Multi-responsive nanocomposite hydrogels with high strength and toughness

2016 ◽  
Vol 4 (9) ◽  
pp. 1733-1739 ◽  
Author(s):  
Jingli Yang ◽  
Shuang Liu ◽  
Ying Xiao ◽  
Guorong Gao ◽  
Yuanna Sun ◽  
...  

Poly(NIPAM-co-DAC) hydrogels containing thermoresponsive units and positive charges show high mechanical properties and responsiveness to temperature, pH, and ion strength.

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Eethar Thanon Dawood ◽  
Mahyuddin Ramli

This study was conducted to determine some physical and mechanical properties of high-strength flowable mortar reinforced with different percentages of palm fiber (0, 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, and 1.6% as volumetric fractions). The density, compressive strength, flexural strength, and toughness index were tested to determine the mechanical properties of this mortar. Test results illustrate that the inclusion of this fiber reduces the density of mortar. The use of 0.6% of palm fiber increases the compressive strength and flexural strength by about 15.1%, and 16%, respectively; besides, the toughness index (I5) of the high-strength flowable mortar has been significantly enhanced by the use of 1% and more of palm fiber.


1988 ◽  
Vol 4 (03) ◽  
pp. 169-185
Author(s):  
I. L. Stern ◽  
M. Wheatcroft ◽  
D. Y. Ku ◽  
R. F. Waite ◽  
W. Hanzalek

Advanced metallurgical processes have made possible the manufacture of steels that—in addition to possessing high strength and toughness characteristics—maintain modest carbon equivalents for good weldabiiity results. These steels show promise of application in the marine industry because of their potential relative insensitivity to heat input and hardening and their potential for reduced requirements for preheat. This paper reviews several candidate steels, their composition, metallurgy and mechanical properties, and analyzes the results of a series of weldabiiity and toughness tests.


2016 ◽  
Vol 4 (40) ◽  
pp. 6609-6609 ◽  
Author(s):  
Jingli Yang ◽  
Shuang Liu ◽  
Ying Xiao ◽  
Guorong Gao ◽  
Yuanna Sun ◽  
...  

Correction for ‘Multi-responsive nanocomposite hydrogels with high strength and toughness’ by Jingli Yang et al., J. Mater. Chem. B, 2016, 4, 1733–1739.


2010 ◽  
Vol 658 ◽  
pp. 416-419 ◽  
Author(s):  
Hyun Hwi Lee ◽  
Seung Ho Kim ◽  
Bhupendra Joshi ◽  
Sung Hun Cho ◽  
Soo Wohn Lee

The ceramic channel is very important in SRL hot dipping system. High strength and fracture toughness of ceramic channel materials can improve the quality, productivity and economic feasibility of zinc plated steel. The purpose of this research was to find out the most suitable conditions of the ceramic channel that have best fracture strength and fracture toughness. The hot pressed composite materials was carried out by hot pressing Al2O3 with different content of ZrO2. The composite contained from 0-20 wt.% ZrO2. Hot pressed composite materials were observed for mechanical properties (density, hardness, fracture toughness and flexural strength) and microstructure.


1976 ◽  
Vol 62 (2) ◽  
pp. 254-266
Author(s):  
Hiroshi KOHIRA ◽  
Masao HORI ◽  
Toru MUTA ◽  
Tadashi NISHI ◽  
Katsumi SUZUKI

2019 ◽  
Vol 71 (4) ◽  
Author(s):  
Qinghua Meng ◽  
Tie Jun Wang

Cellulose nanopaper, which consists of a porous network of cellulose nanofibrils (CNFs), exhibits excellent mechanical properties with high strength and toughness. The physical mechanisms, including a realizable reduction of defect size in the nanopaper and facile formation/reformation of hydrogen bonds among CNFs, suggest a bottom-up material design strategy to address the conflict between strength and toughness. A thorough exploration of the rich potential of such a design strategy requires a fundamental understanding of its mechanical behavior. In this review, we supply a comprehensive perspective on advances in cellulose nanopaper mechanics over the most recent two decades from the three aspects of mechanical properties, structure–property relationship and microstructure-based mechanical modeling. We discuss the effects of size, orientation, polymerization degree, and isolate origins of CNFs; density or porosity and humidity of nanopaper; and hemicellulose and lignin on the mechanical properties of cellulose nanopaper. We also discuss the similarities and differences in the microstructure, mechanical properties, and toughening mechanisms between cellulose nanopaper and cellulose nanocrystal (CNC) nanopaper, chitin nanopaper, carbon nanotube (CNT) nanopaper, and graphene nanopaper. Finally, we present the ideas, status quo, and future trends in mechanical modeling of cellulose nanopaper, including atomistic- and microscale-level numerical modeling, and theoretical modeling. This review serves as a modest spur intended to induce scientists to present their valuable contributions and especially to design more advanced cellulose nanopapers and promote the development of their mechanics.


Author(s):  
A.G. Fox ◽  
V.R. Mattes ◽  
S. Mikalac ◽  
M.G. Vassilaros

Because of their excellent weldability, high strength low alloy (HSLA) ultra low carbon bainitic (ULCB) steels are finding increasing applications in ship and submarine construction. In order to achieve the required strength and toughness in ULCB HSLA steels it is necessary to control chemical composition and thermo-mechanical processing very carefully so that the desired microstructure and mechanical properties can be achieved. For instance HSLA 100 ULCB steel (nominal yield strength 100 ksi) used by the U.S. Navy in shipbuilding applications can derive its strength and toughness from the following sources:- (1) solid solution strengthening (2) small prior austenite grain size derived from niobium carbonitride precipitation at austenite grain boundaries (3) dislocation substructure and (4) from copper precipitates (in aged alloys). The object of the present work is to correlate the microstructure and mechanical properties of production batches of HSLA 100 in the quenched and aged conditions. Because many of the salient features of these microstructures are submicron in size it was found necessary to use SEM and TEM.


Polymers ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1025 ◽  
Author(s):  
Bo Xu ◽  
Yuwei Liu ◽  
Lanlan Wang ◽  
Xiaodong Ge ◽  
Min Fu ◽  
...  

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.


RSC Advances ◽  
2016 ◽  
Vol 6 (64) ◽  
pp. 59131-59140 ◽  
Author(s):  
Jia Yang ◽  
Lin Zhu ◽  
Xiaoqiang Yan ◽  
Dandan Wei ◽  
Gang Qin ◽  
...  

Hybrid nanocomposite hydrogels (NC gels) with physical and chemical crosslinkings exhibit improved mechanical properties and large hysteresis. Moreover, hybrid NC gels also demonstrate excellent self-recovery properties.


2014 ◽  
Vol 608 ◽  
pp. 31-36
Author(s):  
Geun Hee Kim ◽  
Jae Hwan Pee ◽  
Yoo Jin Kim ◽  
Woo Seok Cho ◽  
Dae Wung Kim

Lightweight ceramics have a low density, which leads to a decrease in strength and toughness. In the development of lightweight ceramics, high-strengthening technology is necessary. Alumina fiber was mixed with raw materials for the purpose of producing high-strength lightweight ceramics. After adding alumina fiber at 1, 3, and 5wt% and sintering at 1300°C, we found that strength and toughness increased in proportion to the amount. Instead of the high melting temperature of alumina fiber, it is reacted with matrix and generated mullite phase. And lots of alumina fiber remains in the matrix, thereby allowing improvements in strength and toughness. When alumina fiber was not added, we found a low density of 1.35~1.80 g/m3, along with low values for strength and toughness at 30~60MPa and 0.7~1.2 MPa m1/2 respectively. With 1wt% addition of alumina fiber, we obtained a higher strength of 92MPa at 1300°C, which is close to the strength of general white porcelains at 112MPa.


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