scholarly journals High-Strength Nanocomposite Hydrogels with Swelling-Resistant and Anti-Dehydration Properties

Polymers ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1025 ◽  
Author(s):  
Bo Xu ◽  
Yuwei Liu ◽  
Lanlan Wang ◽  
Xiaodong Ge ◽  
Min Fu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Performance ◽  
High Strength ◽  
Alumina Nanoparticles ◽  
Cross Linking ◽  
Free Radical Copolymerization ◽  
Application Range ◽  
Practical Applications ◽  
Nanocomposite Hydrogels ◽  
Al2o3 Nps

Hydrogels with excellent mechanical properties have potential for use in various fields. However, the swelling of hydrogels under water and the dehydration of hydrogels in air severely limits the practical applications of high-strength hydrogels due to the influence of air and water on the mechanical performance of hydrogels. In this study, we report on a kind of tough and strong nanocomposite hydrogels (NC-G gels) with both swelling-resistant and anti-dehydration properties via in situ free radical copolymerization of acrylic acid (AA) and N-vinyl-2-pyrrolidone (VP) in the water-glycerol bi-solvent solutions containing small amounts of alumina nanoparticles (Al2O3 NPs) as the inorganic cross-linking agents. The topotactic chelation reactions between Al2O3 NPs and polymer matrix are thought to contribute to the cross-linking structure, outstanding mechanical performance, and swelling-resistant property of NC-G gels, whereas the strong hydrogen bonds between water and glycerol endow them with anti-dehydration capacity. As a result, the NC-G gels could maintain mechanical properties comparable to other as-prepared high-strength hydrogels when utilized both under water and in air environments. Thus, this novel type of hydrogel would considerably enlarge the application range of hydrogel materials.

scholarly journals Synthesis, Characterization, and Antifogging Application of Polymer/Al2O3 Nanocomposite Hydrogels with High Strength and Self-Healing Capacity

Polymers ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1362 ◽  
Author(s):  
Bo Xu ◽  
Yuwei Liu ◽  
Jiugang Yuan ◽  
Ping Wang ◽  
Qiang Wang
Keyword(s):  
Large Scale ◽  
Mechanical Performance ◽  
Glass Plate ◽  
Hot Water ◽  
Alumina Nanoparticles ◽  
Great Promise ◽  
Self Healing ◽  
Practical Applications ◽  
Nanocomposite Hydrogels ◽  
Al2o3 Nps

Hydrogels with outstanding mechanical performance, self-healing capacity, and special functionality are highly desirable for their practical applications. However, it remains a great challenge to achieve such hydrogels by a facile approach. Here, we report a new type of nanocomposite hydrogels by in situ copolymerization of acrylic acid (AA) and 2-acrylamido-2-methylpropane sulfonic acid (AMPS) using alumina nanoparticles (Al2O3 NPs) as the cross-linkers. The obtained hydrogels are highly stretchable and compressible, which could sustain large-scale extension (>1700%) or compression (90%) without failure, and exhibit tensile and compressive strength up to 660 kPa and 8.3 MPa, respectively. Furthermore, this kind of hydrogel also display considerable self-healing capacity due to their noncovalent cross-linking mechanism, as well as the hydrogen-bonding interactions between polymer chains. More interestingly, it was found that the resultant gels possess a long-lasting antifogging property that could prevent the formation of fog on the glass plate above hot water for at least 90 min. It is expected that this novel type of hydrogel would show great promise for various applications, including soft robots, artificial muscles, and optical devices.

Tough Hydrogels Based on Macromicelles as Crosslinkers with pH and Ion Sensitive Properties

2019 ◽  
Vol 944 ◽  
pp. 537-542
Author(s):  
Rui Jia Yan ◽  
Yan Zi Yan ◽  
Jing Hong Ma ◽  
Jing Hua Gong
Keyword(s):  
Mechanical Properties ◽  
Fracture Stress ◽  
Mechanical Performance ◽  
High Strength ◽  
Radical Copolymerization ◽  
Pluronic F127 ◽  
Free Radical Copolymerization ◽  
Elongation At Break ◽  
High Toughness ◽  
Stimuli Sensitive

Stimuli-sensitive hydrogels crosslinked by macromolecular micelles usually present good mechanical properties. In this paper, a novel kind of pH and ion sensitive hydrogels with high toughness and strength were prepared using Pluronic F127 diacrylate (F127DA) as crosslinking centers for the free radical copolymerization of acrylamide (AM) and methacrylate (MA) monomers. These hydrogels showed high strength and tensibility with elongation at break of 1208%, fracture stress of 328 kPa and toughness of 1.80 MJ/m-3. The hydrogels not only exhibited enhancement of mechanical performance, but also achieved sensitive response to changes of pH and ionic strength, making an approach for the development of applications in drug delivery and sensors.

scholarly journals Microstructure and Mechanical Performance of Resistance Spot Welded Martensitic Advanced High Strength Steel

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 1021
Author(s):  
Yunzhao Li ◽  
Huaping Tang ◽  
Ruilin Lai
Keyword(s):  
Mechanical Properties ◽  
Failure Modes ◽  
Mechanical Performance ◽  
Strong Dependence ◽  
High Strength ◽  
Weld Nugget ◽  
Resistance Spot ◽  
Pull Out ◽  
Cross Tension ◽  
Spot Welded

Resistance spot welded 1.2 mm (t)-thick 1400 MPa martensitic steel (MS1400) samples are fabricated and their microstructure, mechanical properties are investigated thoroughly. The mechanical performance and failure modes exhibit a strong dependence on weld-nugget size. The pull-out failure mode for MS1400 steel resistance spot welds does not follow the conventional weld-nugget size recommendation criteria of 4t0.5. Significant softening was observed due to dual phase microstructure of ferrite and martensite in the inter-critical heat affected zone (HAZ) and tempered martensite (TM) structure in sub-critical HAZ. However, the upper-critical HAZ exhibits obvious higher hardness than the nugget zone (NZ). In addition, the mechanical properties show that the cross-tension strength (CTS) is about one quarter of the tension-shear strength (TSS) of MS1400 weld joints, whilst the absorbed energy of cross-tension and tension-shear are almost identical.

The effect of trace elements (Cu and Sn) on mechanical properties of steel castings

1980 ◽  
Vol 295 (1413) ◽  
pp. 125-125
Keyword(s):  
Mechanical Properties ◽  
Trace Elements ◽  
Regression Analysis ◽  
Experimental Work ◽  
High Strength Steel ◽  
Mechanical Performance ◽  
High Strength ◽  
Residual Elements ◽  
Steel Castings ◽  
Effect Of Copper

Because of the increase in the levels of residual elements in steel, a programme of work was initiated to determine the limits of copper and tin impurities that were tolerable in steel castings. A 1.5 % Mn—Mo steel was chosen as a base, since any effect of trace elements would be readily apparent in terms of mechanical performance in this medium—high strength steel. The effect of copper was investigated within the range < 0.01-0.5 %, and tin within the range < 0.01-0.26%. The results were analysed by using factorial analysis in the first instance and later, as the amount of experimental work expanded and more results became available, a regression analysis was used.

Effect of Excess Mg on the Microstructure and Mechanical Properties of Al-Mg2Si High Pressure Die Casting Alloys

2013 ◽  
Vol 765 ◽  
pp. 64-68 ◽  
Author(s):  
Feng Yan ◽  
Shou Xun Ji ◽  
Zhong Yun Fan
Keyword(s):  
Mechanical Properties ◽  
High Pressure ◽  
Mechanical Performance ◽  
Eutectic Reaction ◽  
Die Casting ◽  
High Strength ◽  
Primary Phase ◽  
High Pressure Die Casting ◽  
Excess Mg ◽  
Pressure Die Casting

In this work we found that the addition of excess Mg can significantly improve the mechanical properties of pseudo-binary Al-Mg2Si alloys after high pressure die casting (HPDC). Al-8Mg2Si-6Mg alloy offered an excellent combination of high strength and reasonable ductility. Excess Mg lowers the Mg2Si content in the eutectic reaction and promotes the formation of Mg2Si as the primary phase, and this is believed to be the origin of improved mechanical performance.

Mechanical Properties of Hydrogen Functionalized Graphyne - A Molecular Dynamics Investigation

2012 ◽  
Vol 472-475 ◽  
pp. 1813-1817 ◽  
Author(s):  
Yu Lin Yang ◽  
Zhe Yong Fan ◽  
Ning Wei ◽  
Yong Ping Zheng
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Young’S Modulus ◽  
Mechanical Performance ◽  
Young's Modulus ◽  
High Strength ◽  
Strength And Stiffness ◽  
Dynamics Simulations ◽  
Structure Engineering

In this paper the mechanical properties of a series of hydrogen functionalized graphyne are investigated through acting tensile loads on the monolayer networks. Molecular dynamics simulations are performed to calculate the fracture strains and corresponding maximum forces for pristine graphyne along both armchair and zigzag directions. Furthermore, hydrogen functionalized graphynes with different functionalization sites are analyzed to investigate the effect of functionlization on the mechanical performance. Finally, Young's modulus of all the investigated architectures are computed. The obtained results show that monolayer graphyne is mechanically stable with high strength and stiffness, and the mechanical performance can be tuned through structure engineering and functionalization.

scholarly journals Mechanical properties and microstructure of recycled mortar reinforced with hybrid fiber

2018 ◽  
Vol 7 (4) ◽  
pp. 2178 ◽  
Author(s):  
Sallehan Ismail ◽  
Mohammad Asri Abd Hamid ◽  
Zaiton Yaacob ◽  
Dzulkarnaen Ismail ◽  
Hazizan Md Akil
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Mechanical Strength ◽  
Mechanical Performance ◽  
Volume Fraction ◽  
High Strength ◽  
Strength Properties ◽  
Recycled Aggregate ◽  
Hybrid Fiber ◽  
Hybrid Fibers

This study investigated the hybrid effects of two types of microfiber, namely, polypropylene and nylon, on the mechanical properties of high-strength mortar, which produced fine recycled aggregate (FRA). The amount of microfibers was maintained at a volumetric fraction of 0.6%. The microstructure and mechanical strength properties (compressive strength and flexural strength) of recycled mortar reinforced with hybrid-size microfibers were evaluated at various curing ages. Experimental results show that the inclusion of hybrid fibers significantly influenced the mechanical performance of the recycled mortar. The hybridization fiber at volume fraction 0.3% polypropylene + 0.3% nylon yielded the most promising mechanical performance. Enhancements of 8% on compressive and 11% flexural strength were achieved at 28 days. Scanning electron microscopy observations revealed that reinforcement at the microscale prohibited the initiation and growth of cracks at the micro level. High loads were required to form macrocracks within composites, thereby improving the mechanical strength of the mortar matrix.  

Experimental Research on Effect of Hot Works on Mechanical Performance of Ship Steel Plate

2011 ◽  
Vol 311-313 ◽  
pp. 1859-1862
Author(s):  
Hua Ming Wang ◽  
Han Xing Zhao ◽  
Yong Jia Dai ◽  
Xiao Song Rui
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Steel Plate ◽  
Mechanical Performance ◽  
Structural Strength ◽  
High Strength ◽  
Shipbuilding Industry ◽  
Important Method ◽  
Fairing Process

Hot works is an important method for fairing the ship steel plate to improve the quality of shipbuilding, while the mechanical performance of the ship steel plate may be affected during the fairing process, which could result to some safe problems on the structural strength. DH32 high-strength ship steel plate, which is a kind of widely used material in shipbuilding industry, is taken as an object of the present experimental study. Some main parameters of the plate’s mechanical property through hot-works treatment for different times are investigated systematically. Through analyzing the variation of the mechanical properties, some conclusions are drawn and some useful suggestions put forward.

The Synthesis and Property of Neutral Silicone Glass Sealant

2015 ◽  
Vol 1118 ◽  
pp. 67-71
Author(s):  
Xin Chen ◽  
Bing Yu ◽  
Hua Yuan ◽  
Hai Lin Cong ◽  
Xiao Dan Xu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Performance ◽  
Cross Linking ◽  
Reinforcing Agent

The neutral silicone glass sealant was prepared and the mechanical performance of this silicone glass sealant was researched in this paper. The recipe of neutral silicone glass sealant was studied. Besides, the influence of different cross-linking agents was researched; meanwhile, the effect of plasticizer and reinforcing agent on the mechanical properties of the material was studied. To obtain the best properties of neutral silicone glass sealant, the recipe should be taken further efforts to optimize.

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