Herein, the effects of multi-walled carbon nanotubes (CNTs) on the mechanical and dielectric performance of hybrid carbon nanotube-woven glass fiber (GF) reinforced epoxy laminated composited are investigated. CNTs are deposited on woven GF surface using an electrospray deposition method which is rarely reported in the past. The woven GF deposited with CNT and without deposited with CNT are used to produce epoxy laminated composites using a vacuum assisted resin transfer moulding. The tensile, flexural, dielectric constant and dielectric loss properties of the epoxy laminated composites were then characterized. The results confirm that the mechanical and dielectric properties of the woven glass fiber reinforced epoxy laminated composited increases with the addition of CNTs. Field emission scanning electron microscope is used to examine the post damage analysis for all tested specimens. Based on this finding, it can be prominently identified some new and significant information of interest to researchers and industrialists working on GF based products.
The introduction of carbon nanotubes (CNTs) onto glass fibre (GF) to create a hierarchical structure of epoxy laminated composites has attracted considerable interest due to their merits in improving performance and multifunctionality. Field emission scanning electron microscopy (FESEM) was used to analyze the woven hybrid GF-CNT. The results demonstrated that CNT was successfully deposited on the woven GF surface. Woven hybrid GF-CNT epoxy laminated composites were then prepared and compared with woven GF epoxy laminated composites in terms of their tensile properties. The results indicated that the tensile strength and tensile modulus of the woven hybrid GF-CNT epoxy laminated composites were improved by up to 9% and 8%, respectively compared to the woven hybrid GF epoxy laminated composites.
3
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
With regard to the challenges in the automotive production sector, caused by political regulations of CO2 emissions, lightweight concepts are focussed by industrial development. Fibre reinforced plastics (FRP) represent an alternative material compared to monolithic steel. On the one hand FRP materials offer advantages like less density with high specific strength, on the other hand new production concepts and processes are needed. A possible approach is the combination of different forming processes for the production of new hybrid components. Polymer based and conventional sheet metal material characteristics differ strongly. Therefore an extensive material characterisation is needed as well as appropriate mathematical methods concerning the material modelling. This publication deals with the material characterisation of glass mat reinforced thermoplastic composite (GMT) and the finite element based design of a manufacturing process of hybrid components with metallic inlays.
The need for improvement in nitrocellulose (NC) storage safety and convenience of application requires an increase in NC thermal stability and enhancement of its mechanical properties. To this aim, hybrid materials were synthesized by grafting NC with aminopropylisobutyl polyhedral oligomeric silsesquioxane (amino-POSS) using isophorone diisocyanate (IPDI) as a crosslinking agent. The structure and elemental composition of the resulting products were confirmed by Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (1H NMR and 29Si NMR), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). It was found, based on the silicon mapping using energy dispersive X-ray spectroscopy (EDS), that amino-POSS was well dispersed in NC matrix. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) studies showed that hybrid amino-POSS-NC materials have higher thermal decomposition activation energy (Ea) compared to NC control sample. According to TGA results, the temperatures of 5 % weight loss (T5 %) and 50 % weight loss (T50 %) as well as the residual masses at 240 °C (CR240 °C), were increased as a result of NC modification with amino-POSS. As can be seen from the digital and scanning electron microscopy (SEM) images, the char layers of amino-POSS-NC hybrid materials after burning in air became more compact with increasing amino-POSS content. XPS studies have shown an increased content of the graphitized carbon in the char residues of the modified samples. The results of DSC, TGA, SEM and XPS studies have directly proved the enhancement of the thermal stability of amino-POSS-NC hybrid materials. In addition, tensile strengths and Young's moduli of amino-POSS-NC hybrid materials were increased gradually with the amino-POSS content in the uniaxial tensile tests. All these results show that the proposed modification of nitrocellulose improves the safety of manufacture and use of this material.
PL
Poprawa bezpieczeństwa przechowywania nitrocelulozy (NC) wymaga zwiększenia jej stabilności termicznej, a wygoda używania poprawy właściwości mechanicznych. W tym celu zsyntetyzowano materiały hybrydowe, w których NC szczepiono oligomerycznym wielofunkcyjnym aminopropyloizobutylosilseskwioksanem (amino-POSS) stosując jako środek sieciujący izoforonodiizocyjanian (IPDI). Strukturę i skład otrzymanych materiałów potwierdzono za pomocą spektroskopii w podczerwieni z transformatą Fouriera (FT-IR), jądrowego rezonansu magnetycznego (1H NMR i 29SiNMR), dyfraktometrii rentgenowskiej (XRD) oraz spektroskopii fotoelektronów rentgenowskich (XPS). Na podstawie wyników badań mapowania Si, otrzymanych metodą spektroskopii dyspersji energii promieniowania rentgenowskiego (EDS), stwierdzono, że amino-POSS został dobrze zdyspergowany w matrycy NC. Badania stabilności termicznej przeprowadzone za pomocą różnicowej kalorymetrii skaningowej (DSC) wykazały, że materiały hybrydowe typu amino-POSS-NC charakteryzują się większymi wartościami energii aktywacji rozkładu termicznego (Ea) niż próbka kontrolna NC. Zgodnie z wynikami analizy termograwimetrycznej (TGA) wartości temperatury ubytku 5 % (T5 %) i 50% (T50 %) masy próbki oraz pozostałości masy w temperaturze 240 °C (CR240 °C) zwiększały się na skutek modyfikacji NC za pomocą amino-POSS. Według fotografii cyfrowych i fotografii wykonanych metodą skaningowej mikroskopii elektronowej (SEM) warstwy węglowe powstałe po spaleniu materiałów hybrydowych w powietrzu wraz ze zwiększeniem zawartości amino-POSS stawały się coraz bardziej zwarte, a wyniki badań XPS wykazały, że tworzyło się coraz więcej węgla w postaci grafitu. Wszystkie wyniki DSC, TGA, SEM i XPS dowodzą poprawy stabilności termicznej materiałów hybrydowych amino-POSS-NC. Stwierdzono także, że wytrzymałość na rozciąganie i moduł Young'a podczas prób jednoosiowego rozciągania materiałów hybrydowych rosną ze zwiększaniem się zawartości amino-POSS. Wyniki wszystkich przeprowadzonych badań dowodzą, że zaproponowana modyfikacja NC poprawia bezpieczeństwo wytwarzania i użytkowania tych materiałów w porównaniu z niemodyfikowanym NC.
The solid-liquid extraction is one of the most used methods for protection of the environment against organic and inorganic pollutants. The hybrid materials have been synthesized by a simple method from natural clay and modified poly(vinyl chloride) (PVC). The obtained products were characterized by various techniques, infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), and differential thermal analysis (DTA). The final materials were successfully used for entrapping heavy metal ions (Fe, Cu, Cd, Zn, Pb, Mn, and Co). The quantities of adsorbed metal cations were determined by atomic absorption analysis. It has been revealed that the metals extraction was governed essentially by the affinity between the functional groups of the hybrid material and the investigated metal ion. The cations are extracted in the following decreasing order of effectiveness: Fe3+ > Cu2+ > Co2+ ≈ Mn2+ > Pb2+ > Cd2+ ≈ Zn2+.
PL
Proces ekstrakcji w układzie ciało stałe-ciecz jest najczęściej stosowany w celu ochrony środowiska przed działaniem szkodliwych, organicznych i nieorganicznych zanieczyszczeń. Materiały hybrydowe zsyntetyzowano w prosty sposób z modyfikowanego poli(chlorku winylu) i naturalnej, tunezyjskiej glinki. Otrzymane materiały badano różnymi metodami: spektroskopii w podczerwieni (FT-IR), analizy termograwimetrycznej (TGA) oraz różnicowej analizy termicznej (DTA). Oceniano przydatność otrzymanych materiałów hybrydowych w procesach ekstrakcji kationów metali ciężkich: Fe, Cu, Cd, Zn, Pb, Mn i Co w układzie ciało stałe-ciecz. Ilości zaadsorbowanych kationów oceniano metodą absorpcji atomowej. Wykazano, że ekstrakcja metali jest możliwa dzięki powinowactwu grup funkcyjnych kompozytów hybrydowych z jonami metali. Za pomocą wytworzonych materiałów hybrydowych ekstrahowano badane jony w stopniu określonym następującą kolejnością: Fe3+ > Cu2+ > Co2+ ≈ Mn2+ > Pb2+ > Cd2+ ≈ Zn2+.
In this work a modular intelligent fixture system for flexible clamping of large parts is presented. The fixture modules consist of a hybrid material structure involving metal frame elements and mineral casting. These modules can be combined and connected to realize fixtures adapted to the geometry of the workpiece and requirements of the machining processes. By integrated pipes and interfaces, an internal hydraulic supply and active cooling is possible even for combined modules. Temperature and acceleration sensors allow for an active thermal control and process monitoring. The modules and first test fixtures are investigated in experiments.
Functional inorganic-organic hybrids were synthesized using as a precursor silica with the addition of an appropriate amount of lignin as components. Three types of silica were applied as the support: the commercial silicas Syloid 244 and Aerosil 200, and hydrated silica precipitated in a polar system. The silicon dioxide was initially functionalized with aminosilane to activate the surface, and then the silica-based material was combined with lignin oxidized using hydrogen peroxide. The obtained inorganic-organic hybrids underwent physicochemical and dispersive-morphological analysis, with comparison of the results depending on the composition of the test samples. In addition, particle size distributions were determined and the surface structure of the products assessed by scanning electron microscopy. The presence of functional groups was also determined by FTIR spectroscopy. The thermal analysis of the silica/lignin materials was also performed, as well as the elemental and colorimetric analyses, which indirectly confirmed the correctness of the synthesis process. Hybrid materials with the most favorable dispersive and morphological properties were obtained by adding a small amount of biopolymer. The thermogravimetric analysis of the SiO2/lignin hybrids indicated their good thermal stability. With increasing quantity of lignin per 100 parts by weight of silica matrix, progressive deterioration in the thermal stability of the materials was observed.
8
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
W artykule przedstawiono etapy wytwarzania hybrydowego materiału termoizolacyjnego składającego się ze styropianu i włókien pochodzących z recyklingu. Omówiono dobranie odpowiedniej granulacji celulozy, wybór dodatku uniepalniającego, środka grzybobójczego oraz czynnika łączącego składniki międzyfazy z EPS. Podkreślono elementy wpływające na innowacyjność tego produktu.
EN
The article presents the production stages for a hybrid thermal insulation material, composed of expanded polystyrene foam and recycled fibres. It discusses selection of the right cellulose grain size, selection of flame retardant, anti-fungal agent and binding agent for binding the core layers with EPS. Special emphasis was on the elements affecting the innovative quality of the product.
9
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
We współczesnej technice, a zwłaszcza w opakowalnictwie, stosuje się duże ilości materiałów warstwowych. Ich ponowne wykorzystanie jest niemożliwe bez rozdzielenia na poszczególne składniki. Przedstawiono wybrane techniki rozdzielenia hybrydowych materiałów warstwowych takich jak metalizowane tworzywa polimerowe, kartony na napoje i kompozyty polimerowe o bardzo dużej wytrzymałości.
EN
In modern technology and especially the package industry a lot of ply materials are used. Reuse of these materials is not possible without their separation into components. In this paper some possibilities of separation of hybrid ply materials are described e.g. metallized plastics, beverages packaging and polymer composites.
10
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
Hybrid field-effect transistors (FETs) based on poly(3-hexylthiophene) (P3HT) containing CdSe quantum dots (QDs) were fabricated. The effect of the concentration of QDs on charge transport in the hybrid material was studied. The influence of the QDs capping ligand on charge transport parameters was investigated by replacing the conventional trioctylphosphine oxide (TOPO) surfactant with pyridine to provide closer contact between the organic and inorganic components. Electrical parameters of FETs with an active layer made of P3HT:CdSe QDs blend were determined, showing field-effect hole mobilities up to 1.1×104 cm2 /Vs. Incorporation of TOPO covered CdSe QDs decreased the charge carrier mobility while the pyridine covered CdSe QDs did not alter this transport parameter significantly.
11
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
Purpose: This article provides an overview of the daylighting system using existing and advanced submicron technology for buildings. The approaches of movable and fixed sunlight guiding system for saving the energy of artificial lighting will be reviewed. The major part is devoted to the sunlight guide panel / film based on a formed prismatic microstructure on transparent substrate by UV-imprint and roll-to-roll process. Design/methodology/approach: To achieve the prismatic microstructure sunlight guide panel / film, the wide aspects including the suitable materials, optical design of the microstructure and tuning the imprint processes are covered. In addition, to estimate the effectiveness of sunlight guide panel / film, a series of experiments were performed and compared with the prediction. Findings: The analysis reveals the outgoing light above the horizontal level of the transom in a major portion. It indeed provides the adequate indoor daylighting by the proposed sunlight guide panel / film. Research limitations/implications:The use of micro-polygonal-structured sunlight guide panel/film to deliver the daylight into the core area of a building is recommended as future research to enhance the indoor illumination by daylighting system. The portion of outgoing light below 90° causes the glare. Practical implications: The authors conclude the proposed prismatic sunlight guide panel/film is a promising approach for guiding daylight into a room. Originality/value: The reviewed daylighting system with submicron-patterned prismatic sunlight guide panel/film made of inorganic-organic materials is based on the authors’ original work of daylighting techniques. It significantly elevates the use of sunlight and saves energy consumption in a building.
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.