scholarly journals Preparation and Characterization of Polypropylene/Carbon Nanotubes (PP/CNTs) Nanocomposites as Potential Strain Gauges for Structural Health Monitoring

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 814 ◽  
Author(s):  
Bartolomeo Coppola ◽  
Luciano Di Maio ◽  
Loredana Incarnato ◽  
Jean-Marc Tulliani
Keyword(s):  
Carbon Nanotubes ◽  
Thermo Gravimetric Analysis ◽  
Tensile Tests ◽  
Strain Gauges ◽  
Gauge Factor ◽  
Gravimetric Analysis ◽  
Strain Sensing ◽  
Scanning Calorimetry ◽  
Impedance Variation ◽  
Mechanical Tensile

Polypropylene/carbon nanotubes (PP/CNTs) nanocomposites with different CNTs concentrations (i.e., 1, 2, 3, 5 and 7 wt%) were prepared and tested as strain gauges for structures monitoring. Such sensors were embedded in cementitious mortar prisms and tested in 3-point bending mode recording impedance variation at increasing load. First, thermal (differential scanning calorimetry (DSC), thermo-gravimetric analysis (TGA)), mechanical (tensile tests) and morphological (FE-SEM) properties of nanocomposites blends were assessed. Then, strain-sensing tests were carried out on PP/CNTs strips embedded in cementitious mortars. PP/CNTs nanocomposites blends with CNTs content of 1, 2 and 3 wt% did not show significant results because these concentrations are below the electrical percolation threshold (EPT). On the contrary, PP/CNTs nanocomposites with 5 and 7 wt% of CNTs showed interesting sensing properties. In particular, the best result was highlighted for the PP/CNT nanocomposite with 5 wt% CNTs for which an average gauge factor (GF) of approx. 1400 was measured. Moreover, load-unload cycles reported a good recovery of the initial impedance. Finally, a comparison with some literature results, in terms of GF, was done demonstrating the benefits deriving from the use of PP/CNTs strips as strain-gauges instead of using conductive fillers in the bulk matrix.

Microstructure Characterization of Alumina/Carbon Nanotubes Composite Coating

2010 ◽  
Vol 33 ◽  
pp. 168-172
Author(s):  
Song Bi ◽  
Xin Jia Su ◽  
Gen Liang Hou ◽  
Zhou Xiao ◽  
Guo Qiang Gu
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Composite Coating ◽  
Plasma Spray ◽  
Thermo Gravimetric Analysis ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Spray Process ◽  
Α Al2o3

Alumina/carbon nanotubes (Al2O3/CNTs) composite coating was synthesized by plasma spray employing mixtures of Al2O3-coated CNTs and nano-sized α-Al2O3 at atmosphere. This coating was characterized for the microstructure and the composition by X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), high resolution transmission electron microscopy (HRTEM), thermo gravimetric analysis (TG), differential scanning calorimetry analysis (DSC) and scanning electron microscopy (SEM). The results show that the thickness of the coating is about 0.5mm and the constituent elements were changed to α-Al2O3, CNTs and γ-Al2O3 duo to the superhigh temperature during the plasma spray process. The great mass of the mixtures were melted well and the CNTs were dispersed uniformly in the melted ceramic. The oxidation resistance and the microwave absorption properties were discussed simply to describe the functions of the composite coating.

Synthesis and Processing of Solution Spun Cellulose Acetate Fibers Reinforced With Carbon Nanotubes

2015 ◽  
Author(s):  
Quazi Nahida Sultana ◽  
Saheem Absar ◽  
Stephanie Hulsey ◽  
Hans Schanz ◽  
Mujibur Khan
Keyword(s):  
Carbon Nanotubes ◽  
Cellulose Acetate ◽  
Thermo Gravimetric Analysis ◽  
Coagulation Bath ◽  
Binary Solvent ◽  
Gear Pump ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Structural Applications ◽  
Solution Spinning

We report the fabrication of Cellulose Acetate (CA) based fibers reinforced with Multi-Walled Carbon Nanotubes (MWCNTs) using a solution spinning process. The motivation of this work is to produce high performance fibers based on sustainable natural materials as an alternative to synthetic fibers for structural applications. A 30 wt% solution of CA in a binary solvent system of N, N-dimethylacetamide (DMAc) and Acetone (3:7 v/v) was used for the solution spinning of CA fibers. Both neat and CNT-loaded CA fibers were produced. The CNT loading with respect to the polymer was at 0.5 wt%. For CA-MWCNT spinning solutions, the MWCNTs were initially dispersed in the solvent and then CA is added and mixed together. The mixing temperature kept 40–45°C. The viscosity of the CA solution was 8,000 cP. Addition of MWCNT increased the viscosity of the CA solution to 32,000 cP. A lab-scale solution spinning line consisting of a constant torque high temperature gear pump and heated extrusion channels was used to produce both neat and CA-MWCNT fibers. The solution was pumped through a spinneret at the end of the extrusion channel with an orifice as a viscous gel-like filament which was passed through a spool placed in a coagulation bath and then it formed as fiber. The fibers are collected to a takeup roll at a draw ratio of 8.0. Characterization studies of both neat and MWCNT loaded fibers were performed differential scanning calorimetry (DSC), thermo-gravimetric analysis (TGA) and scanning electron microscopy (SEM). DSC analysis of fibers showed reduction in crystallinity of CA upon inclusion of 0.5 wt% MWCNT. TGA analysis showed improvement of thermal stability in CA-MWCNT fibers compared to neat CA. Cross-sections of neat CA fibers showed smooth surfaces with no significant defects, while CA-MWCNT showed formation of micro-voids and irregular features. Longitudinal views of outer surface of both neat CA and CA-MWCNT fibers showed no indication of surface defects or protrusions.

MANUFACTURING AND CHARACTERIZATION OF CARBON NANOTUBE/POLYETHYLENE COMPOSITES

2005 ◽  
Vol 04 (01) ◽  
pp. 55-72 ◽  
Author(s):  
HASSAN MAHFUZ ◽  
ASHFAQ ADNAN ◽  
VIJAYA K. RANGARI ◽  
SHAIK JEELANI
Keyword(s):  
Carbon Nanotubes ◽  
Thermo Gravimetric Analysis ◽  
Extrusion Direction ◽  
Extrusion Process ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Neat Polymer ◽  
Single Screw Extrusion ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

The present study describes a method to fabricate polymer matrix nanocomposites by reinforcing multi-walled carbon nanotubes through an extrusion process. Linear low density polyethylene (LLDPE) powder and multi-walled carbon nanotubes (CNTs) are first dry mixed and extruded in the form of filaments by a single screw extrusion process. After extrusion, the filament is partially cooled by chilled air, dried, and continuously wound in a spool. The filaments are then laid in roving, stacked in a unidirectional fashion, and consolidated in a compression molding machine to come up with laminated composites. Thermo gravimetric analysis (TGA) has been performed to compare the thermal stability of as-fabricated composites with the neat polymer. The TGA result shows that the extruded composites are thermally more stable than their neat counterparts. The crystalline nature of CNTs and of as-fabricated composites were identified by X-ray diffraction (XRD) studies. The XRD results indicate that the nanocomposite materials are more crystalline than the neat systems, and the differential scanning calorimetry studies also confirmed the same trend. The scanning electron microscopy result showed that the sizes of extruded neat and nanophased filaments were about 117 and 73 μm, respectively. Tensile coupons from the consolidated panels were then extracted both in longitudinal (0°) and in transverse (90°) directions and tested in a Minimat Tester. It was found that with the addition of 2% by weight of CNTs in LLDPE, the tensile strength and modulus of the composite has increased by about 34 and 38%, respectively. The (0°) and (90°) coupons have also demonstrated that there are directional effects in the tensile response, which is believed to have been caused by the alignment of CNTs during the extrusion process. It is our understanding that such improvement in properties is because of the increase in crystallinity of the polymer due to CNT infusion, and also due to the alignment of CNTs in the extrusion direction in the nanocomposites. Details of the fabrication procedures, synthesis of composites, and mechanical testing are included in the paper.

scholarly journals Optimization of Thermoplastic Blend Matrix HDPE/PLA with Different Types and Levels of Coupling Agents

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2527 ◽  
Author(s):  
Alessia Quitadamo ◽  
Valérie Massardier ◽  
Carlo Santulli ◽  
Marco Valente
Keyword(s):  
Thermo Gravimetric Analysis ◽  
Random Copolymer ◽  
Tensile Tests ◽  
Thermomechanical Analysis ◽  
Poly Lactic Acid ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Thermo Gravimetric ◽  
Different Types ◽  
Good Potential

High-density polyethylene (HDPE) and poly(lactic) acid (PLA) blends with different ratios of both polymers, namely, 30:70, 50:50, and 70:30, were produced. Polyethylene-grafted maleic anhydride and a random copolymer of ethylene and glycidyl methacrylate were also considered as compatibilizers to modify HDPE/PLA optimal blends and were added in the amounts of 1, 3, and 5 wt.%. Different properties of the blends were evaluated by performing tensile tests and scanning electron microscopy to analyze blend and interfaces morphology. Moreover, thermomechanical analysis through differential scanning calorimetry, thermo-gravimetric analysis, and infrared spectroscopy were also performed. The blend containing equal amounts of HDPE and PLA seemed to present a good balance between amount of bio-derived charge and acceptable mechanical properties. This suggests that these blends have a good potential for the production of composites with lingo-cellulosic fillers.

scholarly journals Influence of different functionalization methods of multi-walled carbon nanotubes on the properties of poly(L-lactide) based nanocomposites

2019 ◽  
Vol 73 (3) ◽  
pp. 183-196 ◽  
Author(s):  
Nevena Vukic ◽  
Ivan Ristic ◽  
Milena Marinovic-Cincovic ◽  
Radmila Radicevic ◽  
Branka Pilic ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Thermo Gravimetric Analysis ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Ft Ir ◽  
Walled Carbon Nanotubes ◽  
Functionalized Mwcnts

This paper presents influence of the type of carbon nanotube functionalization on properties of poly(L-lactide) (PLLA) based nanocomposite materials. For this purpose surface modifications of multi-walled carbon nanotubes (MWCNTs) were performed by chemical and irradiation techniques, while thermo gravimetric analysis, UV-Visible and Fourier-transform infrared (FT-IR) spectroscopies confirmed successful covalent functionalization. Series of PLLA bionanocom-posites with different contents of functionalized MWCNTs (0.7; 1.6; 2.1 wt%), were synthesized via ring-opening solution polymerisation of L-lactide. FT-IR analysis confirmed that grafting of L-lactide, under controlled condition, is possible to perform starting from the surface of functionalized MWCNTs. From differential scanning calorimetry results it was concluded that even low contents of chemically and irradiation functionalized MWCNTs had a significant effect on thermal properties of the prepared nanocomposites, raising the values of melting and glass transition temperatures. Thermogravimetric analysis (TGA) has shown that the degradation onset temperature for composites with chemically functionalized MWCNTs, was much higher than that for the neat poly(L-lactide) sample and composites with irradiation functionalized MWCNTs. Morphology studies by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) indicated that poly(L-lactide) covered surfaces and separated functionalized MWCNTs. Good dispersion of carbon nanotubes in polymer matrix enabled conductivity of synthesized materials, as determined by conductivity tests.

scholarly journals Biocomposites of Bio-Polyethylene Reinforced with a Hydrothermal-Alkaline Sugarcane Bagasse Pulp and Coupled with a Bio-Based Compatibilizer

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2158
Author(s):  
Nanci Vanesa Ehman ◽  
Diana Ita-Nagy ◽  
Fernando Esteban Felissia ◽  
María Evangelina Vallejos ◽  
Isabel Quispe ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
3D Printing ◽  
Water Absorption ◽  
Sugarcane Bagasse ◽  
Thermo Gravimetric Analysis ◽  
Decomposition Temperature ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Cradle To Gate ◽  
Bagasse Pulp

Bio-polyethylene (BioPE, derived from sugarcane), sugarcane bagasse pulp, and two compatibilizers (fossil and bio-based), were used to manufacture biocomposite filaments for 3D printing. Biocomposite filaments were manufactured and characterized in detail, including measurement of water absorption, mechanical properties, thermal stability and decomposition temperature (thermo-gravimetric analysis (TGA)). Differential scanning calorimetry (DSC) was performed to measure the glass transition temperature (Tg). Scanning electron microscopy (SEM) was applied to assess the fracture area of the filaments after mechanical testing. Increases of up to 10% in water absorption were measured for the samples with 40 wt% fibers and the fossil compatibilizer. The mechanical properties were improved by increasing the fraction of bagasse fibers from 0% to 20% and 40%. The suitability of the biocomposite filaments was tested for 3D printing, and some shapes were printed as demonstrators. Importantly, in a cradle-to-gate life cycle analysis of the biocomposites, we demonstrated that replacing fossil compatibilizer with a bio-based compatibilizer contributes to a reduction in CO2-eq emissions, and an increase in CO2 capture, achieving a CO2-eq storage of 2.12 kg CO2 eq/kg for the biocomposite containing 40% bagasse fibers and 6% bio-based compatibilizer.

Synthesis, characterization and corrosion protection properties of polyN-(p-bromophenyl)-2-methacrylamide-co-glycidyl methacrylate on low nickel stainless steel

2011 ◽  
Vol 31 (2-3) ◽  
Author(s):  
Sakvai Mohammed Safiullah ◽  
Deivasigamani Thirumoolan ◽  
Kottur Anver Basha ◽  
K. Mani Govindaraju ◽  
Dhanraj Gopi ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Corrosion Protection ◽  
Glycidyl Methacrylate ◽  
Electrochemical Impedance ◽  
Thermo Gravimetric Analysis ◽  
Gel Permeation Chromatography ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Protection Efficiency ◽  
Ft Ir

Abstract The synthesis of copolymers from different feed ratios of N-(p-bromophenyl)-2- methacrylamide (PBPMA) and glycidyl methacrylate (GMA) was achieved by using free radical solution polymerization technique and characterized using FT-IR, 1H and 13C NMR spectroscopy. The thermal stability of the synthesized copolymers was studied using thermo-gravimetric analysis (TGA) and differential scanning calorimetry (DSC). The molecular weight of the copolymer is determined by gel permeation chromatography (GPC). The corrosion performances of low nickel stainless steel specimens dip coated with different composition of copolymers were investigated in 0.5 M H2SO4 using potentiodynamic polarization and electrochemical impedance spectroscopic (EIS) techniques. The polarization and impedance measurements showed different corrosion protection efficiency with change in composition of the copolymers. It was found that the corrosion protection properties are owing to the barrier effect of the polymer layer covered on the low nickel stainless steel surfaces. However, it is observed that the mole ratio of PBPMA and GMA plays a major role in the protective nature of the copolymer.

Graphene Nanoplates Filled Nylon 6,6 Nanocomposites, Morphological, Thermal, Mechanical and Solvent Uptake Study

2019 ◽  
Vol 41 (3) ◽  
pp. 388-388
Author(s):  
Khalid Saeed Khalid Saeed ◽  
Tariq Shah and Ahmad Hassan Tariq Shah and Ahmad Hassan
Keyword(s):  
Thermo Gravimetric Analysis ◽  
Neutral Red ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Nucleation Effect ◽  
Morphological Studies ◽  
Solvent Uptake ◽  
Nylon 6,6 ◽  
Dsc Analyses ◽  
Graphene Nanoplates

Effect of graphene nanoplates (GNPs) on the properties of Nylon 6,6 (Nyl 6,6) is investigated in present study. The morphological studies presented that the GNPs were dispersed inside the Nyl 6,6 matrix. The thermo gravimetric analysis (TGA) illustrated that the thermal degradation of nanocomposites samples were started at the range of 350-393 oC, which was appreciably higher than neat Nyl 6,6 (360 oC). The differential scanning calorimetry (DSC) analyses revealed that the crystallization temperature (Tc) of GNPs/Nyl 6,6 increased as increased the addition of GNPs, which might be due to the nucleation effect of GNPs. The mechanical properties of Nyl 6,6 was enhanced by incorporation of GNPs upto the addition of an optimal quantity of filler (5%wt GNPs) into the polymer matrix. The stress yield and Young’s modulus of 5%wt GNPs/Nyl 6,6 was 96.79 and 1.54, N/nm2, respectively. Both Nyl 6,6 and nanocomposites samples were also used for the adsorption of Neutral red chloride (NRC) dye, which significantly remove the dye from the aqueous solution. The neat nylon 6,6 and GNPs (5 and 10 wt%)/Nyl 6,6 adsorbed about 88.49, 93.15, and 93.60% within 2 h, respectively.

Characterization of Novel Solid Dispersions of Moringa oleifera Leaf Powder Using Thermo-Analytical Techniques

Processes ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 2230
Author(s):  
Nontsikelelo Noxolo Tafu ◽  
Victoria A. Jideani
Keyword(s):  
Solid Dispersion ◽  
Moringa Oleifera ◽  
Solid Dispersions ◽  
Intermolecular Hydrogen Bond ◽  
Thermo Gravimetric Analysis ◽  
Analytical Techniques ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Hydrogen Bond Interactions ◽  
Leaf Powder

Moringa oleifera leaf powder (MOLP) has been identified as the most important functional ingredient owing to its rich nutritional profile and healthy effects. The solubility and functional properties of this ingredient can be enhanced through solid dispersion technology. This study aimed to investigate the effects of polyethylene glycols (PEGs) 4000 and 6000 as hydrophilic carriers and solid dispersion techniques (freeze-drying, melting, solvent evaporation, and microwave irradiation) on the crystallinity and thermal stability of solid-dispersed Moringa oleifera leaf powders (SDMOLPs). SDMOLPs were dully characterized using powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), thermo-gravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FTIR). The PXRD results revealed that the solid dispersions were partially amorphous with strong diffraction peaks at 2θ values of 19° and 23°. The calorimetric and thermogravimetric curves showed that PEGs conferred greater stability on the dispersions. The FTIR studyrevealed the existence of strong intermolecular hydrogen bond interactions between MOLP and PEG functional groups. MOLP solid dispersions may be useful in functional foods and beverages and nutraceutical formulations.

Decellularized liver-regenerative 3D printing biomaterials for cell-based liver therapies via a designed procedure combined with papain-containing reagent treatments and supercritical fluids

2021 ◽  
pp. 1-8
Author(s):  
Ching-Cheng Huang
Keyword(s):  
3D Printing ◽  
Thermo Gravimetric Analysis ◽  
Extraction Process ◽  
Gravimetric Analysis ◽  
Collagen Scaffolds ◽  
Scanning Calorimetry ◽  
Porcine Liver ◽  
Good Thermal Stability ◽  
Decellularized Liver ◽  
Liver Collagen

BACKGROUND: The biologic scaffolds derived from decellularized tissues and organs have been successfully developed in a variety of preclinical and/or clinical studies. OBJECTIVE: The new decellularized liver-regenerative 3D printing biomaterials were designed and prepared for cell-based liver therapies. METHODS: An extraction process was employed to remove the tissue and cellular molecules from porcine liver via pretreatment of supercritical fluid of carbon dioxide (ScCO2). Varying porosities of the decellularized liver tissues were created using papain-containing reagent treatments after ScCO2. RESULTS: The resulting liver-regenerative 3D printing biomaterials of decellularized liver collagen scaffolds were characterized by Fourier transform infrared spectroscopy, thermo-gravimetric analysis, differential scanning calorimetry and scanning electron microscopy. CONCLUSIONS: The decellularized liver collagen scaffolds with good thermal stability (>150 °C) were obtained and employed as liver-regenerative 3D printing biomaterials for cell-based liver therapies.

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