Surface-modified halloysite nanotubes as fillers applied in reinforcing the performance of polytetrafluoroethylene

Clay Minerals ◽  
2018 ◽  
Vol 53 (4) ◽  
pp. 643-656 ◽  
Author(s):  
Zhi-Lin Cheng ◽  
Xing-Yu Chang ◽  
Zan Liu ◽  
Dun-Zhong Qin
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Sodium Dodecyl ◽  
Halloysite Nanotubes ◽  
Angle Measurements ◽  
Transmission Electron ◽  
Contact Angle Measurements ◽  
Ftir Spectrometry ◽  
Surface Modified ◽  
Scanning Electron

ABSTRACTIn order to improve the dispersibility of halloysite nanotubes (HNTs) in polytetrafluoroethylene (PTFE), the modification of HNT surfaces was studied with three types of modifiers (polymethyl methacrylate [PMMA], sodium dodecyl sulfate [SDS] and carboxylic acid). The modified HNTs were characterized by Fourier-transform infrared (FTIR) spectrometry, transmission electron microscopy (TEM), scanning electron microscopy (SEM) and contact angle measurements. The HNTs were used to reinforce the mechanical properties of PTFE. The mechanical results indicated that the tensile strength of the modified HNT-filled PTFE nanocomposites (F-HNT/PTFE) improved to an acceptable degree and Young's modulus increased significantly. The tribological results showed that the wear rate of F-HNT/PTFE decreased by 21–82 and 9–40 times compared to pure PTFE and the pristine F-HNT/PTFE, respectively.

Modification of PVDF properties by dielectric barrier discharge treatment

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Mihaela Pascu ◽  
Donatella Duraccio ◽  
Sossio Cimmino ◽  
Cornelia Vasile
Keyword(s):  
Electron Microscopy ◽  
Dielectric Barrier Discharge ◽  
Polyvinylidene Fluoride ◽  
Barrier Discharge ◽  
Plasma Exposure ◽  
Dielectric Barrier ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Ftir Spectrometry ◽  
Scanning Electron

AbstractFilms of polyvinylidene fluoride (PVDF) were treated in a dielectric barrier discharge (DBD) in helium, for different exposure times. Modification of PVDF properties was followed by: contact angle measurements, ATR-FTIR spectrometry and scanning electron microscopy. The applied treatment led to the obtainment of polar surfaces, with biocompatibility characteristics. These enhancements in PVDF properties after plasma exposure, associated with the possible increase of the polymer roughness, could lead to an enhanced adhesion with other materials, condition which has to be fulfilled for a series of applications (e.g.: biosensors).

scholarly journals Analysis of PLA Composite Filaments Reinforced with Lignin and Polymerised-Lignin-Treated NFC

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2174
Author(s):  
Diana Gregor-Svetec ◽  
Mirjam Leskovšek ◽  
Blaž Leskovar ◽  
Urška Stanković Elesini ◽  
Urška Vrabič-Brodnjak
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Tensile Strength ◽  
Glassy State ◽  
Nanofibrillated Cellulose ◽  
Dynamic Mechanical Properties ◽  
Initial Modulus ◽  
Surface Modified ◽  
Scanning Electron

Polylactic acid (PLA) is one of the most suitable materials for 3D printing. Blending with nanoparticles improves some of its properties, broadening its application possibilities. The article presents a study of composite PLA matrix filaments with added unmodified and lignin/polymerised lignin surface-modified nanofibrillated cellulose (NFC). The influence of untreated and surface-modified NFC on morphological, mechanical, technological, infrared spectroscopic, and dynamic mechanical properties was evaluated for different groups of samples. As determined by the stereo and scanning electron microscopy, the unmodified and surface-modified NFCs with lignin and polymerised lignin were present in the form of plate-shaped agglomerates. The addition of NFC slightly reduced the filaments’ tensile strength, stretchability, and ability to absorb energy, while in contrast, the initial modulus slightly improved. By adding NFC to the PLA matrix, the bending storage modulus (E’) decreased slightly at lower temperatures, especially in the PLA samples with 3 wt% and 5 wt% NFC. When NFC was modified with lignin and polymerised lignin, an increase in E’ was noticed, especially in the glassy state.

Microstructure Evolution and Mechanical Properties of an Al-Cu-Mg Alloy at Elevated Temperature

2014 ◽  
Vol 1004-1005 ◽  
pp. 148-153
Author(s):  
Min Hao ◽  
Ji Gang Ru ◽  
Ming Liu ◽  
Kun Zhang ◽  
Liang Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Elevated Temperature ◽  
Elevated Temperatures ◽  
Shear Fracture ◽  
S Phase ◽  
Mg Alloy ◽  
Transmission Electron ◽  
Fracture Features ◽  
Scanning Electron

Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were utilized to study the microstructure and mechanical behavior of an Al-Cu-Mg alloy after tensile test at 125°C, 150°C, 175°C and 200 °C, respectively. The yield strength and ultimate tensile strength decreased with the increase of temperature, while the elongation increased firstly and then decreased. The S and S′ precipitate after tension at elevated temperatures. When the temperature was higher than 175°C, the precipitate coarsens rapidly. The alloys displayed a shear fracture features at elevated temperature. The larger S′ and S phase coarsened and dropped which forming crack in the grain boundaries and precipitate interfaces, resulting in the decrease of the elongation of the alloy.

Application and Study of Reactive Polyacrylate Microgel in Pigment Paint of Printed Fabric

2011 ◽  
Vol 311-313 ◽  
pp. 1044-1048
Author(s):  
Hong Long Xing ◽  
Shui Lin Chen
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Transmission Electron Microscopy ◽  
Sodium Dodecyl ◽  
Ammonium Persulfate ◽  
Color Fastness ◽  
Adhesive Film ◽  
Transmission Electron ◽  
Divinyl Benzene

Polyacrylate microgel emulsion was prepared by emulsion polymerization using styrene, α-n-butyl acrylate and methyl methacrylate as monomer, polyoxyethylene octylphenol ether (TX-30) and sodium dodecyl sulfate(SDS) as combine emulsifier, divinyl benzene and ammonium persulfate (APS) as initiator，respectively. The prepared microgel was analyzed by a variety of measurment methods, such as Fourier transform infrared spectroscopy and transmission electron microscopy. The effect of microgel on the rheological properties of adhesives, leveling, mechanical properties and pigment printing performance was studied. The rhelogy and the color fastness of the pigment printing binder of printed fabrics were measured by rheometer and friction color fastness test instruments, respectively. At the same time, the mechanical properties of the adhesive film was measured by strength tester. The results show that the thixotropy, leveling and mechanical properties of adhesive printing binder and pringting quality of coating fabrics were improved when the microgel was added.

scholarly journals Study on Grain Refinement Mechanisms and Mechanical Properties of bi-Modal Ti-55511 Titanium Alloy during Hot Rolling

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3351 ◽  
Author(s):  
Wei Chen ◽  
Xiaoyong Zhang ◽  
YongCheng Lin ◽  
Kechao Zhou
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Hot Rolling ◽  
Shear Bands ◽  
High Ductility ◽  
Α Phase ◽  
Transmission Electron ◽  
Scanning Electron

Multi-pass hot rolling was performed on bi-modal Ti-55511 alloy with 50% rolling reduction at 700 °C. Mechanical properties were evaluated by tensile test, and microstructure evolution was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results show that the Ti-55511 alloy with bi-modal microstructure exhibits good strength and high ductility (1102 MPa, 21.7%). Comparatively, after 50% hot rolling, an enhanced strength and decreased ductility were obtained. The refinement of α phases leads to the increased tensile strength, while the fragmentation of the equiaxed α phase results in a decreased ductility. The fragmentation process of equiaxed α phases followed the sequence of: elongation of α phases → formation of grooves and localized shear bands → the final fragmentation accomplished via deepening grooves.

scholarly journals Effect of Cu on the Fracture and Exfoliation Corrosion Behavior of Al-Zn-Mg-xCu Alloy

Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1048 ◽  
Author(s):  
Huibin Jiao ◽  
Kanghua Chen ◽  
Songyi Chen ◽  
Zhen Yang ◽  
Peng Xie ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Exfoliation Corrosion ◽  
Cu Content ◽  
Short Transverse ◽  
Transmission Electron ◽  
Corrosion Behaviors ◽  
Mechanical Tensile ◽  
Scanning Electron ◽  
Better Than

In the present work, the influence of Cu content on microstructure, mechanical properties and exfoliation corrosion behaviors of Al-Zn-Mg-xCu alloy extrusions has been investigated in longitudinal-transverse (L-T) and short-longitudinal (S-L) directions by means of mechanical tensile and exfoliation corrosion testing combined with optical microscopy (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results showed that a higher Cu content significantly decreased the fracture toughness and ductility of the alloy in S-L direction compared with L-T direction. Concomitant with the increase in Cu content, a transition in fracture mode was observed from transgranular dimpled rupture to intergranular rupture in S-L direction. Moreover, the exfoliation corrosion (EXCO) resistance of the alloy decreased as the Cu content increased and the exfoliation corrosion resistance of the alloy in short-transverse (S-T) direction was better than that of L-T direction. These results were mainly associated with the large number of coarse intermetallics caused by high Cu content in the L-T direction of alloy.

scholarly journals Development of Flexible Polyurethane Nanostructured Biocomposite Foams Derived from Palm Olein-Based Polyol

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Srihanum Adnan ◽  
Tuan Noor Maznee Tuan Ismail ◽  
Norhayati Mohd Noor ◽  
Nik Siti Mariam Nek Mat Din ◽  
Nurul ‘Ain Hanzah ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Palm Olein ◽  
Nanocomposite Foams ◽  
Transmission Electron ◽  
Flexible Polyurethane ◽  
Pu Foams ◽  
Scanning Electron

This study examined the effect of organoclay montmorillonite (OMMT) on the mechanical properties and morphology of flexible polyurethane/OMMT nanocomposite (PU/OMMT) foams prepared from petroleum- and palm olein-based polyols. Palm-based PU foams exhibited inferior mechanical strength as compared to neat petroleum PU foams. However, addition of OMMT significantly improved the foams strength of flexible polyurethane/OMMT nanocomposite foams prepared from palm olein-based polyol (PU bionanocomposite foam). The morphology analysed by scanning electron microscopy (SEM) showed that the cell size of the foam decreased with increasing OMMT content. PU bionanocomposite foam with 5 wt% of OMMT had the most improved tensile (63%) and tear (48%) strengths compared to its neat counterpart. Transmission electron microscopy (TEM) revealed the exfoliated structure of the respective foam. It was concluded that OMMT improved mechanical properties and morphology of PU foams.

Effects of Thermal Treatment on the Morphology and Properties of CSM/Poly(Urethane-Isocyanurate) Composites Formed by SRIM Process

2008 ◽  
Vol 575-578 ◽  
pp. 941-946
Author(s):  
Hong Yan Tang ◽  
Ji Hui Wang ◽  
Guo Qiang Gao ◽  
Wen Xing Chen
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Mechanical Property ◽  
Thermal Analysis ◽  
Scanning Electron Microscopy ◽  
Treatment Time ◽  
Microphase Separation ◽  
Scanning Calorimetry ◽  
Transmission Electron ◽  
Scanning Electron

Fiberglass continuous strand mat(CSM)/poly(urethane-isocyanurate) composites were formed by SRIM process, treated under different conditions and then characterized based on dynamic mechanical thermal analysis (DMTA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) ,transmission electron microscopy (TEM) and the mechanical property tests. The results show that the mechanical properties of the composites could be increased with improving the degree of microphase separation. At a given temperature (120°C), the degree of microphase separation is the highest for 4h and decreases gradually with prolonging treatment time. For a given time (4h), the well microphase-separated morphology is obtained and the degree of microphase mixing is increased at 120°C and 140°C treatments, respectively. The degree of microphase separation of the composites decreases with enhancing the temperature to 140°C.

The Effect of Tungsten on the Nucleation and Growth of thin Aluminum Alloy Films

1993 ◽  
Vol 317 ◽  
Author(s):  
Bea CAO ◽  
N. David Theodore ◽  
Hank Shin ◽  
Peter Fejes ◽  
Les Hendrickson
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Nucleation And Growth ◽  
Growth Behavior ◽  
Aluminum Films ◽  
Surface Energies ◽  
Transmission Electron ◽  
Thin Aluminum ◽  
Scanning Electron

ABSTRACTA variety of alloying elements are currently being investigated for their effects on the mechanical properties and reliability of thin aluminum films. In the present study, scanning electron microscopy and transmission electron microscopy are used to study the nucleation and growth of Al-1.5wt%Cu and Al-1.5wt% Cu-0.2wt% W films. Differences in Microstructure, nucleation and growth behavior are observed and are explained in terms of changes in surface energies and atomic Mobilities.

Hydrophobization of Kraft-type Cellulose and Microfiber Cellulose Obtained from Soybean Husk in Ultrasonic Field

2019 ◽  
Vol 13 (2) ◽  
pp. 151-159
Author(s):  
Blanca I.M. Mejia ◽  
Oxana V. Kharissova ◽  
Boris I. Kharisov
Keyword(s):  
Electron Microscopy ◽  
Tensile Strength ◽  
Sio2 Nanoparticles ◽  
Ultrasonic Field ◽  
Homogeneous Distribution ◽  
Silicon Dioxide Nanoparticles ◽  
Angle Measurements ◽  
Transmission Electron ◽  
Contact Angle Measurements ◽  
20 Nm

Background: The addition of nanoparticles to cellulose paper can improve its mechanical strength, chemical stability, biocompatibility and hydrophobic properties. Silica nanoparticles are known to be inert, hydrophobic, biocompatible, biodegradable and have a good distribution in being deposited on surfaces. The main characteristics of 20 nm SiO2 nanoparticles are good chemical and thermal stability with a melting point of 1610-1728°3C, a boiling point of 2230°C with a purity of 99.5%. Objective: To carry out the hydrophobization of paper based on Kraft cellulose and on cellulose obtained from soybean husk with 20-nm size SiO2 nanoparticles and to study hydrophobicity, morphology and topography of the prepared composites. Methods: The ground and roasted soybean husk was treated with a NaOH, washed and dried. Hydrophobization of paper was carried in aqueous medium by SiO2 addition in weight ratios “paper-SiO2” of 0.01-0.05 wt.%, stirring, filtration and drying. The obtained cellulose sheet composites were characterized by Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), FTIRspectroscopy, Mullen proofs of hydrophobicity, and contact angle measurements. Results: The mechanical properties of paper nanocomposites (tensile strength and compression) increased considerably by varying the concentrations. The tensile strength increased by 41-46% and the compressive strength increased by 55-56%. The existence of fiber nanofoils, good adhesion of 20-nm SiO2 nanoparticles to the paper surface, and their homogeneous distribution were observed. Conclusion: Cellulose was successfully obtained from soybean husk, applying the alkaline-based extraction method. A good reinforcement of cellulose fibers is observed due to the outstanding characteristics of the silicon dioxide nanoparticles.

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