Self-healing polymers and composites Mauldin, T C; Kessler, M R
International materials reviews,
11/2010, Letnik:
55, Številka:
6
Journal Article
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Inspired by the unique and efficient wound healing processes in biological systems, several approaches to develop synthetic polymers that can repair themselves with complete, or nearly complete, ...autonomy have recently been developed. This review aims to survey the rapidly expanding field of self-healing polymers by reviewing the major successful autonomic repairing mechanisms developed over the last decade. Additionally, we discuss several issues related to transferring these self-healing technologies from the laboratory to real applications, such as virgin polymer property changes as a result of the added healing functionality, healing in thin films v. bulk polymers, and healing in the presence of structural reinforcements.
Icing phenomenon that occurs universally in nature and industry gets a great impact on human life. Over the past decades, extensive efforts have been made for a wide range of anti‐icing/deicing ...surfaces, but the preparation of anti‐icing/deicing interfaces that combine stability, rapid self‐healing and excellent anti‐icing/deicing performance remains a challenge. In this study, a photothermal solid slippery surface with excellent comprehensive performance is prepared by integrating cellulose acetate film, carbon nanotubes with paraffin wax (CCP). Apart from the excellent anti‐icing and deicing properties at −17 ± 1.0 °C under 1 sun illumination, the surface can further achieve deicing at temperatures as low as −22 ± 1.0 °C under infrared light. The fabricated surface also exhibits great stability when placed in harsh conditions such as underwater or ultra‐low temperature environments for over 30 days. Even when suffering from physical damage, the prepared surface can rapidly self‐repair under 1 sun illumination or near‐infrared (NIR) illumination within 16.0 ± 1.5 s. Due to the rapid and repeatable self‐healing performance, the lubricating properties of the interface material do not deteriorate even after 50 repeated abrasing‐repairing cycles. The photothermal solid slippery surface possesses wide‐ranging applications and commercial value at high latitude and altitude regions.
In this study, a solar‐assisted slippery surface integrates three main factors for anti/de‐icing materials: excellent anti‐icing/deicing properties, rapid and repeatable self‐healing properties, and excellent stability. It is envisaged that this work will provide new insights into the manufacture of stable surfaces with rapid self‐healing and excellent anti‐icing/deicing properties for effective practical applications.
The ablation/oxidation resistance of a carbon fibre (Cf)/carbon matrix (C)-SiC-TiC-TaC ceramic matrix composite (CMC) produced by melt infiltration of alloy into a Cf/C preform and tested in severely ...oxidising conditions was quantitatively determined and discussed. An oxyacetylene flame shot of 7.5s (4MW/m2 nominal heat flux), as well as oxidising conditions imposed by a radiant furnace in air at 1873K up to 480s were the selected testing conditions. Detailed post-test microstructure investigations of the oxidised/ablated infiltrated CMC samples, compared to unprotected CMCs tested in nominally identical conditions, enabled to establish an increase in ablation/oxidation resistance of one order of magnitude. The occurrence of a self-generating protective high-temperature glass-ceramic, disclosed by microstructure analyses, played a substantial role for that performance jump during oxidation/ablation. The Cf/C-SiC-TiC-TaC composite herein tested can be a valuable candidate for uses in severe aerospace applications (propulsion and hypersonic flight).
Although image inpainting, or the art of repairing the old and deteriorated images, has been around for many years, it has recently gained even more popularity, because of the recent development in ...image processing techniques. With the improvement of image processing tools and the flexibility of digital image editing, automatic image inpainting has found important applications in computer vision and has also become an important and challenging topic of research in image processing. This paper reviews the existing image inpainting approaches, that were classified into three subcategories, sequential-based, CNN-based, and GAN-based methods. In addition, for each category, a list of methods for different types of distortion on images are presented. Furthermore, the paper also presents available datasets. Last but not least, we present the results of real evaluations of the three categories of image inpainting methods performed on the used datasets, for different types of image distortion. We also present the evaluations metrics and discuss the performance of these methods in terms of these metrics. This overview can be used as a reference for image inpainting researchers, and it can also facilitate the comparison of the methods as well as the datasets used. The main contribution of this paper is the presentation of the three categories of image inpainting methods along with a list of available datasets that the researchers can use to evaluate their proposed methodology against.
To improve the tribological performance of piston ring assemblies, this work studies the friction and self-repair behavior of magnesium silicate hydroxide(MSH)/MoS2 nanoparticles as PAO6 lubricant ...additives, whose friction condition is simulated piston ring-cylinder liner operating condition using a friction pair composed of chrome-plated steel balls and gray cast iron. By studying the effect of different concentrations on the friction reduction and anti-wear properties, it was found that the addition of MSH/MoS2 nano-powder to PAO6 could all play a role in the friction reduction and anti-wear effect, with the best friction reduction effect at 0.5 wt% addition. The self-repairing behavior of the lubrications with 0.5 wt% MSH/MoS2 nanopowders was found on grey cast iron specimens after 8 h of friction experiment.
•In this paper, proposing a novel design of DE for Knapsack problems is reported.•A dual representation of solutions in continuous and binary is introduced.•New efficient fitness evaluation and ...repairing method is proposed.•Results demonstrated the efficiency of Novel DE in solving Knapsack problems.•Novel DE defined new solutions, better than best-known ones for 5 large instances.
The capability of the conventional differential evolution algorithm to solve optimization problems in continuous spaces has been well demonstrated and documented in the literature. However, differential evolution has been commonly considered inapplicable for several binary/permutation-based real-world problems because of its arithmetic reproduction operator. Moreover, many limitations of the standard differential evolution algorithm, such as slow convergence and becoming trapped in local optima, have been defined. In this paper, a novel technique which makes a simple differential evolution algorithm suitable and very effective for solving binary-based problems, such as binary knapsack ones, is proposed. It incorporates new components, such as representations of solutions, a mapping method and a diversity technique. Also, a new efficient fitness evaluation approach for calculating and, at the same time, repairing knapsack candidate solutions, is introduced. To assess the performance of this new algorithm, four datasets with a total of 44 instances of binary knapsack problems are considered. Its performance and those of 22 state-of-the-art algorithms are compared, with the experimental results demonstrating its superiority in terms of both the quality of solutions and computational times. It is also capable of finding new solutions which are better than the current best ones for five large knapsack problems.
Mesh repair is a long-standing challenge in computer graphics and related fields. Converting defective meshes into watertight manifold meshes can greatly benefit downstream applications such as ...geometric processing, simulation, fabrication, learning, and synthesis. In this work, by assuming the model is visually correct, we first introduce three visual measures for visibility, orientation, and openness, based on ray-tracing. We then present a novel mesh repair framework incorporating visual measures with several critical steps, i.e., open surface closing, face reorientation, and global optimization, to effectively repair meshes with defects (e.g., gaps, holes, self-intersections, degenerate elements, and inconsistent orientations) and preserve visual appearances. Our method reduces unnecessary mesh complexity without compromising geometric accuracy or visual quality while preserving input attributes such as UV coordinates for rendering. We evaluate our approach on hundreds of models randomly selected from ShapeNet and Thingi10K, demonstrating its effectiveness and robustness compared to existing approaches.
•A clear classification of the current deep eutectic solvents (DESs) recycling technologies is established.•Both traditional DESs leaching and direct repairing technologies are critically ...assessed.•The mechanisms of traditional DESs leaching and direct repairing technologies are outlined.•The challenges and perspectives of DESs-based recycling for spent batteries are discussed.
As one of the most important energy storage devices, lithium-ion batteries (LIBs) have experienced a booming development due to the increasing demands of electronics, especially the tremendous growth of electric vehicles. Consequently, a large amount of end-of-life (EOL) LIBs are generated with the massive use of LIBs, bringing the global concerns of environmental pollutions and the waste of critical materials. Thus, the proper handling of EOL LIBs is necessarily required, especially the recycling of electrode materials. This review summarizes the recent development of cathode recycling for EOL LIBs mainly based on the technologies by using deep eutectic solvents (DESs) which are considered as green solvents because of the low cost and biocompatibility. Herein, we establish a clear classification of the current DESs recycling technologies. The merits and weaknesses of traditional DESs leaching and direct DESs repairing technologies are critically assessed. Moreover, their mechanisms are outlined. We provide an available information for EOL LIBs recycling through DESs, and present the corresponding challenges and future perspectives.
In order to eliminate the volume defects such as keyhole and cavity in friction stir welding (FSW) joint, a new technique called active-passive filling friction stir repairing (A-PFFSR) was put ...forward. In this study, choosing AZ31-B magnesium alloy as research object, repairing experiment of keyhole was mainly investigated. The results show that the keyhole can be successfully repaired and no defects appear in filling zone (FZ) of joint using the plunge speed of 1mm/min and rotational velocity of 1300rpm. The FZ and partial thermo-mechanically affected zone are characterized by fine and equiaxed grains, while the grain size of FZ through the thickness direction presents bigger in the middle and smaller in the top and bottom of joint. With the increase of plunge speed, tensile strength and elongation of repaired joints gradually decrease at the constant rotational velocity of 1300rpm. When the plunge speed is 1mm/min, the tensile strength and elongation of A-PFFSR joint reach the maximum values of 189.7MPa and 7.6%, equivalent to 96.3% and 98% of defect-free FSW joint, respectively. Moreover, the fracture surface consists of dimples with varied size, indicating typical ductile fracture.
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•Active-passive filling friction stir repairing is applied to solve volume defect.•The keyhole of FSW joint of magnesium alloy was successfully repaired.•Decreasing plunge speed increases mechanical property of repaired joint.•Higher heat input is necessary to obtain high quality joint.
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