Search results for: magnesium based composite
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 29228

Search results for: magnesium based composite

28118 Water Absorption Studies on Natural Fiber Reinforced Polymer Composites

Authors: G. L. Devnani, Shishir Sinha

Abstract:

In the recent years, researchers have drawn their focus on natural fibers reinforced composite materials because of their excellent properties like low cost, lower weight, better tensile and flexural strengths, biodegradability etc. There is little concern however that when these materials are put in moist conditions for long duration, their mechanical properties degrade. Therefore, in order to take maximum advantage of these novel materials, one should have a complete understanding of their moisture or water absorption phenomena. Various fiber surface treatment methods like alkaline treatment, acetylation etc. have also been suggested for reduction in water absorption of these composites. In the present study, a detailed review is done for water absorption behavior of natural fiber reinforced polymer composites, and experiments also have been performed on these composites with varying the parameters like fiber loading etc. for understanding the water absorption kinetics. Various surface treatment methods also performed to reduce the water absorption behavior of these materials and effort is made to develop a proper understanding of water absorption mechanism mathematically and experimentally for full potential utilization of natural fiber reinforced polymer composite materials.

Keywords: alkaline treatment, composites, natural fiber, water absorption

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28117 An Experimental and Numerical Study on the Pultruded GFRP I-Sections Beams

Authors: Parinaz Arashnia, Farzad Hatami, Saeed Ghaffarpour Jahromi

Abstract:

Using steel in bridges’ construction because of their desired tensile and compressive strength and light weight especially in large spans was widely popular. Disadvantages of steel such as corrosion, buckling and weaknesses in high temperature and unsuitable weld could be solve with using Fibres Reinforced Polymer (FRP) profiles. The FRP is a remarkable class of composite polymers that can improve structural elements behaviour like corrosion resistance, fir resistance with good proofing and electricity and magnetic non-conductor. Nowadays except FRP reinforced bars and laminates, FRP I-beams are made and studied. The main reason for using FRP profiles is, prevent of corrosion and increase the load carrying capacity and durability, especially in large spans in bridges’ deck. In this paper, behaviour of I-section glass fibres reinforced polymer (GFRP) beam is discussed under point loads with numerical models and results has been compared and verified with experimental tests.

Keywords: glass fibres reinforced polymer, composite, I-section beam, durability, finite element method, numerical model

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28116 Numerical Study for Compressive Strength of Basalt Composite Sandwich Infill Panel

Authors: Viriyavudh Sim, Jung Kyu Choi, Yong Ju Kwak, Oh Hyeon Jeon, Woo Young Jung

Abstract:

In this study, we investigated the buckling performance of basalt fiber reinforced polymer (BFRP) sandwich infill panels. Fiber Reinforced Polymer (FRP) is a major evolution for energy dissipation when used as infill material of frame structure, a basic Polymer Matrix Composite (PMC) infill wall system consists of two FRP laminates surrounding an infill of foam core. Furthermore, this type of component is for retrofitting and strengthening frame structure to withstand the seismic disaster. In-plane compression was considered in the numerical analysis with ABAQUS platform to determine the buckling failure load of BFRP infill panel system. The present result shows that the sandwich BFRP infill panel system has higher resistance to buckling failure than those of glass fiber reinforced polymer (GFRP) infill panel system, i.e. 16% increase in buckling resistance capacity.

Keywords: Basalt Fiber Reinforced Polymer (BFRP), buckling performance, FEM analysis, sandwich infill panel

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28115 Evaluation of Efficiency of Naturally Available Disinfectants and Filter Media in Conventional Gravity Filters

Authors: Abhinav Mane, Kedar Karvande, Shubham Patel, Abhayraj Lodha

Abstract:

Gravity filters are one of the most commonly used, economically viable and moderately efficient water purification systems. Their efficiency is mainly based on the type of filter media installed and its location within the filter mass. Several researchers provide valuable input in decision of the type of filter media. However, the choice is mainly restricted to the chemical combinations of different substances. This makes it very much dependent on the factory made filter media, and no cheap alternatives could be found and used. This paper presents the use of disinfectants and filter medias either available naturally or could be prepared using natural resources in conventional mechanism of gravity filter. A small scale laboratory investigation was made with variation in filter media thickness and its location from the top surface of the filter. A rigid steel frame based custom fabricated test setup was used to facilitate placement of filter media at different height within the filter mass. Finely grinded sun dried Neem (Azadirachta indica) extracts and porous burnt clay pads were used as two distinct filter media and placed in isolation as well as in combination with each other. Ground water available in Marathwada region of Maharashtra, India which mainly consists of harmful materials like Arsenic, Chlorides, Iron, Magnesium and Manganese, etc. was treated in the filters fabricated in the present study. The evaluation was made mainly in terms of the input/output water quality assessment through laboratory tests. The present paper should give a cheap and eco-friendly solution to prepare gravity filter at the merit of household skills and availability.

Keywords: fliter media, gravity filters, natural disinfectants, porous clay pads

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28114 Development of Hydrophilic Materials for Nanofiltration Membrane Achieving Dual Resistance to Fouling and Chlorine

Authors: Xi Quan Cheng, Yan Chao Xu, Xu Jiang, Lu Shao, Cher Hon Lau

Abstract:

A hydrophilic thin-film-composite (TFC) nanofiltration (NF) membrane has been developed through the interfacial polymerization (IP) of amino-functional polyethylene glycol (PEG) and trimesoyl chloride. The selective layer is formed on a polyethersulfone (PES) support that is characterized using FTIR, XPS and SEM, and is dependent on monomer immersion duration, and the concentration of monomers and additives. The higher hydrophilicity alongside the larger pore size of the PEG-based selective layer is the key to a high water flux of 66.0 L m-2 h-1 at 5.0 bar. With mean pore radius of 0.42 nm and narrow pore size distribution, the MgSO4 rejections of the PEG based PA TFC NF membranes can reach up to 80.2 %. The hydrophilic PEG based membranes shows positive charged since the isoelectric points range from pH=8.9 to pH=9.1 and the rejection rates for different salts of the novel membranes are in the order of R(MgCl2)>R(MgSO4)>R(NaCl)>R(Na2SO4). The pore sizes and water permeability of these membranes are tailored by varying the molecular weight and molecular architecture of amino-functional PEG. Due to the unique structure of the selective layer of the PEG based membranes consisting of saturated aliphatic construction unit (CH2-CH2-O), the membranes demonstrate dual resistance to fouling and chlorine. The membranes maintain good salt rejections and high water flux of PEG based membranes after treatment by 2000 ppm NaClO for 24 hours. Interestingly, the PEG based membranes exhibit excellent fouling resistance with a water flux recovery of 90.2 % using BSA as a model molecule. More importantly, the hydrophilic PEG based NF membranes have been exploited to separate several water soluble antibiotics (such as tobramycin, an aminoglycoside antibiotic applied in the treatment of various types of bacterial infections), showing excellent performance in concentration or removal of antibioics.

Keywords: nanofiltration, antibiotic separation, hydrophilic membrane, high flux

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28113 Micropower Composite Nanomaterials Based on Porous Silicon for Renewable Energy Sources

Authors: Alexey P. Antropov, Alexander V. Ragutkin, Nicolay A. Yashtulov

Abstract:

The original controlled technology for power active nanocomposite membrane-electrode assembly engineering on the basis of porous silicon is presented. The functional nanocomposites were studied by electron microscopy and cyclic voltammetry methods. The application possibility of the obtained nanocomposites as high performance renewable energy sources for micro-power electronic devices is demonstrated.

Keywords: cyclic voltammetry, electron microscopy, nanotechnology, platinum-palladium nanocomposites, porous silicon, power activity, renewable energy sources

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28112 Experimental Studies of Sigma Thin-Walled Beams Strengthen by CFRP Tapes

Authors: Katarzyna Rzeszut, Ilona Szewczak

Abstract:

The review of selected methods of strengthening of steel structures with carbon fiber reinforced polymer (CFRP) tapes and the analysis of influence of composite materials on the steel thin-walled elements are performed in this paper. The study is also focused to the problem of applying fast and effective strengthening methods of the steel structures made of thin-walled profiles. It is worth noting that the issue of strengthening the thin-walled structures is a very complex, due to inability to perform welded joints in this type of elements and the limited ability to applying mechanical fasteners. Moreover, structures made of thin-walled cross-section demonstrate a high sensitivity to imperfections and tendency to interactive buckling, which may substantially contribute to the reduction of critical load capacity. Due to the lack of commonly used and recognized modern methods of strengthening of thin-walled steel structures, authors performed the experimental studies of thin-walled sigma profiles strengthened with CFRP tapes. The paper presents the experimental stand and the preliminary results of laboratory test concerning the analysis of the effectiveness of the strengthening steel beams made of thin-walled sigma profiles with CFRP tapes. The study includes six beams made of the cold-rolled sigma profiles with height of 140 mm, wall thickness of 2.5 mm, and a length of 3 m, subjected to the uniformly distributed load. Four beams have been strengthened with carbon fiber tape Sika CarboDur S, while the other two were tested without strengthening to obtain reference results. Based on the obtained results, the evaluation of the accuracy of applied composite materials for strengthening of thin-walled structures was performed.

Keywords: CFRP tapes, sigma profiles, steel thin-walled structures, strengthening

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28111 Strength of the Basement Wall Combined with a Temporary Retaining Wall for Excavation

Authors: Soo-yeon Seo, Su-jin Jung

Abstract:

In recent years, the need for remodeling of many apartments built 30 years ago is increasing. Therefore, researches on the structural reinforcement technology of existing apartments have been conducted. On the other hand, there is a growing need for research on the existing underground space expansion technology to expand the parking space required for remodeling. When expanding an existing underground space, for earthworks, an earth retaining wall must be installed between the existing apartment building and it. In order to maximize the possible underground space, it is necessary to minimize the thickness of the portion of earth retaining wall and underground basement wall. In this manner, the calculation procedure is studied for the evaluation of shear strength of the composite basement wall corresponding to shear span-to-depth ratio in this study. As a result, it was shown that the proposed calculation procedure can be used to evaluate the shear strength of the composite basement wall as safe. On the other hand, when shear span-to-depth ratio is small, shear strength is very underestimated.

Keywords: underground space expansion, combined structure, temporary retaining wall, basement wall, shear connectors

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28110 Regeneration of a Liquid Desiccant Using Membrane Distillation to Unlock Coastal Desert Agriculture Potential

Authors: Kimberly J. Cribbs, Ryan M. Lefers, TorOve Leiknes, Noreddine Ghaffour

Abstract:

In Gulf Cooperation Council (GCC) countries, domestic agriculture is hindered by a lack of freshwater, poor soil quality, and ambient temperatures unsuitable for cultivation resulting in a heavy reliance on imported food. Attempts to minimize the risk of food insecurity by growing crops domestically creates a significant demand on limited freshwater resources in this region. Cultivating food in a greenhouse allows some of these challenges, such as poor soil quality and temperatures unsuitable for cultivation, to be overcome. One of the most common methods for greenhouse cooling is evaporative cooling. This method cools the air by the evaporation of water and requires a large amount of water relative to that needed for plant growth and air with a low relative humidity. Considering that much of the population in GCC countries live within 100 km of a coast and that sea water can be utilized for evaporative cooling, coastal agriculture could reduce the risk of food insecurity and water demand. Unfortunately, coastal regions tend to experience both high temperatures and high relative humidity causing evaporative cooling by itself to be inadequate. Therefore, dehumidification is needed prior to utilizing evaporative cooling. Utilizing a liquid desiccant for air dehumidification is promising, but the desiccant regeneration to retain its dehumidification potential remains a significant obstacle for the adoption of this technology. This project studied the regeneration of a magnesium chloride (MgCl₂) desiccant solution from 20wt% to 30wt% by direct contact membrane distillation (DCMD) and explored the possibility of using the recovered water for irrigation. Two 0.2 µm hydrophobic PTFE membranes were tested at feed temperatures of 80, 70, and 60°C and with a permeate temperature of 20°C. It was observed that the permeate flux increases as the difference between the feed and coolant temperature increases and also as the feed concentration decreases. At 21wt% the permeate flux was 34,17, and 14 L m⁻² h⁻¹ for feed temperatures of 80, 70, and 60°C, respectively. Salt rejection decreased overtime; however, it remained greater than 99.9% over an experimental time span of 10 hours. The results show that DCMD can successfully regenerate the magnesium chloride desiccant solution.

Keywords: agriculture, direct contact membrane distillation, GCC countries, liquid desiccant, water recovery

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28109 In situ Growth of ZIF-8 on TEMPO-Oxidized Cellulose Nanofibril Film and Coated with Pectin for pH and Enzyme Dual-Responsive Controlled Release Active Packaging

Authors: Tiantian Min, Chuanxiang Cheng, Jin Yue

Abstract:

The growth and reproduction of microorganisms in food packaging can cause food decay and foodborne diseases, which pose a serious threat to the health of consumers and even cause serious economic losses. Active food packaging containing antibacterial bioactive compounds is a promising strategy for extending the shelf life of products and maintaining the food quality, as well as reducing the food waste. However, most active packaging can only act as slow-release effect for antimicrobials, which causes the release rate of antimicrobials not match the growth rate of microorganisms. Stimuli-responsive active packaging materials based on biopolymeric substrates and bioactive substances that respond to some biological and non-biological trigger factors provide more opportunities for fresh food preservation. The biological stimuli factors such as relative humidity, pH and enzyme existed in the exudate secreted by microorganisms have been expected to design food packaging materials. These stimuli-responsive materials achieved accurate release or delivery of bioactive substances at specific time and appropriate dose. Recently, metal-organic-frameworks (MOFs) nanoparticles become attractive carriers to enhance the efficiency of bioactive compounds or drugs. Cellulose nanofibrils have been widely applied for film substrates due to their biodegradability and biocompatibility. The abundant hydroxyl groups in cellulose can be oxidized to carboxyl groups by TEMPO, making it easier to anchoring MOFs and to be further modification. In this study, a pH and enzyme dual-responsive CAR@ZIF-8/TOCNF/PE film was fabricated by in-situ growth of ZIF-8 nanoparticles onto TEMPO-oxidized cellulose (TOCNF) film and further coated with pectin (PE) for stabilization and controlled release of carvacrol (CAR). The enzyme triggered release of CAR was achieved owing to the degradation of pectin by pectinase secreted by microorganisms. Similarly, the pH-responsive release of CAR was attributed to the unique skeleton degradation of ZIF-8, further accelerating the release of CAR from the topological structure of ZIF-8. The composite film performed excellent crystallinity and adsorb ability confirmed by X-ray diffraction and BET analysis, and the inhibition efficiency against Escherichia coli, Staphylococcus aureus and Aspergillus niger reached more than 99%. The composite film was capable of releasing CAR when exposure to dose-dependent enzyme (0.1, 0.2, and 0.3 mg/mL) and acidic condition (pH = 5). When inoculated 10 μL of Aspergillus niger spore suspension on the equatorial position of mango and raspberries, this composite film acted as packaging pads effectively inhibited the mycelial growth and prolonged the shelf life of mango and raspberries to 7 days. Such MOF-TOCNF based film provided a targeted, controlled and sustained release of bioactive compounds for long-term antibacterial activity and preservation effect, which can also avoid the cross-contamination of fruits.

Keywords: active food packaging, controlled release, fruit preservation, in-situ growth, stimuli-responsive

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28108 The Effect of Sodium Bicarbonate on the Mg and P Concentrations in Turkish Black and Green Tea

Authors: E. Moroydor Derun, T. Yalcin, O. Dere Ozdemir, S. Kipcak, N. Tugrul, S. Piskin

Abstract:

Tea is one of the most consumed beverages all over the world. Especially, black and green teas are preferred to consume. In Turkey, some local tea houses use sodium bicarbonate (SB) to obtain more infusion by using less amount of tea. Therefore, the addition of SB to black and green teas affects element concentrations of these teas. In this study, determination of magnesium (Mg) and phosphorus (P) contents in black and green teas is aimed for conscious consumption, after the addition of SB. Inductively coupled plasma optical emission spectrometry (ICP-OES) was used for these analysis. The results of this study showed that the concentrations of Mg and P decreased by adding SB from 11.020, 21.915 to 10.009, 17.520 in black tea and from 12.605, 14.550 to 8.118, 9.425 in green tea, respectively. The addition of SB on analyzed teas is not recommended as it reduces intake percentages of Mg and P from the essential elements.

Keywords: elements, ICP-OES, sodium bicarbonate, tea

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28107 Solid State Fermentation: A Technological Alternative for Enriching Bioavailability of Underutilized Crops

Authors: Vipin Bhandari, Anupama Singh, Kopal Gupta

Abstract:

Solid state fermentation, an eminent bioconversion technique for converting many biological substrates into a value-added product, has proven its role in the biotransformation of crops by nutritionally enriching them. Hence, an effort was made for nutritional enhancement of underutilized crops viz. barnyard millet, amaranthus and horse gram based composite flour using SSF. The grains were given pre-treatments before fermentation and these pre-treatments proved quite effective in diminishing the level of antinutrients in grains and in improving their nutritional characteristics. The present study deals with the enhancement of nutritional characteristics of underutilized crops viz. barnyard millet, amaranthus and horsegram based composite flour using solid state fermentation (SSF) as the principle bioconversion technique to convert the composite flour substrate into a nutritionally enriched value added product. Response surface methodology was used to design the experiments. The variables selected for the fermentation experiments were substrate particle size, substrate blend ratio, fermentation time, fermentation temperature and moisture content having three levels of each. Seventeen designed experiments were conducted randomly to find the effect of these variables on microbial count, reducing sugar, pH, total sugar, phytic acid and water absorption index. The data from all experiments were analyzed using Design Expert 8.0.6 and the response functions were developed using multiple regression analysis and second order models were fitted for each response. Results revealed that pretreatments proved quite handful in diminishing the level of antinutrients and thus enhancing the nutritional value of the grains appreciably, for instance, there was about 23% reduction in phytic acid levels after decortication of barnyard millet. The carbohydrate content of the decorticated barnyard millet increased to 81.5% from initial value of 65.2%. Similarly popping and puffing of horsegram and amaranthus respectively greatly reduced the trypsin inhibitor activity. Puffing of amaranthus also reduced the tannin content appreciably. Bacillus subtilis was used as the inoculating specie since it is known to produce phytases in solid state fermentation systems. These phytases remarkably reduce the phytic acid content which acts as a major antinutritional factor in food grains. Results of solid state fermentation experiments revealed that phytic acid levels reduced appreciably when fermentation was allowed to continue for 72 hours at a temperature of 35°C. Particle size and substrate blend ratio also affected the responses positively. All the parameters viz. substrate particle size, substrate blend ratio, fermentation time, fermentation temperature and moisture content affected the responses namely microbial count, reducing sugar, pH, total sugar, phytic acid and water absorption index but the effect of fermentation time was found to be most significant on all the responses. Statistical analysis resulted in the optimum conditions (particle size 355µ, substrate blend ratio 50:20:30 of barnyard millet, amaranthus and horsegram respectively, fermentation time 68 hrs, fermentation temperature 35°C and moisture content 47%) for maximum reduction in phytic acid. The model F- value was found to be highly significant at 1% level of significance in case of all the responses. Hence, second order model could be fitted to predict all the dependent parameters. The effect of fermentation time was found to be most significant as compared to other variables.

Keywords: composite flour, solid state fermentation, underutilized crops, cereals, fermentation technology, food processing

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28106 Arothron Stellatus Fish Skin Collagen Based Composite Biosheet Incorporated with Mupirocin as a Potential Dermal Substitute for Skin Tissue Regeneration

Authors: Giriprasath Ramanathan, Sivakumar Singaravelu, M. D. Raja, Uma Tirichurapalli Sivagnanam

Abstract:

Collagen is the abundant protein found in the skin of the animal body that has been designed to provide adequate structural support for the adhesion of cells. The dressing material widely used for tissue engineering and biomedical application has to posses good swelling and biological property for the absorption of exudates and cell proliferation. Acid solubilised collagen from the fish skin of the Arothron stellatus was extracted. The collagen with hydroxypropyl and carboxy methyl cellulose has the better biological property to enhance the healing efficiency. The inter property of collagen with interesting perspectives in the tissue engineering process leads to the development of biomaterial with natural polymer with biologically derived collagen. Keeping this as an objective, the composite biomaterial was fabricated to improve the wound healing and biological properties. In this study the collagen from Arothron stellatus fish skin (ACO) was uniformly blended separately with hydroxypropyl methyl cellulose (HPMC) and carboxyl methyl cellulose (CMC) as biosheets. The casted biosheets were impregnated with mupirocin to get rid of infection from the microbes. Further, the results obtained from differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), tensile studies and biocompatibility of the biosheets were assessed. The swelling, porosity and degradation of the casted biosheets were studied to make the biosheets as a suitable wound dressing material. ACO-HPMC and ACO-CMC biosheets both showed good results, but ACO-HPMC biosheet showed better results than ACO-CMC and hence it can be used as a potential dermal substitute in skin tissue engineering.

Keywords: arothron stellatus, biocompatibility, collagen, tensile strenght

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28105 Interface Fracture of Sandwich Composite Influenced by Multiwalled Carbon Nanotube

Authors: Alak Kumar Patra, Nilanjan Mitra

Abstract:

Higher strength to weight ratio is the main advantage of sandwich composite structures. Interfacial delamination between the face sheet and core is a major problem in these structures. Many research works are devoted to improve the interfacial fracture toughness of composites majorities of which are on nano and laminated composites. Work on influence of multiwalled carbon nano-tubes (MWCNT) dispersed resin system on interface fracture of glass-epoxy PVC core sandwich composite is extremely limited. Finite element study is followed by experimental investigation on interface fracture toughness of glass-epoxy (G/E) PVC core sandwich composite with and without MWCNT. Results demonstrate an improvement in interface fracture toughness values (Gc) of samples with a certain percentages of MWCNT. In addition, dispersion of MWCNT in epoxy resin through sonication followed by mixing of hardener and vacuum resin infusion (VRI) technology used in this study is an easy and cost effective methodology in comparison to previously adopted other methods limited to laminated composites. The study also identifies the optimum weight percentage of MWCNT addition in the resin system for maximum performance gain in interfacial fracture toughness. The results agree with finite element study, high-resolution transmission electron microscope (HRTEM) analysis and fracture micrograph of field emission scanning electron microscope (FESEM) investigation. Interface fracture toughness (GC) of the DCB sandwich samples is calculated using the compliance calibration (CC) method considering the modification due to shear. Compliance (C) vs. crack length (a) data of modified sandwich DCB specimen is fitted to a power function of crack length. The calculated mean value of the exponent n from the plots of experimental results is 2.22 and is different from the value (n=3) prescribed in ASTM D5528-01for mode 1 fracture toughness of laminate composites (which is the basis for modified compliance calibration method). Differentiating C with respect to crack length (a) and substituting it in the expression GC provides its value. The research demonstrates improvement of 14.4% in peak load carrying capacity and 34.34% in interface fracture toughness GC for samples with 1.5 wt% MWCNT (weight % being taken with respect to weight of resin) in comparison to samples without MWCNT. The paper focuses on significant improvement in experimentally determined interface fracture toughness of sandwich samples with MWCNT over the samples without MWCNT using much simpler method of sonication. Good dispersion of MWCNT was observed in HRTEM with 1.5 wt% MWCNT addition in comparison to other percentages of MWCNT. FESEM studies have also demonstrated good dispersion and fiber bridging of MWCNT in resin system. Ductility is also observed to be higher for samples with MWCNT in comparison to samples without.

Keywords: carbon nanotube, epoxy resin, foam, glass fibers, interfacial fracture, sandwich composite

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28104 Thermo-Elastic and Self-Healing Polyacrylamide: 2D Polymer Composite Hydrogels for Water Shutoff Treatment

Authors: Edreese H. Alsharaeh, Feven Mattews Michael, Ayman Almohsin

Abstract:

Self-healing hydrogels have many advantages since they can resist various types of stresses, including tension, compression, and shear, making them attractive for various applications. In this study, thermo-elastic and self-healing polymer composite hydrogels were prepared from polyacrylamide (PAM) and 2D fillers using in-situ method. In addition, the PAM and fillers were prepared in presence of organic crosslinkers, i.e., hydroquinone (HQ) and hexamethylenediamine (HMT). The swelling behavior of the prepared hydrogels was studied by hydrating the dried hydrogels. The thermal and rheological properties of the prepared hydrogels were evaluated before and after swelling study using thermogravimetric analysis, differential scanning calorimetric technique and dynamic mechanical analysis. From the results obtained, incorporating fillers into the PAM matrix enhanced the swelling degree of the hydrogels with satisfactory mechanical properties, attaining up to 77% self-healing efficiency compared to the neat-PAM (i.e., 29%). This, in turn, indicates addition of 2D fillers improved self-healing properties of the polymer hydrogel, thus, making the prepared hydrogels applicable for water shutoff treatments under high temperature.

Keywords: polymer hydrogels, 2D fillers, elastic self-healing hydrogels, water shutoff, swelling properties

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28103 Electrospun Conducting Polymer/Graphene Composite Nanofibers for Gas Sensing Applications

Authors: Aliaa M. S. Salem, Soliman I. El-Hout, Amira Gaber, Hassan Nageh

Abstract:

Nowadays, the development of poisonous gas detectors is considered to be an urgent matter to secure human health and the environment from poisonous gases, in view of the fact that even a minimal amount of poisonous gas can be fatal. Of these concerns, various inorganic or organic sensing materials have been used. Among these are conducting polymers, have been used as the active material in the gassensorsdue to their low-cost,easy-controllable molding, good electrochemical properties including facile fabrication process, inherent physical properties, biocompatibility, and optical properties. Moreover, conducting polymer-based chemical sensors have an amazing advantage compared to the conventional one as structural diversity, facile functionalization, room temperature operation, and easy fabrication. However, the low selectivity and conductivity of conducting polymers motivated the doping of it with varied materials, especially graphene, to enhance the gas-sensing performance under ambient conditions. There were a number of approaches proposed for producing polymer/ graphene nanocomposites, including template-free self-assembly, hard physical template-guided synthesis, chemical, electrochemical, and electrospinning...etc. In this work, we aim to prepare a novel gas sensordepending on Electrospun nanofibers of conducting polymer/RGO composite that is the effective and efficient expectation of poisonous gases like ammonia, in different application areas such as environmental gas analysis, chemical-,automotive- and medical industries. Moreover, our ultimate objective is to maximize the sensing performance of the prepared sensor and to check its recovery properties.

Keywords: electro spinning process, conducting polymer, polyaniline, polypyrrole, polythiophene, graphene oxide, reduced graphene oxide, functionalized reduced graphene oxide, spin coating technique, gas sensors

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28102 The Effect of Addition of Dioctyl Terephthalate and Calcite on the Tensile Properties of Organoclay/Linear Low Density Polyethylene Nanocomposites

Authors: A. Gürses, Z. Eroğlu, E. Şahin, K. Güneş, Ç. Doğar

Abstract:

In recent years, polymer/clay nanocomposites have generated great interest in the polymer industry as a new type of composite material because of their superior properties, which includes high heat deflection temperature, gas barrier performance, dimensional stability, enhanced mechanical properties, optical clarity and flame retardancy when compared with the pure polymer or conventional composites. The investigation of change of the tensile properties of organoclay/linear low density polyethylene (LLDPE) nanocomposites with the use of Dioctyl terephthalate (DOTP) (as plasticizer) and calcite (as filler) has been aimed. The composites and organoclay synthesized were characterized using the techniques such as XRD, HRTEM and FTIR techniques. The spectroscopic results indicate that platelets of organoclay were well dispersed within the polymeric matrix. The tensile properties of the composites were compared considering the stress-strain curve drawn for each composite and pure polymer. It was observed that the composites prepared by adding the plasticizer at different ratios and a certain amount of calcite exhibited different tensile behaviors compared to pure polymer.

Keywords: linear low density polyethylene, nanocomposite, organoclay, plasticizer

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28101 Automation of Finite Element Simulations for the Design Space Exploration and Optimization of Type IV Pressure Vessel

Authors: Weili Jiang, Simon Cadavid Lopera, Klaus Drechsler

Abstract:

Fuel cell vehicle has become the most competitive solution for the transportation sector in the hydrogen economy. Type IV pressure vessel is currently the most popular and widely developed technology for the on-board storage, based on their high reliability and relatively low cost. Due to the stringent requirement on mechanical performance, the pressure vessel is subject to great amount of composite material, a major cost driver for the hydrogen tanks. Evidently, the optimization of composite layup design shows great potential in reducing the overall material usage, yet requires comprehensive understanding on underlying mechanisms as well as the influence of different design parameters on mechanical performance. Given the type of materials and manufacturing processes by which the type IV pressure vessels are manufactured, the design and optimization are a nuanced subject. The manifold of stacking sequence and fiber orientation variation possibilities have an out-standing effect on vessel strength due to the anisotropic property of carbon fiber composites, which make the design space high dimensional. Each variation of design parameters requires computational resources. Using finite element analysis to evaluate different designs is the most common method, however, the model-ing, setup and simulation process can be very time consuming and result in high computational cost. For this reason, it is necessary to build a reliable automation scheme to set up and analyze the di-verse composite layups. In this research, the simulation process of different tank designs regarding various parameters is conducted and automatized in a commercial finite element analysis framework Abaqus. Worth mentioning, the modeling of the composite overwrap is automatically generated using an Abaqus-Python scripting interface. The prediction of the winding angle of each layer and corresponding thickness variation on dome region is the most crucial step of the modeling, which is calculated and implemented using analytical methods. Subsequently, these different composites layups are simulated as axisymmetric models to facilitate the computational complexity and reduce the calculation time. Finally, the results are evaluated and compared regarding the ultimate tank strength. By automatically modeling, evaluating and comparing various composites layups, this system is applicable for the optimization of the tanks structures. As mentioned above, the mechanical property of the pressure vessel is highly dependent on composites layup, which requires big amount of simulations. Consequently, to automatize the simulation process gains a rapid way to compare the various designs and provide an indication of the optimum one. Moreover, this automation process can also be operated for creating a data bank of layups and corresponding mechanical properties with few preliminary configuration steps for the further case analysis. Subsequently, using e.g. machine learning to gather the optimum by the data pool directly without the simulation process.

Keywords: type IV pressure vessels, carbon composites, finite element analy-sis, automation of simulation process

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28100 Fabrication of Wollastonite/Hydroxyapatite Coatings on Zirconia by Room Temperature Spray Process

Authors: Jong Kook Lee, Sangcheol Eum, Jaehong Kim

Abstract:

Wollastonite/hydroxyapatite composite coatings on zirconia were obtained by room temperature spray process. Wollastonite powder was synthesized by solid-state reaction between calcite and silica powder. Hydroxyapatite powder was prepared from bovine bone by the calcination at 1200oC 1h. From two starting raw powders, three kinds of powder mixture were obtained by the ball milling for 24h. By using these powders, wollastonite/hydroxyapatite coatings were fabricated on zirconia substrates by a room temperature spray process, and their microstructure and biological behavior were investigated and compared with pure wollastonite and hydroxyapatite coatings. Wollastonite/hydroxyapatite coatings on zirconia substrates were homogeneously formed in microstructure and had a nanoscaled grain size. The phase composition of the resultant wollastonite/hydroxyapatite coatings was similar to that of the starting powders, however, the grain size of the wollastonite or hydroxyapatite particles was reduced to about 100 nm due to their formation by particle impaction and fracture. The wollastonite/hydroxyapatite coating layer exhibited bioactivity in a stimulated body fluid and forming ability of new hydroxyapatite precipitates of 25 nm during in vitro test in SBF solution, which was enhanced by the increasing wollastonite content.

Keywords: wollastonite, hydroxyapatite composite coatings, room temperature spay process, zirconia

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28099 The Applications of Wire Print in Composite Material Research and Fabrication Process

Authors: Hsu Yi-Chia, Hoy June-Hao

Abstract:

FDM (Fused Deposition Modeling) is a rapid proofing method without mold, however, high material and time costs have always been a major disadvantage. Wire-printing is the next generation technology that can more flexible, and also easier to apply on a 3D printer and robotic arms printing. It can create its own construction methods. The research is mainly divided into three parts. The first is about the method of parameterizing the generated paths and the conversion of g-code to the wire-printing. The second is about material attempts and the application of effects. Third, is about the improvement of the operation of mechanical equipment and the design of robotic tool-head. The purpose of this study is to develop a new wire-print method that can efficiently generate line segments and paths in three- dimensions space. The parametric modeling software transforms the digital model into a 3D printer or robotic arms g-code, this article uses thermoplastics/ clay/composites materials for testing. The combination of materials and wire-print process makes architects and designers have the ability to research and develop works and construction in the future.

Keywords: parametric software, wire print, robotic arms fabrication, composite filament additive manufacturing

Procedia PDF Downloads 124
28098 Ectopic Osteoinduction of Porous Composite Scaffolds Reinforced with Graphene Oxide and Hydroxyapatite Gradient Density

Authors: G. M. Vlasceanu, H. Iovu, E. Vasile, M. Ionita

Abstract:

Herein, the synthesis and characterization of chitosan-gelatin highly porous scaffold reinforced with graphene oxide, and hydroxyapatite (HAp), crosslinked with genipin was targeted. In tissue engineering, chitosan and gelatin are two of the most robust biopolymers with wide applicability due to intrinsic biocompatibility, biodegradability, low antigenicity properties, affordability, and ease of processing. HAp, per its exceptional activity in tuning cell-matrix interactions, is acknowledged for its capability of sustaining cellular proliferation by promoting bone-like native micro-media for cell adjustment. Genipin is regarded as a top class cross-linker, while graphene oxide (GO) is viewed as one of the most performant and versatile fillers. The composites with natural bone HAp/biopolymer ratio were obtained by cascading sonochemical treatments, followed by uncomplicated casting methods and by freeze-drying. Their structure was characterized by Fourier Transform Infrared Spectroscopy and X-ray Diffraction, while overall morphology was investigated by Scanning Electron Microscopy (SEM) and micro-Computer Tomography (µ-CT). Ensuing that, in vitro enzyme degradation was performed to detect the most promising compositions for the development of in vivo assays. Suitable GO dispersion was ascertained within the biopolymer mix as nanolayers specific signals lack in both FTIR and XRD spectra, and the specific spectral features of the polymers persisted with GO load enhancement. Overall, correlations between the GO induced material structuration, crystallinity variations, and chemical interaction of the compounds can be correlated with the physical features and bioactivity of each composite formulation. Moreover, the HAp distribution within follows an auspicious density gradient tuned for hybrid osseous/cartilage matter architectures, which were mirrored in the mice model tests. Hence, the synthesis route of a natural polymer blend/hydroxyapatite-graphene oxide composite material is anticipated to emerge as influential formulation in bone tissue engineering. Acknowledgement: This work was supported by the project 'Work-based learning systems using entrepreneurship grants for doctoral and post-doctoral students' (Sisteme de invatare bazate pe munca prin burse antreprenor pentru doctoranzi si postdoctoranzi) - SIMBA, SMIS code 124705 and by a grant of the National Authority for Scientific Research and Innovation, Operational Program Competitiveness Axis 1 - Section E, Program co-financed from European Regional Development Fund 'Investments for your future' under the project number 154/25.11.2016, P_37_221/2015. The nano-CT experiments were possible due to European Regional Development Fund through Competitiveness Operational Program 2014-2020, Priority axis 1, ID P_36_611, MySMIS code 107066, INOVABIOMED.

Keywords: biopolymer blend, ectopic osteoinduction, graphene oxide composite, hydroxyapatite

Procedia PDF Downloads 99
28097 Investigation of Distortion and Impact Strength of 304L Butt Joint Using Different Weld Groove

Authors: A. Sharma, S. S. Sandhu, A. Shahi, A. Kumar

Abstract:

The aim of present investigation was to carry out Finite element modeling of distortion in the case of butt weld. 12mm thick AISI 304L plates were butt welded using three different combinations of groove design namely Double U, Double V and Composite. A full simulation of shielded metal arc welding (SMAW) of nonlinear heat transfer is carried out. Aspects like, temperature-dependent thermal properties of AISI stainless steel above liquid phase, the effect of thermal boundary conditions, were included in the model. Since welding heat dissipation characteristics changed due to variable groove design significant changes in the microhardness tensile strength and impact toughness of the joints were observed. The cumulative distortion was found to be least in double V joint followed by the Composite and Double U-joints. All the joints have joint efficiency more than 100%. CVN value of the Double V-groove weld metal was highest. The experimental results and the FEM results were compared and reveal a very good correlation for distortion and weld groove design for a multipass joint with a standard analogy of 83%.

Keywords: AISI 304 L, Butt joint, distortion, FEM, groove design, SMAW

Procedia PDF Downloads 397
28096 Elaboration and Characterization of a Composite Based on Plant Sisal Fiber

Authors: Biskri Yasmina, Laidi Babouri, Dehas Ouided, Bougherira Nadjiba, Baghloul Rahima

Abstract:

Algeria is one of the countries which have extraordinary resources in vegetable fibers (Palmier, Alfa, Cotton, Sisal). Unfortunately, their valorization in the practical fields, among other things, in building materials, is still little exploited. Several works align with the fact that the use of plant fibers in mortar is an advantageous solution, given its abundance and its socio-economic and environmental impact. The idea of introducing plant fiber into the field of Civil Engineering is not new. Based on the work of several researchers in this field, we propose to study the mechanical behavior of mortar based on Sisal fibers. This work consists of the experimental characterization in the fresh state (workability) and in the hardened state (mechanical resistance to compression and traction by three-point bending) on the scale of mortar mortars based on sisal plant fibers. The main objective of this work is the study of the effect of fiber incorporation on mechanical properties (compressive strength and three-point bending strength). In this study, we varied two parameters, such as the length of the fiber (7cm, 10 cm) and the fibers percentage (0.25%, 0.5%, 0.75%, 1%, 1.25% and 1.5%). The results show that there is a slight increase in the compressive strength of the fiber-reinforced mortars compared to the reference mortar (mortar without fibers). With regard to the three-point bending tests, the fiber-reinforced mortars presented higher resistances compared to the reference mortar and this was for the different lengths and different percentages studied.

Keywords: mortar, plant fiber, experimentation, mechanical characterization, analysis

Procedia PDF Downloads 81
28095 Discrete Element Simulations of Composite Ceramic Powders

Authors: Julia Cristina Bonaldo, Christophe L. Martin, Severine Romero Baivier, Stephane Mazerat

Abstract:

Alumina refractories are commonly used in steel and foundry industries. These refractories are prepared through a powder metallurgy route. They are a mixture of hard alumina particles and graphite platelets embedded into a soft carbonic matrix (binder). The powder can be cold pressed isostatically or uniaxially, depending on the application. The compact is then fired to obtain the final product. The quality of the product is governed by the microstructure of the composite and by the process parameters. The compaction behavior and the mechanical properties of the fired product depend greatly on the amount of each phase, on their morphology and on the initial microstructure. In order to better understand the link between these parameters and the macroscopic behavior, we use the Discrete Element Method (DEM) to simulate the compaction process and the fracture behavior of the fired composite. These simulations are coupled with well-designed experiments. Four mixes with various amounts of Al₂O₃ and binder were tested both experimentally and numerically. In DEM, each particle is modelled and the interactions between particles are taken into account through appropriate contact or bonding laws. Here, we model a bimodal mixture of large Al₂O₃ and small Al₂O₃ covered with a soft binder. This composite is itself mixed with graphite platelets. X-ray tomography images are used to analyze the morphologies of the different components. Large Al₂O₃ particles and graphite platelets are modelled in DEM as sets of particles bonded together. The binder is modelled as a soft shell that covers both large and small Al₂O₃ particles. When two particles with binder indent each other, they first interact through this soft shell. Once a critical indentation is reached (towards the end of compaction), hard Al₂O₃ - Al₂O₃ contacts appear. In accordance with experimental data, DEM simulations show that the amount of Al₂O₃ and the amount of binder play a major role for the compaction behavior. The graphite platelets bend and break during the compaction, also contributing to the macroscopic stress. Firing step is modeled in DEM by ascribing bonds to particles which contact each other after compaction. The fracture behavior of the compacted mixture is also simulated and compared with experimental data. Both diametrical tests (Brazilian tests) and triaxial tests are carried out. Again, the link between the amount of Al₂O₃ particles and the fracture behavior is investigated. The methodology described here can be generalized to other particulate materials that are used in the ceramic industry.

Keywords: cold compaction, composites, discrete element method, refractory materials, x-ray tomography

Procedia PDF Downloads 132
28094 Analysis of Rural Roads in Developing Countries Using Principal Component Analysis and Simple Average Technique in the Development of a Road Safety Performance Index

Authors: Muhammad Tufail, Jawad Hussain, Hammad Hussain, Imran Hafeez, Naveed Ahmad

Abstract:

Road safety performance index is a composite index which combines various indicators of road safety into single number. Development of a road safety performance index using appropriate safety performance indicators is essential to enhance road safety. However, a road safety performance index in developing countries has not been given as much priority as needed. The primary objective of this research is to develop a general Road Safety Performance Index (RSPI) for developing countries based on the facility as well as behavior of road user. The secondary objectives include finding the critical inputs in the RSPI and finding the better method of making the index. In this study, the RSPI is developed by selecting four main safety performance indicators i.e., protective system (seat belt, helmet etc.), road (road width, signalized intersections, number of lanes, speed limit), number of pedestrians, and number of vehicles. Data on these four safety performance indicators were collected using observation survey on a 20 km road section of the National Highway N-125 road Taxila, Pakistan. For the development of this composite index, two methods are used: a) Principal Component Analysis (PCA) and b) Equal Weighting (EW) method. PCA is used for extraction, weighting, and linear aggregation of indicators to obtain a single value. An individual index score was calculated for each road section by multiplication of weights and standardized values of each safety performance indicator. However, Simple Average technique was used for weighting and linear aggregation of indicators to develop a RSPI. The road sections are ranked according to RSPI scores using both methods. The two weighting methods are compared, and the PCA method is found to be much more reliable than the Simple Average Technique.

Keywords: indicators, aggregation, principle component analysis, weighting, index score

Procedia PDF Downloads 142
28093 Transport Properties of Alkali Nitrites

Authors: Y. Mateyshina, A.Ulihin, N.Uvarov

Abstract:

Electrolytes with different type of charge carrier can find widely application in different using, e.g. sensors, electrochemical equipments, batteries and others. One of important components ensuring stable functioning of the equipment is electrolyte. Electrolyte has to be characterized by high conductivity, thermal stability, and wide electrochemical window. In addition to many advantageous characteristic for liquid electrolytes, the solid state electrolytes have good mechanical stability, wide working range of temperature range. Thus search of new system of solid electrolytes with high conductivity is an actual task of solid state chemistry. Families of alkali perchlorates and nitrates have been investigated by us earlier. In literature data about transport properties of alkali nitrites are absent. Nevertheless, alkali nitrites MeNO2 (Me= Li+, Na+, K+, Rb+ and Cs+), except for the lithium salt, have high-temperature phases with crystal structure of the NaCl-type. High-temperature phases of nitrites are orientationally disordered, i.e. non-spherical anions are reoriented over several equivalents directions in the crystal lattice. Pure lithium nitrite LiNO2 is characterized by ionic conductivity near 10-4 S/cm at 180°C and more stable as compared with lithium nitrate and can be used as a component for synthesis of composite electrolytes. In this work composite solid electrolytes in the binary system LiNO2 - A (A= MgO, -Al2O3, Fe2O3, CeO2, SnO2, SiO2) were synthesized and their structural, thermodynamic and electrical properties investigated. Alkali nitrite was obtained by exchange reaction from water solutions of barium nitrite and alkali sulfate. The synthesized salt was characterized by X-ray powder diffraction technique using D8 Advance X-Ray Diffractometer with Cu K radiation. Using thermal analysis, the temperatures of dehydration and thermal decomposition of salt were determined.. The conductivity was measured using a two electrode scheme in a forevacuum (6.7 Pa) with an HP 4284A (Precision LCR meter) in a frequency range 20 Hz < ν < 1 MHz. Solid composite electrolytes LiNO2 - A A (A= MgO, -Al2O3, Fe2O3, CeO2, SnO2, SiO2) have been synthesized by mixing of preliminary dehydrated components followed by sintering at 250°C. In the series of nitrite of alkaline metals Li+-Cs+, the conductivity varies not monotonically with increasing radius of cation. The minimum conductivity is observed for KNO2; however, with further increase in the radius of cation in the series, the conductivity tends to increase. The work was supported by the Russian Foundation for Basic research, grant #14-03-31442.

Keywords: conductivity, alkali nitrites, composite electrolytes, transport properties

Procedia PDF Downloads 307
28092 Effect of Formulated Insect Enriched Sprouted Soybean /Millet Based Food on Gut Health Markers in Albino Wistar Rats

Authors: Gadanya, A.M., Ponfa, S., Jibril, M.M., Abubakar, S. M.

Abstract:

Background: Edible insects such as grasshopper are important sources of food for humans, and have been consumed as traditional foods by many indigenous communities especially in Africa, Asia, and Latin America. These communities have developed their skills and techniques in harvesting, preparing, consuming, and preserving edible insects, widely contributing to the role played by the use of insects in human nutrition. Aim/ objective: This study was aimed at determining the effect of insect enriched sprouted soyabean /millet based food on some gut health markers in albino rats. Methods. Four different formulations of Complementary foods (i.e Complementary Food B (CFB): sprouted millet (SM), Complementary Food C (CFC): sprouted soyabean (SSB), Complementary Food D (CFD): sprouted soybean and millet (SSBM) in a ratio of (50:50) and Complementary Food E (CFE): insect (grasshopper) enriched sprouted soybean and millet (SSBMI) in a ratio of (50:25:25)) were prepared. Proximate composition and short chain fatty acid contents were determined. Thirty albino rats were divided into5 groups of six rats each. Group 1(CDA) were fed with basal diet and served as a control group, while groups 2,3,4 and 5 were fed with the corresponding complimentary foods CFB, CFC, CFD and CFE respectively daily for four weeks. Concentrations of fecal protein, serum total carotenoids and nitric oxide were determined. DNA extraction for molecular isolation and characterization were carried out followed by PCR, the use of mega 11 software and NCBI blast for construction of the phylogenetic tree and organism identification respectively. Results: Significant increase (P<0.05) in percentage ash, fat, protein and moisture contents, as well as short chain fatty acid (acetate, butyrate and propionate) concentrations were recorded in the insect enriched sprouted composite food (CFE) when compared with the CFA, CFB, CFC and CFD composite food. Faecal protein, carotenoid and nitric oxide concentrations were significantly lower (P>0.05) in group 5 in comparison to groups 1to 4. Ruminococcus bromii and Bacteroidetes were molecularly isolated and characterized by 16s rRNA from the sprouted millet/sprouted soybean and the insect enriched sprouted soybean/sprouted millet based food respectively. The presence of these bacterial strains in the feaces of the treated rats is an indication that the gut of the treated rats is colonized by good gut bacteria, hence, an improved gut health. Conclusion: Insect enriched sprouted soya bean/sprouted millet based complementary diet showed a high composition of ash, fat, protein and fiber. Thus, could increase the availability of short chain fatty acids whose role to the host organism cannot be overemphasized. It was also found to have decrease the level of faecal protein, carotenoid and nitric oxide in the serum which is an indication of an improvement in the immune system function.

Keywords: gut-health, insect, millet, soybean, sprouted

Procedia PDF Downloads 53
28091 Eco-Friendly Silicone/Graphene-Based Nanocomposites as Superhydrophobic Antifouling Coatings

Authors: Mohamed S. Selim, Nesreen A. Fatthallah, Shimaa A. Higazy, Hekmat R. Madian, Sherif A. El-Safty, Mohamed A. Shenashen

Abstract:

After the 2003 prohibition on employing TBT-based antifouling coatings, polysiloxane antifouling nano-coatings have gained in popularity as environmentally friendly and cost-effective replacements. A series of non-toxic polydimethylsiloxane nanocomposites filled with nanosheets of graphene oxide (GO) decorated with magnetite nanospheres (GO-Fe₃O₄ nanospheres) were developed and cured via a catalytic hydrosilation method. Various GO-Fe₃O₄ hybrid concentrations were mixed with the silicone resin via solution casting technique to evaluate the structure–property connection. To generate GO nanosheets, a modified Hummers method was applied. A simple co-precipitation method was used to make spherical magnetite particles under inert nitrogen. Hybrid GO-Fe₃O₄ composite fillers were developed by a simple ultrasonication method. Superhydrophobic PDMS/GO-Fe₃O₄ nanocomposite surface with a micro/nano-roughness, reduced surface-free energy (SFE), high fouling release (FR) efficiency was achieved. The physical, mechanical, and anticorrosive features of the virgin and GO-Fe₃O₄ filled nanocomposites were investigated. The synergistic effects of GO-Fe₃O4 hybrid's well-dispersion on the water-repellency and surface topological roughness of the PDMS/GO-Fe₃O₄ nanopaints were extensively studied. The addition of the GO-Fe₃O₄ hybrid fillers till 1 wt.% could increase the coating's water contact angle (158°±2°), minimize its SFE to 12.06 mN/m, develop outstanding micro/nano-roughness, and improve its bulk mechanical and anticorrosion properties. Several microorganisms were employed for examining the fouling-resistance of the coated specimens for 1 month. Silicone coatings filled with 1 wt.% GO-Fe₃O₄ nanofiller showed the least biodegradability% among all the tested microorganisms. Whereas GO-Fe₃O4 with 5 wt.% nanofiller possessed the highest biodegradability% potency by all the microorganisms. We successfully developed non-toxic and low cost nanostructured FR composite coating with high antifouling-resistance, reproducible superhydrophobic character, and enhanced service-time for maritime navigation.

Keywords: silicone antifouling, environmentally friendly, nanocomposites, nanofillers, fouling repellency, hydrophobicity

Procedia PDF Downloads 93
28090 Electrospinning in situ Synthesis of Graphene-Doped Copper Indium Disulfide Composite Nanofibers for Efficient Counter Electrode in Dye-Sensitized Solar Cells

Authors: Lidan Wang, Shuyuan Zhao, Jianxin He

Abstract:

In this paper, graphene-doped copper indium disulfide (rGO+CuInS2) composite nanofibers were fabricated via electrospinning, in situ synthesis, and carbonization, using polyvinyl pyrrolidone (PVP), copper dichloride (CuCl2), indium trichloride (InCl3), thiourea (C2H5NS) and graphene oxide nanosheets (Go) as the precursor solution for electrospinning. The average diameter of rGO+CuInS2 nanofibers were about 100 nm, and graphene nanosheets anchored with chalcopyrite CuInS2 nanocrystals 8-15 nm in diameter were overlapped and embedded, aligning along the fiber axial direction. The DSSC with a rGO+CuInS2 counter electrode exhibits a power conversion efficiency of 5.93%; better than the corresponding values for a DSSC with a CuInS2 counter electrode, and comparable to that of a reference DSSC with a Pt counter electrode. The excellent photoelectric performance of the rGO+CuInS2 counter electrode was attributed to its high specific surface area, which facilitated permeation of the liquid electrolytes, promoted electron and ion transfer and provided numerous catalytically active sites for the oxidation reaction of the electrolytic (I- /I3-).

Keywords: dye-sensitized solar cells, counter electrode, electrospinning, graphene

Procedia PDF Downloads 448
28089 Moisture Absorption Analysis of LLDPE-NR Nanocomposite for HV Insulation

Authors: M. S. Kamarulzaman, N. A. Muhamad, N. A. M. Jamail, M. A. M. Piah, N. F. Kasri

Abstract:

Insulation for high voltage application that has been service for a very long time is subjected to several types of degradation. The degradation can lead to premature breakdown and definitely will spent highly cost to replace the cable. Thus, there are many research on nano composite material get serious attention attention due to their abilities to enhance electrical performance by addition of nano filler. In this paper, water absorption of Low Linear Density Polyethyelene (LLDPE) with different amount of nano filler added is studied. This study is necessary to be conducted since most of electrical apparatus such as cable insulation are dominant used especially in high voltage application. The cable insulation are continuously exposed in uncontrolled environment may suffer degradation process. Three type of nano fillers, was used in this study are: Silicon dioxide (SiO2), Titanium dioxide (TiO2) and Monmorillonite (MMT). The percentage absorption of water was measured by weighted using high precision scales for absorption process up to 92 days. Experimental result demonstrate that SiO2 absorb less water than other filler while, the MMT has hydrophilic properties which it absorbs more water compare to another sample.

Keywords: nano composite, nano filler, water absorption, hydrophilic properties

Procedia PDF Downloads 345