the energy gap. In addition, nanoparticle content causes changes of the surface morphology, which is an important parameter of thin films in potential applications. Originality/value: The properties of films depend not only on the individual components used, but also on the morphology and the interfacial characteristics.

7

Adhezja warstw SiO2 naniesionych metodą ALD i zol-żel na stal 316LVM

Basiaga M., Walke W., Kajzer A., Kajzer W., Staszuk M., Kurtyka P.

Engineering of Biomaterials

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2017

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Vol. 20, no. 141

13--19

PL

Celem prezentowanej pracy była ocena przydatności stosowania warstw SiO2 naniesionych dwiema metodami Atomic Layer Depositon (ALD) i zol-żel na podłoże ze stali 316LVM stosowanej na implanty w układzie sercowo-naczyniowym. Do badań wytypowano stal austenityczną 316LVM i poddano ją następującym modyfikacją powierzchni: polerowanie elektrochemiczne, pasywacja chemiczna, naniesienie warstw SiO2 zarówno metodą ALD, jak i zol-żel. Wymienione metody są obecnie najczęściej stosowane w przypadku nanoszenia warstw powierzchniowych na implanty. W ramach oceny przydatności zaproponowanych metod modyfikacji powierzchni analizowanej stali autorzy pracy przeprowadzili badania własności mechanicznych, elektrochemicznych oraz fizycznych. Na podstawie uzyskanych wyników stwierdzono, że niezależnie od metody nanoszenia zaobserwowano korzystny wpływ warstwy SiO2 na badane własności w porównaniu do stanu wyjściowego. Ponadto stwierdzono, że najkorzystniejszym zespołem własności mechanicznych, elektrochemicznych i fizycznych charakteryzuje się warstwa SiO2 naniesioną metodą ALD. Tak naniesiona warstwa charakteryzowała się większą siłą krytyczną powodującą delaminację warstwy, większą odpornością na korozję wżerową oraz większym kątem zwilżania wodą (charakter hydrofobowy), co w przypadku implantów stosowanych w układzie krwionośnym jest zjawiskiem pożądanym, ponieważ wymagana jest mała adsorpcja białek, która ogranicza proces krzepnięcia krwi. Zaproponowanie odpowiednich wariantów obróbki powierzchniowej z wykorzystaniem metody ALD oraz zol-żel ma perspektywiczne znaczenie i przyczyni się do opracowania warunków technologicznych o sprecyzowanych parametrach wytwarzania powłok tlenkowych na implantach stosowanych w układzie sercowo-naczyniowym.

EN

The aim of this study was to evaluate the usefulness of SiO2 layers deposited by two methods - atomic layer deposition (ALD) and sol-gel, on the surface of stainless steel 316LVM used in application of cardiovascular implants. In assessing the suitability of the proposed methods to modify surfaces of the analysed steel, authors carried out tests of mechanical, electrochemical and physical properties. The austenitic steel 316LVM was chosen and subjected to the following surface modifications: electrochemical polishing, chemical passivation and application of the SiO2 layer using both methods – ALD and sol-gel. These methods were proposed for research, because they are most commonly used in the case of applying surface layers to implants. Based on the obtained results, it was observed that regardless of the method of application, the SiO2 layer has beneficial effect on examined properties compared to control. Moreover, it was found that the SiO2 layer deposited by ALD is characterized by the most preferred combination of mechanical, physical and electrochemical properties. The layer obtained by this method is characterized by a higher critical force, which causes delamination of the layers, higher resistance to pitting corrosion and higher water contact angle (hydrophobic character), which is a desirable phenomenon in the case of implants used in the circulatory system, resulting in lower adsorption of proteins and blood clothing. Proposing of suitable variants of surface treatment using the ALD and sol-gel methods is of perspective importance. It will contribute to the development of technological conditions with specified parameters for the production of oxide coatings on implants used in the cardiovascular system.

8

Badanie możliwości syntezy mullitu za pomocą mikrofal

Taźbierski P., Dziubak C., Tymowicz-Grzyb P.

Materiały Ceramiczne

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2016

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T. 68, nr 2

98--104

PL

Niewielkie występowanie mullitu w środowisku naturalnym powoduje, że praktyczne znaczenie ma minerał syntetyczny. Wytwarzanie mullitu związane jest z takimi właściwościami surowców jak czystość chemiczna, uziarnienie, postać chemiczna, a także z procesem syntezy w wysokiej temperaturze. Przedstawiono wyniki syntezy mullitu z wykorzystaniem pieca mikrofalowego z surowców (Al2O3, SiO2) o uziarnieniu mikrometrycznym oraz nanometrycznym. Wyniki badań obejmują skład fazowy produktów odpowiednio do właściwości surowców wyjściowych i temperatury syntezy.

EN

Small presence of mullite in nature results in practical importance of a synthetic mineral. Preparation of mullite is related to the properties of raw materials such as: chemical purity, grain size, phase and the synthesis process at a high temperature. The synthesis of mullite with the use of a microwave oven is presented. Al2O3, and SiO2 powders with micrometer and nanometer grain sizes were used for the synthesis. The test results include the phase composition of products in relation to the properties of raw materials and synthesis temperature.

9

Morphological, chemical and structural characterization of silica-containing polyvinylpyrrolidone electrospun nanofibers prepared by sol-gel technique

Tański T., Matysiak W., Zaborowska M., Łukowiec D., Krzesiński M.

Journal of Achievements in Materials and Manufacturing Engineering

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2016

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Vol. 79, nr 1

5--12

EN

Purpose: The aim of this study was to produce poly(vinylpyrrolidone) (PVP) containing silica nanofibers using electrospinning method from 10% PVP/EtOH solutions with different mass concentration 0 and 30% of tetraethoxysilane. Sol-gel technique was used to obtain nanofiber membranes with high amount of inorganic phase. In the case when metal alkoxide, such as tetraethyl orthosilicate (TEOS) is mixed with an organic polymer, hydrolysis and condensation reaction of TEOS occur in-situ with polymer matrix, which allows to fabricate organic-inorganic hybrid structures with uniform dispersion. Design/methodology/approach: The examination of the morphology of the obtained PVP/silicon dioxide nanofibers using scanning electron microscope (SEM) has been made. The chemical structure of produced nanostructures was investigated by Fourier - Transform Infrared spectroscopy (FTIR) and Energy Dispersive Spectrometry (EDX) to analyze the regular dispersion by examining types of bonds occurring between polymer matrix and SiO2 phase. Findings: Results obtained in this paper shows that the mass concentration of the reinforcing phase in form of TEOS have an influence on the average diameter of nanofibers and with the increase of tetraethyl orthosilicate in solution nanofibers diameters decrease. Moreover, structural examination shows uniform dispersion of the reinforcing phase in hybrid materials. Research limitations/implications: Uniform dispersion of the reinforcing phase in silica-containing PVP nanofibers gives the opportunity to make nanowires in calcination process from such obtained fibrous mats and use in novel electrical devices. Originality/value: This paper describes an easy and more effective way of making polymer nanofibers with the content of silicon dioxide with the perspective way of making silica nanowires in the future from obtained hybrid nanofibers, so that this method can replace commonly used nanowires growth processes.

10

Symulacje ab-initio warstwy grafenowej wykorzystywanej w detektorze IR

Woźny J., Ruta Ł., Lisik Z.

Elektronika : konstrukcje, technologie, zastosowania

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2016

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Vol. 57, nr 10

31--32

PL

W artykule przedstawione zostały wyniki symulacji ab-initio z wykorzystaniem oprogramowania MedeA VASP warstwy grafenowej w obecności wybranych materiałów wykorzystywanych w konstrukcji detektora podczerwieni. Symulacje miały za zadanie odpowiedzieć, czy i w jaki sposób zmieniają się parametry warstwy grafenowej w obecności SiO₂ i Al₂O₃. Ocenie poddany został kształt pasm energetycznych.

EN

The article presents the results of ab-initio simulations by the means of Medea VASP tool of graphene layer in the presence of selected materials used in the production of infrared detector. The simulations have been performed to answer whether and how the parameters of the graphene sheet may change in the presence of SiO₂ and Al₂O₃. Assessment has been done on the basis of the energy bands shape. Graphene is a material that has opened new perspectives in the design of electronic devices and launched studies on various 2D materials. The correct determination of the parameters of graphene must take into account the conditions in which the graphene layer operates. Within this work we show preliminary the free layer graphene band structure. Obtaining a correct shape of the energy bands is possible by the means of DFT approach when appropriate mesh in the k domain is used: Δk = 0.05 1/Ä. Simulations of the graphene layer placed and SiO₂ and between SiO₂ and Al₂O₃ confirmed that the shape of band structure remains untouched at Dirac point and p-type doping of graphene layer has been observed for simulated structures.

11

Ocena własności fizykochemicznych warstwy SiO2 w warunkach odkształcenia

Król A., Walke W., Basiaga M., Karasiński P.

Aktualne Problemy Biomechaniki

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2016

|

z. 11

81--86

PL

W pracy przeprowadzono badania odporności korozyjnej, twardości oraz adhezji warstwy SiO2 naniesionej na powierzchnię stopu Ni-Ti. Badania realizowano zarówno dla próbek nieodkształconych, jak i odkształconych. Badania odporności na korozję przeprowadzono metodą potencjodynamiczną i impedancyjną w warunkach symulujących środowisko tkankowe – roztwór Ringera. Z kolei adhezję warstwy do podłoża oceniano metodą zarysowania (scratch-test). Do wyznaczenia twardości warstwy zastosowano metodę Vickersa wykorzystując wgłębnik Berkovicha. Przeprowadzone badania nie wykazały znaczących zmian własności fizykochemicznych warstw poddanych odkształceniu w stosunku do warstw nieodkształconych.

EN

The project preformed researches corrosion resistance, hardness and adhesion of SiO2 layer on Ni-Ti alloy. Researches were realized on deformed and not deformed specimen. Corrosion resistance research was performed by using potentiodynamic and impedance methods in conditions which simulate tissue environment – Ringer solution. Adhesion layer to metal substrate was evaluate by scratch test method. To get the hardness of layer the Vickers method with indenter Berkovich was used. The studies which were done did not show significant changes of physical-chemical properties for deformed and not deformed specimen.

12

Effects of TiO2/SiO2 reinforced nanoparticles on the mechanical properties of green hybrid coating

Gobara M.

International Letters of Chemistry, Physics and Astronomy

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2015

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Vol. 47

56--66

EN

Titanium and silica oxides nanoparticles were introduced into hybrid silica sol–gel/epoxy coating to enhance the mechanical properties of coatings. Titanium dioxide (TiO2) and silica oxide (SiO2) were chemically synthesised before adding to the prepared silica sol gel coating. X-ray diffraction (XRD), Energy-dispersive x-ray analysis (EDX) and Transmission Electron microscope (TEM) were used to characterize the prepared nanoparticles. The coating was then applied to 3003 aluminium alloy (AA3003) surface. The adhesion performance of different sol gel coating compositions was investigated using shear test to define the influence of nanoparticles on adhesive strength of the coating. The Rockwell C hardness test was used to study the micro-hardness of different compositions of sol gel coating. Also, contact angel was used to investigate the hydrophobicity of the coatings. The results showed that there was a significant improvement of the adhesion performance of hybrid silica sol gel coating due to addition of TiO2 and the hydrophobicity of sol gel coating was increased due to addition of SiO2 nanoparticles.

13

Synthesis And Characterization Of SiO2, SnO2 And TiO2 Metal Oxide Shells Covering Cu2O Particles

Yu R., Yun J., Kim Y.

Archives of Metallurgy and Materials

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2015

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Vol. 60, iss. 2B

1159--1163

EN

In this work is described a means of improving the chemical stability of Cu2O@SiO2, Cu2O@SnO2 and Cu2O@TiO2 materials. The SiO2, SnO2 and TiO2 coated samples were stable from pH 3 to pH 10 for up to seven days. To determine the stability of the coated nanoparticles, and their colloidal solutions under acidic and basic conditions, colloidal nanoparticle solutions with various pH values were prepared and monitored over time. Details of the effect of variations in pH on the phase stability of core-shell type Cu2O were characterized using transmission electron microscopy and X-ray diffraction.

14

Ocena wybranych własności użytkowych warstwy SiO2 naniesionej na powierzchnię stopu Ni-Ti

Król A., Walke W., Basiaga M.

Aktualne Problemy Biomechaniki

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2015

|

z. 9

61--66

PL

W pracy przeprowadzono ocenę własności elektrochemicznych w oparciu o badania impedancyjne stopu Ni-Ti z naniesioną warstwą SiO2. Pomiary przeprowadzono z wykorzystaniem systemu pomiarowego Auto Lab PGSTAT 302N wyposażonego w moduł FRA2. Jako elektrodę odniesienia zastosowano nasyconą elektrodę kalomelową. Elektrodę pomocniczą stanowił drut platynowy. W celu zasymulowania warunków występujących w środowisku rzeczywistym pomiary przeprowadzono w roztworze Tyrode’a w temperaturze T = 37±1oC i pH = 6,8 ±0,2. W celu określenia przyczepności warstwy SiO2 do podłoża metalowego przeprowadzono badania scratch-test. Do tego celu zastosowano platformę otwartą wyposażoną w MicroCombi-Tester firmy CSM. Podsumowując, przeprowadzone badania jednoznacznie wykazały, że warstwa SiO2 jest przydatna dla poprawy biokompatybilności stopu Ni-Ti.

EN

The project included studies about electrochemical properties based on impedance Ni-Ti alloy with an SiO2 layer. The measurements were performed by using Auto Lab PGSTAT 302N system, equipped in FRA module. As a reference electrode, were used saturated chloro – silver electrode. An auxiliary electrode was a platinum wire. To provide and simulate conditions in real environment, measurements were performed in Ringer solution at the temperature of 37 ± 1°C and pH = 6.8 ± 0.2. To define the SiO2 layers adhesion to metal substrate, it was made the scratch – test . We used the CSM’s open platform squipped with MicroCombi – Tester. In conclusion, the studies which were made showed clearly, that the SiO2 layer is useful to improve biocompatibility of Ni-Ti alloy.

15

Silicon oxides as alignment surfaces for vertically-aligned nematics in photonic devices

Oton E., López-Andrés S., Bennis N., Otón J. M., Geday M. A.

Opto-Electronics Review

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2014

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Vol. 22, No. 2

92-100

EN

A comparative study on alignment performance and microstructure of inorganic layers used for liquid crystal cell conditioning has been carried out. The study has focused on two specific materials, SiOx and SiO₂, deposited under different conditions. The purpose was to establish a relationship between layer microstructure and liquid crystal alignment. The surface morphology has been studied by FESEM and AFM. An analysis on liquid crystal alignment, pretilt angle, response time, contrast ratio and the conditions to develop backflow effect (significant rise time increase due to pure homeotropic alignment) on vertically-aligned nematic cells has been carried out. A technique to overcome the presence of backflow has been identified. The full comparative study of SiOx and SiO₂ layer properties and their influence over liquid crystal alignment and electrooptic response is presented.

16

Optical properties of the Al2O3/SiO2 and Al2O3/HfO2/SiO2 antireflective coatings

Marszalek K, Winkowski P, Jaglarz J.

Materials Science Poland

|

2014

|

Vol. 32, No. 1

80--87

EN

Investigations of bilayer and trilayer Al2O3/SiO2 and Al2O3/HfO2/SiO2 antireflective coatings are presented in this paper. The oxide films were deposited on a heated quartz glass by e-gun evaporation in a vacuum of 5 × 10 -3 [Pa] in the presence of oxygen. Depositions were performed at three different temperatures of the substrates: 100 °C, 200 °C and 300 °C. The coatings were deposited onto optical quartz glass (Corning HPFS). The thickness and deposition rate were controlled with Inficon XTC/2 thickness measuring system. Deposition rate was equal to 0.6 nm/s for Al2O3, 0.6 nm – 0.8 nm/s for HfO2 and 0.6 nm/s for SiO2. Simulations leading to optimization of the thin film thickness and the experimental results of optical measurements, which were carried out during and after the deposition process, have been presented. The optical thickness values, obtained from the measurements performed during the deposition process were as follows: 78 nm/78 nm for Al2O3/SiO2 and 78 nm/156 nm/78 nm for Al2O3 /HfO2/SiO2. The results were then checked by ellipsometric technique. Reflectance of the films depended on the substrate temperature during the deposition process. Starting from 240 nm to the beginning of visible region, the average reflectance of the trilayer system was below 1 % and for the bilayer, minima of the reflectance were equal to 1.6 %, 1.15 % and 0.8 % for deposition temperatures of 100 °C, 200 °C and 300 °C, respectively.

17

Solvent-free synthesis and assessment of substituent effects from IR & NMR spectra of some substituted benzylidene-5-ethyl-1,3,4-thiadiazole-2-amines

Thirunarayanan G.

International Letters of Chemistry, Physics and Astronomy

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2014

|

Vol. 5

89--98

EN

A series containing ten titled compounds were synthesized by SiO2:H3PO4 catalyzed solvent-free condensation of substituted benzaldehydes and 2-amino-5-ethyl-1,3,4-thiadiazole under microwave irradiation. The yields of prepared amines are more than 90 %. The synthesized amines were characterized by their physical constants and spectroscopic data reported in literature earlier for known compounds. The assigned spectral group frequencies such as infrared νC=N, C-S-C, N-N (cm-1) and NMR chemical shifts (δ, ppm) of CH, C=N have been correlated with Hammett substituent constants, F and R parameters using single and multi-linear regression analysis. From the results of statistical analyses, the effects of substituent on the above spectral data have been discussed.

18

Otrzymywanie i zastosowanie funkcjonalizowanych napełniaczy hybrydowych SiO2/F-SF POSS w żelowych elektrolitach polimerowych

Szwarc-Rzepka K., Walkowiak M., Osińska-Broniarz M., Dutkiewicz M., Maciejewski H., Jesionowski T.

Polimery

|

2013

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T. 58, nr 10

748--758

PL

Metodą odparowania rozpuszczalnika wytwarzano układy hybrydowe SiO2/POSS. Do modyfikacji powierzchni krzemionki uwodnionej lub otrzymanej techniką emulsyjną zastosowano oktakis(dimetylosiloksy-1,1',2,2',3,3',4,4'-oktafluoropentyloksypropylo) oktasilseskwioksan (F-SF POSS). Efektywność modyfikacji napełniaczy potwierdzano przy użyciu spektroskopii w podczerwieni (FT-IR) oraz jądrowego rezonansu magnetycznego (29Si oraz 13C CP MAS NMR). Określano parametry struktury porowatej wytworzonych napełniaczy hybrydowych, takie jak: powierzchnia właściwa BET, średnica oraz objętość porów. Układy hybrydowe poddano ponadto analizie dyspersyjnej (metodą nieinwazyjnego wstecznego rozproszenia światła — NIBS) oraz morfologicznej (za pomocą transmisyjnej mikroskopii elektronowej TEM). Otrzymane modyfikowane napełniacze zastosowano jako dodatek do żelowych elektrolitów polimerowych. Elektrolity żelowe uzyskano na drodze aktywacji suchych membran kompozytowych w ciekłym roztworze soli litu. Badania elektrochemiczne obejmowały pomiary przewodnictwa właściwego techniką spektroskopii impedancyjnej w szerokim zakresie temperatury oraz wyznaczenie okien potencjałowych techniką liniowej woltametrii cyklicznej. Dodatek kompozytów POSS wpływa korzystnie na transport kationów litu, zwiększając przewodnictwo żeli na bazie PVdF/HFP w temperaturze pokojowej o ponad jeden rząd wielkości. Obserwowany wzrost przewodnictwa jest słabo skorelowany z ich zdolnością do absorpcji fazy ciekłej. Stabilność anodowa żeli rośnie nieznacznie w wyniku dodania napełniaczy POSS do membran PVdF/HFP. Badane napełniacze wykazują obiecujące właściwości w kontekście przyszłych prac badawczo-rozwojowych nad nowatorskimi elektrolitami stałymi do akumulatorów litowych o zwiększonym poziomie bezpieczeństwa.

EN

Hybrid SiO2/POSS fillers were obtained using the method based on solvent evaporation. Octakis({1,1,2,2,3,3,4,4-octafluoropentyloxypropyl}dimethylsiloxy) octasilsesquioxane (F-SF POSS) was used to modify the surface of silica, hydrated or prepared via emulsion method. The effectiveness of modification was evaluated by FT-IR spectroscopy and nuclear magnetic resonance (29Si and 13C CP MAS NMR). The parameters of porous structure of the prepared hybrid fillers, such as surface area BET, mean pore diameter and pore volume were determined. The hybrid products were subjected to dispersive analysis (non-invasive backscattering method, NIBS) and morphological characterization (using transmission electron microscopy — TEM). The obtained hybrid systems were used as additives in gel polymer electrolytes, prepared by activation of dry composite membranes in a liquid solution of lithium salt. The electrolytes were subjected to electrochemical studies, including the measurements of specific conductivity by impedance spectroscopy in a wide range of temperatures and the determination of potential windows by the linear cyclic voltammetry. The addition of POSS composites had a beneficial effect on the transport of lithium cations and the room temperature conductivity of gel electrolytes based on PVdF/HFP membranes was enhanced by an order of magnitude. The observed increase in gel conductivity was poorly correlated with the ability of liquid phase absorption. The anodic stability of gels only slightly increased upon the addition of POSS to PVdF/HFP membranes. The fillers studied show promising properties in the context of future research and development studies on new solid electrolytes for lithium cells with increased safety.

19

Wstępne badania wpływu podwyższonych temperatur na wytrzymałość drewna impregnowanego środkiem ogniochronnym zawierającym SiO2

Ogrodnik P., Pieniak D., Jaskółowski W., Gil L., Szulej J.

TTS Technika Transportu Szynowego

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2012

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R. 19, nr 9

1395--1401, CD

PL

Dotychczasowe materiały drewniane i drewnopochodne miały wiele wad ograniczających ich zastosowanie w infrastrukturze transportu. Problem stanowiły ograniczenia co do maksymalnych wymiarów przekrojów elementów oraz możliwości wykonywania elementów o znacznych rozpiętościach, również trwałość powierzchni a także łatwopalność ograniczały ich zastosowanie. Obecnie coraz częściej w infrastrukturze transportu wykorzystuje się drewno. Wykorzystywane jest m.in. do wykończenia środków i infrastruktury budowlanej transportu, w konstrukcji ekranów przeciwhałasowych, przystanków i innych. W artykule przedstawiono wyniki badań wytrzymałości drewna świerkowego. Badano próbki impregnowane zabezpieczone środkiem ogniochronnym zawierającym krzemionkę. Badania wytrzymałości prowadzono po ekspozycji próbek w podwyższonych temperaturach oraz na próbkach nie obrobionych termicznie. W badaniach nie wykazano istotnego wpływu zastosowanej impregnacji oraz podwyższony temperatur na wytrzymałość drewna świerkowego. Wykazano wpływ podwyższonych temperatur na charakterystykę zniszczenia próbek.

EN

Previously applied wood and wood-based materials have had many drawbacks limiting their use in transport infrastructure. A problem was due to such limitations as the maximum cross-sections of the elements, ability to manufacture large-span elements, durability of the surface, as well as flammability. Nowadays, the wood is used more often in the transport infrastructure. It is applied among the others to finish the means of transportation and building infrastructure, construction of the noise barriers, bus stops etc. In this paper the results of strength tests for the spruce timber are presented. The studied samples were treated with fire retardant containing silica. The strength studies were carried out after high-temperature exposure of the samples and for the samples not treated thermally. The studies have not revealed any significant influence of the wood treatment or increased temperatures on the strength of the spruce timber. However, the impact of increased temperatures on characteristics of the samples destruction has been demonstrated.

20

Formowanie kompozytu tlenkowego TiO₂-SiO₂ w emulsji z wykorzystaniem heksanu lub heptanu jako rozpuszczalnika organicznego

Siwińska-Stefańska K., Michalak J., Jesionowski T.

Przemysł Chemiczny

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2012

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T. 91, nr 5

964-969

PL

Ustalono najkorzystniejsze parametry procesu formowania kompozytów tlenkowych TiO₂-SiO₂ otrzymywanych metodą precypitacji emulsyjnej z użyciem heksanu lub heptanu jako fazy organicznej. Kompozyty TiO₂-SiO₂ strącano z roztworów krzemianu sodu oraz siarczanu(VI) tytanu(IV). Jako emulgatory zastosowano niejonowe związki powierzchniowo czynne. Uzyskane kompozyty tlenkowe TiO₂-SiO₂ poddano wszechstronnej charakterystyce fizykochemicznej. Szczegółowo określono ich właściwości dyspersyjne, wyznaczając w tym celu rozkłady wielkości cząstek oraz indeks polidyspersyjności (technika NIBS). Wykorzystując skaningową mikroskopię elektronową, dokonano obserwacji mikroskopowych, które pozwoliły na ocenę morfologii powierzchni badanych form tlenkowych. Analizę rentgenograficzną wybranych próbek kompozytów tlenkowych przeprowadzono przy użyciu techniki WAXS. Właściwości adsorpcyjne określono przez wyznaczenie izoterm adsorpcji-desorpcji azotu oraz wyznaczenie powierzchnii właściwej, objętości oraz średniej wielkości porów. Celem określenia właściwości hydrofilowo-hydrofobowych kompozytów TiO₂-SiO₂ wyznaczono profile zwilżalności wodą.

EN

TiO₂-SiO₂ composites were pptd. from aq.-org. emulsions contg. TiOSO₄ and Na₃SiO₃ (water glass), oxyethylated alkylphenol surfactant and hexane or heptane as org. solvents. The composite was sepd. by filtration, dried at 105°C for 18 h, calcined at 1000°C for 1 h and analyzed for dispersion, crystal structure, adsorption ability and water wettability. Use of hexane resulted in formation of composites with lower polydyspersity and higher pore vol., sp. surface area (up to 35.6 m²/g) and wettability than those produced in presence of heptane.