Mechanics of Strong and Tough Cellulose Nanopaper

2019 ◽  
Vol 71 (4) ◽  
Author(s):  
Qinghua Meng ◽  
Tie Jun Wang
Keyword(s):  
Mechanical Properties ◽  
Cellulose Nanofibrils ◽  
High Strength ◽  
Material Design ◽  
Design Strategy ◽  
Mechanical Modeling ◽  
Structure Property ◽  
Porous Network ◽  
Cellulose Nanopaper ◽  
Strength And Toughness

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.

scholarly journals Anomalous scaling law of strength and toughness of cellulose nanopaper

2015 ◽  
Vol 112 (29) ◽  
pp. 8971-8976 ◽  
Author(s):  
Hongli Zhu ◽  
Shuze Zhu ◽  
Zheng Jia ◽  
Sepideh Parvinian ◽  
Yuanyuan Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Scaling Law ◽  
Functional Materials ◽  
Material Design ◽  
Cellulose Fibers ◽  
Building Blocks ◽  
General Mechanism ◽  
Intrinsic Defect ◽  
Cellulose Nanopaper ◽  
Strength And Toughness

The quest for both strength and toughness is perpetual in advanced material design; unfortunately, these two mechanical properties are generally mutually exclusive. So far there exists only limited success of attaining both strength and toughness, which often needs material-specific, complicated, or expensive synthesis processes and thus can hardly be applicable to other materials. A general mechanism to address the conflict between strength and toughness still remains elusive. Here we report a first-of-its-kind study of the dependence of strength and toughness of cellulose nanopaper on the size of the constituent cellulose fibers. Surprisingly, we find that both the strength and toughness of cellulose nanopaper increase simultaneously (40 and 130 times, respectively) as the size of the constituent cellulose fibers decreases (from a mean diameter of 27 μm to 11 nm), revealing an anomalous but highly desirable scaling law of the mechanical properties of cellulose nanopaper: the smaller, the stronger and the tougher. Further fundamental mechanistic studies reveal that reduced intrinsic defect size and facile (re)formation of strong hydrogen bonding among cellulose molecular chains is the underlying key to this new scaling law of mechanical properties. These mechanistic findings are generally applicable to other material building blocks, and therefore open up abundant opportunities to use the fundamental bottom-up strategy to design a new class of functional materials that are both strong and tough.

scholarly journals Properties of High-Strength Flowable Mortar Reinforced with Palm Fibers

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Eethar Thanon Dawood ◽  
Mahyuddin Ramli
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Physical And Mechanical Properties ◽  
High Strength ◽  
Test Results ◽  
Palm Fiber ◽  
Toughness Index ◽  
Strength And Toughness

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.

High-Strength Steels Produced by Advanced Metallurgical Processes

1988 ◽  
Vol 4 (03) ◽  
pp. 169-185
Author(s):  
I. L. Stern ◽  
M. Wheatcroft ◽  
D. Y. Ku ◽  
R. F. Waite ◽  
W. Hanzalek
Keyword(s):  
Mechanical Properties ◽  
Heat Input ◽  
High Strength Steels ◽  
High Strength ◽  
Marine Industry ◽  
Metallurgical Processes ◽  
Strength And Toughness

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.

High Strength and Toughness Al2O3 Composite Materials for the Improvement of Ceramic Channel in SRL Hot Dipping System

2010 ◽  
Vol 658 ◽  
pp. 416-419 ◽  
Author(s):  
Hyun Hwi Lee ◽  
Seung Ho Kim ◽  
Bhupendra Joshi ◽  
Sung Hun Cho ◽  
Soo Wohn Lee
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Composite Materials ◽  
Flexural Strength ◽  
Fracture Strength ◽  
Hot Pressing ◽  
High Strength ◽  
Economic Feasibility ◽  
Different Content ◽  
Strength And Toughness

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.

scholarly journals Manufacture, Mechanical Properties and Rolling Performance of Large Cast Steel Rolls with High Strength and Toughness

1976 ◽  
Vol 62 (2) ◽  
pp. 254-266
Author(s):  
Hiroshi KOHIRA ◽  
Masao HORI ◽  
Toru MUTA ◽  
Tadashi NISHI ◽  
Katsumi SUZUKI
Keyword(s):  
Mechanical Properties ◽  
Cast Steel ◽  
High Strength ◽  
Steel Rolls ◽  
Strength And Toughness

Electron Microscope studies of the microstructures in as-quenched and aged HSLA-100 production steels and correlation with mechanical properties

1991 ◽  
Vol 49 ◽  
pp. 582-583
Author(s):  
A.G. Fox ◽  
V.R. Mattes ◽  
S. Mikalac ◽  
M.G. Vassilaros
Keyword(s):  
Mechanical Properties ◽  
High Strength ◽  
Low Carbon ◽  
Austenite Grain Size ◽  
Solid Solution Strengthening ◽  
Austenite Grain ◽  
Microstructure And Mechanical Properties ◽  
Hsla Steels ◽  
Carbonitride Precipitation ◽  
Strength And Toughness

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.

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 ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Strength ◽  
Nanocomposite Hydrogels ◽  
Strength And Toughness

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

Improvement of Mechanical Properties of Lightweight Ceramics with the Addition of Alumina Fiber

2014 ◽  
Vol 608 ◽  
pp. 31-36
Author(s):  
Geun Hee Kim ◽  
Jae Hwan Pee ◽  
Yoo Jin Kim ◽  
Woo Seok Cho ◽  
Dae Wung Kim
Keyword(s):  
Mechanical Properties ◽  
Raw Materials ◽  
High Strength ◽  
Low Density ◽  
High Melting ◽  
Alumina Fiber ◽  
Mullite Phase ◽  
High Melting Temperature ◽  
The Matrix ◽  
Strength And Toughness

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.

scholarly journals Tailoring Heterogeneous Microstructure in a High-Strength Low-Alloy Steel for Enhanced Strength-Toughness Balance

Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1983
Author(s):  
Yishuang Yu ◽  
Minliang Gao ◽  
Bin Hu ◽  
Chang Tian ◽  
Xuequan Rong ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Annealing Temperature ◽  
Volume Fraction ◽  
Hsla Steel ◽  
High Strength ◽  
Back Stress ◽  
Heterogeneous Microstructure ◽  
Hsla Steels ◽  
Two Factors ◽  
Strength And Toughness

The attainment of both strength and toughness is of vital importance to most structural materials, although unfortunately they are generally mutually exclusive. Here, we report that simultaneous increases in strength and toughness in a high-strength low-alloy (HSLA) steel were achieved by tailoring the heterogeneous microstructure consisting of soft intercritical ferrite and hard martensite via intercritical heat treatment. The heterogeneous microstructure features were studied from the perspective of morphology and crystallography to uncover the effect on mechanical properties. Specifically, the volume fraction of martensite increased with increasing annealing temperature, which resulted in increased back stress and effective stress, and thereby an improved strength-ductility combination. The enrichment of carbon and alloying elements in the martensite was lowered with the increase in annealing temperature. As a result, the hardness difference between the intercritical ferrite and martensite was reduced. In addition, the globular reversed austenite preferentially grew into the adjacent austenite grain that held no Kurdjumov-Sachs (K-S) orientation relationship with it, which effectively refined the coarse prior austenite grains and increased the density of high angle grain boundaries. The synergy of these two factors contributed to the improved low-temperature toughness. This work demonstrates a strategy for designing heterostructured HSLA steels with superior mechanical properties.

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