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Adhesion between tiles and mortars is of paramount importance to the overall stability of ceramic tile systems. In this sense, from the chemical perspective, weak forces such as van der Waals forces and hydrophilic interactions are expected to occur preferably at the tiles and polymer-modified Portland cement mortar interfaces. Thus, the main goal of this study was to chemically modify the ceramic tile surface through organosilanes aiming to improve adhesion with polymer-modified mortars (PMMs). Glass tile surfaces were treated with five silane derivatives bearing specific functionalities. Fourier transform infrared spectroscopy and contact angle measurements were used for characterizing the novel surfaces produced as the chemical moieties were immobilized onto them. In addition, pull-off tests were conducted to assess the effect on adhesion properties between tile and poly(ethylene-co-vinyl acetate) modified mortar. The bond strength results have given strong evidence of the improvement on adherence at the tile–PMM interface, reflecting the whole balance of silane, cement, and polymer interactions.

In this study, Al/Al₂O₃ composites have been fabricated by combined stir casting and accumulative press bonding (APB) processes. The effect of APB method on the bonding properties of bulk samples such as the number of APB process, Al₂O₃wt.% and the pressing temperature has been investigated by the peeling test. It is established that stronger bonding with a good quality can be obtained by increasing the pressing temperature and decreasing the Al₂O₃ particleswt.% as the reinforcement. Also, growing the step number of the APB method increases the bonding strength up to step#2 and then reduces the average peeling force due to the strain hardening result of the metallic matrix during the accumulative pressing. Finally, the effect of the APB method on the peeling surface of samples has been investigated using the scanning electron microscopy.

This paper describes a series of tests on Carbon Fiber Reinforced Polymers (CFRP) sheet bonded steel plates. The specimens were tensioned to failure after enduring a pre-set number of fatigue cycles at various load ratios (defined as the ratio of the maximum load in the fatigue test to the corresponding static strength). The aim of the study is to investigate the effect of fatigue loading on bond strength and failure modes. Both normal modulus (E = 240 GPa) and high modulus (E = 640 GPa) CFRP sheets were used in the tests. The experimental results were compared with those for specimens subjected to static tension alone. It was found that the failure modes of the CFRP-sheet bonded steel plates were not affected greatly by the fatigue loading except for those bonded with high modulus CFRP, where fiber fracture extended over more than one cross-section. The fatigue loads appear to have less effect on the bond strength of high modulus CFRP-sheet bonded steel plates. Reduction in bond strength from 10% to 20% was observed for normal modulus CFRP-sheet bonded steel plates when the load ratio is less than 30%.

This paper presents an experimental investigation of the bond strength between carbon fiber reinforced polymer (CFRP) and steel substrate by utilizing the pull-off test and scanning electron microscope (SEM) analysis. A series of pull-off experiments was conducted by using three types of CFRP (CFRP sheets and CFRP laminates with/without woven mesh) and two types of epoxy adhesive (ductile and brittle epoxy adhesive) with/without carbon nanotube (CNT) modification. Pull-off samples with CFRP laminates possess higher (about double) bond strength than that of samples with CFRP sheets, due to the good saturation of fibers in the laminates. The steel-CFRP bond with ductile epoxy adhesive (Araldite 2011) is found to have about 16% higher bond strength when compared to that of brittle epoxy (MBrace Saturant), even though the tensile strength of Araldite 2011 is about 40% less than that of MBrace Saturant. Also, it is shown that modified epoxy with CNTs is more efficient than neat epoxy for bonding CFRP to steel at a moderately elevated temperature, and increasing the bond strength about twofold.

Si-to-glass wafer bonding process has been quantitatively evaluated based on the Taguchi analysis of the interface integrity and bond strength. Four process parameters: bonding temperature, voltage, bonding time and vacuum condition, are considered. In the experiments, the bonding temperature ranges from 200°C to 300°C and the voltage ranges from 200 volts to 400 volts. The bond efficiency ranges from 95.7% to 99.9% and the bond strength ranges from 15.7 MPa to 29 MPa. The bonding temperatures and the voltages have been designed at low levels so as to prevent the devices from degrading and warping. Among the process parameters, the bonding temperature is the dominant factor for the bond quality, followed by the voltage for bond strength and vacuum for bond efficiency. A higher temperature causes high ion mobility and a higher voltage produces a higher electric field, which will increase the ion drift velocity. Therefore, they can enhance the bond strength. A higher vacuum can reduce air bubble trap in the interface and improve the bond efficiency. The anodic bonding mechanisms are comprised of the oxidation of silicon and the hydrogen bonding between hydroxyl groups.

Low temperature direct wafer bonding was performed in vacuum. Different loads were applied during bonding processes. In all cases, the bond strength is above 19 MPa, which is high enough for practical applications. More interestingly, in contrast to the findings by others, we found that the applied load does play a very important role in wafer bonding, the higher the applied load, the lower the bond strength. The bonded wafers were examined by means of scanning acoustic microscope (SAM). It was found that both the bubble size and bubble number increase with an increase in applied load. This phenomenon is contributed to the applied load. High applied force keeps two wafer surfaces in tight contact. If there is any gas trapped during bonding process, such as hydrogen and water molecules, the tight contact prevents them from escaping out of the bonding interfaces, which results in the low bond strength. It also can be explained by one low temperature direct wafer bonding model.

Low temperature bonding of two silicon wafers with significant high bond strength has been prepared successfully using sol-gel coating as intermediate layer. The effects of bonding temperature, solution aging time and spin speed on bonding quality have been investigated by a full 2³ factorial design. Under the 75% confidence level, the statistic result shows that only the interaction effect between bonding temperature and spin speed is significant. Design of experiments (DoE) is used to study the effects of key parameters on bond strength, and bonding mechanism are discussed. The possible reason for the observed high bond strength is the absence of absorbed water on the smooth coating surface, which results in the direct condensation reactions between OH groups to form strong Si-O-Si bonds even at low temperatures.

The most important function of proteins may well be to bind to other biomolecules. It has long been felt that kinetic rates of bond formation and dissociation between soluble receptors and ligands might account for most features of the binding process. Only theoretical considerations allowed to predict the behaviour of surface-attached receptors from the properties of soluble forms. During the last decade, experimental progress essentially based on flow chambers, atomic force microscopes or biomembrane force probes allowed direct analysis of biomolecule interaction at the single bond level and gave new insight into previously ignored features such as bond mechanical properties or energy landscapes. The aim of this review is (i) to describe the main advances brought by laminar flow chambers, including information on bond response to forces, multiplicity of binding states, kinetics of bond formation between attached structures, effect of molecular environment on receptor efficiency and behaviour of multivalent attachment, (ii) to compare results obtain by this and other techniques on a few well defined molecular systems, and (iii) to discuss the limitations of the flow chamber method. It is concluded that a new framework may be needed to account for the effective behaviour of biomolecule association.

Mechanical evaluations of plasma sprayed HA coatings have assumed vast importance in the orthopaedic applications where the demands of operational stresses of the coatings are stringently required. The determination of the mechanical properties such as Knoop hardness, elastic modulus, fracture toughness and bond strength are therefore essential and necessary for the assessment of the service behaviour and performance of the bioceramic coatings. The inherent properties of the coatings have been investigated and were found to have direct and impacting relationship with the feedstock characteristics, processing conditions as well as microstructural deformities. The presence of inter- and intralamellar thermal microcracks, voids and porosities with limited true contact between lamellae were found to degrade the mechanical characteristics of the coatings.

This paper aims to provide an insight to the mechanical properties of the HA coatings by plasma spray process, and the effect of microstructural defects on the resultant mechanical and structural integrity of the coatings. The elastic response behaviour and fracture toughness of both the as-sprayed and heat-treated HA coatings using Knoop and Vickers indentations at different loadings have been investigated. Results have shown that the mechanical properties (hardness, modulus, fracture toughness and bond strength) of the coatings have improved significantly despite increasing crack density after heat treatment. These properties were also found to deteriorate with increasing spray distance and particle size.