Engineering Commons^™

Designing Fire Safe Composites, Maude Jimenez

Composites at Lake Louise (CALL 2015)

Composites are increasingly used in transportation (railway, aircrafts,…) and their applications are more and more oriented toward structural parts. However the fire risk linked to the use of such organic materials has to be strongly reduced to keep this attractiveness and hence flame retardant solutions have to be used to fire proof them. A classical way to achieve fire performance is to incorporate fire retardants (FRs) in the bulk of the polymeric matrix of the composites at loading between 15 and 40wt%. However with such an approach, flammability properties of the composites will be achieved at the expense of their …

Stimuli Responsive Nanocomposites Based On Cellulose Nanocrystals, Sandra Camarero, Tobias Kuhnt, Christoph Weder

Composites at Lake Louise (CALL 2015)

Cellulose nanocrystals (CNCs) are high-aspect ratio, mechanically stiff fibers which can serve as both a bio-renewable reinforcing agent in nanocomposites, as well as a handle for adding stimuli responsiveness. CNCs can be extracted from a wide range of natural cellulosic materials, with characteristics such as crystal structure, crystallinity and aspect ratio fluctuate widely between sources. Here, we report small molecule functionalized cellulose prepared for sustained delivery in a variety of environments. Moieties attached to the surface of cellulose nanocrystals show that both irreversible and reversible changes can be induced by application of an external stimuli.

Moreover, we present the case …

Structural Composites From High Performance Bioepoxies, Daniel Schmidt

Composites at Lake Louise (CALL 2015)

The increased utilization of structural composites has had a significant and tangible impact on everyday life, enabling real progress in a broad range of application areas from transportation to wind energy to sporting goods. Unfortunately, however, the vast majority of these materials are petroleum derived, and tend to be difficult or impossible to truly recycle, with downcycling, landfilling or even incineration much more common. This represents both a major waste and a lost opportunity.

In this talk, an overview is provided of our efforts to date aimed at addressing these issues, as well as some of our most recent results …

Role Of Molecular Interactions On The Mechanics Of Nanocomposites, Dinesh Katti, Kalpana Katti

Composites at Lake Louise (CALL 2015)

Nanocomposite materials are well characterized using a variety of advanced microscopy and spectroscopy techniques. In particular, the interfaces in the nanocomposites are often tailored (in engineered composites) and evolved (in biological nanocomposites) to unique molecular characteristics that provide optimized and superior properties to the nanocomposites. In this presentation, we will describe a multiscale mechanics perspective on role of molecular interactions as well as the nano and microstructures on the mechanics of nanocomposites. Specific examples including biological and synthetic nanocomposites will be presented. We have demonstrated a quantitative correlation of energies of molecular interactions albeit nonbonded in the nanocomposites to the …

Graphene/ Polymer Composites For Biomedical Applications: Tissue Scaffolds, Prosthetic Joints And Gene Delivery, Kaushik Chatterjee

Composites at Lake Louise (CALL 2015)

No abstract provided.

Self-Organized Soft-Hard Interfaces: From Surfaces To Biologically Integrated Hybrid Materials, Candan Tamerler

Composites at Lake Louise (CALL 2015)

The biological material systems promise the possibility of developing innovative materials that simultaneously self-assembled, self-organized and self-regulated; characteristics that are difficult to achieve in purely synthetic systems. Proteins play an essential role in fabrication of biological materials due to their diverse functions ranging from structural to biochemical. The ability to mimic any of these functions can be a game changer in designing new biomaterials. There are several challenges in these strategies including replicating the hierarchical organization of biological materials, organization that provides multi-scale structure/property interdependence. The interfacial interactions become critical in tuning the individual components towards the functional needs. There …

Nanoclay Based Composite Scaffolds For Development Of Novel Humanoid Environment, Kalpana Katti, Shahajahan Molla, Dinesh Katti

Composites at Lake Louise (CALL 2015)

Cancer cells are adept at invading, migrating to and colonizing on an organ away from its origin resulting in metastatic cancer. The process through which cancer cells colonize on a distant organ is known as metastasis. It is estimated that about 90% of the deaths associated with cancer are attributed to metastasis, yet the fundamental mechanisms of cancer metastasis are unknown. Several cancers are known to metastasize to bone. Of these, the most prolific are prostate, breast and colon cancers. Molecular, microstructural and physiological interactions between the metastatic cancer cells and bone microenvironment have been shown to be suggestive of …

Amorphous Metal Sandwich Composites With Unprecedented Strength, Jay Hanan

Composites at Lake Louise (CALL 2015)

Engineered cellular materials widely used in structural applications have similarity to those in nature. Wood, cork, and a human cancellous bone are examples of well-known natural cellular materials that resemble foams and honeycombs used for structural engineering applications. In structural applications, one role of a honeycomb core is to maintain separation between face sheets, often for specific point loads or a range of stress states from bending to compression or even expansion. This is best done with a minimal increase in weight. Therefore, lower densities are desired to maximize the advantage of a sandwich composite.

Achievable strengths in honeycombs are …

The Break Evolution Process In Composite Microcomposites, Gale Holmes

Composites at Lake Louise (CALL 2015)

The mechanical integrity of a structural composite is strongly affected by the strength and toughness of the fiber–matrix interface/interphase (Norwood, 1994), with interfacial shear strength (IFSS) considered the best quantifying metric. Because the IFSS outputs are used in unidirectional (UD) composite failure models (CFMs) to predict strength and failure behavior, where the interaction between fibers can be important, the validity of extrapolating from test results based upon the repeated failure of a single isolated fiber has often been questioned. In this presentation, the spatial distributions of fiber breaks in a single fiber fragmentation test (SFFT) specimen, such as used in …

Low Cost Synthesis Of Silicon-Based Ceramic Powders From Na, K And Cs Geopolymer, Cengiz Bagci, Gregory Kutyla, Walftraud Kriven

Composites at Lake Louise (CALL 2015)

Geopolymer carbon precursors (1:1:4.5:12+18C) for carbothermal reduction and nitridation were prepared by the following route. NaGP, KGP and CsGP resins were prepared by mixing metakaolin (Al₂O₃.2SiO₂) in NaOH, KOH, or CsOH alkaline solutions, respectively. The viscous and homogenous slurries was poured into a Teflon mold to obtain bar samples at ambient temperature and cured in a constant 50 °C temperature/humidity oven for 24 h. GP bars were powdered by following additional drying in an open air furnace at 300 °C for 1 h. To obtain GP18C precursors, the powdered pure GPs were ball milled …

Design And Fabrication Of Microstructured Composites Using Mechanical And Magnetic Stimuli, Rafael Libaroni, Randall Erb, Andre Studart

Composites at Lake Louise (CALL 2015)

Combining soft and hard building blocks is a widely used approach to fabricate composite materials exhibiting mechanical properties that are not achievable by their single components alone. Remarkably, the design strategies applied in engineering and biological processes lead to striking differences in the nano/microstructure and mechanical performance of such composite materials. While nature is able to grow composites with deliberate control over the orientation and spatial distribution of anisotropic reinforcing particles, the use of intricate and tailored architectures to optimize the mechanical and functional properties remains largely unexplored in synthetic materials. Although magnetic manipulation has been successfully applied as a …

Designer Electrocatalysts From Transition Metal Oxide Heterostructure, Jin Suntvich

Composites at Lake Louise (CALL 2015)

One of the largest cost and efficiency limitations of electrochemical energy storage and conversion devices such as fuel cells, electrolyzers and metal-air batteries lies in the sluggish kinetics of the oxygen electrochemical reactions. To increase the reaction kinetics and reduce the inefficiency, it is essential to find electrocatalysts that can facilitate and catalyze these electrochemical processes. Developing a “design” principle” that links material structure and chemistry to the catalytic activity can accelerate the search for highly active electrocatalyst that is cost effective and abundant in nature. In this contribution, we present our effort in establishing this structure-activity connection using transition …

Composites On Fire At Reduced Scale: Evaluation, Characterization And Modeling, Serge Bourbigot, Fabienne Samyn, Sophie Duquesne

Composites at Lake Louise (CALL 2015)

Composite materials are increasingly being used in the design of aircraft, train, ship and buildings. They are very often structural parts and they must meet the difficult challenge of having adequate structural fire protection. In fire scenarios of particular relevance according to the targeted applications, suitable strategies to control fire hazards are needed for composite structures. There are three main methods available to design composite structures with improved fire resistance behavior: (i) use “normal” structural materials and add surface protection, (ii) use fire retarded versions of “normal” structural materials, and (iii) use structural materials with inherently good fire retardant properties. …

Functional Nanogels Applied To Materials Development, Jeffrey Stansbury

Composites at Lake Louise (CALL 2015)

Nanogels are commonly used in the controlled delivery of therapeutic agents, DNA/RNA and proteins as well as for imaging and sensing in other biomedical applications. Nanogels are rarely utilized to modify or create macroscopic polymeric structure, which is the focus of this report. Our unique version of reactive polymeric nanogel materials involves globular particles that have well-controlled swollen dimensions of approximately 10 nm. These particles are composed of many short yet highly interconnected primary chains that cumulatively provide particles with molecular weights of 10⁴-10⁶ Da.

Deposition Dynamics For Processing Functional Polymer Nanocomposite Membranes, John Howater

Composites at Lake Louise (CALL 2015)

Polymer functionalized nanoparticles have garnered strong research interests due to promising uses in a wide range of applications including drug delivery, tribology and stabilized composite solutions. Here we report on the synthesis of polymer nanocomposite thin films for applications related to membrane-based water treatment where the nanoparticle is functionalized for targeted sequestration or remediation of pollutants. The filler material for the model nanocomposite membranes are comprised of a ~10 nm silica core surrounded by chemically attached polymer “brushes”; these “hairy nanoparticles” (hNPs) are embedded in a polymer matrix to form the nanocomposite films.

Suspensions of highly uniform polyacrylic acid(PAA)-silica hybrid …

Direct Printing Of 2-Component Silicones In Facial & Body Prostheses, Jim Smay, Trevor Coward

Composites at Lake Louise (CALL 2015)

Traditionally maxillofacial prostheses are fabricated by hand carving the missing anatomical defect in wax, and creating a mould into which pigmented silicone elastomer is placed. Modern technologies have been used to manufacture anatomical face/body parts utilizing computed tomography (CT) data in conjunction with rapid prototyping (RP) techniques utilizing a hard plastic resin or thermoformed wax. However, these methods still require moulds into which a biocompatible pigmented silicone elastomer is placed. The purpose of this paper is to explore the development of direct printing of two component silicone elastomers in conjunction with a PVA support structure to create complex shapes using …

Cellulose Nanofibers Networks For Structural Nanomaterials And Biocomposites With Multiple Functions, Lars Berglund

Composites at Lake Louise (CALL 2015)

Cellulose-based composites offer interesting potential as environmentally friendly materials. Wood nanocellulose disintegrated from chemical pulp is an interesting component, which can be used in materials of increased structural, sophistication, extended property range and new functions [1]. The network forming character of cellulose nanofibers (CNF) makes it possible to form other types of nanomaterials than biocomposites such as nanopaper, aerogels, hydrogels, foams and honeycombs. The CNF can also be combined with inorganic nanoparticles to prepare organic/inorganic hybrid materials.

The structure of CNF is discussed and routes to improve the properties of the CNF are suggested. For the purpose of nanomaterials preparation, …

Laser-Based Three-Dimensional Printing Of Zirconium Oxide Hybrid Materials, Roger Narayan

Composites at Lake Louise (CALL 2015)

We have recently examined use of an additive manufacturing approach known as two-photon polymerization to create structures out of zirconium oxide hybrid materials for medical device applications. Two photon polymerization involves processing of a structure with sub-microscale features in an additive manner directly from a computer-generated model. In two-photon polymerization, a femtosecond laser beam is focused within a small volume in a near infrared light-transparent photosensitive material; nearly simultaneous absorption of two photons within a small volume in the photosensitive material results in polymerization and hardening of the material. Because of the quadratic dependence of two-photon absorption probability on intensity, …

Processing, Properties And Prospects For Melt Infiltrated (Mi) Sicf-Ceramic Composites, Raj Singh

Composites at Lake Louise (CALL 2015)

Ceramic materials exhibit superior mechanical properties at high temperatures. But, their use as structural components is severely limited because of their brittleness. Fiber-reinforced ceramic matrix composites (FRCMC), by incorporating fibers in ceramic matrices, not only exploit their attractive high-temperature strength but also enhance their toughness thereby rendering these attractive for many applications. Some of these applications require an understanding of the interrelationship among processing, fiber-matrix interface and mechanical properties both at room and elevated temperatures.

Processing of FRCMC is typically done by chemical vapor infiltration (CVI), filament winding and hot-pressing, and polymer infiltration and pyrolysis (PIP) approaches. Most of these …

Chemically Modified Graphene-Based Composite Paper Electrodes For Longcycle Metal-Ion Batteries, Gurpreet Singh

Composites at Lake Louise (CALL 2015)

No abstract provided.

Dynamical Mechanical Behavior Of Graphene And Cnt Materials Under Hypersonic Projectile Penetration, Edwin Thomas

Composites at Lake Louise (CALL 2015)

We utilize laser pulses to send micro-projectiles at hypervelocity into various targets. Thick films of (a poly(styrene – b – dimethyl siloxane) (PS-PDMS) lamellar block copolymer – a model glassy-rubbery nanocomposite consisting of a self-assembled ordered arrangement of parallel periodic 20 nm thick layers of polystyrene and polydimethylsiloxane were impacted by 3 micron spheres of silica at velocities of 0.5 – 1.5 km/sec. We also use the silica spheres to study penetration through thin membranes of multilayer graphene. Soft projectiles, such as single crystal cubes of Ag are impacted onto hard impenetrable targets to observe the extensive plastic deformation of …

Composite Materials For Energy And Sustainable Development, Alan Hurd

Composites at Lake Louise (CALL 2015)

The essential link to a sustainable future on our planet may be composite materials. Energy efficiency drives research and development toward lighter, stronger, and cheaper materials, and the general strategy of greater inhomogeneity at ever-finer length scales appears a good bet for technology development via a qualitatively new scaling. Advanced composites offer superb advantages, and this hope shines brighter with the promise of greater control in manufacture, voxel-by-voxel, under digital control.

However, even the prospect of doing fundamental research let alone development and widespread production in this important area will eventually be limited by the availability of materials unless we …

Substitution And Sustainability In Functional Materials And Devices, Ian Reaney

Composites at Lake Louise (CALL 2015)

Functional Materials and Devices (FMD) is a rapidly evolving subject which underpins many aspects of modern life such as antennas, energy storage devices, multicomponent sensors and smart materials. At a segment size of ~£3Bn p.a., the UK represents ~25% of the total EU production. However, the FMD sector in the EU and UK relies heavily on raw materials which have geopolitical, geological and environmental constraints. The response to materials scarcity and environmental restrictions depends on the industry, but companies indicate that resource efficiency, R&D, and innovations for substitution are necessary. Our vision is to utilise materials engineering, multiscale modeling, advanced …

Constructing Nanocrystal-In-Glass Composites For Smart Windows, Delia Milliron

Composites at Lake Louise (CALL 2015)

The integration of inorganic nanocrystals as building units into mesoscale architectures yields materials wherein the components and their interfaces are both essential in defining structure and function. Randomly mesostructured nanocrystal-in-amorphous niobia composites can be formed by chemically linking niobium polyoxometalate (POM) clusters to colloidal nanocrystals in the solution phase. When films of these assemblies are thermally annealed, the clusters undergo condensation. They cross-link to form a continuous amorphous niobia matrix surrounding, and covalently linked to, the embedded nanocrystals. The resulting composite materials combine intrinsic characteristics of each component and exhibit unique functionality that we ascribe to reconstruction at the nanocrystal-glass …

Engineered Gag-Based Coatings For Mesenchymal Stem Cells, Johna Temenoff

Composites at Lake Louise (CALL 2015)

The therapeutic potency of delivered mesenchymal stem cells (MSCs) in tissue engineering applications may be improved by priming cells toward a differentiated state prior to implantation. Mimicking native extracellular matrix (ECM) interactions, the electrostatic attraction between negatively-charged glycosaminoglycans (GAGs such as heparin and chondroitin sulfate) and positively-charged proteins may act to locally sequester factors present in the culture media (or secreted by nearby cells) to further enhance stem cell response to soluble factors prior to cell transplantation for musculoskeletal disorders.

In these experiments, we desulfated the GAG heparin and heparin (Hep) and desulfated (Hep-) heparin were biotinylated via HOBT/EDC chemistry. …

Single And Double Heterojunction Nanorods For Optoelectronics, Moonsub Shim

Composites at Lake Louise (CALL 2015)

Understanding charge separation and recombination processes and developing materials that can efficiently direct charge carriers with nanoscale precision are of fundamental importance in advancing next-generation electronics, optoelectronics and energy technologies. As semiconductor heterostructures have enabled today’s electronics and optoelectronics, the introduction of active heterojunctions can impart new and improved capabilities that will facilitate integration of colloidal quantum dots into high performance devices. With anisotropic shapes that can be exploited for assembly, charge carrier manipulation and optical anisotropy, incorporating heterojunctions in colloidal semiconductor nanorods presents a promising direction. Various motifs of epitaxial heterojunctions introduced in nanorods through solution chemistry will be …

Concept And Development Of Solid State Ionic Capacitors, Takaaki Tsurumi, Ryoma Ishikawa, Takuya Hoshina, Hiroaki Takeda, Yukio Sakabe

Composites at Lake Louise (CALL 2015)

Development of a new energy storage device that can replace lithium ion batteries is one of the most important subjects for the future of human. Capacitors have an advantage over batteries with respect to the endurance for charge - discharge recycling. Electric double-layer capacitor (EDLC) has been used for some applications but they are still restricted because of relatively low energy density of EDLC in comparison with lithium ion battery and the leakage of liquid electrolyte from packages. Another issue on capacitors is the limit of capacitance density of multi-layered ceramic capacitors (MLCCs). MLCCs are currently used for many electronic …

Electric Eels: Bizarre Natural Phenomena Or Inspiration For Novel Nanocomposite Energy Storage, Erik Spoerke

Composites at Lake Louise (CALL 2015)

The global rush to develop new high energy density, high power density electrical energy storage has motivated a variety of creative, alternative approaches to new technology development. We have adopted one such creative approach, looking to the electric eel as a model for how to manipulate and store electrical energy. These remarkable organisms are capable of repeatedly generating and discharging 1 Ampere of current at over 600V!

The cellular machinery responsible for electrical energy storage in organisms like the electric eel is quite complex (Figure 1), but the driving force behind these sophisticated processes hinges on the relatively simple concept …

Structural Optimization Of Fiber-Reinforced Composite Dental Bridges, Yung Chen, Alex Fok

Composites at Lake Louise (CALL 2015)

The much improved strength of dental restorative materials has brought more flexibility to the design of dental prosthesis, leading to the concept of minimally invasive dentistry. Fiber-reinforced composite (FRC) systems, for example, which provide excellent tooth-colored appearance, allow the amount of tooth removal to be minimized. Clinically, the ideal indication of FRC restoration is single tooth replacement. Depending on the position of the missing tooth, the periodontal status of the neighboring teeth, and the patient’s occlusal force or any existing parafunctional habits, the following two fixed partial denture (FPD) designs can be prescribed: a 3-unit dental bridge supported by two …

Pgx – Technology: A Versatile Technology For Generating Advanced Biopolymer Materials, Bernhard Seifried

Composites at Lake Louise (CALL 2015)

A novel technology is presented utilizing Pressurized Gas eXpanded (PGX) liquids for processing aqueous solutions or dispersions of high molecular weight biopolymers, such as starch, polysaccharides, gums, pectins or cellulose nanocrystals into open-porous morphologies, consisting of nano-scale particles and pores. The highly tune-able PGX process can generate exfoliated nano-composites and highly porous morphologies ranging from sub-micron particles (50nm) to micron-sized granules (2mm), as well as micro- and nanofibrils, granules, fine powders and aerogels with porosities of >99% and specific surface areas exceeding 300 m²/gram. The technology is based on a spray drying method, operating at mild temperatures (40°C) …