Mechanical and Structural Properties of Maltodextrin/Agarose Gel Composites

2006 ◽  
Vol 16 (5) ◽  
pp. 248-257 ◽  
Author(s):  
Chrystel Loret ◽  
William J. Frith ◽  
Peter J. Fryer
Keyword(s):  
Mechanical Properties ◽  
Phase Separation ◽  
Confocal Microscopy ◽  
Large Deformation ◽  
Mechanical Behaviour ◽  
Composite Structure ◽  
Volume Fraction ◽  
Dispersed Phase ◽  
Agarose Gel ◽  
Mechanical And Structural Properties

Abstract When two biopolymers are mixed together, they will normally phase separate to give two distinct phases. If the biopolymers are gelled during this phase separation, for instance by reducing the temperature, one phase is trapped in this other one and an emulsion-like composite structure is obtained. In this study, we investigated the effect of volume fraction and droplet size of this dispersed phase on the mechanical properties of maltodextrin/agarose gel composites, where agarose is the dispersed phase. Mechanical properties of the different composites were investigated under large deformation using a rheometer with a vane geometry. These composites were also observed by confocal microscopy, allowing conclusions to be drawn regarding the microstructural origins of the observed mechanical behaviour.

On Crystallographic Texture of As-Drawn Doped-W Wires

2005 ◽  
Vol 495-497 ◽  
pp. 913-918 ◽  
Author(s):  
S.K. Yerra ◽  
Bert Verlinden ◽  
Paul van Houtte
Keyword(s):  
Mechanical Properties ◽  
Mechanical Behaviour ◽  
Crystallographic Texture ◽  
Deformation Zone ◽  
Room Temperature ◽  
Volume Fraction ◽  
Wire Diameter ◽  
Texture Characteristics ◽  
The Wire ◽  
Textural Changes

Industrially processed doped-tungsten wires in the as-drawn condition have essentially a <110>-fibre texture with attractive mechanical properties. The main objectives of the present work are to investigate (I) if any textural changes occur as the wire diameter decreases and (II) if such changes influence the mechanical behaviour of the wire. A wire of about ∅1.5mm is drawn to about ∅0.15mm following a standard industrial route and samples were collected from five intermediate drawing passes. Bulk texture measurements using X-radiations were then carried on the transverse sections of the wires and texture characteristics such as volume fraction of textural components and sharpness index were quantified with respect to the wire diameter. It was observed that the texture in the as-drawn wires remains chiefly the same <110>-fibre as the wire diameter decreases. However, the sharpness of texture reaches a maximum at a certain diameter and decreases with further decrease in the wire diameter. An explanation is offered based on the concept of deformation zone geometry. An attempt was also made to determine if texture weakening has any effect on the mechanical properties of the wire at room temperature.

scholarly journals The High Density Polyethylene Composite with Recycled Radiation Cross-Linked Filler of rHDPEx

Polymers ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1361 ◽  
Author(s):  
David Manas ◽  
Miroslav Manas ◽  
Ales Mizera ◽  
Pavel Stoklasek ◽  
Jan Navratil ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Behaviour ◽  
Composite Structure ◽  
High Density Polyethylene ◽  
Industrial Waste ◽  
Room Temperature ◽  
High Density ◽  
Polyethylene Composite ◽  
Processing Properties ◽  
Better Than

This article discusses the possibilities of using radiation cross-linked high density polyethylene (HDPEx) acting as a filler in the original high density polyethylene (HDPE) matrix. The newly created composite is one of the possible answers to questions relating to the processing of radiation cross-linked thermoplastics. Radiation cross-linked networking is—nowadays, a commonly used technology that can significantly modify the properties of many types of thermoplastics. This paper describes the influence of the concentration of filler, in the form of grit or powder obtained by the grinding/milling of products/industrial waste from radiation cross-linked high density polyethylene (rHDPEx) on the mechanical and processing properties and the composite structure. It was determined that, by varying the concentration of the filler, it is possible to influence the mechanical behaviour of the composite. The mechanical properties of the new composite—measured at room temperature, are generally comparable or better than the same properties of the original thermoplastic. This creates very good assumptions for the effective and economically acceptable, processing of high density polyethylene (rHDPEx) waste. Its processability however, is limited; it can be processed by injection moulding up to 60 wt %.

The Effect of Nano-Sized Air Bubbles on the Mechanical Properties and Natural Frequencies of a Multi-Cracked Composite Bar

2017 ◽  
Vol 30 ◽  
pp. 65-84 ◽  
Author(s):  
Ahmad Al-Maharma ◽  
Naser Al-Huniti
Keyword(s):  
Mechanical Properties ◽  
Epoxy Resin ◽  
Composite Structure ◽  
Hybrid Composite ◽  
Composite Structures ◽  
Natural Frequencies ◽  
Volume Fraction ◽  
Multiple Cracks ◽  
Air Bubbles ◽  
The Impact

In this research, the effect of nanosized air bubbles embedded within carbon nanotubes (CNTs) coated by various thicknesses of alumina (Al2O3) reinforced epoxy resin based composite on the natural frequencies of a multi-cracked bar is investigated in details. The impact of cracks’ locations and depths within the hybrid composite structure on the natural frequency profiles is investigated. The volume fraction of CNTs is fixed to 0.5 wt. % due to the significant improvements reported in the literature when the composite is reinforced with this volume fraction of CNTs. The results of the multi-scale finite element analysis are verified by comparing with previous studies and a good agreement is shown relating to the longitudinal natural frequencies. The results of the research show that the dynamic response of cracked bar is highly sensitive to the volume fractions of nanosized air bubbles located within the composite. The results of the study supported the hypothesis that the nanosized air bubbles can be used to reduce the weight of heavy composite structures along with using of suitable coatings to improve the mechanical properties of the hybrid composite. Furthermore. The results of the study can be employed to detect multiple cracks located within similar structures like wind turbine blade (WTB) fabricated from a hybrid composite structure composed of carbon fiber reinforced modified epoxy resin which contains nanosized air bubbles and CNTs nanofillers coated by Al2O3 at different thicknesses.

Mechanical and Structural Properties of Maltodextrin/Agarose Microgels Composites

2007 ◽  
Vol 17 (3) ◽  
pp. 31412-1-31412-13 ◽  
Author(s):  
Chrystel Loret ◽  
William J. Frith ◽  
Peter J. Fryer
Keyword(s):  
Mechanical Properties ◽  
Droplet Size ◽  
Dispersed Phase ◽  
Phase Volume ◽  
Reinforcement Effect ◽  
Modulus Ratio ◽  
New Approach ◽  
Mechanical And Structural Properties ◽  
Observed Behaviour ◽  
Composite Properties

Abstract We present results from a new approach to the study of multicomponent gels, which allows independent investigation of the effect of phase volume and droplet size of the dispersed phase on the mechanical properties of the mixed gel composites. The method involves preparation of agarose microgels with different sizes, which are then embedded in maltodextrin gel matrices with different gel strengths. The effects of both phase volume and droplet size on composite properties are dependent on the phase modulus ratio. The higher the phase modulus ratio, the larger is the reinforcement effect and the effect of droplet size on mechanical properties of the maltodextrin/agarose composites. The observed behaviour was compared with literature models for the behaviour of composite materials.

scholarly journals Mechanical Behaviour of Nickel Aluminide Reinforced Alumina (AL2O3-NiAl) Composites

2002 ◽  
Vol 11 (6) ◽  
pp. 096369350201100 ◽  
Author(s):  
I. J. Davies ◽  
G. Pezzotti ◽  
A. Bellosi ◽  
D. Sciti ◽  
S. Guicciardi
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Grain Size ◽  
Flexural Strength ◽  
Mechanical Behaviour ◽  
Nickel Aluminide ◽  
Volume Fraction ◽  
Matrix Composites ◽  
Microstructure And Mechanical Properties ◽  
The Mean

The microstructure and mechanical properties of hot-pressed alumina (Al2O3) matrix composites containing 20, 35, or 50 vol% of nickel aluminide (NiAl) were investigated. The mean Al2O3 grain size was found to decrease from approximately 2.0 μm (monolithic Al2O3) to 1.0 μm for the composite containing 50 vol% NiAl. Composite flexural strength values were lower than both the monolithic Al2O3 and NiAl and attributed to the weakly bonded NiAl particles acting as flaw origins. In contrast to this, the fracture toughness increased with NiAl volume fraction to a maximum of 4.90 MPa·m1/2, thus confirming the toughening effect of NiAl addition on Al2O3 ceramics, with the slope of the rising R-curve for the composite being approximately 8 times that of monolithic Al2O3.

scholarly journals Mechanical Behaviour of Multifunctional Epoxy/Hollow Glass Microspheres/Paraffin Microcapsules Syntactic Foams for Thermal Management

Polymers ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 2896
Author(s):  
Francesco Galvagnini ◽  
Giulia Fredi ◽  
Andrea Dorigato ◽  
Luca Fambri ◽  
Alessandro Pegoretti
Keyword(s):  
Mechanical Properties ◽  
Thermal Management ◽  
Mechanical Behaviour ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Hollow Glass Microsphere ◽  
Automotive Electronics ◽  
Syntactic Foams ◽  
Particle Volume ◽  
Hollow Glass

Epoxy/hollow glass microsphere (HGM) syntactic foams (SFs) are peculiar materials developed to combine low density, low thermal conductivity, and elevated mechanical properties. In this work, multifunctional SFs endowed with both structural and thermal management properties were produced for the first time, by combining an epoxy matrix with HGM and a microencapsulated phase change material (PCM) having a melting temperature of 43 °C. Systems with a total filler content (HGM + PCM) up to 40 vol% were prepared and characterized from the mechanical point of view with a broad experimental campaign comprising quasi-static, impact, and fracture toughness tests. The experimental results were statistically treated and fitted with a linear model, to produce ternary phase diagrams to provide a comprehensive interpretation of the mechanical behaviour of the prepared foams. In quasi-static tests, HGM introduction helps to retain the specific tensile elastic modulus and to increase the specific compressive modulus. The brittle nature of HGMs decreases the Charpy impact properties of the SFs, while the PCM insertion improve their toughness. This result is confirmed in KIC and GIC tests, where the composition with 20 vol% of PCM shows an increase of 80% and 370% in KIC and GIC in to neat epoxy, respectively. The most promising compositions are those combining PCM and HGMs with a total particle volume fraction up to 40 vol%, thanks to their optimal combination of thermal management capability, lightness, thermal insulation, and mechanical properties. The ability to fine-tune the properties of the SFs, together with the acquired thermal energy storage (TES) capability, confirm the great potential of these multifunctional materials in automotive, electronics, and aerospace industries.

Macroprobe Mode for the Study of Segregation in Steels

1990 ◽  
Vol 48 (2) ◽  
pp. 260-261
Author(s):  
Auclair Gilles ◽  
Benoit Danièle
Keyword(s):  
Mechanical Properties ◽  
Spatial Distribution ◽  
High Performance ◽  
Volume Fraction ◽  
Sheet Steel ◽  
Acquisition Time ◽  
Chemical Information ◽  
X Ray ◽  
Accurate Quantitative Analysis ◽  
Optical Micrographs

During these last 10 years, high performance correction procedures have been developed for classical EPMA, and it is nowadays possible to obtain accurate quantitative analysis even for soft X-ray radiations. It is also possible to perform EPMA by adapting this accurate quantitative procedures to unusual applications such as the measurement of the segregation on wide areas in as-cast and sheet steel products.The main objection for analysis of segregation in steel by means of a line-scan mode is that it requires a very heavy sampling plan to make sure that the most significant points are analyzed. Moreover only local chemical information is obtained whereas mechanical properties are also dependant on the volume fraction and the spatial distribution of highly segregated zones. For these reasons we have chosen to systematically acquire X-ray calibrated mappings which give pictures similar to optical micrographs. Although mapping requires lengthy acquisition time there is a corresponding increase in the information given by image anlysis.

Porous Gel Coatings Obtained by Phase Separation in ORMOSIL System

2000 ◽  
Vol 628 ◽  
Author(s):  
Kazuki Nakanishi ◽  
Souichi Kumon ◽  
Kazuyuki Hirao ◽  
Hiroshi Jinnai
Keyword(s):  
Phase Separation ◽  
Reaction Time ◽  
Volume Fraction ◽  
Sol Gel ◽  
Reaction Times ◽  
Dip Coating ◽  
Coating Solution ◽  
Coating Method ◽  
Gel Phase ◽  
Dip Coating Method

ABSTRACTMacroporous silicate thick films were prepared by a sol-gel dip-coating method accompanied by the phase separation using methyl-trimethoxysilane (MTMS), nitric acid and dimethylformamide (DMF) as starting components. The morphology of the film varied to a large extent depending on the time elapsed after the hydrolysis until the dipping of the coating solution. On a glass substrate, the films prepared by early dipping had inhomogeneous submicrometer-sized pores on the surface of the film. At increased reaction times, relatively narrow sized isolated macropores were observed and their size gradually decreased with the increase of reaction time. On a polyester substrate, in contrast, micrometer-sized isolated spherical gel domains were homogeneously deposited by earlier dippings. With an increase of reaction time, the volume fraction of the gel phase increased, then the morphology of the coating transformed into co-continuous gel domains and macropores, and finally inverted into the continuous gel domains with isolated macropores. The overall morphological variation with the reaction time was explained in terms of the phase separation and the structure freezing by the forced gelation, both of which were induced by the evaporation of methanol during the dipping operation.

Sign in / Sign up

Export Citation Format

Share Document