scholarly journals Mechanical Performance of Cementitious Composites by MWCNTs Addition for Structural Applications

2020 ◽  
Vol 9 (2) ◽  
pp. 51-62
Author(s):  
Mohd Moonis Zaheer
Keyword(s):  
Mechanical Performance ◽  
Optimum Concentration ◽  
Sem Images ◽  
Mwcnt Content ◽  
Disperse Carbon ◽  
Structural Applications ◽  
Multi Walled Carbon Nanotubes ◽  
Carbon Nano Tubes ◽  
Strength And Durability ◽  
Walled Carbon Nanotubes

This paper presents the investigation on the behaviour of a prism reinforced with multi walled carbon nanotubes (MWCNTs) to study mainly the strength and durability aspects for structural applications. Prisms were made by varying the MWCNT content from 0.1 to 0.5% by weight of cement. Ultrasonic energy was employed to disperse carbon nano tubes (CNTs) in water. For evaluating mechanical property such as load-deflection, tests were performed on CNT admixed prisms under flexure. The outcomes were then compared with plain mortar prisms. An attempt has also been made to explore the optimum concentration of MWCNT additions that will give ideal performance with respect to mechanical and durability properties. Flexural and compressive strength is enhanced by 25% and 19%, respectively compared to control prisms at 28 days when CNT was used in the cementitious matrix. Both porosity and water absorption are reduced by about 25% at 28 days. Based on the parametric study, a tentative optimum CNT concentration (0.3% by weight of cement) has been proposed. SEM images shows perfect crack bridging mechanism; several of the CNTs were shown as crack arrestor across the fine cracks along with some CNTs breakage.

Experimental Investigation of Morphological and Electrical Characteristics of PS/MWCNT Nanocomposite Films

2018 ◽  
Vol 915 ◽  
pp. 104-109
Author(s):  
Barış Demirbay ◽  
Şaziye Uğur
Keyword(s):  
Annealed Film ◽  
Nanocomposite Films ◽  
Electrical Characteristics ◽  
Liquid Form ◽  
Mwcnt Content ◽  
Electrical Percolation ◽  
Glass Substrates ◽  
Multi Walled Carbon Nanotubes ◽  
Electrical Percolation Threshold ◽  
Walled Carbon Nanotubes

Electrical characteristics and morphology of nanocomposite films composed of two different polystyrene (PS) latexes impregnated with multi-walled carbon nanotubes (MWCNT) in the range between 0 wt% and 20 wt% were assessed by considering photon transmission (UV-Vis) technique and electrical conductivity measurements. Emulsion polymerization technique was employed both to synthesize very fine PS particles dispersed in water and to tailor the sizes of the PS particles as 382 nm and 560 nm, respectively. PS/MWCNT nanocomposite films were obtained from the liquid form on glass substrates via drop-casting method and all they dried at 40 QUOTE C. Each dried sample was then annealed at varying temperatures between 100 QUOTE C and 250 QUOTE C for 10 min. The surface conductivity QUOTE of each annealed film at 250 QUOTE C was measured and was found to increase dramatically above a certain mass fraction of MWCNT content, QUOTE . Each set of PS/MWCNT nanocomposite film had a similar electrical percolation threshold of QUOTE =1.5 wt% as the MWCNT content and critical exponents of QUOTE were found to be 2.64 and 1.19 for 382 nm and 560 nm PS latex systems, respectively.

scholarly journals Multifunctional Ionogels Incorporated with Lanthanide (Eu3+, Tb3+) Complexes Covalently Modified Multi-Walled Carbon Nanotubes

Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1099 ◽  
Author(s):  
Qiuping Li
Keyword(s):  
Carbon Nanotubes ◽  
Ionic Liquids ◽  
Uv Light ◽  
Green Emission ◽  
Sem Images ◽  
Hybrid Gels ◽  
Multi Walled Carbon Nanotubes ◽  
Electric Materials ◽  
Walled Carbon Nanotubes ◽  
Functionalized Mwcnts

Ionogels refer to an emerging composite material made from the confinement of ionic liquids within some specific cross-linked network matrices. They have potential applications in areas such as electrochemical and optical-electric materials. Incorporation of lanthanide (Eu3+, Tb3+) complexes covalently functionalized multi-walled carbon nanotubes (MWCNTs) in ionogels provide new ideas to design and synthesize novel luminescent hybrid materials that have excellent characteristics of luminescence and ionic conductivity. Here, the multifunctional ionogels were synthesized by confining an ionic liquid and the rare earth functionalized MWCNTs in the cross-linked polymethyl methacrylate (PMMA) networks, resulting in a novel optical/electric multifunctional hybrid material. The SEM images and digital photographs suggest that the lanthanide functionalized MWCNTs are evenly dispersed in the hybrid matrices, thus leading to a certain transparency bulky gel. The resulting ionogels exhibit certain viscosity and flexibility, and display an intense red/green emission under UV-light irradiation. The intrinsic conductibility of the embedded ionic liquids and carbon nanotubes in conjunction with the outstanding photoluminescent properties of lanthanide complexes makes the soft hybrid gels a material with great potential and valuable application in the field of optical-electric materials.

Bioactive poly(etheretherketone) composite containing calcium polyphosphate and multi-walled carbon nanotubes for bone repair: Mechanical property and in vitro biocompatibility

2018 ◽  
Vol 33 (5) ◽  
pp. 543-557 ◽  
Author(s):  
Jianfei Cao ◽  
Yue Lu ◽  
Hechun Chen ◽  
Lifang Zhang ◽  
Chengdong Xiong
Keyword(s):  
Mechanical Property ◽  
Carbon Nanotubes ◽  
Bone Repair ◽  
Mechanical Performance ◽  
Injection Molding Process ◽  
Molding Process ◽  
Calcium Polyphosphate ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Poly(etheretherketone) exhibits good biocompatibility, excellent mechanical properties, and bone-like stiffness. However, the natural bio-inertness of pure poly(etheretherketone) hinders its applications in biomedical field, especially when direct bone-implant osteo-integration is desired. For developing an alternative biomaterial for load-bearing orthopedic application, combination of bioactive fillers with poly(etheretherketone) matrix is a feasible approach. In this study, a bioactive multi-walled carbon nanotubes/calcium polyphosphate/poly(etheretherketone) composite was prepared through a compounding and injection-molding process for the first time. Bioactive calcium polyphosphate was added to polymer matrix to enhance the bioactivity of the composite, and incorporation of multi-walled carbon nanotubes to composite was aimed to improve both the mechanical property and biocompatibility. Furthermore, the microstructures, surface hydrophilicity, and mechanical property of multi-walled carbon nanotubes/calcium polyphosphate/poly(etheretherketone) composite, as well as the cellular responses of MC3T3-E1 osteoblast cells to this material were investigated. The mechanical testing revealed that mechanical performance of the resulting ternary composite was significantly enhanced by adding the multi-walled carbon nanotubes and the mechanical values obtained were close to or higher than those of human cortical bone. More importantly, cell culture tests showed that initial cell adhesion, cell viability, and osteogenic differentiation of MC3T3-E1 cells were significantly promoted on the multi-walled carbon nanotubes/calcium polyphosphate/poly(etheretherketone) composite. Accordingly, the multi-walled carbon nanotubes/calcium polyphosphate/poly(etheretherketone) composite may be used as a promising bone repair material in dental and orthopedic applications.

The Research on the Electrical Properties Change in Extrusion Molding of Resin Matrix Multi-Walled Carbon Nano Tubes Composites

2012 ◽  
Vol 443-444 ◽  
pp. 866-871
Author(s):  
Ling Sun ◽  
Mao Shun Chen ◽  
Xian Shu Zheng
Keyword(s):  
Electrical Properties ◽  
Low Cost ◽  
Test Sample ◽  
Extrusion Temperature ◽  
Resin Matrix ◽  
Cooling Mode ◽  
Multi Walled Carbon Nanotubes ◽  
Carbon Nano Tubes ◽  
Temperature Rate ◽  
Walled Carbon Nanotubes

Prepare poly butylene terephthalate (PBT)/multi-walled carbon nanotubes (MWNTs) composites through the method of melt blending. Then use low-cost single screw extruder to conduct experimental research and analysis on the extrusion test sample of PBT/MWNTs composites of different proportions under the conditions of changing the extrusion temperature, rate, cooling mode and so on. As a result, the process parameters of the better extrusion temperature, critical extrusion rate, and high-gloss molding etc. to reinforce the electrical properties of composites under low-cost experiment condition have been obtained. The experiment results also indicate that with the increasing of the MWNTs content, the surface resistivity of the composites shows a declining trend.

scholarly journals Electrodeposition of Sn and Sn Composites with Carbon Materials Using Choline Chloride-Based Ionic Liquids

Coatings ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 798
Author(s):  
Ana T. S. C. Brandão ◽  
Liana Anicai ◽  
Oana Andreea Lazar ◽  
Sabrina Rosoiu ◽  
Aida Pantazi ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Materials ◽  
Electrochemical Impedance ◽  
Choline Chloride ◽  
Composite Films ◽  
Growth Stages ◽  
Initial Growth ◽  
Sem Images ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Nano carbons, such as graphene and carbon nanotubes, show very interesting electrochemical properties and are becoming a focus of interest in many areas, including electrodeposition of carbon–metal composites for battery application. The aim of this study was to incorporate carbon materials (namely oxidized multi-walled carbon nanotubes (ox-MWCNT), pristine multi-walled carbon nanotubes (P-MWCNT), and reduced graphene oxide (rGO)) into a metallic tin matrix. Formation of the carbon–tin composite materials was achieved by electrodeposition from a choline chloride-based ionic solvent. The different structures and treatments of the carbon materials will create metallic composites with different characteristics. The electrochemical characterization of Sn and Sn composites was performed using chronoamperometry, potentiometry, electrochemical impedance, and cyclic voltammetry. The initial growth stages of Sn and Sn composites were characterized by a glassy-carbon (GC) electrode surface. Nucleation studies were carried out, and the effect of the carbon materials was characterized using the Scharifker and Hills (SH) and Scharifker and Mostany (SM) models. Through a non-linear fitting method, it was shown that the nucleation of Sn and Sn composites on a GC surface occurred through a 3D instantaneous process with growth controlled by diffusion. According to Raman and XRD analysis, carbon materials were successfully incorporated at the Sn matrix. AFM and SEM images showed that the carbon incorporation influences the coverage of the surface as well as the size and shape of the agglomerate. From the analysis of the corrosion tests, it is possible to say that Sn-composite films exhibit a comparable or slightly better corrosion performance as compared to pure Sn films.

scholarly journals Humic acid assisted stabilization of dispersed single-walled carbon nanotubes in cementitious composites

2019 ◽  
Vol 8 (1) ◽  
pp. 513-522 ◽  
Author(s):  
Tao Hu ◽  
Hongwen Jing ◽  
Luan Li ◽  
Qian Yin ◽  
Xinshuai Shi ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Humic Acid ◽  
Mechanical Performance ◽  
Single Walled Carbon Nanotubes ◽  
Cementitious Composites ◽  
Cement Slurry ◽  
Sem Images ◽  
Single Walled Carbon ◽  
Alkaline Environment ◽  
Walled Carbon Nanotubes

AbstractSignificant research has been done in recent decades in the field of the dispersion of carbon nanotubes in aqueous solutions and the reinforcement of ordinary Portland cement (OPC). However, the cementitious mixture, as an alkaline environment, easily leads to the re-agglomeration of dispersed single-walled carbon nanotubes (SWCNTs) and influences their enhancing effects. Humic acid (HA) is a type of natural organic matter which can assist the stabilization of dispersed single-walled carbon nanotubes in cementitious composites. The present study characterizes the influence of HA in stabilizing the dispersion of SWCNTs by means of ultraviolet spectrophotometer tests. The fluidity of fresh cement slurry and mechanical performance of hardened OPC pastes were measured to better illustrate the dispersion of SWCNTs in real cement composites. The results not only reveal that the addition of an alkaline environment to the SWCNT suspensions results in a rapid decrease of the dispersion, but also suggest that the appropriate content of HA (0.12 wt.%) can play a significant role in stabilizing the dispersion of SWCNTs. When the mixed hybrid of SWCNTs and HA with a concentration of HA/c equal to 0.05 wt.% is used, the fluidity of the fresh cement slurry experiences a maximum decline and this mixture content of materials will dramatically increase the compressive and flexural strength by about 31% and 48%, which indicates that more SWCNTs are in a dispersed state under this concentration. SEM images further prove that a suitable HA/c can inhibit the expansion of cracks in the cementitious composites.

scholarly journals On the Feasibility of Printing 3D Composite Objects Based on Polypropylene/Multi-walled Carbon Nanotubes

2019 ◽  
Vol 290 ◽  
pp. 03017 ◽  
Author(s):  
Nicoleta-Violeta Stanciu ◽  
Felicia Stan ◽  
Catalin Fetecau ◽  
Florin Susac
Keyword(s):  
Fused Deposition Modeling ◽  
Mechanical Performance ◽  
Extrusion Process ◽  
Flow Activation Energy ◽  
Fused Deposition ◽  
Multi Walled Carbon Nanotubes ◽  
3D Composite ◽  
Trial And Error Method ◽  
Walled Carbon Nanotubes ◽  
Printing Direction

In this paper, the feasibility of 3D printing polypropylene/ multi-walled carbon nanotube (PP/MWCNT) composites by fused deposition modeling. First, the rheological behavior of PP with 0.3, 0.5 and 1 wt.% of MWCNT was investigated in order to determine the printability in terms of melt shear viscosity and flow activation energy. Second, the filament extrusion process was optimized by the trial-and-error method in order to obtain round and constant filaments. Finally, tensile specimens were printed and tested in order to determine the mechanical properties at various printing direction. Experimental results show that the PP/MWCNT composite filaments with MWCNT loading up to 1 wt.% have good printability characteristics and can be successfully 3D printed with good mechanical performance.

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