There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

This critical review provides a processing-structure-property perspective on recent advances in cellulose nanoparticles and composites produced from them. It summarizes cellulose nanoparticles in terms of particle morphology, crystal structure, and properties. Also described are the self-assembly and rheological properties of cellulose nanoparticle suspensions. The methodology of composite processing and resulting properties are fully covered, with an emphasis on neat and high fraction cellulose composites. Additionally, advances in predictive modeling from molecular dynamic simulations of crystalline cellulose to the continuum modeling of composites made with such particles are reviewed (392 references).

/pdf/cellulose-nanomaterials-review-structure-properties-and-2z8x922p3v.pdf

Cellulose nanomaterials review: structure, properties and nanocomposites

The Young's modulus, strength, and toughness of nanostructures are important to proposed applications ranging from nanocomposites to probe microscopy, yet there is little direct knowledge of these key mechanical properties. Atomic force microscopy was used to determine the mechanical properties of individual, structurally isolated silicon carbide (SiC) nanorods (NRs) and multiwall carbon nanotubes (MWNTs) that were pinned at one end to molybdenum disulfide surfaces. The bending force was measured versus displacement along the unpinned lengths. The MWNTs were about two times as stiff as the SiC NRs. Continued bending of the SiC NRs ultimately led to fracture, whereas the MWNTs exhibited an interesting elastic buckling process. The strengths of the SiC NRs were substantially greater than those found previously for larger SiC structures, and they approach theoretical values. Because of buckling, the ultimate strengths of the stiffer MWNTs were less than those of the SiC NRs, although the MWNTs represent a uniquely tough, energy-absorbing material.

http://science.sciencemag.org/content/sci/277/5334/1971.full.pdf

Nanobeam mechanics: Elasticity, strength, and toughness of nanorods and nanotubes

http://www.uniroma2.it/didattica/tbs2/deposito/Manufacture,_characterisation_and_application_of_cellular_metals_and_metal_foams.pdf

Manufacture, characterisation and application of cellular metals and metal foams

We have used the pH-induced self-assembly of a peptide-amphiphile to make a nanostructured fibrous scaffold reminiscent of extracellular matrix. The design of this peptide-amphiphile allows the nanofibers to be reversibly cross-linked to enhance or decrease their structural integrity. After cross-linking, the fibers are able to direct mineralization of hydroxyapatite to form a composite material in which the crystallographic c axes of hydroxyapatite are aligned with the long axes of the fibers. This alignment is the same as that observed between collagen fibrils and hydroxyapatite crystals in bone.

http://science.sciencemag.org/content/sci/294/5547/1684.full.pdf

Self-assembly and mineralization of peptide-amphiphile nanofibers

This fully expanded and updated edition provides both scientists and engineers with all the information they need to understand composite materials, covering their underlying science and technological usage It includes four completely new chapters on surface coatings, highly porous materials, bio-composites and nano-composites, as well as thoroughly revised chapters on fibres and matrices, the design, fabrication and production of composites, mechanical and thermal properties, and industry applications Extensively expanded referencing engages readers with the latest research and industrial developments in the field, and increased coverage of essential background science makes this a valuable self-contained text A comprehensive set of homework questions, with model answers available online, explains how calculations associated with the properties of composite materials should be tackled, and educational software accompanying the book is available online An invaluable text for final-year undergraduates in materials science and engineering, and graduate students and researchers in academia and industry

An Introduction to Composite Materials

Preface 1. General introduction 2. Basic composite models 3. The Eshelby approach to modelling composites 4. Plastic deformation 5. Thermal effects and high temperature behaviour 6. The interfacial region 7. Fracture processes and failure mechanisms 8. Transport properties and environmental performance 9. Fabrication processes 10. Development of matrix microstructure 11. Testing and characterisation techniques 12. Applications Appendix 1. Nomenclature Appendix 2. Matrices and reinforcements - selected thermophysical properties Appendix 3. The basic Eshelby S-tensors Appendix 4. Listing of a program for an Eshelby calculation.

An introduction to metal matrix composites

Plasma sprayed hydroxyapatite coatings on titanium substrates Part 1: Mechanical properties and residual stress levels

Unidimensional solute redistribution during freezing is modelled for the important case of complete diffusion in the liquid and incomplete back-diffusion in the solid by the Brody and Flemings analysis. The treatment, however, does not conserve solute and leads to predictions which are incorrect unless solid state diffusion is very limited. This paper outlines the origin of this effect and presents a modification to the model in which the predicted behavior is quantitatively correct in the important limits. Application of the modified analysis is shown to be simple and to lead to realistic descriptions of the solidification behavior in mushy freezing alloys. As an example, the model is applied to two steels solidifying over a range of cooling rates and the results indicate that such systems will in many cases be quite close to thermodynamic equilibrium with respect to carbon redistribution.

T.W. Clyne

Papers

An Introduction to Composite Materials

An introduction to metal matrix composites

Plasma sprayed hydroxyapatite coatings on titanium substrates Part 1: Mechanical properties and residual stress levels

Solute redistribution during solidification with rapid solid state diffusion

The quenching stress in thermally sprayed coatings