Effect of Liquid Oxidation Surface Treatment on Bonding Properties of Wood/Polyethylene Composites

2011 ◽  
Vol 66-68 ◽  
pp. 907-910 ◽  
Author(s):  
Xiao Lei Teng ◽  
Ming Wei Di

In this paper the surface of wood/polyethylene (PE) composites were treated by liquid oxidation, and the structure of surface for wood/polyethylene composites before and after treatment was characterized by contact angle, fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM); combined with bonding strength test, the effect of concentration for handling solution and addition of oxidant on bonding properties of wood/polyethylene composites was also investigated. The results showed that the contact angle of surface for wood/polyethylene composites reduced and the surface wettability had been improved after liquid oxidation; the -C-O- and C=O functional groups were formed on the treated surface and the surface roughness increased; meanwhile, the shear bonding strength for the treated sample increased significantly after treatment. And these changes would be more obvious when enhancing the concentration of handling solution and adding oxidant.

2011 ◽  
Vol 311-313 ◽  
pp. 59-62
Author(s):  
Hui Wang ◽  
Xin Ying Lv ◽  
Ming Wei Di

The surface of wood/polyethylene (PE) composites were treated by mechanical polishing treatment and coating treatment, and the structure of surface for wood/PE composites before and after treatment was characterized by fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM) in this paper. Combined with bonding strength test, the effect of coupling agent KH-560 (2,3-epoxypropoxypropyltrimethoxysilicane) on bonding properties of wood/PE composites was also investigated. The results showed that, the -OH, -C-O- and C=O functional groups were appeared on the treated surface and the surface roughness increased after mechanical polishing treatment and coating treatment, which increased the shear bonding strength for the treated sample significantly. And the coupling agent KH-560 can increase the bonding strength for the composite more significantly due to the co-reaction of epoxy groups which introduced by coupling agent with epoxy resin adhesives.


Scanning ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Hyun-Jung Kim ◽  
Donghyun Lee ◽  
Seungryong Cho ◽  
Ji-Hyun Jang ◽  
Sahng Gyoon Kim ◽  
...  

Introduction. Elastin-like polypeptide (ELP) supplementation was previously reported to enhance the physical properties of mineral trioxide aggregate (MTA). The aim of this study was to investigate the effect of ELP supplementation on the bonding properties of MTA to dentin. Methods. Two types of ELPs were synthesized and mixed with MTA in a 0.3 liquid/powder ratio. The push-out bond strength test and interfacial observation with scanning electron microscopy were performed for ELP-supplemented MTA. The porosity of MTA fillings in the cavity was observed with microcomputed tomography. The stickiness, flow rate, and contact angle were additionally measured for potential increased bonding properties. Results. ELP supplementation improved the bond strength of MTA to dentin. MTA supplemented by a specific ELP exhibited a less porous structure, higher stickiness, and higher flow rate. ELPs also decreased the contact angle to dentin. Conclusions. This research data verifies that ELP improves the bonding properties of MTA to a tooth structure. The sticky and highly flowable characteristics of ELP-supplemented MTA may provide intimate contact with dentin and supply a less porous cement structure, which might improve the bonding properties of MTA.


2017 ◽  
Vol 23 (3) ◽  
pp. 270 ◽  
Author(s):  
Josef Hlinka ◽  
Stanislav Lasek ◽  
Nadimul Faisal

<p class="AMSmaintext"><span lang="EN-GB">In this paper corrosion </span><span lang="EN-GB">properties</span><span lang="EN-GB"> and microstructure features of amorphous self-organised TiO<sub>2</sub> nanotubes electrochemically deposited on titanium are discussed. There was titanium of second grade used as a substrate for these experiments. There was a specific solution of ammonium fluoride, ethylenglycol and deionized water used to create an oxide layer with advantageous properties. Relation between changes of roughness indexes before and after anodization was found out. The wettability (contact angle) of artificial plasma on surface was measured using sessile drop method. It was found out that titanium dioxide nanotubes formed on the surface significantly decreases contact angle and time of anodization reduces it even more. Corrosion potentials, corrosion rate or polarization resistance were determined by linear polarization methods performed by ASTM standards. Corrosion potential of anodized samples is substantially more positive (≈ -50mV) compared with non-treated sample (≈ - 280mV). On the other hand polarization resistance was significantly higher for non-treated sample. Also potentials of passive layer breakdowns were found. Structure of nanotubes and influence of anodization on surface profile was studied by SEM. </span></p>


2020 ◽  
Vol 198 ◽  
pp. 01045
Author(s):  
Zhihang Wang ◽  
Jinyu Xu ◽  
Wei Xia ◽  
Zhe Huang ◽  
Xin Meng ◽  
...  

Using the slotting method to process the interface of ordinary mortar, based on ordinary mortar specimens, new and old mortar bonding specimens were prepared, and the bond strength test was carried out. The effect of interface roughness on the bonding strength of VAE rubber powder modified mortar and styrene-acrylic emulsion modified mortar was tested, and then the interfacial bonding properties of polymer modified mortar were studied. The test results show that the bonding strength of polymer-modified mortar increases with the increase of interface roughness; in engineering applications, the interface can be properly chiseled to increase the interface roughness, which is beneficial to the bonding of polymer-modified mortar firm. At the same time, the application prospects of VAE rubber powder modified mortar in the field of concrete anti-corrosion, and the application prospect of styrene-acrylic emulsion modified mortar in the repair and freeze-thaw damage of concrete structure and anti-seepage treatment are prospected.


Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 450
Author(s):  
Apinya Limvisitsakul ◽  
Suppason Thitthaweerat ◽  
Pisol Senawongse

This paper presents the effect of blade type and feeding force during resin-bonded dentin specimen preparation on the microtensile bond strength (μTBS) test. Forty resin-bonded flat middle dentin specimens were divided into four groups. The specimens of each group were sectioned according to type of blade and feeding force as follows: fine grit/20 N, fine grit/40 N, medium grit/20 N, and medium grit/40 N to obtain resin-dentin sticks with a cross-sectional area of 1.0 mm2. Four sticks from the center of each tooth were subjected to the μTBS test. Five remaining sticks of each group were selected for surface topography observation under a scanning electron microscope (SEM). As a result, the bond strength of the medium-grit group was higher than that of the fine-grit group (p < 0.001), whereas the feeding force had no influence on bond strength values (p = 0.648). From the SEM, sticks prepared with the fine-grit blade showed a smoother surface integrity and fewer defects on the specimen edges in comparison with the sticks prepared with the medium-grit blade. The grit type of the blade is one of the considerable factors that may affect the bond strength and the surface integrity of resin-dentin specimens for microtensile testing.


2021 ◽  
Vol 22 (13) ◽  
pp. 6805
Author(s):  
Mihaela-Cristina Bunea ◽  
Victor-Constantin Diculescu ◽  
Monica Enculescu ◽  
Horia Iovu ◽  
Teodor Adrian Enache

The electrochemical behavior and the interaction of the immunosuppressive drug azathioprine (AZA) with deoxyribonucleic acid (DNA) were investigated using voltammetric techniques, mass spectrometry (MS), and scanning electron microscopy (SEM). The redox mechanism of AZA on glassy carbon (GC) was investigated using cyclic and differential pulse (DP) voltammetry. It was proven that the electroactive center of AZA is the nitro group and its reduction mechanism is a diffusion-controlled process, which occurs in consecutive steps with formation of electroactive products and involves the transfer of electrons and protons. A redox mechanism was proposed and the interaction of AZA with DNA was also investigated. Morphological characterization of the DNA film on the electrode surface before and after interaction with AZA was performed using scanning electron microscopy. An electrochemical DNA biosensor was employed to study the interactions between AZA and DNA with different concentrations, incubation times, and applied potential values. It was shown that the reduction of AZA molecules bound to the DNA layer induces structural changes of the DNA double strands and oxidative damage, which were recognized through the occurrence of the 8-oxo-deoxyguanosine oxidation peak. Mass spectrometry investigation of the DNA film before and after interaction with AZA also demonstrated the formation of AZA adducts with purine bases.


2012 ◽  
Vol 730-732 ◽  
pp. 271-276
Author(s):  
H.R. Pakravan ◽  
M. Jamshidi ◽  
M. Latifi ◽  
F. Pacheco-Torgal

This paper compares the adhesion strength between three polymeric fibres (polypropylene (PP), nylon66 (N66) and polyacrylonitrile (PAN)) embedded in a cement paste. The specimens were prepared at a water to cement ratio (w/c) of 0.5 and tested after 7, 14 and 28 curing days. It was found that although the adhesion between the polymeric fibres to the cement matrix is an important factor, the energy absorption capacity or energy dissipation ability of the fibres, plays a more important role in the improvement of the cementitious composites fracture toughness. Scanning electron micrographs were used to characterize the fibres surface before and after the Pull-out tests.


2016 ◽  
Vol 869 ◽  
pp. 913-917 ◽  
Author(s):  
Ana Lucia do Amaral Escada ◽  
Javier Andres Muñoz Chaves ◽  
Ana Paula Rosifini Alves Claro

The purpose of this study was to evaluate the TiO2 nanotubes growth and the variation in its diameter to improve the surface properties of Ti-7.5Mo to use for biomedical applications. For the nanotubes TiO2 growth, the samples were anodized in glycerol and ammonium fluoride and divided according to the anodizing potential at 5V to 10V and 24 hour time. The surfaces were examined by scanning electron microscope (SEM), X-ray analysis (XRD) and contact angle measurements. The average tube diameter, ranging in size from 13 to 23 nm, was found to increase with increasing anodizing voltage. It was also observed a decrease in contact angle in accordance with the increase in the anodizing potential. The X-ray analysis showed the presence of anatase phase in samples whose potential was 10V and this condition represents a simple surface treatment for Ti-7.5Mo alloy that has high potential for biomedical applications.


2015 ◽  
Vol 1112 ◽  
pp. 359-362
Author(s):  
Aisyah Nor Hasnan ◽  
Azizah Hanom Ahmad

Dammar plant resin is a local natural resin that can be bled from Dipterocaupacea sp of tree. It can be found abundantly in Malaysia’s tropical forest especially in Sarawak. Dammar and Titanium Dioxide was mixed in a various wt% to produce Dammar-modified Titanium Dioxide coating system. The modified coating systems were then spin-coated onto Aluminium Q-panel as the substrate. Coated Q-panels were left to cure at room temperature. The curing time was evaluated using dust free stage. The addition of Titanium Dioxide into the coating system fastens the curing time taken for the coated Q-panel to be cure. It only took about 11-12 minutes to dry compared to the coating system before the addition of Titanium Dioxide where a quite long duration required, 32 minutes. Contact angle measurement was also carried out in order to determine the wettability of the coating system. The surface coated with dammar-modified titanium dioxide found to be hydrophobic where a quite large contact angle obtained for the sample with 3 wt% of Titanium Dioxide (PDT3). The water droplets actually rest on the coating surface without wetting the surface. Water absorption test was done to strengthen the contact angle results where coated substrate was soaked into distilled water for 24 hours and being weighed before and after soaking. The difference of before and after soaking weigh showed that the coating surface does not absorb that much water where only approximately 0.02% of water being absorbed by the coating system for 3 wt%. It proved that the coating systems applied are hydrophobic.


2020 ◽  
Vol 10 (4) ◽  
pp. 6007-6014

Scanning electron microscope allowed us to get screens of different cheese microstructure that form a base for further investigation of a cheese structure state before and after the process of drying and for their comparison. Any cheese structure presents a matrix of proteins penetrated with moisture capillaries; fat globules are located both inside the protein matrix and on a cheese surface. Shape of capillaries is either round or oval. Capillaries vary in size and number that has an impact on the cheese pattern which is described by hole and void shapes and order. Electron microscopy was also used for detecting deposition of calcium phosphate. Particles of calcium phosphate changed in size, before drying they were 10–12 µm, and after drying they reached 20–30 µ. These particles concentrate in the dried cheese and agglomerate into larger particles. The most concentrated calcium phosphate proportion was found in pores and micro-voids of the dry cheese. As for mature cheese samples, calcium lactate was established as well.


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