scholarly journals Robust Silica-Cellulose Composite Aerogels with a Nanoscale Interpenetrating Network Structure Prepared Using a Streamlined Process

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 807
Author(s):  
Huazheng Sai ◽  
Jing Zhang ◽  
Zhiqiang Jin ◽  
Rui Fu ◽  
Meijuan Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Modulus ◽  
Silica Aerogels ◽  
Preparation Process ◽  
High Tensile Strength ◽  
Interpenetrating Network ◽  
The Matrix ◽  
Supercritical Co2 Drying ◽  
Composite Aerogels ◽  
Cellulose Composite

Silica aerogels can be strengthened by forming a nanoscale interpenetrating network (IPN) comprising a silica gel skeleton and a cellulose nanofiber network. Previous studies have demonstrated the effectiveness of this method for improving the mechanical properties and drying of aerogels. However, the preparation process is generally tedious and time-consuming. This study aims to streamline the preparation process of these composite aerogels. Silica alcosols were directly diffused into cellulose wet gels with loose, web-like microstructures, and an IPN structure was gradually formed by regulating the gelation rate. Supercritical CO2 drying followed to obtain composite aerogels. The mechanical properties were further enhanced by a simple secondary regulation process that increased the quantity of bacterial cellulose (BC) nanofibers per unit volume of the matrix. This led to the production of aerogels with excellent bendability and a high tensile strength. A maximum breaking stress and tensile modulus of 3.06 MPa and 46.07 MPa, respectively, were achieved. This method can be implemented to produce robust and bendable silica-based composite aerogels (CAs).

Cellulose nanofibril reinforced silica aerogels: optimization of the preparation process evaluated by a response surface methodology

RSC Advances ◽  
2016 ◽  
Vol 6 (102) ◽  
pp. 100326-100333 ◽  
Author(s):  
Jingjing Fu ◽  
Chunxia He ◽  
Jingda Huang ◽  
Zhilin Chen ◽  
Siqun Wang
Keyword(s):  
Mechanical Properties ◽  
Response Surface Methodology ◽  
Response Surface ◽  
Ambient Pressure ◽  
Silica Aerogels ◽  
Ambient Pressure Drying ◽  
Preparation Process ◽  
Cellulose Nanofibril ◽  
Drying Method ◽  
Composite Aerogels

CNF–silica composite aerogels with reinforced mechanical properties were prepared under an ambient pressure drying method and optimized by a response surface methodology.

Wear Resistance and Mechanical Properties of Polymeric Fibers Filled with Inorganic Fillers

2006 ◽  
Vol 977 ◽  
Author(s):  
Toshihira Irisawa ◽  
Masatoshi Shioya ◽  
Haruki Kobayashi ◽  
Junichi Kaneko
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Tensile Modulus ◽  
Nylon 6 ◽  
Polymeric Fibers ◽  
Poly Ethylene Terephthalate ◽  
The Matrix ◽  
Pet Fibers ◽  
Inorganic Fillers ◽  
Poly Ethylene

AbstractThe wear resistance and the mechanical properties of polymer matrix composite fibers filled with inorganic fillers have been investigated in order to find out the way to increase the wear resistance of the fibers without losing tensile modulus and strength. Nylon 6 and poly(ethylene terephthalate) have been used as the matrix polymer and aluminum borate whisker and carbon nanotube have been used as the fillers. The wear resistance of the fibers has been evaluated by observing the fiber cross section after the side of the fiber was worn using a rotating drum covered with abrasive paper. The wear resistance of the nylon 6 and PET fibers was increased by the addition of these fillers without the loss of tensile modulus and strength. The effects of the addition of the fillers on the wear resistance have been compared with the effects of stretching and heat treatment of the fibers.

Microstructures and Mechanical Properties of Welded Joints of Several High Tensile Strength Steel

2018 ◽  
Vol 941 ◽  
pp. 224-229
Author(s):  
Takahiro Izumi ◽  
Tatsuya Kobayashi ◽  
Ikuo Shohji ◽  
Hiroaki Miyanaga
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Weld Metal ◽  
Welded Joints ◽  
Welded Joint ◽  
Steel Plates ◽  
Fatigue Properties ◽  
High Tensile Strength ◽  
The Matrix ◽  
Microstructures And Mechanical Properties

Microstructures and mechanical properties of lap fillet welded joints of several high and ultra-high tensile strength steel by arc welding were investigated. Steel plates having tensile strength of 400 (SPH400W), 590 (SPC590Y, SPC590R), 980 (SPC980Y) and 1500 MPa (SAC1500HP) class with 2 mm thickness were prepared. Four types of joints were formed by MAG welding; SPH400W/SPH400W, SPC590Y/SPC590Y, SPC980Y/SPC980Y and SAC1500HP/SPC590R. In joints with SPC590Y, SPC980Y and SAC1500HP steel which matrixes are martensitic microstructures, the HAZ softens due to transformation of martensite into ferrite with precipitating cementite. By using high and ultra-high tensile strength steel, the weld metal is strengthened due to dilution of the matrix into the weld metal and thus tensile shear strength of the welded joint increases. In the fatigue test, similar S-N diagrams were obtained in the all welded joints investigated. It seems that the effect of stress concentration due to the shape of the welded joint on fatigue properties is larger than that of the strength of the matrix.

Effect of Preparation Process on Bending Modulus and Strength of Fiber Tubes in Radial Direction

2017 ◽  
Vol 726 ◽  
pp. 3-7
Author(s):  
Zhao Liu ◽  
Chun Lin Hu ◽  
Yi Wang Bao
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Radial Direction ◽  
Bending Strength ◽  
Potential Method ◽  
Preparation Process ◽  
Bending Modulus ◽  
Closed Ring ◽  
The Matrix ◽  
Ring Method

To explore the effects of preparation process on the mechanical properties of fiber reinforced tubes in radial direction, the closed ring method was applied to assess the elastic modulus and bending strength of GFRP and CFRP prepared by winding method and pultrusion method, respectively. The results indicate that there are two obvious differences between the winding tube and the pultrusion tube: i) the elastic modulus and bending strength of the winding tube for two materials are larger than that of the pultrusion tube. It should be attributed to the position of materials under stress: the former is the fibers while the latter is the matrix; ii) the failure mode for the winding tube is brittle fracture while elastic-plastic fracture is for the pultrusion tube. Compared with other experimental methods, the results of the closed ring method are accurate and reliable, which is demonstrated to be a potential method to evaluate the mechanical properties of fiber tubes in radial direction rapidly and conveniently.

scholarly journals Microstructure and Mechanical Properties of Heterogeneous Ceramic-Polymer Composite Using Interpenetrating Network

2012 ◽  
Vol 2012 ◽  
pp. 1-6
Author(s):  
Eun-Hee Kim ◽  
Yeon-Gil Jung ◽  
Chang-Yong Jo
Keyword(s):  
Mechanical Properties ◽  
Fracture Strength ◽  
Porous Alumina ◽  
Porous Ceramic ◽  
Crosslinking Density ◽  
Porous Matrix ◽  
Interpenetrating Network ◽  
Polyurethane Acrylate ◽  
The Matrix ◽  
Distribution Of Stress

Prepolymer, which can be polymerized by a photo, has been infiltrated into a porous ceramic to improve the addition effect of polymer into the ceramic, as a function of the functionality of prepolymer. It induces the increase in the mechanical properties of the ceramic. The porous alumina (Al2O3) and the polyurethane acrylate (PUA) with a network structure by photo-polymerization were used as the matrix and infiltration materials, respectively. The porous Al2O3matrix without the polymer shows lower values in fracture strength than the composites, since the stress is transmitted more quickly via propagation of cracks from intrinsic defects in the porous matrix. However, in the case of composites, the distribution of stress between heterophases results in the improved mechanical properties. In addition, the mechanical properties of composites, such as elastic modulus and fracture strength, are enhanced with increasing the functionality of prepolymer attributed to the crosslinking density of polymer.

scholarly journals Regulation of hard α-keratin mechanics via control of intermediate filament hydration: matrix squeeze revisited

2013 ◽  
Vol 280 (1750) ◽  
pp. 20122158 ◽  
Author(s):  
Daniel A. Greenberg ◽  
Douglas S. Fudge
Keyword(s):  
Mechanical Properties ◽  
Yield Stress ◽  
Critical Role ◽  
Tensile Modulus ◽  
Modulus Ratio ◽  
Swelling Behaviour ◽  
Highly Sensitive ◽  
The Matrix ◽  
High Matrix ◽  
And Function

Mammalian hard α-keratins are fibre-reinforced biomaterials that consist of 10 nm intermediate filaments (IFs) embedded in an elastomeric protein matrix. Recent work suggests that the mechanical properties of IFs are highly sensitive to hydration, whereas hard α-keratins such as wool, hair and nail are relatively hydration insensitive. This raises the question of how mammalian keratins remain stiff in water. The matrix squeeze hypothesis states that the IFs in hard α-keratins are stiffened during an air-drying step during keratinization, and subsequently locked into a dehydrated state via the oxidation and cross-linking of the keratin matrix around them. The result is that even when hard α-keratins are immersed in water, their constituent IFs remain essentially ‘dry’ and therefore stiff. This hypothesis makes several predictions about the effects of matrix abundance and function on hard α-keratin mechanics and swelling behaviour. Specifically, it predicts that high matrix keratins in water will swell less, and have a higher tensile modulus, a higher yield stress and a lower dry-to-wet modulus ratio. It also predicts that disruption of the keratin matrix in water should lead to additional swelling, and a drop in modulus and yield stress. Our results are consistent with these predictions and suggest that the keratin matrix plays a critical role in governing the mechanical properties of mammalian keratins via control of IF hydration.

Mechanical properties of unidirectional aligned bagasse fibers/vinyl ester composite

2016 ◽  
Vol 36 (2) ◽  
pp. 157-163 ◽  
Author(s):  
Ayyanar Athijayamani ◽  
Balasubramaniam Stalin ◽  
Susaiyappan Sidhardhan ◽  
Azeez Batcha Alavudeen
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Impact Strength ◽  
Vinyl Ester ◽  
Flexural Modulus ◽  
Tensile Modulus ◽  
Short Beam ◽  
Beam Shear ◽  
The Matrix ◽  
The Impact

Abstract The present study describes the preparation of aligned unidirectional bagasse fiber-reinforced vinyl ester (BFRVE) composites and their mechanical properties such as tensile, flexural, shear and impact strength. Composites were prepared by a hand lay-up technique developed in our laboratory with the help of a hot press. Mechanical properties were obtained for different fiber contents by varying the number of layers. The obtained tensile property values were compared with the theoretical results. The results show that the tensile strength increased linearly up to 44 wt% and then dropped. However, the tensile modulus increased linearly from 17 wt% to 60 wt%. In the case of flexural properties, the flexural strength increased up to 53 wt% and started to decrease. However, the flexural modulus also increased linearly up to 60 wt%. The impact strength values were higher than the matrix materials for all the specimens. The short beam shear strength values were also increased up to 53 wt% and then dropped. The modified Bowyer and Bader (MBB) model followed by the Hirsch model shows a very good agreement with experimental results in both tensile strength and modulus.

Mechanical Properties of Bamboo Charcoal (BC)/Poly(Lactic) Acid (PLA) Composites

2019 ◽  
Vol 801 ◽  
pp. 121-126
Author(s):  
Rapeeporn Srisuk ◽  
Laongdaw Techawinyutham ◽  
Wantana Koetniyom ◽  
Rapeephun Dangtungee
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Lactic Acid ◽  
Shear Viscosity ◽  
Tensile Modulus ◽  
Poly Lactic Acid ◽  
Bamboo Charcoal ◽  
Elongation At Break ◽  
The Matrix

The influence of bamboo charcoal (BC) in Poly (lactic) acid (PLA) matrix as masterbatch was studied on mechanical 40:60, 50:50 and 60:40 of masterbatch. BC MBs were diluted at 1 phr, 3 phr, and 5 phr. BC showed even distribution in PLA matrix; however,, it decreased compatibility in the matrix. The infusion of BC in PLA matrix enhanced the tensile modulus; however, there was a reduction in the tensile strength and the elongation at break. It could also be ascertained that there is no signification difference in the hardness of BC/PLA composites compared with neat PLA. The addition of BC slightly decreased shear viscosity of the composites. The optimal BC content in the composites was found to be 2.82wt.% (5 phr 60:40).

Influence of Preparation Process on the Performance of Strain Hardening Cementitious Composite

2017 ◽  
Vol 898 ◽  
pp. 2050-2053
Author(s):  
Song Gao ◽  
Jian Lin Luo ◽  
Xian Mao Wang ◽  
Qiu Yi Li
Keyword(s):  
Mechanical Properties ◽  
Strain Hardening ◽  
Preparation Process ◽  
Fiber Distribution ◽  
Cementitious Composite ◽  
Important Method ◽  
Fresh State ◽  
The Matrix ◽  
Binder Ratio ◽  
Water Binder Ratio

The modification of matrix is an important method to improve the mechanical properties of strain hardening cementitious composite (SHCC). The influence of the properties of the matrix water binder ratio (W/B) and fresh state rheology on SHCC tensile behaviors are useful for the SHCC design. The W/B influences only on tensile strength, but not the stain capacity, if the fresh state workability remains uniform. On the other hand, the workability has a significant influence on SHCC strain capacity through its influence on the fiber distribution. Consequently, it is important to cast SHCC carefully and make sure the even fiber distribution to insure the bridging function and mechanical properties of SHCC.

Impact and Quasi-Static Mechanical Properties of a Carbon Fiber Reinforced Carbon Nanotube/Epoxy

2012 ◽  
Author(s):  
Mehran Tehrani ◽  
Ayoub Y. Boroujeni ◽  
Timothy B. Hartman ◽  
Thomas P. Haugh ◽  
Scott W. Case ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Fiber ◽  
Tensile Modulus ◽  
Fiber Reinforced ◽  
Reinforced Plastics ◽  
Structural Applications ◽  
The Matrix ◽  
Static Mechanical ◽  
Carbon Fiber Reinforced ◽  
Composite Energy

Carbon fiber reinforced plastics (CFRPs) possess superior in-plane mechanical properties and are widely used in structural applications. Altering the interphase of CFRPs could alleviate the shortcomings of their out-of-plane performance. In this work, the effects of adding multi-walled carbon nanotubes (MWCNTs) to the epoxy matrix of a CFRP are investigated. Two sets of CFRPs with matrices comprising MWCNTs/epoxy and neat epoxy, respectively, were fabricated. The tensile properties of the two systems, namely the stiffness, the ultimate strength, and the strain to failure were evaluated. The results of the tension tests showed slight changes on the on-axis (along the fiber) tensile modulus and strength of the carbon fiber reinforced epoxy/MWCNT compared to composites with no MWCNTs. The addition of MWCNTs to the matrix moderately increased the strain to failure of the composite. Energy absorption capabilities for the two sets of composites under an intermediate impact velocity (100 m.s−1) test were measured. The energy dissipation capacity of the CFRPs incorporating MWCNTs was higher by 17% compared to the reference CFRPs.

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