Mechanical Resistance Properties Research Articles

High stretchable and self-healing nanocellulose-poly(acrylic acid) composite hydrogels for sustainable CO2 shutoff

The injection of CO2 into oil reservoirs to enhance oil recovery (EOR) has become a widely accepted and effective technical method, which, however, remains subject to the gas channeling caused by the reservoir fractures. Herein, this work developed a novel plugging gel combining excellent mechanical properties, fatigue resistance, elastic and self-healing properties for the CO2 shutoff purpose. This gel consisting of grafted nanocellulose and polymer network was synthesized via a free-radical polymerization, and reinforced by using Fe3+ to cross-link the two networks. The as-prepared PAA-TOCNF-Fe3+ gel has a stress of 1.03 MPa and a high strain of 1491 %, and self-heals to its original 98 % in stress and 96 % in strain after rupture, respectively. The introduce of TOCNF/Fe3+ improves the excellent energy dissipation and self-healing via the synergy effect of dynamical coordination bonds and hydrogen bonds. Further, the PAA-TOCNF-Fe3+ gel is both flexible and high-strength in plugging the multi-round CO2 injection, during which the CO2 breakthrough pressure is above 9.9 MPa/m, the plugging efficiency exceeds 96 %, and the self-healing rate is larger than 90 %. Given that above, this gel shows a great potential to plug the high-pressure CO2 flow, which could offer a new method for CO2-EOR and carbon storage.

A porous GO/PI coating prepared via breath figure method: Low dielectric constant with improved mechanical and water resistance properties

It is important to reduce dielectric constant while maintaining or improving water resistance and mechanical properties for the practical use of porous low-dielectric materials. Herein, a composite film in which GO and fluorinated PI (FPI) contained porous structure located on the surface of flat PI film was prepared by the simple breath figure method. The incorporation of GO/surfactant can break the design contradiction between low dielectric constant and high mechanical strength for porous structure, thereby realizing the synchronous promotion of dielectric and mechanical properties. Moreover, the water absorption of composite film was decreased significantly due to the synergy of fluorine atoms, porous structure and GO/surfactant, guarantee its high robustness to humid stress. The dielectric, water resistance and mechanical properties of the composite film could be regulated through varying the casting humidity and GO/surfactant content. A low dielectric constant of 2.3, water absorption of 0.6 % and high tensile strength of 122 MPa, with 31.11 % and 75.88 % of decrease and 26.99 % of increase compared to flat PI film was exhibited with the GO/surfactant loading of only 0.5 wt%. The dielectric constant of composite film is still below 2.5 after moisture treatment. These excellent properties facilitate the application of GO/PI composite film in microelectronics.

Characterization and strengthening mechanism of CNT/TiB2 particulates added AZ91D composites

In the current work, magnesium (AZ91D) matrix composites reinforced with different weight fractions (5, 10, and 15%) of titanium diboride (TiB2) and 1.5 wt% carbon nanotubes (CNTs) are fabricated using stir casting. The improvements in mechanical, wear and corrosion resistance properties are evaluated as per ASTM guidelines. The synergistic strengthening effect of TiB2 and CNT is also studied. It was discovered that the AZ91D/(1.5CNT-10TiB2) composite outperformed other magnesium matrix composites in terms of strength and ductility. Experimental characterization and quantity analysis revealed that the load transfer process of CNT, thermal mismatch, and grain refinement are the primary factors leading to the composite’s increased tensile strength. Porosity tends to increase due to variance in the thermal expansion coefficient of particles and matrix material; Orowan strengthening mechanism plays a prominent role in enhancing tensile strength. Because of the influence of synergistic strengthening, microparticles TiB2 increased the proportion of load transmission mechanisms, and thermal mismatch facilitated the homogenous distribution of CNTs. Wear resistance and corrosion resistance increase with the inclusion of CNTs and TiB2 content. An abrasive-type wear mechanism is seen in the SEM image, and the wear craters are also seen in all the SEM images. Adding TiB2 significantly improves the cast composites’ resistance to corrosion because of grain refinement. Higher addition of TiB2 influences higher pitting corrosion due to poor grain refinement.

Development of high strength high plasticity refractory high entropy alloy based on Mo element optimization and advanced forming process

Refractory high entropy alloy is a potential substitute material for high temperature structures because of its excellent mechanical properties of high temperature resistance. In this paper, three kinds of refractory high-entropy alloys, M0, M10 and M20, were designed by adjusting the content of Mo element and formed by Laser powder bed melting(LPBF) technology. The solidification thermodynamics, microstructure and mechanical properties of the three kinds of alloys were analyzed. The effect of Mo content on the microstructure and mechanical properties of the three kinds of alloys was studied. With the increase of Mo element content, the grain size of the alloy becomes smaller and smaller, the yield strength increases greatly, and the plasticity of the alloy decreases continuously. The compressive yield strength of high strength M20 alloy is up to 1285 MPa, the ultimate strength is 2447 MPa, and the elongation is 27%. The high plasticity M0 alloy exhibits compressive superplasticity. The tensile yield strength and ultimate strength of M10 alloy are 1184 MPa and 1403 MPa, and the elongation is 5.1%. In this paper, the matching problem between plasticity and strength of refractory high-entropy alloys at room temperature is solved by combining alloy composition optimization and LPBF forming technology, which lays a foundation for the industrial application of refractory high-entropy alloys.

Peanut oil and protein extraction using an aqueous enzymatic method and analysis of the characteristics of the emulsions produced

AbstractBackground and ObjectiveThe high cost of enzyme preparation and the stable emulsion produced in the process limit the large‐scale application of aqueous enzymatic method. In this study, a new aqueous enzymatic method for efficient peanut oil and protein extraction was optimized. And the composition, structure, and stability of the produced emulsions were characterized.FindingsPeanut emulsion proteins were mainly composed of oleosin, steroleosin, caleosin, lipoxygenase, and arachin. The composition of phospholipids in the emulsions was essentially the same as that in peanut raw materials. A surface protein wrapped the oil droplets. The ζ‐potential, particle size, and surface protein concentration properties of the second step extracted the emulsion (E2) were consistent with those produced using the conventional aqueous enzymatic method, whereas the first step extracted the emulsion (E1) was more prone to unstable aggregation between oil droplets. The mechanical properties of shear deformation resistance (viscosity, storage modulus, and loss modulus) were better in E1 than in E2.ConclusionsFollowing new method, highest yields obtained for oil and protein were 95.48% and 80.74%, respectively. The new method reduced the conditions of enzymatic hydrolysis and accelerated the demulsification of emulsions.Significance and NoveltyThe study provides a two‐step aqueous enzymatic method for extracting emulsions and proteins from peanut. Process cost and efficiencies ensure industrial scale‐up of the method.

Synthesis of Carboxyl Cellulose Nanocrystals/Copper Nanohybrids to Endow Waterborne Polyurethane Film with Improved Mechanical and Antibacterial Properties

The multifunctional nanohybrid fillers have attracted widespread attention in the field of polymer nanocomposites. In this study, carboxyl cellulose nanocrystals/copper nanoparticles (TCNC/Cu NP) nanohybrids were prepared by in situ growth of copper ions on the modified carboxyl CNC, and further doped into waterborne polyurethane (WPU) via solution blending. TEM, FTIR, XRD, and UV–vis analysis were used to characterize the morphology, composition, crystallization and structure of the as-prepared nanohybrid. TCNC/Cu NP nanohybrids exhibited good dispersion and interface compatibility in WPU matrix. The nanocomposite film obtained significantly enhanced mechanical, thermal stability and scratch resistance properties, which was attributed to a hydrogen bond network structure formed in the WPU matrix. Additionally, colony count method was performed to test antibacterial properties of various films. Compared to the pure WPU film, all of nanocomposite films showed better antibacterial properties against Escherichia coli and Staphylococcus aureus. The antibacterial ratio of the WPU nanocomposite film with the addition of TCNC/Cu NP (1:1) reach 99%. Furthermore, the results of a copper ion sustained release experiment showed that the nanocomposite film had a long-term release effect, which was ascribed to the strong bonding between TCNC/Cu NP nanohybrids and WPU matrix. Thus, Cu NP was firmly embedded in the hydrogen bonding network structure formed. This work gives a new approach to prepare the antibacterial WPU film with well mechanical properties.

New Biodegradable Materials for Re-Thought Packaging from Pre-Consumer Wastes by Controlling the Storage Time as Method to Increase the Mechanical Recycling Efficiency

The influence of storage conditions on the mechanical recycling of pre-consumer waste (PRE-CW) from the manufacture of multilayer packaging films starting from starch compounds using a renewable-based polymer with PCL and PBAT, which are biodegradable conventional-based polyesters, was studied. It was found that, unlike materials based on conventional-origin polymers that accumulate in the environment for hundreds of years, the studied compounds degraded, even in the solid state, duringstorage in unventilated spaces and during the rainy hot summers with alternatingheat and rain. The degradation of the mechanically recycled compounds obtained from PRE-CW stored in such conditions was highlighted by the comparative analysis with the primary compounds, which proved the following: specific FTIR spectra changes; 2-3-times higher melt fluidity than for primary compounds; melting in successive processes over the entire positive temperatures range, up to 115 °C, such as in cases of compositional de-mixing of incompatible blends, faced to a single melting endotherm with a maximum at around 120 °C for the primar thermal degradation with the movement of the main destruction stages towards higher temperatures; a high quantity residue at 750 °C in air; dispersed mechanical resistance properties y compounds; crystallization at temperatures 10 °C-15 °C higher. The elimination of storage before the mechanical recycling of the pre-consumer waste from this type of polymeric compound fabrication is a way to increase the mechanical recycling efficiency while obtaining new materials with functional properties required by the applications.

Multifunctional nanocomposites integrate electromagnetic shielding, thermal, mechanical, and wear resistance properties

AbstractThe SiCnws/SiC nanocomposites were in situ synthesized by using nickel carbon foam as catalyst and skeleton. This technique has a series of advantages including simple operation, low cost, and high efficiency. Due to the excellent microwave absorption and thermal properties of SiCnws, SiCnws/SiC nanocomposites possess excellent electromagnetic shielding performance with a high SET value of 38.3 dB and good thermal properties with thermal conductivity of 13.77 ± 0.098 wm−1k−1 at room temperature. Meanwhile, the bending strength of the nanocomposites is 110.9 ± 7.7 MPa. The friction coefficient of nanocomposites is about 0.26 with a wear speed of about 67 um3/s. Therefore, the nanocomposites integrate many advantages including lightweight (2.0 g/cm3), excellent electromagnetic shielding, good heat conduction, high strength, and wear resistance.

Preparation and Characterization of Acrylonitrile Butadiene Rubber Reinforced with Bio-Hydroxyapatite from Fish Scale.

This work aims to enhance the mechanical properties, oil resistance, and thermal properties of acrylonitrile butadiene rubber (NBR) by using the Nile tilapia fish scales as a filler and using bis(triethoxysilylpropyl)tetrasulfide (TESPT) as a coupling agent (CA). The prepared fish scale particles (FSp) are B-type hydroxyapatite and the particle shape is rod-like. The filled NBR with FSp at 10 phr increased tensile strength up to 180% (4.56 ± 0.48 MPa), reduced oil absorption up to 155%, and increased the decomposition temperature up to 4 °C, relative to the unfilled NBR. The addition of CA into filled NBR with FSp at 10 phr increased tensile strength up to 123% (5.62 ± 0.42 MPa) and percentage of elongation at break up to 122% relative to the filled NBR with FSp at 10 phr. This work demonstrated that the prepared FSp from the Nile tilapia fish scales can be used as a reinforcement filler to enhance the NBR properties for use in many high-performance applications.

Influence of TiO2 nanoparticles content as reinforce material to enhance the mechanical and corrosion resistance properties of Sn and Sn–Ag alloy for dental applications

This study evaluated the influence of the TiO2 nanoparticles (NPs) on the mechanical and chemical performance of Sn and Sn–Ag alloys. The XRD (X-ray diffraction) and HR-TEM (high resolution-transmission electron microscopy) methods were used to characterize the NPs synthesized by the sol-gel microwave process. The chemical composition of the alloys was Sn, Sn+3TiO2 NPs, Sn–5Ag+1.5TiO2 NPs, Sn–10Ag, and Sn–10Ag+3TiO2 NPs, obtained from an experimental factorial design (EFD). A statistical model was used to determine the mechanical and chemical properties, showing the Vickers hardness response surface, tensile strength, wear, and corrosion resistance. The wear and corrosion tests for the various alloy compositions were performed using human artificial saliva solution. The results indicated that the Sn–10Ag+3TiO2 NPs exhibited the highest mechanical performance due to their increased hardness (380 HV), tensile strength (370 N), and wear resistance (0.34 × 10−3 mm3 Nm−1); in all the cases, the inclusion of TiO2 NPs enhanced the corrosion resistance of the alloys. According to the American Dental Association (ADA), Sn–10Ag+3TiO2 NPs alloy could be classified as a possible type IV restorative material.

Cobalt free metallic binders for HVOF thermal sprayed wear resistant coatings

Thermal sprayed HVOF WC-based cermet coatings containing various metallic binders have been used in several different applications in industries that require abrasive sliding wear resistance, such as hydraulic pistons, shafts or bearings. The potential dangerousness and cost increase off cobalt-based metallic binders, underlining the challenge in reducing reliance on this metal as metallic binder in wear resistant coatings. The present work aims to study the feasibility of WC-NiMoCrFeCo, WC-CrC-Ni and WC-FeCrAl coatings, in contrast to conventional WC-CoCr, by evaluating their microstructure, mechanical, tribological and corrosion resistance properties. Commercially feedstock powders were sprayed onto steel plates using a kerosene-fuelled HVOF WokaJet 400 gun. The WC-CoCr coating shows a slightly highest hardness than WC-NiMoCrFeCo and WC-FeCrAl coatings, showing a slight trend towards an increase in the wear rate as the coating hardness decreases. The WC-CrC-Ni coating is significantly the softest and least wear resistant coating, as a consequence of the presence of a high percentage of lower hardness CrC particles. Nevertheless, this coating shows similar corrosion resistance to of conventional WC-CoCr coating, while the WC-NiMoCrFeCo and WC-FeCrAl coatings show a slightly worse corrosion resistance.

Effect of pre-consolidated interlayer on the interfacial evolution and mechanical properties of thermo-compensated resistance brazing welded Al/steel joints

Effect of pre-consolidated interlayer on the interfacial evolution and mechanical properties of thermo-compensated resistance brazing welded Al/steel joints

Wheat gluten-based coatings and films: Preparation, properties, and applications.

Effective food packaging that can protect foodstuffs from physical, chemical, and biological damage and maintain freshness and quality is essential to the food industry. Wheat gluten shows promise as food packaging materials due to its edibility, biodegradability, wide availability, low cost, film-forming potential, and high resistance to oxygen. The low mechanical properties and poor water permeability of wheat gluten coatings and films limit their wide applications; however, some inferior properties can be improved through various solutions. This work presents a comprehensive review about wheat gluten-based coatings and films, including their formulation, processing methods, properties, functions, and applications. The mechanical and water resistance properties of coatings and films can be reinforced through wheat gluten modification, combinations of different processing methods, and the incorporation of reinforcing macromolecules, antioxidants, and nanofillers. Antioxidants and antimicrobial agents added to wheat gluten can inhibit microbial growth on foodstuffs, maintain food quality, and extend shelf life. Performances of wheat gluten-based coatings and films can be further improved to expand their applications in food packaging. Current research gaps are identified. Future research is needed to examine the optimal formulation and processing of wheat gluten-based coatings and films and their performance.

Mechanical, physical, blast waves and ballistic impact resistance properties of a concrete incorporating thermally treated PET inclusions

Polyethylene terephthalate (PET) plastics are widely used worldwide, and large amounts end up discarded in nature as waste after use. While the incorporation of PET in the concrete composite is known to be environmentally beneficial, it appears to also improve some characteristics of concrete. In this work the effect of PET strip shaped inclusions on concrete performance is investigated with PET fractions up to 20 kg/m3, while focusing on thermally treated plastic. The heat treatment has been shown to elevate the tensile strength of the inclusions by up to 120 %. This has led to a significant improvement in the mechanical properties of the concrete. In addition, the use of PET strips reduces thermal conductivity by up to 30 %. The ballistic impact resistance and blast waves resistance of concrete with treated PET strips is also investigated. The results show a better protection against the threat of explosive and bullet attacks.

Multifunctional amorphous FeCoNiTixSi high-entropy alloys with excellent electromagnetic-wave absorption performances.

Amorphous high-entropy alloys (HEAs) as electromagnetic-wave absorbing materials have been rarely reported. In this work, amorphous FeCoNiTixSi HEAs were synthesized by introducing a high content of large-atom Ti using the high-energy ball-milling technique. This amorphous structure could improve the saturated magnetization and coercivity of HEAs, but slightly degraded the mechanical and oxidation resistance properties. In terms of electromagnetic properties, FeCoNiTi0.01Si and FeCoNiTiSi exhibit excellent electromagnetic-wave absorption performances, with significant absorptions of -68.4 dB at 6.14 GHz and -63.4 dB at 9.12 GHz, corresponding to bandwidths of 5.15 GHz (1.69 mm) and 3.64 GHz (1.43 mm), respectively. Overall, the prepared FeCoNiTixSi HEAs exhibited superior comprehensive performances compared to other HEA absorption materials. This work provided a novel strategy for the development of new electromagnetic-wave absorption materials with low weight, high absorption efficiency, and resistance to harsh environments.

Excellent mechanical and chemical resistance properties exhibited by bamboo fiber reinforced poly(lactic acid) - epoxy composites

Excellent mechanical and chemical resistance properties exhibited by bamboo fiber reinforced poly(lactic acid) - epoxy composites

Improvement of Fire Resistance and Mechanical Properties of Glass Fiber Reinforced Plastic (GFRP) Composite Prepared from Combination of Active Nano Filler of Modified Pumice and Commercial Active Fillers

Glass fiber reinforced plastic (GFRP) composites have great potential to replace metal components in vehicles by maintaining their mechanical properties and improving fire resistance. Ease of form, anti-corrosion, lightweight, fast production cycle, durability and high strength-to-weight ratio are the advantages of GFRP compared to conventional materials. The transition to the use of plastic materials can be performed by increasing their mechanical, thermal and fire resistance properties. This research aims to improve the fire resistance of GFRP composite and maintain its strength by a combination of pumice-based active nano filler and commercial active filler. The nano active filler of pumice particle (nAFPP) was obtained by the sol-gel method. Aluminum trihydroxide (ATH), sodium silicate (SS) and boric acid (BA) were commercial active fillers that were used in this study. The GFRP composite was prepared by a combination of woven roving (WR) and chopped strand mat (CSM) glass fibers with an unsaturated polyester matrix. The composite specimens were produced using a press mold method for controlling the thickness of specimens. Composites were tested with a burning test apparatus, flexural bending machine and Izod impact tester. Composites were also analyzed by SEM, TGA, DSC, FT-IR spectroscopy and macro photographs. The addition of nAFPP and reducing the amount of ATH increased ignition time significantly and decreased the burning rate of specimens. The higher content of nAFPP significantly increased the flexural and impact strength. TGA analysis shows that higher ATH content had a good contribution to reducing specimen weight loss. It is also strengthened by the lower exothermic of the specimen with higher ATH content. The use of SS and BA inhibited combustion by forming charcoal or protective film; however, excessive use of them produced porosity and lowered mechanical properties.

Enhancement on the hardness and oxidation resistance property of TiN/Ag composite films for high temperature applications by addition of Si

Titanium nitride and silver (TiN/Ag) composite films exhibited the excellent self-lubricating properties in a wide temperature range due to the formation of the Ag rich tribolayer in the contact. However, Ag addition usually reduces the hardness and oxidation resistance properties of the films. In this paper, TiN/Ag/Si3N4 composite films were deposited using RF magnetron co-sputtering system to improve the mechanical and oxidation resistance properties of the TiN/Ag film. XRD and TEM analysis revealed that three-phases could be identified on the TiN/Ag/Si3N4 films: face-centered cubic (fcc) TiN, fcc-Ag and amorphous Si3N4 phases. The hardness of the TiN/Ag film increased from ∼16 GPa to ∼24 GPa for TiN/Ag/Si3N4 with 15.3 at.% of Si due to the formation of the nanocomposite structure. The addition of Si allowed a significant improvement on the oxidation resistance temperature, and effectively avoiding of Ag diffusion, and thereby contributing the stability of the hardness of the film after annealing treatment.

Application of multipolymers system in the development of hydrogel-forming microneedle integrated with polyethylene glycol reservoir for transdermal delivery of albendazole

Parasitic infection is one of the health problems that cause many deaths in developing countries. One of the infectious parasites that is a problem for the world community is cystic echinococcosis (CE). The most popular medication for treating CE is albendazole (ABZ), however, it has limited intestinal absorption and poor water solubility, making it less effective. Therefore, developing an alternative ABZ delivery system is necessary to increase drug bioavailability and avoid first-pass metabolism. Here, we developed hydrogel-forming microneedles (HFM) combined with a polyethylene glycol (PEG) reservoir to deliver ABZ transdermally. HFM was made through a crosslinking process between polyvinyl alcohol (PVA) and polyvinyl pyrrolidone (PVP) as polymers and citric acid as a crosslinking agent. This HFM was developed to be integrated with a reservoir of polyethylene glycol (PEG) of varying molecular weights. HFM was successfully developed with desirable mechanical resistance and insertion properties. The evaluation of swelling capability resulted in >500 % swelling percentage. Moreover, the penetration result showed HFM could penetrate up to 68 % into the skin with only 3,83 % of height decrease. The skin integrity study also showed that the permeation of HFM into the skin caused no changes to skin integrity. Incorporated with a PEG reservoir, the ex vivo permeation test showed that 4584.43 ± 26.61 µg/cm2 of ABZ was permeated through the skin. ABZ has been successfully developed into an HFM integrated with a PEG reservoir that is safe, painless, and non-irritating and has promising results for increasing the effectiveness of cystic echinococcosis therapy through the transdermal route.

Effect of bias voltage and nitrogen content on the morphological, structural, mechanical, and corrosion resistance properties of micro-alloyed Ti1−xAl0.8xP0.2XNy films deposited by high power impulse magnetron sputtering

The applications of multicomponent coatings (such as doped ternary or quaternary coatings) with superior functional properties have been shown to efficiently and sustainably improve the life span of engineering materials. This study reports the synergistic effect of negative substrate bias voltages Us and reactive gas QN2 ratio on the properties of phosphorous (P) microalloyed Ti1−xAl0.8xP0.2xN multicomponent coatings deposited using high power impulse magnetron sputtering. It is found that an increase of Us enhances the densification of the deposited coatings, with mixed cubic (c)-TiN and cubic (c)-AlN phases, as identified from the XRD pattern analysis. Furthermore, Raman spectroscopy showed that the incorporation of Al and P into the TiN structure increases the gap region between the acoustic and optic bands. An optimized mechanical property of the coatings, with a maximum hardness of 28.6 GPa was measured at Us = − 40 V and QN2 = 7 SCCM, and improved adhesion of coatings with H/E > 0.081, was possible. Improved corrosion resistance was also measured for microalloyed TiAlPN coatings. The microalloying of P with TiAlN has, thus, been shown to affect both the anodic and cathodic reactions and inhibit the corrosion of AISI 5206 steel.