scholarly journals Ultrafine and High-Strength Silk Fibers Secreted by Bimolter Silkworms

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2537 ◽  
Author(s):  
Kaiyu Guo ◽  
Xiaolu Zhang ◽  
Zhaoming Dong ◽  
Yuhui Ni ◽  
Yuqing Chen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
High Strength ◽  
Silk Gland ◽  
X Ray Diffraction ◽  
Ultrafine Fibers ◽  
Silk Fibers ◽  
Warmth Retention ◽  
The Relationship ◽  
Β Sheet

Ultrafine fibers are widely employed because of their lightness, softness, and warmth retention. Although silkworm silk is one of the most applied natural silks, it is coarse and difficult to transform into ultrafine fibers. Thus, to obtain ultrafine high-performance silk fibers, we employed anti-juvenile hormones in this study to induce bimolter silkworms. We found that the bimolter cocoons were composed of densely packed thin fibers and small apertures, wherein the silk diameter was 54.9% less than that of trimolter silk. Further analysis revealed that the bimolter silk was cleaner and lighter than the control silk. In addition, it was stronger (739 MPa versus 497 MPa) and more stiffness (i.e., a higher Young’s modulus) than the trimolter silk. FTIR and X-ray diffraction results revealed that the excellent mechanical properties of bimolter silk can be attributed to the higher β-sheet content and crystallinity. Chitin staining of the anterior silk gland suggested that the lumen is narrower in bimolters, which may lead to the formation of greater numbers of β-sheet structures in the silk. Therefore, this study reveals the relationship between the structures and mechanical properties of bimolter silk and provides a valuable reference for producing high-strength and ultrafine silk fibers.

scholarly journals Basic Principles in the Design of Spider Silk Fibers

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1794
Author(s):  
José Pérez-Rigueiro ◽  
Manuel Elices ◽  
Gustavo R. Plaza ◽  
Gustavo V. Guinea
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
Spider Silk ◽  
Design Principles ◽  
Tensile Behavior ◽  
Original Design ◽  
Basic Principles ◽  
Silk Fibers ◽  
The Relationship ◽  
Selection Of

The prominence of spider silk as a hallmark in biomimetics relies not only on its unrivalled mechanical properties, but also on how these properties are the result of a set of original design principles. In this sense, the study of spider silk summarizes most of the main topics relevant to the field and, consequently, offers a nice example on how these topics could be considered in other biomimetic systems. This review is intended to present a selection of some of the essential design principles that underlie the singular microstructure of major ampullate gland silk, as well as to show how the interplay between them leads to the outstanding tensile behavior of spider silk. Following this rationale, the mechanical behavior of the material is analyzed in detail and connected with its main microstructural features, specifically with those derived from the semicrystalline organization of the fibers. Establishing the relationship between mechanical properties and microstructure in spider silk not only offers a vivid image of the paths explored by nature in the search for high performance materials, but is also a valuable guide for the development of new artificial fibers inspired in their natural counterparts.

Effect of Modified Phosphogypsum on the Mechanical Properties of Super Sulphate Cement

2012 ◽  
Vol 161 ◽  
pp. 264-268 ◽  
Author(s):  
Yu Xin Gao ◽  
Bao Ying Yu ◽  
Fen Lian Xu
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Compressive Strength ◽  
Chemical Composition ◽  
High Performance ◽  
High Strength ◽  
Strengthening Mechanisms ◽  
Particle Size Analyzer ◽  
Composition Analyzer ◽  
The Relationship

The effect of phosphogypsum (PG) modified on mechanical properties of super sulphate cement (SSC) was systematically studied in this paper. Then attentions and researches were focused on the relationship between specific surface (SSA) and the mechanical properties of SSC containing PG modified by calcining, floating, neutralizing with alkali. Strengthening mechanisms of SSC were further investigated and analyzed by laser particle size analyzer and chemical composition analyzer at last. Results showed that the high strength SSC with the compressive strength 35MPa at 7 days, over 60MPa at 28 days, and some even more than 70MPa at 56 days, could be successfully developed. This research can provide a key reference for the utilization of PG and development of high performance eco-SSC.

Effect of Stacking Fault Energy on the Mechanical Properties of Cold-Rolling Cu and Cu-Al-Zn Alloys

2011 ◽  
Vol 399-401 ◽  
pp. 708-712
Author(s):  
Lian Ping Cheng ◽  
Xiao Guang Liang ◽  
Xing Yuan San ◽  
Yu Lan Gong ◽  
Xin Kun Zhu
Keyword(s):  
Mechanical Properties ◽  
Cold Rolling ◽  
High Strength ◽  
Stacking Fault ◽  
Stacking Fault Energy ◽  
X Ray Diffraction ◽  
Peak Broadening ◽  
Energy Lowering ◽  
The Relationship ◽  
Zn Alloys

Sacking fault energy (SFE) plays a significant role for metals or alloys to getting high strength and expected ductility simultaneously. Here the effect of SFE variation on mechanical properties has been studied in cold-rolling Cu and Cu-Al-Zn alloys. Tensile testing results show that the strength and ductility of the materials increase simultaneously with decreasing SFE. X-ray diffraction measurements indicate the peak broadening for the crystallite size decreasing and the lattice strain increasing with the stacking fault energy lowering . The relationship between the microstructure and mechanical properties of the materials is briefly discussed in this paper.

scholarly journals Enhancement of Chloroprene/Natural/Butadiene Rubber Nanocomposite Properties Using Organoclays and Their Combination with Carbon Black as Fillers

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1085
Author(s):  
Patricia Castaño-Rivera ◽  
Isabel Calle-Holguín ◽  
Johanna Castaño ◽  
Gustavo Cabrera-Barjas ◽  
Karen Galvez-Garrido ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Black ◽  
High Performance ◽  
Rubber Matrix ◽  
Butadiene Rubber ◽  
X Ray Diffraction ◽  
X Ray ◽  
Rubber Blends ◽  
Ft Ir ◽  
Chloroprene Rubber

Organoclay nanoparticles (Cloisite® C10A, Cloisite® C15) and their combination with carbon black (N330) were studied as fillers in chloroprene/natural/butadiene rubber blends to prepare nanocomposites. The effect of filler type and load on the physical mechanical properties of nanocomposites was determined and correlated with its structure, compatibility and cure properties using Fourier Transformed Infrared (FT-IR), X-ray Diffraction (XRD), Thermogravimetric Analysis (TGA) and rheometric analysis. Physical mechanical properties were improved by organoclays at 5–7 phr. Nanocomposites with organoclays exhibited a remarkable increase up to 46% in abrasion resistance. The improvement in properties was attributed to good organoclay dispersion in the rubber matrix and to the compatibility between them and the chloroprene rubber. Carbon black at a 40 phr load was not the optimal concentration to interact with organoclays. The present study confirmed that organoclays can be a reinforcing filler for high performance applications in rubber nanocomposites.

Effect of Heat Setting Methods on Structures and Properties of High Strength Polyvinyl Alcohol Fibre

2015 ◽  
Vol 815 ◽  
pp. 643-648
Author(s):  
Yin Zhu ◽  
Jiong Xin Zhao
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Polyvinyl Alcohol ◽  
Setting Time ◽  
High Strength ◽  
Single Fibre ◽  
X Ray Diffraction ◽  
Heat Setting ◽  
Heat Treated ◽  
Setting Process

The effect of heat setting methods on the structures and mechanical properties of high strength polyvinyl alcohol (PVA) fibre is studied in this article. The microstructure and mechanical properties of heat treated PVA fibre is investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), and single fibre electronic tensile strength tester. Results show that the heat setting method with constant tension is a good heat setting method which can largely enhance the tensile strength of PVA fibre. During the heat setting process, the mechanical properties of PVA fibre are greatly affected by the temperature, tension and setting time. When the temperature is 220°C, tension is 5cN/dtex and setting time is 90sec, the tensile strength of PVA fibre increases from 12.0cN/dtex to 16.4cN/dtex in compare with the PVA fibre without heat setting

scholarly journals Effect of Locally Available Wheat Straw Ash in Developing High Strength Concrete

2021 ◽  
pp. 19-28
Author(s):  
Muhammad Armaghan Siffat ◽  
Muhammad Ishfaq ◽  
Afaq Ahmad ◽  
Khalil Ur Rehman ◽  
Fawad Ahmad
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Wheat Straw ◽  
High Strength Concrete ◽  
High Strength ◽  
Optimum Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Strength Concrete ◽  
Straw Ash

This study is supervised to assess the characteristics of the locally available wheat straw ash (WSA) to consume as a substitute to the cement and support in enhancing the mechanical properties of concrete. Initially, after incineration at optimum temperature of 800°C for 0.5, the ash of wheat straw was made up to the desirable level of fineness by passing through it to the several grinding cycles. Subsequently, the X-ray fluorescence (XRF) along with X-ray diffraction (XRD) testing conducted on ash of wheat straw for the evaluation its pozzolanic potential. Finally, the specimens of concrete were made by consuming 10% and 20% percentages of wheat straw ash as a replacement in concrete to conclude its impact on the compressive strength of high strength concrete. The cylinders of steel of dimensions 10cm diameter x 20cm depth were acquired to evaluate the compressive strength of high strength concrete. The relative outcomes of cylinders made of wheat straw ash substitution presented the slight increase in strength values of the concrete. Ultimately, the C-100 blends and WSA aided cement blends were inspected for the rheology of WSA through FTIR spectroscopy along with Thermogravimetric technique. The conclusions authenticate the WSA potential to replace cement in the manufacturing of the high strength concrete.

Investigation on the Stress Relaxation Aging Behavior of 2195 Al-Li Alloy

2021 ◽  
Vol 315 ◽  
pp. 37-42
Author(s):  
Hai Long Liao ◽  
Li Hua Zhan ◽  
Yuan Gao ◽  
Xue Ying Chen ◽  
Ming Hui Huang
Keyword(s):  
Mechanical Properties ◽  
Stress Relaxation ◽  
High Performance ◽  
Aging Process ◽  
Artificial Aging ◽  
Ageing Time ◽  
High Strength ◽  
Aging Behavior ◽  
Stress Corrosion Resistance ◽  
Scanning Electron

2195 Al-Li alloy is famous for high strength, excellent fatigue strength and good stress corrosion resistance, which is widely used in the manufacture of high-performance aerospace components. The aim of this study is to validate how the stress relaxation aging behavior effect on the mechanical properties of 2195 Al-Li alloy. Through mechanical property test, the research was found that the performance after stress relaxation aging is higher than artificial aging (AA). In addition, the analysis of scanning electron microscopy SEM and TEM revealed that dislocations should be introduced by the stress relaxation aging process, which is more conducive to the precipitation of the T1 phase and strengthened the material with prolong ageing time. The results show that stress relaxation aging can significantly promote the precipitation of the T1. Therefore, this paper sheds new light on how SRA can improve mechanical properties and that SRA make better improve the distribution of precipitates in the grain boundary.

scholarly journals Influence of Temperature on Mechanical Properties of P(BAMO-r-THF) Elastomer

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2507
Author(s):  
Jinxian Zhai ◽  
Hanpeng Zhao ◽  
Xiaoyan Guo ◽  
Xiaodong Li ◽  
Tinglu Song
Keyword(s):  
Mechanical Properties ◽  
X Ray Diffraction ◽  
Polymeric Chains ◽  
Different Temperatures ◽  
Influence Of Temperature On ◽  
Strain Induced Crystallization ◽  
Thermal Histories ◽  
Static Conditions ◽  
The Relationship ◽  
Induced Crystallization

The relationship between temperature and the mechanical properties of an end cross-linked equal molar random copolyether elastomer of 3,3-bis(azidomethyl)oxetane and tetrahydrofuran (P(BAMO-r-THF)) was investigated. During this investigation, the performances of two P(BAMO-r-THF) elastomers with different thermal histories were compared at different temperatures. The elastomer as prepared at 20 °C (denoted as S0) exhibited semi-crystallization morphology. Wide angle X-ray diffraction analysis indicated that the crystal grains within elastomer S0 result from the crystallization of BAMO micro-blocks embedded in P(BAMO-r-THF) polymeric chains, and the crystallinity is temperature irreversible under static conditions. After undergoing a heating-cooling cycle, this elastomer became an amorphous elastomer (denoted as S1). Regarding mechanical properties, at 20 °C, break strains and stresses of 315 ± 22% and 0.46 ± 0.01 MPa were obtained for elastomer S0; corresponding values of 294 ± 6% and 0.32 ± 0.02 MPa were obtained for elastomer S1. At −40 °C, these strains and stresses simultaneously increased to 1085 ± 21% and 8.90 ± 0.72 MPa (S0) and 1181 ± 25% and 10.23 ± 0.44 MPa (S1), respectively, owing to the strain-induced crystallization of BAMO micro-blocks within the P(BAMO-r-THF) polymeric chains.

Achieving high-performance epoxy nanocomposites with trifunctional poly(oxypropylene)amines functionalized graphene oxide

2019 ◽  
Vol 31 (5) ◽  
pp. 557-569 ◽  
Author(s):  
Tong Sun ◽  
Huawei Zou ◽  
Ya Zhou ◽  
Rui Li ◽  
Mei Liang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Graphene Oxide ◽  
High Performance ◽  
Flexural Modulus ◽  
Covalent Bonds ◽  
Spectra Analysis ◽  
Functionalized Graphene Oxide ◽  
Ep Matrix ◽  
Functional Graphene Oxide ◽  
The Relationship

In this article, two types of functional graphene oxide (GO) with amine-rich surface were synthesized through chemically grafting two different molecular chain length trifunctional poly(oxypropylene)amines T5000 and T403, which were named as T5000-GO and T403-GO, respectively. The functionalized GO was then added to epoxy (EP) resin. Fourier transform infrared spectra analysis confirmed successful chemical functionalization on GO. Both T403-GO and T5000-GO were tightly embedded in the EP, because the amine-rich surface of functionalized-GO could form covalent bonds with the EP matrix, thereby contributing to the enhancement of mechanical properties. Particularly, T5000-GO, which has longer grafting molecule chains, achieved better compatibility and dispersibility in the EP matrix, resulting in a better reinforcing efficiency in mechanical properties. For example, the T5000-GO/EP composites showed an incremental enhancement in tensile strength with increasing filler concentrations, whereas their T403-GO/EP counterparts failed to follow the same trend. Meanwhile, the T5000-GO/EP composites with only 0.1-wt% T5000-GO achieved a prominent increase in flexural strength (approximately 50%) and flexural modulus (approximately 26.8%), which were higher than those of T403-GO-filled counterparts. This work indicated that the compatibility and interphase between GO and EP could be designed by manipulating the length of grafting molecule chains, thereby providing a better understanding of the relationship between the structure and mechanical properties of the graphene/EP nanocomposites.

scholarly journals Isotropic microscale mechanical properties of coral skeletons

2015 ◽  
Vol 12 (106) ◽  
pp. 20150168 ◽  
Author(s):  
Luca Pasquini ◽  
Alan Molinari ◽  
Paola Fantazzini ◽  
Yannicke Dauphen ◽  
Jean-Pierre Cuif ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Nacreous Layer ◽  
X Ray Diffraction ◽  
Stylophora Pistillata ◽  
Force Microscopy ◽  
Coral Skeletons ◽  
Atomic Force ◽  
Diffraction Patterns ◽  
The Relationship ◽  
Atrina Rigida

Scleractinian corals are a major source of biogenic calcium carbonate, yet the relationship between their skeletal microstructure and mechanical properties has been scarcely studied. In this work, the skeletons of two coral species: solitary Balanophyllia europaea and colonial Stylophora pistillata , were investigated by nanoindentation. The hardness H IT and Young's modulus E IT were determined from the analysis of several load–depth data on two perpendicular sections of the skeletons: longitudinal (parallel to the main growth axis) and transverse. Within the experimental and statistical uncertainty, the average values of the mechanical parameters are independent on the section's orientation. The hydration state of the skeletons did not affect the mechanical properties. The measured values, E IT in the 76–77 GPa range, and H IT in the 4.9–5.1 GPa range, are close to the ones expected for polycrystalline pure aragonite. Notably, a small difference in H IT is observed between the species. Different from corals, single-crystal aragonite and the nacreous layer of the seashell Atrina rigida exhibit clearly orientation-dependent mechanical properties. The homogeneous and isotropic mechanical behaviour of the coral skeletons at the microscale is correlated with the microstructure, observed by electron microscopy and atomic force microscopy, and with the X-ray diffraction patterns of the longitudinal and transverse sections.

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