Universal behaviour in the mechanical properties of weakly aggregated colloidal particles

Soft Matter ◽  
2009 ◽  
Vol 5 (12) ◽  
pp. 2438 ◽  
Author(s):  
Stephen W. Kamp ◽  
Maria L. Kilfoil
Keyword(s):  
Mechanical Properties ◽  
Colloidal Particles ◽  
Universal Behaviour

The mechanical properties of polymer–colloid hybrid hydrogels

Soft Matter ◽  
2017 ◽  
Vol 13 (27) ◽  
pp. 4786-4790 ◽  
Author(s):  
H. Dehne ◽  
F. M. Hecht ◽  
A. R. Bausch
Keyword(s):  
Mechanical Properties ◽  
Functional Properties ◽  
Colloidal Particles ◽  
Hybrid Gels ◽  
Hybrid Hydrogels ◽  
Polymer Colloid

The incorporation of monodisperse colloidal particles in hydrogels is a promising approach to create hybrid gels with unique structural, mechanical and functional properties.

Theory and Simulation of Polymers at Interfaces

MRS Bulletin ◽  
1997 ◽  
Vol 22 (1) ◽  
pp. 13-15 ◽  
Author(s):  
Anna C. Balazs
Keyword(s):  
Mechanical Properties ◽  
Polymer Films ◽  
Colloidal Particles ◽  
Structural Integrity ◽  
Solid Surfaces ◽  
Polymer Layer ◽  
Polymer Interfaces ◽  
New Materials ◽  
Immiscible Polymers ◽  
The Individual

The articles in this issue illustrate how various theoretical and computer models have been used to probe behavior of polymers at penetrable and impenetrable interfaces. Interest in polymer interfaces stems from the control interfaces commonly have over macroscopic properties—such as the strength or biocompatibility of the material. Consider the “alloying” or blending of existing polymers. This technique provides an inexpensive means of fabricating new materials that can display the desirable properties of the individual components. Most polymer pairs however are immiscible, and the mixture segregates into macroscopic domains separated by relatively weak interfaces. To enhance the structural integrity of the blend, copolymer “compatibilizers” are added to the mixture. These chains localize at the interface between the immiscible polymers, enhance the adhesion between the phase-separated regions, and thereby improve the mechanical properties of the blend.On an impenetrable interface, polymer films or coatings are commonly used to modify the properties of the underlying substrate. For example the polymer layer can be utilized to tailor biocompatibility, wettability, or roughness of the surface. Polymers anchored to solid surfaces can also be used to control the interaction between these surfaces. Thus the tethered layer can promote the adhesion between dissimilar solids or prevent the aggregation of colloidal particles.

scholarly journals Carbonaceous Materials Coated Carbon Fibre Reinforced Polymer Matrix Composites

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2771 ◽  
Author(s):  
Bidita Salahuddin ◽  
Shaikh N. Faisal ◽  
Tajwar A. Baigh ◽  
Mohammed N. Alghamdi ◽  
Mohammad S. Islam ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Fibre ◽  
Colloidal Particles ◽  
Polymer Matrix Composites ◽  
Matrix Material ◽  
Fibre Surface ◽  
Coating Materials ◽  
Reinforced Polymer ◽  
Carbon Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer

Carbon fibre reinforced polymer composites have high mechanical properties that make them exemplary engineered materials to carry loads and stresses. Coupling fibre and matrix together require good understanding of not only fibre morphology but also matrix rheology. One way of having a strongly coupled fibre and matrix interface is to size the reinforcing fibres by means of micro- or nanocarbon materials coating on the fibre surface. Common coating materials used are carbon nanotubes and nanofibres and graphene, and more recently carbon black (colloidal particles of virtually pure elemental carbon) and graphite. There are several chemical, thermal, and electrochemical processes that are used for coating the carbonous materials onto a carbon fibre surface. Sizing of fibres provides higher interfacial adhesion between fibre and matrix and allows better fibre wetting by the surrounded matrix material. This review paper goes over numerous techniques that are used for engineering the interface between both fibre and matrix systems, which is eventually the key to better mechanical properties of the composite systems.

scholarly journals Probing cellular response to topography in three dimensions

2017 ◽  
Author(s):  
Colin D. Paul ◽  
Alex Hruska ◽  
Jack R. Staunton ◽  
Hannah A. Burr ◽  
Kathryn M. Daly ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cellular Response ◽  
Colloidal Particles ◽  
Myosin Ii ◽  
Tissue Mechanics ◽  
Three Dimensions ◽  
Cell Alignment ◽  
Ecm Proteins ◽  
Aligned Fibers

ABSTRACTBiophysical aspects of in vivo tissue microenvironments include microscale mechanical properties, fibrillar alignment, and architecture or topography of the extracellular matrix (ECM). These aspects act in concert with chemical signals from a myriad of diverse ECM proteins to provide cues that drive cellular responses. Here, we used a bottom-up approach to build fibrillar architecture into 3D amorphous hydrogels using magnetic-field driven assembly of paramagnetic colloidal particles functionalized with three types of human ECM proteins found in vivo. We investigated if cells cultured in matrices comprised of fibrils of the same size and arranged in similar geometries will show similar behavior for each of the ECM proteins tested. We were able to resolve spatial heterogeneities in microscale mechanical properties near aligned fibers that were not observed in bulk tissue mechanics. We then used this platform to examine factors contributing to cell alignment in response to topographical cues in 3D laminin-rich matrices. Multiple human cell lines extended protrusions preferentially in directions parallel or perpendicular to aligned fibers independently of the ECM coating. Focal adhesion proteins, as measured by paxillin localization, were mainly diffuse in the cytoplasm, with few puncta localized at the protrusions. Integrin β1 and fascin regulated protrusion extension but not protrusion alignment. Myosin II inhibition did not reduce observed protrusion length. Instead, cells with reduced myosin II activity generated protrusions in random orientations when cultured in hydrogels with aligned fibers. Similarly, myosin II dependence was observed in vivo, where cells no longer aligned along the abluminal surfaces of blood vessels upon treatment with blebbistatin. These data suggest that myosin II can regulate sensing of topography in 3D engineered matrices for both normal and transformed cells.

Phase Transformations in Ti-7w/oMo-3w/oMe Alloy

1974 ◽  
Vol 32 ◽  
pp. 514-515
Author(s):  
S. Fujishiro
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Transmission Electron Microscopy ◽  
Tensile Strength ◽  
Mechanical Processing ◽  
Ray Method ◽  
X Ray ◽  
Transmission Electron ◽  
Water Quench ◽  
Alpha Beta

The mechanical properties of three titanium alloys (Ti-7Mo-3Al, Ti-7Mo- 3Cu and Ti-7Mo-3Ta) were evaluated as function of: 1) Solutionizing in the beta field and aging, 2) Thermal Mechanical Processing in the beta field and aging, 3) Solutionizing in the alpha + beta field and aging. The samples were isothermally aged in the temperature range 300° to 700*C for 4 to 24 hours, followed by a water quench. Transmission electron microscopy and X-ray method were used to identify the phase formed. All three alloys solutionized at 1050°C (beta field) transformed to martensitic alpha (alpha prime) upon being water quenched. Despite this heavily strained alpha prime, which is characterized by microtwins the tensile strength of the as-quenched alloys is relatively low and the elongation is as high as 30%.

Effects of cooling rate on the mechanical properties of dual phase treated vanadium steels

1983 ◽  
Vol 41 ◽  
pp. 220-221
Author(s):  
L.J. Chen ◽  
H.C. Cheng ◽  
J.R. Gong ◽  
J.G. Yang
Keyword(s):  
Mechanical Properties ◽  
Cooling Rate ◽  
Automobile Industry ◽  
High Strength ◽  
Weight Percent ◽  
Low Alloy Steels ◽  
Dual Phase ◽  
Resource Requirement ◽  
Alloy Steels ◽  
Potential Weight

For fuel savings as well as energy and resource requirement, high strength low alloy steels (HSLA) are of particular interest to automobile industry because of the potential weight reduction which can be achieved by using thinner section of these steels to carry the same load and thus to improve the fuel mileage. Dual phase treatment has been utilized to obtain superior strength and ductility combinations compared to the HSLA of identical composition. Recently, cooling rate following heat treatment was found to be important to the tensile properties of the dual phase steels. In this paper, we report the results of the investigation of cooling rate on the microstructures and mechanical properties of several vanadium HSLA steels.The steels with composition (in weight percent) listed below were supplied by China Steel Corporation: 1. low V steel (0.11C, 0.65Si, 1.63Mn, 0.015P, 0.008S, 0.084Aℓ, 0.004V), 2. 0.059V steel (0.13C, 0.62S1, 1.59Mn, 0.012P, 0.008S, 0.065Aℓ, 0.059V), 3. 0.10V steel (0.11C, 0.58Si, 1.58Mn, 0.017P, 0.008S, 0.068Aℓ, 0.10V).

Lattice Imaging of Grain Boundaries in Ceramics

1977 ◽  
Vol 35 ◽  
pp. 114-115
Author(s):  
D. R. Clarke ◽  
G. Thomas
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Silicon Nitride ◽  
Grain Boundaries ◽  
High Temperature Strength ◽  
Current Interest ◽  
Lattice Imaging ◽  
Special Significance ◽  
Structural Applications ◽  
Refractory Ceramics

Grain boundaries have long held a special significance to ceramicists. In part, this has been because it has been impossible until now to actually observe the boundaries themselves. Just as important, however, is the fact that the grain boundaries and their environs have a determing influence on both the mechanisms by which powder compaction occurs during fabrication, and on the overall mechanical properties of the material. One area where the grain boundary plays a particularly important role is in the high temperature strength of hot-pressed ceramics. This is a subject of current interest as extensive efforts are being made to develop ceramics, such as silicon nitride alloys, for high temperature structural applications. In this presentation we describe how the techniques of lattice fringe imaging have made it possible to study the grain boundaries in a number of refractory ceramics, and illustrate some of the findings.

Electron Microscopic Observation of the Longitudinal Organization of Poly (p-Phenylene Terephthalamide) Fibers

1982 ◽  
Vol 40 ◽  
pp. 680-681
Author(s):  
Li Li-Sheng ◽  
L.F. Allard ◽  
W.C. Bigelow
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Microscopic Observation ◽  
Electron Microscopic Observation ◽  
Electron Microscopic ◽  
Aromatic Polyamides ◽  
Radial Arrangement ◽  
Scanning Electron ◽  
Better Than

The aromatic polyamides form a class of fibers having mechanical properties which are much better than those of aliphatic polyamides. Currently, the accepted morphology of these fibers as proposed by M.G. Dobb, et al. is a radial arrangement of pleated sheets, with the plane of the pleats parallel to the axis of the fiber. We have recently obtained evidence which supports a different morphology of this type of fiber, using ultramicrotomy and ion-thinning techniques to prepare specimens for transmission and scanning electron microscopy.

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