scholarly journals Synthesis Based on a Preceramic Polymer and Alumina Nanoparticles via UV Lithography for High Temperature Applications

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1140
Author(s):  
Mohammed S. Almeataq ◽  
Eid M. Alosime
Keyword(s):  
Ceramic Materials ◽  
Primary Objective ◽  
Alumina Nanoparticles ◽  
High Tech ◽  
Al2o3 Nanoparticles ◽  
Preceramic Polymers ◽  
Uv Lithography ◽  
Low Thermal Expansion ◽  
Temperature Ranges ◽  
Silicon Based

Because of the increased demand for preceramic polymers in high-tech applications, there has been growing interest in the synthesis of preceramic polymers, including polysiloxanes and alumina. These polymers are preferred because of their low thermal expansion, conformability to surfaces over large areas, and flexibility. The primary objective was to evaluate the aspects of polymer-derived ceramic routs, focusing on the UV lithography process of preceramic polymers and the pyrolyzing properties of the final ceramics. We found that the p(DMS-co-AMS) copolymer was effective in scattering the hydrophilic Al2O3 nanoparticles into the exceedingly hydrophobic solvent. The physico-chemical behavior of characterized copolymers was explored during their pyrolytic transformation into amorphous silicon-based ceramics. The results indicate that an increase of the pyrolysis temperature degraded the Si–O network through the carbothermic reaction of silicon. We also found a rapid elimination of copolymer pores and densification when the temperature increased (1100 to 1200 °C). At different but specific temperature ranges, there are different distinct rearrangement reactions in the conversion of polymer to ceramic; reductions of the melting point (Tm) of the total heat of melting (ΔHm) of the pyrolysis process resulted in the crystallization of ceramic materials; hence, lithography based on pyrolysis properties of preceramic polymers is a critical method in the conversation of polymers.

scholarly journals Open Innovation Session as a Tool Supporting Innovativeness in Strategies for High-Tech Companies in the Czech Republic

Economies ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 69 ◽  
Author(s):  
Pavla Matulova ◽  
Petra Maresova ◽  
Mohammad Ali Tareq ◽  
Kamil Kuča
Keyword(s):  
Czech Republic ◽  
Open Innovation ◽  
Innovation Process ◽  
Secondary Data ◽  
Primary Objective ◽  
Primary Data ◽  
High Tech ◽  
Regional Government ◽  
The Czech Republic ◽  
General Managers

Open innovation has developed over several decades from a small pool of innovation pioneers, mostly active in high-tech industries, to be widely discussed and implemented in innovation strategy. The primary objective of the Open Innovation Session (OIS) is to create a platform where firms are able to facilitate knowledge transfer. This paper focuses on the contribution of OIS, implemented by regional government, in formulating companies’ strategic management and to overcome barriers to innovation for high-tech companies in the South Moravian region of the Czech Republic. The methodology adopted for this paper includes monitoring and analysing the activities of this programme over seven years, followed by a quantitative study using both primary and secondary data. The primary data for the research were gathered through questionnaires, where the respondents were general managers of companies that had at least some experience of an innovation process. Secondary data were taken from the Czech Statistical Office. This paper has found that the association between an aspiration for innovation leadership and expenditure for research and development is high, further that participation in OIS led to a shift in the perception of the objectives, needs and conditions of the business and finally the major barriers to the innovation process are a lack of highly motivated people with the necessary technical and business experience.

CERAMICS BASED ON ORGANOSILICON POLYMERS-PRECURSORS: MICROSTRUCTURE AND PROPERTIES (review). Part 1

2021 ◽  
pp. 21-33
Author(s):  
A.M. Shestakov ◽  
Keyword(s):  
Ceramic Composite ◽  
Porous Ceramic ◽  
Ceramic Materials ◽  
Structure And Properties ◽  
Ceramic Foams ◽  
Controlled Porosity ◽  
Composition Structure ◽  
Silicon Based ◽  
Porous Ceramic Materials ◽  
Organosilicon Polymers

The paper considers the process of pyrolysis of polymers-precursors, and also shows the influence of various parameters of technological processes for obtaining ceramics on its composition, structure, and properties. The main types of binary, ternary and multicomponent silicon-based ceramics, methods of its preparation, features of structure and properties are considered, and promising directions of application of ceramics are determined. The possibility of obtaining porous ceramic materials (ceramic foams) with controlled porosity and ceramic composite materials with a given composition is noted.

Nanoparticle Reinforced Metal Composites Prepared by Electrocodeposition

2013 ◽  
Author(s):  
Michael J. Koludrovich ◽  
Yong X. Gan
Keyword(s):  
Thin Films ◽  
Nanocomposite Films ◽  
Alumina Nanoparticles ◽  
Al2o3 Nanoparticles ◽  
Nanoparticle Agglomeration ◽  
Control Film ◽  
Significant Difference ◽  
Nanocomposite Thin Films ◽  
Agglomeration Of Nanoparticles ◽  
Pure Cu

Improving the physical and mechanical properties such as hardness and strength of metal thin films can be achieved by incorporating nanoparticles into the pure metals, for example via electrocodeposition. However, the agglomeration of nanoparticles during electrocodeposition of nanocomposite thin films is an unresolved issue. This paper presents the preliminary results of electrocodeposition thin nanocomposite films under different processing conditions. The microstructure and distribution of Al2O3 nanoparticles in electrocodeposited Cu matrix nanocomposite thin films on a pure Al plate were examined. In addition, the effect of electrolyte concentration on the agglomeration of nanoparticles was studied. Different stirring times were used for electrodepositing the alumina/Cu nanocomposite and the pure Cu control film. Under the constant stirring condition, different deposition times including 1, 4, 8, 12, and 24 hours were taken to study the differences between the agglomeration states of the alumina nanoparticles with the time change. We also examined the effect of turning the electromagnetic stirrer ON and OFF at different time intervals from as short as every 20 minutes to as long as ON and OFF every 2 hours on the nanoparticle agglomeration in the film. Optical and electron microscopic studies were made to reveal the microstructure of the nanocomposite. It is found that there is no significant difference in microstructures for the specimens that made under either intermittent stirring or constant stirring for the same length of time.

ASEAN NCAP Crash Tests: Modifier Assessment Justified

2014 ◽  
Vol 663 ◽  
pp. 547-551
Author(s):  
Solah Mohd Syazwan ◽  
Hamzah Azhar ◽  
Aqbal Hafeez Ariffin ◽  
Md Isa Mohd Hafzi ◽  
Rahman Mohd Khairudin ◽  
...  
Keyword(s):  
Standardized Test ◽  
Safety Information ◽  
Primary Objective ◽  
Vehicle Safety ◽  
Crash Test ◽  
High Tech ◽  
Point System ◽  
Safety Level ◽  
Testing Procedures ◽  
Rating Scheme

ASEAN New Car Assessment Program (ASEAN NCAP) is a newly established automobile safety rating program in the Southeast Asia region, which the primary objective is to provide consumers with vehicle safety information and concurrently acknowledge manufacturers’ effort in elevating vehicle safety level. This information is comprehensively gathered through scientific and objective testing procedures in full scale crash test simulation. To ensure consistency and high repeatability, ASEAN NCAP operates standardized test and assessment protocols which utilize high-tech equipment and sensors, data acquisition system and also human surrogates (instrumented “dummies”). A point system is derived for marking purposes and a star rating scheme is designed to reflect the level of safety afforded to occupants. To cater for variation in crash configurations, occupants’ sizes and kinematics as well as other potential risks during crash impacts, a point deduction system (penalty-based) named as “modifiers” were introduced. Hence, this work attempts to describe the modifiers, their basis and justifications for inclusion in the safety rating scheme. A few case studies are demonstrated in this paper to enhance the understandings of modifiers concept.

CO 2 (10.6 μm) laser for high tech ceramic materials production

2006 ◽  
Author(s):  
A. Casas Bedoya ◽  
H. A. Garcia Mejia ◽  
C. Goyes ◽  
E. Solarte
Keyword(s):  
Ceramic Materials ◽  
High Tech

Morphological and physical properties of kefiran-whey protein isolate bionanocomposite films reinforced with Al2O3 nanoparticles

2020 ◽  
Vol 26 (8) ◽  
pp. 666-675
Author(s):  
Zahra Moradi
Keyword(s):  
Mechanical Properties ◽  
Whey Protein ◽  
Water Solubility ◽  
Whey Protein Isolate ◽  
Protein Isolate ◽  
Alumina Nanoparticles ◽  
Vapor Permeability ◽  
Al2o3 Nanoparticles ◽  
Bionanocomposite Films ◽  
The Impact

Considering environmental pollution caused by the non-biodegradable polymers used in food packaging, developing and enhancing the properties of biodegradable films seem to be necessary. For this aim, in the present study, kefiran-whey protein isolate bionanocomposite films were prepared and the impact of different concentrations (1, 3 and 5% w/w) of Al2O3 (alumina) nanoparticles on their physical, morphological, thermal and mechanical properties was studied. Based on the obtained results, an increase in the nanoparticles content led to a significant decrease (p < 0.05) in the water vapor permeability, moisture absorption, moisture content, and water solubility. Scanning electron microscope images showed a homogeneous structure, confirming the good dispersion of alumina nanoparticles with smooth surface up to concentration of 3%. In addition, both thermal stability and mechanical properties of the films were improved by the increased concentrations of alumina. The results of X-ray diffraction indicated that the intensity of the crystalline peaks of film increased with the addition of Al2O3 to kefiran-whey protein isolate matrix. By considering all results, the concentration of 3% was proposed as the appropriate concentration of Al2O3 for the nano-reinforcement of kefiran-whey protein isolate bionanocomposites.

Influence of electrosynthesis conditions and Al2O3 nanoparticles on corrosion protection effect of polypyrrole films

2014 ◽  
Vol 61 (3) ◽  
pp. 146-152 ◽  
Author(s):  
Ali Ehsani ◽  
Mohammad Ghasem Mahjani ◽  
Maryam Nasseri ◽  
Majid Jafarian
Keyword(s):  
Oxygen Reduction ◽  
Corrosion Protection ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Reduction Process ◽  
Artificial Seawater ◽  
Alumina Nanoparticles ◽  
Al2o3 Nanoparticles ◽  
Active Dissolution ◽  
Content Type

Purpose – The purpose of this paper was to investigate the anti-corrosion behavior of polypyrrole (PPy) films in different states and presence of alumina nanoparticles synthesized by galvanostatic electropolymerization on stainless steel (SS) electrodes in an artificial seawater solution using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). Design/methodology/approach – The electrochemical measurements were used to examine the effects of PPy and its nanocomposite on the corrosion behavior of SS type 316L in artificial seawater. A standard electrochemical cell with three electrodes was used for the measurements. The electrochemical response of the coated electrodes in the doped and the undoped state was compared with that of a bare electrode. Corrosion rate information was obtained by the Tafel extrapolation method, where the intersection point of a cathodic and an anodic polarization curve provides both the corrosion potential and the corrosion current. EIS measurements confirmed the potentiodynamic and open circuit potential (OCP) results. The microstructure of the obtained films was investigated by scanning electron microscopy. Findings – The results showed that the coated polymer films shifted the electrode potential toward more positive potentials, but this shift did not lead to passivation. However, a notable synergy was observed between PPy undoped film, oxygen reduction and iron dissolution. The potential of the SS remained in the active dissolution region, and it was not possible to produce a passive oxide layer in this region. PPy separates the metal dissolution process from the oxygen reduction process. This would prevent the local pH increase at the metal surface and subsequent delamination. The polarization curves, EOCP and impedance measurements showed that PPy undoped/Al2O3 layers show promise as good candidates for the corrosion protection of reactive metals. Originality/value – This paper presents that electrodes coated with undoped PPy synthesized in the presence of dodecyl sulfate anions and Al2O3 nanoparticles offered a noticeable enhancement of protection against corrosion processes.

Functionalisation of Textiles with Nanotechnology

2006 ◽  
Vol 920 ◽  
Author(s):  
Torsten Textor ◽  
Frank Schröter ◽  
Eckhard Schollmeyer
Keyword(s):  
Sol Gel ◽  
Ceramic Materials ◽  
Nano Particles ◽  
Alumina Nanoparticles ◽  
Medical Systems ◽  
Hybrid Polymers ◽  
Organic Hybrid ◽  
Technical Textiles ◽  
Stab Resistance ◽  
Technical Effort

AbstractThe present development of textile market is connected with an ever increasing demand for new functionalities for highly specific applications. At the same time, the industrial supply has been restricted to only a few types of synthetic fibers. Given that background, surface modification became one of the most important topics to create new textiles. Beside other techniques, the functionalisation of fibers by making use of concepts of the nanotechnology is part of our work for several years. Coatings based on nanosols and inorganic-organic hybrid polymers, derived from sol-gel process, have an immense potential for creative modifications of surface properties and can be applied with a comparatively low technical effort and at moderate temperatures. The coatings often combine properties of organic polymers with those of ceramic materials [1-11]. Therefore those hybrid polymers are of an enormous interest for technical textiles. The basic materials offer the opportunity to produce very hard but flexible coatings, especially by filling or modifying the networks with nano-particles. Approaches to modify these systems by various inorganic or organic substances can lead to a huge number of additional functionalities which are increasingly demanded from the textile industries [12-18]. Coatings of a thickness of less then one micron can act as effective barriers against chemical attacks, super-repellent surfaces can be created, or the wear-resistance of textile materials can be improved. Coatings incorporating nanoparticles as employed in sun creams protect sensitive polymers against decomposition due to ultraviolet radiation. Ballistic body wear based on fabrics protects against gun attacks but generally not against knives. For these products, thin coatings based on inorganic-organic hybrid polymers filled with alumina nanoparticles were found to give good stab-resistance. Further approaches deal e.g. with reversible photochromic coatings – coatings that change its color if irradiated with sun light -, (superpara-)magnetic hybrid polymers or medical systems based on porous sol-gel-coatings with immobilized drugs that are released in contact with skin. This paper will focus on approaches to improve ballistic body wear with respect to stab-resistance, UV-protection and water and oil repellence.

scholarly journals Interfacial Microstructure and Corrosion Behaviour of Mild Steel Coated with Alumina Nanoparticles Doped Tin Composite via Direct Tinning Route

Coatings ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1318
Author(s):  
Abdulaziz S. Alghamdi ◽  
K. S. Abdel Halim ◽  
Mohammed A. Amin ◽  
Abdullah S. Alshammari ◽  
Naglaa Fathy ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Mild Steel ◽  
Coating Layer ◽  
Corrosion Behaviour ◽  
Steel Substrate ◽  
Composite Layer ◽  
Interfacial Microstructure ◽  
Alumina Nanoparticles ◽  
Al2o3 Nanoparticles ◽  
Metallic Materials

The improvement of the surface properties of ferrous metallic materials has become a crucial criterion for advanced engineering applications. The interfacial microstructure and corrosion behaviour of mild steel coated with alumina nanoparticles doped in tin composite using the direct tinning technique were investigated. A coating layer of tin composite containing different loads of Al2O3 nanoparticles (0.25 wt.%, 0.50 wt.%, 1.00 wt.% and 1.5 wt.%) was prepared and directly deposited on a mild steel substrate. This type of a direct tinning process is considered to be a simple and low-cost route for protecting metallic materials from corrosion. It was found that the thickness of both the composite layer and Fe-Sn intermetallic layer at the coated interfaces was highly affected by the presence of alumina nanoparticles that effectively inhibit the diffusion of Sn atoms into the Fe substrate. For the samples coated with lower content of alumina nanoparticles (0.25 wt.% and 0.50 wt.%), the thickness of the Fe-Sn intermetallic coating (IMC) layer is decreased due to Fe-Sn IMC suppression. Otherwise, for the addition of more alumina nanoparticles (1.00 wt.% and 1.50 wt.%), the thickness of the Fe-Sn IMC layer is slightly increased because of nanoparticle’s agglomeration and flotation. It can be reported that the presence of alumina nanoparticles in the coating layer improves, to a great extent, the corrosion resistance of Sn-composites surface on mild steel substrates. Although the tin composite coating layer with a high quantity of alumina nanoparticles (1.0 wt.%) exhibited better corrosion resistance than the other tested samples, such nanoparticle additions have become increasingly difficult to obtain. It was observed that the Al2O3 nanoparticles agglomeration and flotation that were detected in the coating surface may be related to high fraction nanoparticles loading and to the difference in the gravity for Sn and Al2O3 nanoparticles. However, based on our investigation, a coating layer that contains 0.50 wt.% alumina nanoparticles is highly recommended for achieving long lasting and high-performance corrosion resistance for coated mild steel with minimal coating layer defects.

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