scholarly journals High strength and conductive hydrogel with fully interpenetrated structure from alginate and acrylamide

e-Polymers ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 391-397
Author(s):  
Tao Liu ◽  
Ripeng Zhang ◽  
Jianzhi Liu ◽  
Ling Zhao ◽  
Yueqin Yu
Keyword(s):  
Mechanical Performance ◽  
Three Dimensional ◽  
High Strength ◽  
Extreme Environment ◽  
Natural Polymers ◽  
Conductive Hydrogel ◽  
Wide Range ◽  
Interpenetrated Structure ◽  
Conductive Hydrogels ◽  
Conductive Properties

Abstract Highly stretched and conductive hydrogels, especially synthetized from natural polymers, are beneficial for highly stretched electronic equipment which is applied in extreme environment. We designed and prepared robust and tough alginate hydrogels (GMA-SA-PAM) using the ingenious strategy of fully interpenetrating cross-linking, in which the glycidyl methacrylate (GMA) was used to modify sodium alginate (SA) and then copolymerized with acrylamide (AM) and methylenebisacrylamide (BIS) as cross-linkers. The complete cross-linked structures can averagely dissipate energy and the polymer structures can maintain hydrogels that are three-dimensional to greatly improve the mechanical performance of hydrogels. The GMA-SA-PAM hydrogels display ultra-stretchable (strain up to ∼407% of tensile strain) and highly compressible (∼57% of compression strain) properties. In addition, soaking the GMA-SA-PAM hydrogel in 5 wt% NaCl solution also endows the conductivity of the hydrogel (this hydrogel was named as GSP-Na) with excellent conductive properties (5.26 S m−1). The GSP-Na hydrogel with high stability, durability, as well as wide range extent sensor is also demonstrated by researching the electrochemical signals and showing the potential for applications in wearable and quickly responded electronics.

Three-Dimensional Unit Cell Study of a Porous Bulk Metallic Glass Under Various Stress States

2019 ◽  
Vol 86 (6) ◽  
Author(s):  
S Gouripriya ◽  
Parag Tandaiya
Keyword(s):  
Volume Fraction ◽  
Hydrostatic Stress ◽  
Three Dimensional ◽  
High Strength ◽  
Absorption Capacity ◽  
Unit Cell ◽  
Wide Range ◽  
Tension And Compression ◽  
Softening Parameter ◽  
Stress States

Porous bulk metallic glasses (BMGs) exhibit an excellent combination of superior mechanical properties such as high strength, high resilience, large malleability, and energy absorption capacity. However, a mechanistic understanding of their response under diverse states of stress encountered in practical load-bearing applications is lacking in the literature. In this work, this gap is addressed by performing three-dimensional finite element simulations of porous BMGs subjected to a wide range of tensile and compressive states of stress. A unit cell approach is adopted to investigate the mechanical behavior of a porous BMG having 3% porosity. A parametric study of the effect of stress triaxialities T = 0, ±1/3, ±1, ±2, ±3, and ±∞, which correspond to stress states ranging from pure deviatoric stress to pure hydrostatic stress under tension and compression, is conducted. Apart from the influence of T, the effects of friction parameter, strain-softening parameter and Poisson’s ratio on the mechanics of deformation of porous BMGs are also elucidated. The results are discussed in terms of the simulated stress-strain curves, pore volume fraction evolution, strain to failure, and development of plastic deformation near the pore. The present results have important implications for the design of porous BMG structures.

Nanocellulose-based Hydrogels for Biomedical Applications

2019 ◽  
Vol 15 (4) ◽  
pp. 371-381 ◽  
Author(s):  
Amalnath John ◽  
Wen Zhong
Keyword(s):  
Biomedical Applications ◽  
High Performance ◽  
Polymer Networks ◽  
Three Dimensional ◽  
Drug Carriers ◽  
Wound Dressings ◽  
Self Healing ◽  
Natural Polymers ◽  
Wide Range ◽  
Materials Used

Hydrogels are three-dimensional polymer networks capable of absorbing and holding a large amount of water. They have a wide range of biomedical applications including drug carriers, biosensors, tissue scaffolds and wound dressings owning to their innate resemblance to the living tissue. Recently biodegradable and renewable natural polymers, especially nanocellulose, have gained immense attention in the development of hydrogels for biomedical applications. This review provides a brief analysis of the various nanocellulosic materials used in the fabrication of hydrogels for various biomedical applications. Recent developments in high performance hydrogels based on nanocellulose, including self-healing, highly tough and/or stretchable and 3D printable hydrogels will also be covered in this review.

scholarly journals Three-Dimensional Au/Ag Nanoparticle/Crossed Carbon Nanotube SERS Substrate for the Detection of Mixed Toxic Molecules

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2026
Author(s):  
Haonan Wei ◽  
Zhisheng Peng ◽  
Cheng Yang ◽  
Yuan Tian ◽  
Lianfeng Sun ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Large Scale ◽  
Three Dimensional ◽  
High Strength ◽  
Sers Substrate ◽  
Ag Nanoparticle ◽  
Distribution Method ◽  
Relative Standard ◽  
Wide Range ◽  
Good Signal

Research on engineering “hotspots” in the field of surface-enhanced Raman scattering (SERS) is at the forefront of contributing to the best sensing indicators. Currently, there is still an urgent need to design a high-strength and large-scale electric field distribution method in order to obtain an ideal SERS sensor. Here, we designed a three-dimensional (3D) Au/Ag nanoparticle (NP)/crossed carbon nanotube film SERS substrate. The proposed structure formed by the simple preparation process can perfectly coordinate the interaction between the SERS substrates, lasers, and molecules. The denser “hotspots” can be induced and then distributed in holes enclosed by Au/AgNPs and the gaps between them. This process was verified by numerical simulations. The experimental results show that the proposed SERS substrate possesses an excellent sensitivity of 10−12 M (rhodamine 6G (R6G)), an enhancement factor of 1.60 × 109, and a good signal reproducibility (the relative standard deviation is ~6.03%). We further use a Au/AgNP/crossed CNT substrate to detect complex solutions composed of toxic molecules, which shows that our proposed SERS substrate has a wide range of application potentials, especially in food safety.

scholarly journals 3D bioprinting of conductive hydrogel for enhanced myogenic differentiation

2021 ◽  
Vol 8 (5) ◽  
Author(s):  
Ying Wang ◽  
Qingshuai Wang ◽  
Shengchang Luo ◽  
Zhoujiang Chen ◽  
Xiang Zheng ◽  
...  
Keyword(s):  
Myogenic Differentiation ◽  
Three Dimensional ◽  
C2c12 Cells ◽  
3D Bioprinting ◽  
Hydrogel Scaffold ◽  
Electrical Signals ◽  
Conductive Hydrogel ◽  
Conductive Property ◽  
Conductive Hydrogels

Abstract Recently, hydrogels have gained enormous interest in three-dimensional (3D) bioprinting toward developing functional substitutes for tissue remolding. However, it is highly challenging to transmit electrical signals to cells due to the limited electrical conductivity of the bioprinted hydrogels. Herein, we demonstrate the 3D bioprinting-assisted fabrication of a conductive hydrogel scaffold based on poly-3,4-ethylene dioxythiophene (PEDOT) nanoparticles (NPs) deposited in gelatin methacryloyl (GelMA) for enhanced myogenic differentiation of mouse myoblasts (C2C12 cells). Initially, PEDOT NPs are dispersed in the hydrogel uniformly to enhance the conductive property of the hydrogel scaffold. Notably, the incorporated PEDOT NPs showed minimal influence on the printing ability of GelMA. Then, C2C12 cells are successfully encapsulated within GelMA/PEDOT conductive hydrogels using 3D extrusion bioprinting. Furthermore, the proliferation, migration and differentiation efficacies of C2C12 cells in the highly conductive GelMA/PEDOT composite scaffolds are demonstrated using various in vitro investigations of live/dead staining, F-actin staining, desmin and myogenin immunofluorescence staining. Finally, the effects of electrical signals on the stimulation of the scaffolds are investigated toward the myogenic differentiation of C2C12 cells and the formation of myotubes in vitro. Collectively, our findings demonstrate that the fabrication of the conductive hydrogels provides a feasible approach for the encapsulation of cells and the regeneration of the muscle tissue.

Theoretical study of the prestressing strand's stress by computer modeling methods

2020 ◽  
Vol 76 (11) ◽  
pp. 1139-1148
Author(s):  
A. G. Korchunov ◽  
E. M. Medvedeva ◽  
E. M. Golubchik
Keyword(s):  
Residual Stresses ◽  
High Strength ◽  
Pearlitic Steel ◽  
Internal Stresses ◽  
Steel Microstructure ◽  
Compressive Stresses ◽  
Wide Range ◽  
Prestressing Strands ◽  
Increasing Temperature ◽  
Wire Strand

The modern construction industry widely uses reinforced concrete structures, where high-strength prestressing strands are used. Key parameters determining strength and relaxation resistance are a steel microstructure and internal stresses. The aim of the work was a computer research of a stage-by-stage formation of internal stresses during production of prestressing strands of structure 1х7(1+6), 12.5 mm diameter, 1770 MPa strength grade, made of pearlitic steel, as well as study of various modes of mechanical and thermal treatment (MTT) influence on their distribution. To study the effect of every strand manufacturing operation on internal stresses of its wires, the authors developed three models: stranding and reducing a 7-wire strand; straightening of a laid strand, stranding and MTT of a 7-wire strand. It was shown that absolute values of residual stresses and their distribution in a wire used for strands of a specified structure significantly influence performance properties of strands. The use of MTT makes it possible to control in a wide range a redistribution of residual stresses in steel resulting from drawing and strand laying processes. It was established that during drawing of up to 80% degree, compressive stresses of 1100-1200 MPa degree are generated in the central layers of wire. The residual stresses on the wire surface accounted for 450-500 MPa and were tension in nature. The tension within a range of 70 kN to 82 kN combined with a temperature range of 360-380°С contributes to a two-fold decrease in residual stresses both in the central and surface layers of wire. When increasing temperature up to 400°С and maintaining the tension, it is possible to achieve maximum balance of residual stresses. Stranding stresses, whose high values entail failure of lay length and geometry of the studied strand may be fully eliminated only at tension of 82 kN and temperature of 400°С. Otherwise, stranding stresses result in opening of strands.

SP 700

Alloy Digest ◽  
1995 ◽  
Vol 44 (6) ◽  
Keyword(s):  
High Strength ◽  
Heat Treating ◽  
Bend Strength ◽  
Beta Titanium Alloy ◽  
Superplastic Behavior ◽  
Temperature Performance ◽  
Beta Titanium ◽  
Wide Range ◽  
Alpha Beta ◽  
Cold Workability

Abstract SP 700 is a high strength, beta-rich alpha-beta titanium alloy. It was developed with the following attributes: (1) excellent hot- and cold-workability; (2) enhanced hardenability with a wide range of mechanical properties that can be obtained by heat treatment; and (3) superior superplastic behavior at low temperature (around 1050 K). This datasheet provides information on composition, physical properties, microstructure, elasticity, tensile properties, and bend strength. It also includes information on high temperature performance as well as heat treating. Filing Code: TI-107. Producer or source: NKK Corporation.

ALMAR 300 ALLOY

Alloy Digest ◽  
1978 ◽  
Vol 27 (7) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Elevated Temperature ◽  
Cold Working ◽  
High Strength ◽  
Heat Treating ◽  
Age Hardening ◽  
Ultra High Strength Steel ◽  
Wide Range ◽  
Iron Nickel ◽  
Useful Yield

Abstract ALMAR 300 Alloy is a vacuum-melted ultra-high-strength steel. The annealed structure of this alloy is essentially a carbon-free, iron-nickel martensite (a relatively soft Rockwell C 28) that can be strengthened by cold working and elevated-temperature (900-950 F) age hardening to useful yield strengths as high as 300,000 psi. The unique properties of this alloy make it suitable for a wide range of section sizes. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SA-349. Producer or source: Allegheny Ludlum Corporation.

USS TENELON

Alloy Digest ◽  
1975 ◽  
Vol 24 (5) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Elevated Temperatures ◽  
Stress Rupture ◽  
High Strength ◽  
Heat Treating ◽  
Creep Properties ◽  
United States Steel Corporation ◽  
Excellent Corrosion Resistance ◽  
Wide Range ◽  
Mild Acid

Abstract USS TENELON is a completely austenitic, nickel-free stainless steel with exceptionally high strength which is retained at elevated temperatures. It has excellent corrosion resistance in atmospheric and mild acid exposures and maintains nonmagnetic characteristics even when 60% cold reduced. It also has good stress-rupture and creep properties in the range 1200-1500 F. It has a wide range of applications. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as fracture toughness, creep, and fatigue. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: SS-311. Producer or source: United States Steel Corporation.

SAE 8642

Alloy Digest ◽  
1981 ◽  
Vol 30 (7) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
Surface Treatment ◽  
Tensile Properties ◽  
Alloy Steel ◽  
High Strength ◽  
Heat Treating ◽  
Steel Mills ◽  
Wide Range ◽  
Strength And Toughness

Abstract SAE 8642 is a triple-alloy steel that can be hardened by austenitizing and quenching in oil. This steel has moderate hardenability with relative high strength and toughness, especially in the quenched-and-tempered condition. It is used in a wide range of components, parts and tools; examples are bolts, shafts, gears, wrenches, axles and housings. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: SA-382. Producer or source: Alloy steel mills and foundries.

DOMEX 550MC

Alloy Digest ◽  
2009 ◽  
Vol 58 (3) ◽  
Keyword(s):  
Physical Properties ◽  
Hsla Steel ◽  
Steel Structures ◽  
High Strength ◽  
Heat Treating ◽  
Bend Strength ◽  
Cold Forming ◽  
Wide Range ◽  
Hot Rolled ◽  
Earthmoving Machines

Abstract Domex 550MC is a hot-rolled, high-strength low-alloy (HSLA) steel for cold forming operations. It is available in thicknesses of 2.00-12.80 mm. The alloy meets or exceeds the requirements of S550MC in EN 10149-2. Applications include a wide range of fabricated components and steel structures, including truck chassis, crane booms, and earthmoving machines. This datasheet provides information on composition, physical properties, tensile properties, and bend strength as well as fatigue. It also includes information on forming, heat treating, and joining. Filing Code: SA-594. Producer or source: SSAB Swedish Steel Inc.

Sign in / Sign up

Export Citation Format

Share Document