scholarly journals The Effect of Titanium Dioxide Surface Modification on the Dispersion, Morphology, and Mechanical Properties of Recycled PP/PET/TiO2 PBNANOs

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1692 ◽  
Author(s):  
Eider Matxinandiarena ◽  
Agurtzane Múgica ◽  
Manuela Zubitur ◽  
Cristina Yus ◽  
Víctor Sebastián ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Tio2 Nanoparticles ◽  
Crystallization Rate ◽  
Pet Bottles ◽  
Hydrophobically Modified ◽  
Angle Measurements ◽  
Transmission Electron ◽  
Titanium Dioxide Surface ◽  
Contact Angle Measurements ◽  
Pet Crystallization

Titanium dioxide (TiO2) nanoparticles have recently appeared in PET waste because of the introduction of opaque PET bottles. We prepare polymer blend nanocomposites (PBNANOs) by adding hydrophilic (hphi), hydrophobic (hpho), and hydrophobically modified (hphoM) titanium dioxide (TiO2) nanoparticles to 80rPP/20rPET recycled blends. Contact angle measurements show that the degree of hydrophilicity of TiO2 decreases in the order hphi > hpho > hphoM. A reduction of rPET droplet size occurs with the addition of TiO2 nanoparticles. The hydrophilic/hydrophobic balance controls the nanoparticles location. Transmission electron microscopy (TEM_ shows that hphi TiO2 preferentially locates inside the PET droplets and hpho at both the interface and PP matrix. HphoM also locates within the PP matrix and at the interface, but large loadings (12%) can completely cover the surfaces of the droplets forming a physical barrier that avoids coalescence, leading to the formation of smaller droplets. A good correlation is found between the crystallization rate of PET (determined by DSC) and nanoparticles location, where hphi TiO2 induces the highest PET crystallization rate. PET lamellar morphology (revealed by TEM) is also dependent on particle location. The mechanical behavior improves in the elastic regime with TiO2 addition, but the plastic deformation of the material is limited and strongly depends on the type of TiO2 employed.

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.

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.

scholarly journals Wettability of DPPC Monolayers Deposited from the Titanium Dioxide–Chitosan–Hyaluronic Acid Subphases on Glass

2019 ◽  
Vol 3 (1) ◽  
pp. 15 ◽  
Author(s):  
Agata Ładniak ◽  
Małgorzata Jurak ◽  
Agnieszka Ewa Wiącek
Keyword(s):  
Titanium Dioxide ◽  
Hyaluronic Acid ◽  
Contact Angles ◽  
Surface Polarity ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Concentration Of Ions ◽  
Sbf Solution ◽  
The Given ◽  
Glass Support

The investigations were carried out to determine wettability of the 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) monolayers transferred from the liquid subphases containing chitosan (Ch), hyaluronic acid (HA), and/or titanium dioxide (TiO2) to a glass support by means of the Langmuir–Blodgett (LB) technique. For comparative purposes, the analysis of the plates surfaces emerged from the analogous subphases without the phospholipid film was also made. Characterization of the DPPC monolayers was based on the contact angle measurements using three test liquids (water, formamide, diiodomethane) and a simulated body fluid (SBF) solution in which the concentration of ions was close to that of human plasma. After deposition of the DPPC monolayers on the glass plates, a significant increase in the contact angles of all the probe liquids was observed compared to the plates pulled out from the given subphase without floating DPPC. The presence of phospholipid monolayer increased the hydrophobic character of the surface due to orientation of its molecules with hydrocarbon chains towards the air. In addition, the components of the subphase attached along with DPPC to the glass support modify the surface polarity. The largest changes were observed in the presence of TiO2.

PREPARATION AND PROPERTIES OF NANOCOMPOSITE FROM NR AND NATURAL NA+-MONTMORILLONITE

2020 ◽  
Vol 93 (2) ◽  
pp. 286-296
Author(s):  
N. T. Thuong ◽  
N. P. D. Linh ◽  
C. H. Ha ◽  
P. T. Nghia ◽  
S. Kawahara
Keyword(s):  
Electron Microscopy ◽  
Tensile Testing ◽  
Testing Machine ◽  
Nanocomposite Materials ◽  
Water Soluble ◽  
Tensile Testing Machine ◽  
Angle Measurements ◽  
Transmission Electron ◽  
Contact Angle Measurements ◽  
High Ammonia

ABSTRACT NR/Na+-montmorillonite (NR/Na+-MMT) nanocomposites were prepared through mixing in the latex stage. NR/Na+-MMT nanocomposites with various amounts of Na+-MMT were fabricated using three types of NR latexes: fresh NR (FNR), high ammonia NR, and deproteinized NR latex. The Na+-MMT and NR latexes were characterized by particle size distribution and Fourier transform infrared spectroscopy analyses. The nanocomposite materials were then analyzed by scanning electron microscopy, transmission electron microscopy, and contact angle measurements. The mechanical properties of the resulting products were measured by tensile testing machine. The composite prepared from FNR gave the best tensile strength at 3 phr MMT loading. The outstanding properties are proposed to be due to the contribution of the water-soluble compounds present in FNR that possess similar hydrophilicity to Na+-MMT.

scholarly journals Emulsion Electrospinning as an Approach to Fabricate PLGA/Chitosan Nanofibers for Biomedical Applications

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Fatemeh Ajalloueian ◽  
Hossein Tavanai ◽  
Jöns Hilborn ◽  
Olivier Donzel-Gargand ◽  
Klaus Leifer ◽  
...  
Keyword(s):  
Biomedical Applications ◽  
Composite Scaffold ◽  
Electrospun Nanofibers ◽  
Electrospinning Process ◽  
Culture Studies ◽  
Angle Measurements ◽  
Transmission Electron ◽  
Contact Angle Measurements ◽  
Fibroblast Attachment ◽  
Tissue Reconstruction

Novel nanofibers from blends of polylactic-co-glycolic acid (PLGA) and chitosan have been produced through an emulsion electrospinning process. The spinning solution employed polyvinyl alcohol (PVA) as the emulsifier. PVA was extracted from the electrospun nanofibers, resulting in a final scaffold consisting of a blend of PLGA and chitosan. The fraction of chitosan in the final electrospun mat was adjusted from 0 to 33%. Analyses by scanning and transmission electron microscopy show uniform nanofibers with homogenous distribution of PLGA and chitosan in their cross section. Infrared spectroscopy verifies that electrospun mats contain both PLGA and chitosan. Moreover, contact angle measurements show that the electrospun PLGA/chitosan mats are more hydrophilic than electrospun mats of pure PLGA. Tensile strengths of 4.94 MPa and 4.21 MPa for PLGA/chitosan in dry and wet conditions, respectively, illustrate that the polyblend mats of PLGA/chitosan are strong enough for many biomedical applications. Cell culture studies suggest that PLGA/chitosan nanofibers promote fibroblast attachment and proliferation compared to PLGA membranes. It can be assumed that the nanofibrous composite scaffold of PLGA/chitosan could be potentially used for skin tissue reconstruction.

scholarly journals An Experimental Investigation of ZnO Nanoparticles Effect on the Acrylic Coatings

2019 ◽  
Vol 35 (1) ◽  
pp. 216-220
Author(s):  
Ghazaleh Khalaji ◽  
Mostafa Maleki ◽  
Ashkan `Memand
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Zno Nanoparticles ◽  
Steel Plates ◽  
Angle Measurements ◽  
Transmission Electron ◽  
Efficient Performance ◽  
Contact Angle Measurements ◽  
Acrylic Coatings ◽  
Positive Effect

In this study, the properties of acrylic coatings based on paraloid B-72 were improved by adding of ZnO nanoparticles. Steel plates were used as substrate. ZnO nanoparticles was analyzed by transmission electron microscopy (TEM). The effect of adding ZnO nanoparticles on the the coatings was investigated using contact angle measurements. The modified coating with a ZnO nanoparticles showed more efficient performance than the net coating after 30 days UV radiation. Generally, this work confirm the positive effect of adding ZnO nanoparticles on acrylic coatings.

Investigation of Nanophysical Properties of Aging Polyamide Nanofibrillar Tissue Scaffolds by TEM, SAED, Contact Angle and Raman Spectroscopies

2012 ◽  
Vol 1417 ◽  
Author(s):  
Virginia M. Ayres ◽  
Kan Xie ◽  
Volkan Mujdat Tiryaki ◽  
Ijaz Ahmed ◽  
David I. Shreiber
Keyword(s):  
Contact Angle ◽  
Physical Properties ◽  
Tissue Scaffolds ◽  
Tissue Scaffold ◽  
3 Dimensional ◽  
Cell Responses ◽  
Selected Area Electron Diffraction ◽  
Angle Measurements ◽  
Transmission Electron ◽  
Contact Angle Measurements

ABSTRACTThe nanoscale physical properties of newly electrospun polyamide nanofibrillar matrices < 1 year old versus those that were > 3 year old were investigated with transmission electron microscopy, selected area electron diffraction, contact angle measurements, and Raman spectroscopy. Significant differences in crystallinity, hydrophobicity, and chemistry were found and correspondingly different cell responses by cerebellar granular neurons were observed. The properties of the aged nanofibrillar scaffolds evoked a response for neuron burrowing into a more 3-dimensional environment in addition to better facilitation of neurite outgrowth. The nanophysical properties of tissue scaffolds have been recently shown to directly and indirectly regulate cellular responses. As physical properties can evolve over time, the present investigation addresses the issue of tissue scaffold shelf life, with possible changes in directive signals to cells.

Nanostructured Polymer Brushes With Reversibly Changing Properties

2002 ◽  
Vol 727 ◽  
Author(s):  
Denys Usov ◽  
Manfred Stamm ◽  
Sergiy Minko ◽  
Christian Froeck ◽  
Andreas Scholl ◽  
...  
Keyword(s):  
Polymer Brushes ◽  
Phase Segregation ◽  
Water Contact ◽  
Angle Measurements ◽  
Nanostructured Polymer ◽  
Contact Angle Measurements ◽  
Vertical Segregation ◽  
Oxygen Plasma Etching ◽  
Grafting From ◽  
Photoemission Electron

AbstractWe investigated the interplay between different mechanisms of the lateral and vertical segregation in the synthesized via “grafting from” approach symmetric A/B (where A and B are poly(styrene-co-2,3,4,5,6-pentafluorostyrene) and poly(methylmethacrylate), respectively) polymer brushes upon exposure to different solvents. We used X-ray photoemission electron spectroscopy and microscopy (X-PEEM), AFM, water contact angle measurements, and oxygen plasma etching to study morphology of the brushes. The ripple morphology after toluene (nonselective solvent) revealed elongated lamellar-like domains of A and B polymers alternating across the surface. The dimple-A morphology consisting of round clusters of the polymer A was observed after acetone (selective solvent for B). The top layer was enriched with the polymer B showing that the brush underwent both the lateral and vertical phase segregation. A qualitative agreement with predictions of SCF theory was found.

Wrinkling Poly(trimethylene 2,5-Furanoate) Free-standing Films: Nanostructure Formation and Physical Properties

2020 ◽  
Author(s):  
Michelina Soccio ◽  
Nadia Lotti ◽  
Andrea Munari ◽  
Esther Rebollar ◽  
Daniel E Martínez-Tong
Keyword(s):  
Irradiation Time ◽  
Polymer Surface ◽  
Laser Source ◽  
Free Standing ◽  
Force Microscopy ◽  
Nanostructure Formation ◽  
Physicochemical Changes ◽  
Angle Measurements ◽  
Atomic Force ◽  
Contact Angle Measurements

<p>Nanostructured wrinkles were developed on fully bio-based poly(trimethylene furanoate) (PTF) films by using the technique of Laser Induced Periodic Surface Structures (LIPSS). We investigated the effect of irradiation time on wrinkle formation using an UV pulsed laser source, at a fluence of 8 mJ/cm2. It was found that the pulse range between 600 and 4800 pulses allowed formation of periodic nanometric ripples. The nanostructured surface was studied using a combined macro- and nanoscale approach. We evaluated possible physicochemical changes taking place on the polymer surface after irradiation by infrared spectroscopy, contact angle measurements and atomic force microscopy. The macroscopic physicochemical properties of PTF showed almost no changes after nanostructure formation, differently from the results previously found for the terephthalic counterparts, as poly(ethyleneterephthalate), PET, and poly(trimethyleneterephthalate), PTT. The surface mechanical properties of the nanostructured PTF were found to be improved, as evidenced by nanomechanical force spectroscopy measurements. In particular, an increased Young’s modulus and higher stiffness for the nanostructured sample were measured. <br></p>

scholarly journals Adhesion Studies during Generative Hybridization of Textile-Reinforced Thermoplastic Composites via Additive Manufacturing

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3888
Author(s):  
Johanna Maier ◽  
Christian Vogel ◽  
Tobias Lebelt ◽  
Vinzenz Geske ◽  
Thomas Behnisch ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Polyamide 6 ◽  
Thermoplastic Composites ◽  
Efficient Production ◽  
Angle Measurements ◽  
Small Series ◽  
Contact Angle Measurements ◽  
Static Tensile ◽  
Pre Treatment ◽  
Manufacturing Technologies

Generative hybridization enables the efficient production of lightweight structures by combining classic manufacturing processes with additive manufacturing technologies. This type of functionalization process allows components with high geometric complexity and high mechanical properties to be produced efficiently in small series without the need for additional molds. In this study, hybrid specimens were generated by additively depositing PA6 (polyamide 6) via fused layer modeling (FLM) onto continuous woven fiber GF/PA6 (glass fiber/polyamide 6) flat preforms. Specifically, the effects of surface pre-treatment and process-induced surface interactions were investigated using optical microscopy for contact angle measurements as well as laser profilometry and thermal analytics. The bonding characteristic at the interface was evaluated via quasi-static tensile pull-off tests. Results indicate that both the bond strength and corresponding failure type vary with pre-treatment settings and process parameters during generative hybridization. It is shown that both the base substrate temperature and the FLM nozzle distance have a significant influence on the adhesive tensile strength. In particular, it can be seen that surface activation by plasma can significantly improve the specific adhesion in generative hybridization.

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