Online determination of anisotropy during cellulose nanofibril assembly in a flow focusing device

RSC Advances ◽  
2015 ◽  
Vol 5 (24) ◽  
pp. 18601-18608 ◽  
Author(s):  
Karl M. O. Håkansson
Keyword(s):  
Cellulose Nanofibrils ◽  
High Strength ◽  
Cellulose Nanofibril ◽  
Flow Focusing ◽  
Strength And Stiffness

In order to utilize the high strength and stiffness of cellulose nanofibrils in a macroscopic material or composite, the structure of the elongated fibrils in the material must be controlled.

scholarly journals Biomimetic Composites with Enhanced Toughening Using Silk Inspired Triblock Proteins and Aligned Nanocellulose Reinforcements

2019 ◽  
Author(s):  
Pezhman Mohammadi ◽  
A. Sesilja Aranko ◽  
Christopher P. Landowski ◽  
Olli Ikkala ◽  
Kristaps Jaudzems ◽  
...  
Keyword(s):  
Spider Silk ◽  
Cellulose Nanofibrils ◽  
High Strength ◽  
Beta Sheets ◽  
Conformational Switching ◽  
Multiple Length Scales ◽  
The Matrix ◽  
Strength And Stiffness ◽  
Flow Alignment

Silk and cellulose are biopolymers that show a high potential as future sustainable materials.They also have complementary properties, suitable for combination in composite materials where cellulose would form the reinforcing component and silk the tough matrix. Therein, a major challenge concerns balancing structure and properties in the assembly process. We used recombinant proteins with triblock architecture combining structurally modified spider silk with terminal cellulose affinity modules. Flow-alignment of cellulose nanofibrils and triblock protein allowed a continuous fiber production.The protein assembly involved phase separation into concentrated coacervates, with subsequent conformational switching from disordered structures to beta sheets. This gave the matrix a tough adhesiveness, forming a new composite material with high strength and stiffness combined with increased toughness. We show that versatile design possibilities in protein engineering enable new fully biological materials, and emphasize the key role of controlled assembly at multiple length scales for realization.<br>

scholarly journals A general aerosol-assisted biosynthesis of functional bulk nanocomposites

2018 ◽  
Vol 6 (1) ◽  
pp. 64-73 ◽  
Author(s):  
Qing-Fang Guan ◽  
Zi-Meng Han ◽  
Tong-Tong Luo ◽  
Huai-Bin Yang ◽  
Hai-Wei Liang ◽  
...  
Keyword(s):  
Electromagnetic Interference ◽  
Large Scale ◽  
Bulk Material ◽  
Cellulose Nanofibrils ◽  
High Strength ◽  
Building Blocks ◽  
Scale Production ◽  
Cellulose Nanofibril ◽  
Practical Applications ◽  
Wide Range

Abstract Although a variety of nanoparticles with better-than-bulk material performances can be synthesized, it remains a challenge to scale the extraordinary properties of individual nanoscale units to the macroscopic level for bulk nanostructured materials. Here, we report a general and scalable biosynthesis strategy that involves simultaneous growth of cellulose nanofibrils through microbial fermentation and co-deposition of various kinds of nanoscale building blocks (NBBs) through aerosol feeding on solid culture substrates. We employ this biosynthesis strategy to assemble a wide range of NBBs into cellulose nanofibril-based bulk nanocomposites. In particular, the biosynthesized carbon nanotubes/bacterial cellulose nanocomposites that consist of integrated 3D cellulose nanofibril networks simultaneously achieve an extremely high mechanical strength and electrical conductivity, and thus exhibit outstanding performance as high-strength lightweight electromagnetic interference shielding materials. The biosynthesis approach represents a general and efficient strategy for large-scale production of functional bulk nanocomposites with enhanced performances for practical applications. Industrial-scale production of these bulk nanocomposite materials for practical applications can be expected in the near future.

scholarly journals Biomimetic Composites with Enhanced Toughening Using Silk Inspired Triblock Proteins and Aligned Nanocellulose Reinforcements

2019 ◽  
Author(s):  
Pezhman Mohammadi ◽  
A. Sesilja Aranko ◽  
Christopher P. Landowski ◽  
Olli Ikkala ◽  
Wolfgang Wagermaier ◽  
...  
Keyword(s):  
Spider Silk ◽  
Cellulose Nanofibrils ◽  
High Strength ◽  
Beta Sheets ◽  
Conformational Switching ◽  
Multiple Length Scales ◽  
The Matrix ◽  
Strength And Stiffness ◽  
Flow Alignment

Silk and cellulose are biopolymers that show a high potential as future sustainable materials.They also have complementary properties, suitable for combination in composite materials where cellulose would form the reinforcing component and silk the tough matrix. Therein, a major challenge concerns balancing structure and properties in the assembly process. We used recombinant proteins with triblock architecture combining structurally modified spider silk with terminal cellulose affinity modules. Flow-alignment of cellulose nanofibrils and triblock protein allowed a continuous fiber production.The protein assembly involved phase separation into concentrated coacervates, with subsequent conformational switching from disordered structures to beta sheets. This gave the matrix a tough adhesiveness, forming a new composite material with high strength and stiffness combined with increased toughness. We show that versatile design possibilities in protein engineering enable new fully biological materials, and emphasize the key role of controlled assembly at multiple length scales for realization.

scholarly journals Biomimetic Composites with Enhanced Toughening Using Silk Inspired Triblock Proteins and Aligned Nanocellulose Reinforcements

2019 ◽  
Author(s):  
Pezhman Mohammadi ◽  
A. Sesilja Aranko ◽  
Christopher P. Landowski ◽  
Olli Ikkala ◽  
Wolfgang Wagermaier ◽  
...  
Keyword(s):  
Spider Silk ◽  
Cellulose Nanofibrils ◽  
High Strength ◽  
Beta Sheets ◽  
Conformational Switching ◽  
Multiple Length Scales ◽  
The Matrix ◽  
Strength And Stiffness ◽  
Flow Alignment

Silk and cellulose are biopolymers that show a high potential as future sustainable materials.They also have complementary properties, suitable for combination in composite materials where cellulose would form the reinforcing component and silk the tough matrix. Therein, a major challenge concerns balancing structure and properties in the assembly process. We used recombinant proteins with triblock architecture combining structurally modified spider silk with terminal cellulose affinity modules. Flow-alignment of cellulose nanofibrils and triblock protein allowed a continuous fiber production.The protein assembly involved phase separation into concentrated coacervates, with subsequent conformational switching from disordered structures to beta sheets. This gave the matrix a tough adhesiveness, forming a new composite material with high strength and stiffness combined with increased toughness. We show that versatile design possibilities in protein engineering enable new fully biological materials, and emphasize the key role of controlled assembly at multiple length scales for realization.

Determination of Winding Tension in Manufacturing Strip Wound Die

2010 ◽  
Vol 97-101 ◽  
pp. 162-165 ◽  
Author(s):  
Qiang Wang ◽  
Xiao Li Lai ◽  
Xiu Sheng Chen ◽  
Dong Mei Cai
Keyword(s):  
Working Condition ◽  
Yield Criterion ◽  
High Strength ◽  
Steel Strips ◽  
Manufacture Process ◽  
Die Materials ◽  
Die Material ◽  
Strength And Stiffness ◽  
Winding Tension

The strip wound die, which is characterized by significant improvement in strength and stiffness over the conventional compound die with several layers of stress rings, is prestressed by the thin high-strength steel strips. The performance of the strip wound die is determined mainly by the winding tension during manufacture process. In this paper, the stress analysis of die body is conducted based on Lamé’s equation. Two kinds of die materials are analyzed based on strength theory in order to establish the required contact pressure in working condition which keeps the die material within the safety range. The number of winding layers can be determined by considering the strength of strip in working condition. The analytical method and the equations to determine the winding tension have been presented by following yield criterion, Euler’s equation and iso-strength principle.

scholarly journals Biomimetic composites with enhanced toughening using silk-inspired triblock proteins and aligned nanocellulose reinforcements

2019 ◽  
Vol 5 (9) ◽  
pp. eaaw2541 ◽  
Author(s):  
Pezhman Mohammadi ◽  
A. Sesilja Aranko ◽  
Christopher P. Landowski ◽  
Olli Ikkala ◽  
Kristaps Jaudzems ◽  
...  
Keyword(s):  
Spider Silk ◽  
Cellulose Nanofibrils ◽  
High Strength ◽  
Conformational Switching ◽  
Multiple Length Scales ◽  
The Matrix ◽  
Sustainable Materials ◽  
Strength And Stiffness ◽  
Flow Alignment

Silk and cellulose are biopolymers that show strong potential as future sustainable materials. They also have complementary properties, suitable for combination in composite materials where cellulose would form the reinforcing component and silk the tough matrix. A major challenge concerns balancing structure and functional properties in the assembly process. We used recombinant proteins with triblock architecture, combining structurally modified spider silk with terminal cellulose affinity modules. Flow alignment of cellulose nanofibrils and triblock protein allowed continuous fiber production. Protein assembly involved phase separation into concentrated coacervates, with subsequent conformational switching from disordered structures into β sheets. This process gave the matrix a tough adhesiveness, forming a new composite material with high strength and stiffness combined with increased toughness. We show that versatile design possibilities in protein engineering enable new fully biological materials and emphasize the key role of controlled assembly at multiple length scales for realization.

Bestimmung der Dauerhaftigkeit von Hochleistungsbeton mit Hilfe des CDF-Tests / Determination of the durability of high performance concrete by means of CDF-test

1999 ◽  
Vol 5 (1) ◽  
pp. 29-40
Author(s):  
R. Krumbach ◽  
U. Schmelter ◽  
K. Seyfarth
Keyword(s):  
Frost Resistance ◽  
High Strength Concrete ◽  
High Performance ◽  
High Performance Concrete ◽  
High Strength ◽  
Strength Concrete ◽  
Factors Influencing

Abstract Variable obsen>ations concerning frost resistance of high performance concrete have been made. The question arises which are the decisive factors influencing durability under the action of frost and de-icing salt. The proposed experiments are to be carried out in cooperation with F.A.- Finger - Institute of Bauhaus University Weimar. The aim of this study is to determine possible change of durability of high strength concrete, and to investigate the origin thereof. Measures to reduce the risk of reduced durability have to be found.

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