scholarly journals Surface Mechanical Characterization of Carbon Nanofiber Reinforced Low-Density Polyethylene by Nanoindentation and Comparison with Bulk Properties

Nanomaterials ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1357 ◽  
Author(s):  
Peyman Nikaeen ◽  
Dilip Depan ◽  
Ahmed Khattab
Keyword(s):  
Tensile Test ◽  
Carbon Nanofiber ◽  
Surface Preparation ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Force Microscopy ◽  
Atomic Force ◽  
Macro Scale ◽  
Data Points

Surface mechanical properties of low-density polyethylene (LDPE) reinforced by carbon nanofibers (CNFs) up to 3% weight load were investigated using nanoindentation (NI). Surface preparation of the nanocomposite was thoroughly investigated and atomic force microscopy (AFM) was used to analyze the surface roughness of the polished surfaces. The dispersion of nanofillers in the LDPE matrix was examined using scanning electron microscopy (SEM). The effect of various penetration loads on the results and scattering of the data points was discussed. It was found by NI results that the addition of 3% weight CNF increased the elastic modulus of LDPE by 59% and its hardness up to 12%. The nano/micro-scale results were compared with macro-scale results obtained by the conventional tensile test as well as the theoretical results calculated by the Halpin-Tsai (HT) model. It was found that the modulus calculated by nanoindentation was twice that obtained by the conventional tensile test which was shown to be in excellent agreement with the HT model. Experimental results indicated that the addition of CNF to LDPE reduced its wear resistance property by reducing the hardness to modulus ratio. SEM micrographs of the semicrystalline microstructure of the CNF/LDPE nanocomposite along with the calculated NI imprints volume were examined to elaborate on how increasing the penetration depth resulted in a reduction of the coefficient of variation of the NI data/more statistically reliable data.

Material Property Characterization of Costal Cartilage Using AFM Indentation

2009 ◽  
Author(s):  
S. Tripathy ◽  
E. J. Berger
Keyword(s):  
Material Characterization ◽  
Costal Cartilage ◽  
Indentation Modulus ◽  
Hertz Contact ◽  
Force Microscopy ◽  
Afm Indentation ◽  
Atomic Force ◽  
Macro Scale ◽  
Property Characterization

Costal cartilage is one of the load bearing tissues of the rib cage. Literature on the material characterization of the costal cartilage is limited. Atomic force microscopy has been extremely successful in characterizing the elastic properties of articular cartilage, but no studies have been published on costal cartilage. In this study AFM indentations on human costal cartilage were performed and compared with macro scale indentation data. Spherical beaded tips of three sizes were used for the AFM indentations. The Hertz contact model for spherical indenter was used to analyze the data and obtain the Young’s modulus. The costal cartilage was found to be almost linearly elastic till 600 nm of indentation depth. It was also found that the modulus values decreased with the distance from the junction. The modulus values from macro indentations were found to be 2-fold larger than the AFM indentation modulus.

Thermocatalytic Degradation of Low Density Polyethylene Films at Artificial Aging Treatment under Lower Temperature

2014 ◽  
Vol 804 ◽  
pp. 43-46
Author(s):  
Si Zhao Zhang ◽  
Xue Guang Luo ◽  
Feng Ding ◽  
Ke Li ◽  
Xiao Yan Lin ◽  
...  
Keyword(s):  
Artificial Aging ◽  
Aging Treatment ◽  
Degradation Process ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Force Microscopy ◽  
Atomic Force ◽  
Ft Ir ◽  
Lower Temperature ◽  
Chemical Groups

Low density polyethylene (LDPE) films added thermal catalyst were investigated at artificial aging time of 0, 10, 20, and 30 days, respectively. The samples obtained were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), gel permeation chromatograph (GPC) and fourier transform infrared spectroscopy (FT-IR). It shows that the surface of film was destroyed via thermocatalytic reactions at lower temperature. In addition, the changes of chemical groups were also observed in the thermocatalytic degradation process. Thus, the validation to the thermocatalytic route has been confirmed over lower temperature excitation. It is hoped that our work may provide a new insight into the degradation of polymeric films at lower temperature.

scholarly journals Tribo-Mechanical Properties of the Antimicrobial Low-Density Polyethylene (LDPE) Nanocomposite with Hybrid ZnO–Vermiculite–Chlorhexidine Nanofillers

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2811
Author(s):  
Karla Čech Barabaszová ◽  
Sylva Holešová ◽  
Marianna Hundáková ◽  
Alena Kalendová
Keyword(s):  
Mechanical Properties ◽  
Zinc Oxide ◽  
Xrd Analysis ◽  
Surface Topology ◽  
Low Density Polyethylene ◽  
Indentation Hardness ◽  
Low Density ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Atomic Force

Materials made from low-density polyethylene (LDPE) in the form of packages or catheters are currently commonly applied medical devices. Antimicrobial LDPE nanocomposite materials with two types of nanofillers, zinc oxide/vermiculite (ZnO/V) and zinc oxide/vermiculite_chlorhexidine (ZnO/V_CH), were prepared by a melt-compounded procedure to enrich their controllable antimicrobial, microstructural, topographical and tribo-mechanical properties. X-ray diffraction (XRD) analysis and Fourier transform infrared spectroscopy (FTIR) revealed that the ZnO/V and ZnO/V_CH nanofillers and LDPE interacted well with each other. The influence of the nanofiller concentrations on the LDPE nanocomposite surface changes was studied through scanning electron microscopy (SEM), and the surface topology and roughness were studied using atomic force microscopy (AFM). The effect of the ZnO/V nanofiller on the increase in indentation hardness (HIT) was evaluated by AFM measurements and the Vickers microhardness (HV), which showed that as the concentration of the ZnO/V nanofiller increased, these values decreased. The ZnO/V and ZnO/V_CH nanofillers, regardless of the concentration in the LDPE matrix, slightly increased the average values of the friction coefficient (COF). The abrasion depths of the wear indicated that the LDPE_ZnO/V nanocomposite plates exhibited better wear resistance than LDPE_ZnO/V_CH. Higher HV and HIT microhardness values were measured for both nanofillers than the natural LDPE nanocomposite plate. Very positive antimicrobial activity against S. aureus and P. aeruginosa after 72 h was found for both nanofiller types.

Influence of organoclay filler and dicumyl peroxide (DCP) on the properties of the low-density polyethylene (LDPE)/thermoplastic starch (TPS) blend

2020 ◽  
pp. 096739112097627
Author(s):  
Dalila Smail ◽  
Saliha Chaoui
Keyword(s):  
Thermoplastic Starch ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Dicumyl Peroxide ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
The Impact

In this study low-density polyethylene (LDPE)/thermoplastic starch (TPS)/nanoclay (O-Mt) nanocomposites were prepared by a melt blending process using a Brabender mixer. Dicumyl peroxide (DCP) and nanoclay (O-Mt) were studied to improve interfacial adhesion and to obtain the various desired properties of the nanocomposites. The structure and properties of the materials were studied by X-Ray Diffraction (XRD), Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and by tensile and Izod impact tests. X-ray diffraction analysis of the nanocomposites showed that the characteristic peaks of the clay were shifted to the lower angles, indicating an intercalated structure in the presence of dicumyl peroxide (DCP). The TGA curve indicated an improvement in the thermal stability of the materials with the amount of silicate and DCP. The mechanical properties of the materials were improved as a consequence of the increase in phase adhesion which gave an improvement in crystallinity confirmed by DSC. In addition, the impact strength of the modified materials was improved compared to the original materials. A modification of morphology as well as roughness was demonstrated by SEM and AFM.

Nondestructive Characterization and Enzyme Cleaning of Painted Surfaces: Assessment from the Macro to Nano Level

2013 ◽  
Vol 19 (6) ◽  
pp. 1632-1644 ◽  
Author(s):  
Catarina Pereira ◽  
Tito Busani ◽  
Luis C. Branco ◽  
Ineke Joosten ◽  
Irina Crina Anca Sandu
Keyword(s):  
Specific Treatment ◽  
Egg White ◽  
Force Microscopy ◽  
Atomic Force ◽  
Macro Scale ◽  
Before And After ◽  
White Animal ◽  
Nondestructive Characterization ◽  
Cleaning Treatment

AbstractThis work establishes a multiscale and multitechnique nondestructive approach as valid methodology for monitoring surface properties and evaluating the effectiveness of enzymatic removal of varnishes from paintings/polychrome artefacts.Mock-up samples (documented reconstructions of oil, tempera, and gilded layers on canvas and wooden supports) were covered with different proteinaceous varnishes (egg white, animal and fish glue, casein) and then characterized before and after the removal of these coatings with enzyme-based solutions. The varnish was cleaned in several steps (two dry swabs and two wet swabs) with a clearance step for removing the residues from proteinaceous varnish or from enzyme solution.Microscopy [stereomicroscopy (SM), optical microscopy (OM), atomic force microscopy (AFM), and scanning electron microscopy (SEM)] and colorimetric (CIE L*a*b* system) techniques were used for characterization of the reconstruction surfaces at different scales (macro-scale by SM and OM; micro-scale by SEM and nano-scale by AFM). These techniques were also used to monitor the cleaning treatment.Although results presented in this work were obtained for the specific treatment of enzyme removal, the methodology could be extended to other types of materials and cleaning. Further experiments on real works of art are needed for a complete validation of the methodology.

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