bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Need for Microstructural Measurement Techniques in the Study of Cosmetic Product Properties
Authors: Cummins P. G. , Fthenakis C. 
Published: February 2011

AbstractA cosmetic product is often a complex non-homogeneous mixture of physicochemical units including polymers, small molecules, surface-active species, and particles. In use, it is applied to an equally heterogeneous substrate, skin. Consequently, materials structure as well as composition and the nature of the surfaces are relevant to a clear understanding of any technologically important product property or process. No longer is it sufficient to answer the classical questions of analysis—what and how much?—for many applications; we must now ask the additional questions of where, how organized, and how is it manifest to the customer? Although analytical sciences have, for many years, been applied to the problem of characterizing what is in chemical systems, the need to understand spatial and interfacial interactions has received much less attention. The explosive growth, however, in electronics, computing, biology, mathematical methodologies, microscopy, and optics now present the cosmetic industry with a new set of tools that can be utilized to address this issue. It is the objective of this article to highlight some of these measurement advances and how they might have relevance in the cosmetics industry in the coming years.
Coupled Quantum–Atomistic and Quantum–Continuum Mechanics Methods in Materials Research
Authors: Ramasubramaniam Ashwin , Carter Emily A. 
Published: February 2011

AbstractThe interface of quantum mechanics methods with classical atomistic simulation techniques, such as molecular dynamics and Monte Carlo, continues to be an area of considerable promise and interest. Such coupled quantum–atomistic approaches have been developed and employed, for example, to gain a comprehensive understanding of the energetics, kinetics, and dynamics of chemical processes involving surfaces and interfaces of hard materials. More recently, it has become possible to directly couple first-principles electronic structure techniques to continuum solid mechanics, either on the fly with feedback between length scales or by information passing between length scales. We discuss, with tutorial examples, the merging of quantum mechanics with molecular dynamics and Monte Carlo simulations, as well as quantum–continuum coupled techniques. We illustrate the opportunities offered by incorporation of information from quantum mechanics (reducing assumptions in higher length-scale models) and outline the challenges associated with achieving full predictive capability for the behavior of materials.
Hybrid Continuum Mechanics and Atomistic Methods for Simulating Materials Deformation and Failure
Authors: Miller Ronald E. , Tadmor Ellad B. 
Published: February 2011

AbstractMany aspects of materials deformation and failure are controlled by atomic-scale phenomena that can be explored using molecular statics and molecular dynamics simulations. However, many of these phenomena involve processes on multiple length scales with the result that full molecular statics/molecular dynamics simulations of the entire system are too large to be tractable. In this review, we discuss hybrid models that perform molecular statics/molecular dynamics simulations “without all the atoms,” aimed at retaining atomistic detail at a fraction of the computational cost. These methods couple a fully atomistic model in critical regions to regions described by less-expensive continuum methods where they can provide an adequate representation of the important physics. We give an overview of the challenges such models present, with a focus on recent work to address issues of dynamics and finite (non-zero) temperature.
Atomic-Resolution Environmental Transmission Electron Microscopy for Probing Gas–Solid Reactions in Heterogeneous Catalysis
Authors: Gai Pratibha L. , Boyes Edward D. , Helveg Stig , Hansen Poul L. , Giorgio Suzanne , Henry Claude R. 
Published: February 2011

AbstractAdvances in atomic-resolution environmental transmission electron microscopy (ETEM) and related techniques for probing gas–solid reactionsin situare described. The capabilities of ETEM allow the dynamic nanostructure of heterogeneous catalysts in their functioning states to be directly monitored in real time. Applications of ETEM in catalysis are outlined, and they illustrate significant new insights into the dynamic nanostructure of the catalyst materials and their modes of operation.
Challenges and Opportunities in Multifunctional Nanocomposite Structures for Aerospace Applications
Authors: Baur Jeff , Silverman Edward 
Published: February 2011

AbstractOne important application of nanocomposites is their use in engineered structural composites. Among the wide variety of structural applications, fiber-reinforced composites for aerospace structures have some of the most demanding physical, chemical, electrical, thermal, and mechanical property requirements. Nanocomposites offer tremendous po tential to improve the properties of advanced engineered composites with modest additional weight and easy integration into current proc essing schemes. Sig nificant progress has been made in fulfilling this vision. In particular, nanocomposites have been applied at numerous locations within hierarchical composites to improve specific properties and optimize the multifunctional properties of the overall structure. Within this ar ticle, we review the status of nanocomposite incorporation into aerospace composite structures and the need for continued development.
Polymer Nanocomposites for Biomedical Applications
Authors: Hule Rohan A. , Pochan Darrin J. 
Published: February 2011

AbstractBionanocomposites have established themselves as a promising class of hybrid materials derived from natural and synthetic biodegradable polymers and organic/inorganic fillers. Different chemistries and compositions can lead to applications from tissue engineering to load-bearing composites for bone reconstruction. A critical factor underlying biomedical nanocomposite properties is interaction between the chosen matrix and the filler. This ar ticle discusses current efforts and key research challenges in the development of these ma te rials for use in potential biomedical applications.
Advanced Inorganic Materials for Photovoltaics
Authors: Slaoui Abdelilah , Collins Reuben T. 
Published: February 2011

AbstractBy 2050, world annual energy consumption is predicted to grow from the present 13 terawatt - years (TWyr) to nearly 30 TWyr. Although all energy sources must be considered in meeting this challenge, solar energy may arguably be the only carbon-free source capable of supplying a significant fraction of energy at these levels. This issue of MRS Bulletin reviews the status and future development of solar photovoltaic technologies based on inorganic materials. The discussion begins with materials and cell designs for second-generation photovoltaics based on thin films [a-Si:H, Si, Cu(In, Ga)(Se, S)2, CdTe]. Recent advances in tandem cells and concentrators are alsoreported, along with photovoltaic approaches involving nanoscale materials such as quantum dot arrays. Finally, work on transparent conducting oxides that are critical to nearly all cell designs are discussed.
Amorphous Silicon, Microcrystalline Silicon, and Thin-Film Polycrystalline Silicon Solar Cells
Authors: Schropp Ruud E.I. , Carius Reinhard , Beaucarne Guy 
Published: February 2011

AbstractThin-film solar cell technologies based on Si with a thickness of less than a few micrometers combine the low-cost potential of thin-film technologies with the advantages of Si as an abundantly available element in the earth's crust and a readily manufacturable material for photovoltaics (PVs). In recent years, several technologies have been developed that promise to take the performance of thin-film silicon PVs well beyond that of the currently established amorphous Si PV technology. Thin-film silicon, like no other thin-film material, is very effective in tandem and triple-junction solar cells. The research and development on thin crystalline silicon on foreign substrates can be divided into two different routes: a low-temperature route compatible with standard float glass or even plastic substrates, and a high-temperature route (>600°C). This article reviews the material properties and technological challenges of the different thin-film silicon PV materials.
Materials Challenges for CdTe and CuInSe2Photovoltaics
Authors: Beach Joseph D. , McCandless Brian E. 
Published: February 2011

AbstractThe record laboratory cell (∼1 cm2area) efficiency for thin-film cadmium telluride (CdTe) is 16.5%, and that for a copper indium diselenide (CuInSe2) thin-film alloy is 19.5%. Commercially produced CdTe and CuInSe2modules (0.5–1 m2area) have efficiencies in the 7–11% range. Research is needed both to increase laboratory cell efficiencies and to bring those small - area efficiencies to large-area production. Increases in laboratory CdTe cell efficiency will require increasing open-circuit voltage, which will allow cells to harvest more energy from each absorbed photon. This will require extending the minority carrier lifetime from its present τ ≤ 2 ns to τ ≥ 10 ns and increasing hole concentration in the CdTe beyond 1015cm2, which appears to be limited by compensating defects. Increasing laboratory CuInSe2-based cell efficiency significantly beyond 19.5% will also require increasing the open-circuit voltage, either by increasing the bandgap, the doping level, or the minority carrier lifetime. The photovoltaic cells in commercial modules occupy tens of square centimeters, and both models and experiments have shown that low-performing regions in small fractions of a cell can significantly reduce the overall cell per formance. Increases in commercial module efficiency will require control of materials properties across large deposition areas in a high-throughput environment to minimize such non-uniformities. This article discusses approaches used and research needed to increase the ultimate efficiencies of CdTe- and CuInSe2-based devices and translate these gains to commercial photovoltaic modules.
High-Efficiency Multijunction Solar Cells
Authors: Dimroth Frank , Kurtz Sarah 
Published: February 2011

AbstractThe efficiency of a solar cell can be increased by stacking multiple solar cells with a range of bandgap energies, resulting in a multijunction solar cell with a maximum the oretical efficiency limit of 86.8% III–V compound semiconductors are good candidates for fabricating such multijunction solar cells for two reasons: they can be grown with excellent material quality; and their bandgaps span a wide spectral range, mostly with direct bandgaps, implying a high absorption coefficient. These factors are the reason for the success of this technology, which has achieved 39% efficiency, the highest solar-to-electric conversion efficiency of any photovoltaic device to date. This article explores the materials science of today's high-efficiency multijunction cells and describes challenges associated with new materials developments and how they may lead to next-generation, multijunction solar cell concepts.
Solar Cells Based on Quantum Dots: Multiple Exciton Generation and Intermediate Bands
Authors: Luque Antonio , Martí Antonio , Nozik Arthur J. 
Published: February 2011

AbstractSemiconductor quantum dots may be used in so-called third-generation solar cells that have the potential to greatly increase the photon conversion efficiency via two effects: (1) the production of multiple excitons from a single photon of sufficient energy and (2) the formation of intermediate bands in the bandgap that use sub-bandgap photons to form separable electron–hole pairs. This is possible because quantization of energy levels in quantum dots produces the following effects: enhanced Auger processes and Coulomb coupling between charge carriers; elimination of the requirement to conserve crystal momentum; slowed hot electron–hole pair (exciton) cooling; multiple exciton generation; and formation of minibands (delocalized electronic states) in quantum dot arrays. For exciton multiplication, very high quantum yields of 300–700% for exciton formation in PbSe, PbS, PbTe, and CdSe quantum dots have been reported at photon energies about 4–8 times the HOMO–LUMO transition energy (quantum dot bandgap), respectively, indicating the formation of 3–7 excitons/photon, depending upon the photon energy. For intermediate-band solar cells, quantum dots are used to create the intermediate bands from the con fined electron states in the conduction band. By means of the intermediate band, it is possible to absorb below-bandgap energy photons. This is predicted to produce solar cells with enhanced photocurrent without voltage degradation.
Piezoelectric Nanostructures: From Growth Phenomena to Electric Nanogenerators
Authors: Wang Zhong Lin 
Published: February 2011

AbstractZinc oxide is a unique material that exhibits semiconducting, piezoelectric, and pyroelectric multifunctionalities. By controlling the size and orientation of the polar surfaces of ZnO nanobelts, single - crystal nanocombs, nanorings, nanohelices, nanosprings, and nanobows of ZnO have been synthesized. This article centers on the fundamental growth mechanism and fabrication of electromechanical devices based on piezoelectric ZnO nanostructures, including a nanogenerator using aligned ZnO nanowires for converting nanoscale mechanical energy into electric energy. The mechanism of the electric nanogenerator relies on the unique coupling of the piezoelectric and semiconducting properties of ZnO, which is the fundamental principle of nano - piezotronics, a new field using the piezoelectric effect for fabricating electronic devices and components. The approach has the potential of converting biological mechanical energy, acoustic/ultrasonic vibration energy, and biofluid hydraulic energy into electricity, demonstrating a new pathway for self - powering of wireless nanodevices and nanosystems.
Directed Growth of Branched Nanowire Structures
Authors: Dick Kimberly A. , Deppert Knut , Karlsson Lisa S. , Larsson Magnus W. , Seifert Werner , Wallenberg L. Reine , Samuelson Lars 
Published: February 2011

AbstractWe describe the production of hierarchical branched nanowire structures by the sequential seeding of multiple wire generations with metal nanoparticles. Such complex structures represent the next step in the study of functional nanowires, as they increase the potential functionality of nanostructures produced in a self-assembled way. It is possible, for example, to fabricate a variety of active heterostructure segments with different compositions and diameters within a single connected structure. The focus of this work is on epitaxial III-V semiconductor branched nanowire structures, with the two materials GaP and In As used as typical examples of branched structures with cubic (zinc blende) and hexagonal (wurtzite) crystal structures. The general morphology of these structures will be described, as well as the relationship between morphology and crystal structure.
Fundamentals of Focused Ion Beam Nanostructural Processing: Below, At, and Above the Surface
Authors: MoberlyChan Warren J. , Adams David P. , Aziz Michael J. , Hobler Gerhard , Schenkel Thomas 
Published: February 2011

AbstractThis article considers the fundamentals of what happens in a solid when it is impacted by a medium-energy gallium ion. The study of the ion/sample interaction at the nanometer scale is applicable to most focused ion beam (FIB)–based work even if the FIB/sample interaction is only a step in the process, for example, micromachining or microelectronics device processing. Whereas the objective in other articles in this issue is to use the FIB tool to characterize a material or to machine a device or transmission electron microscopy sample, the goal of the FIB in this article is to have the FIB/sample interaction itself become the product. To that end, the FIB/sample interaction is considered in three categories according to geometry: below, at, and above the surface. First, the FIB ions can penetrate the top atom layer(s) and interact below the surface. Ion implantation and ion damage on flat surfaces have been comprehensively examined; however, FIB applications require the further investigation of high doses in three-dimensional profiles. Second, the ions can interact at the surface, where a morphological instability can lead to ripples and surface self-organization, which can depend on boundary conditions for site-specific and compound FIB processing. Third, the FIB may interact above the surface (and/or produce secondary particles that interact above the surface). Such ion beam–assisted deposition, FIB–CVD (chemical vapor deposition), offers an elaborate complexity in three dimensions with an FIB using a gas injection system. At the nanometer scale, these three regimes—below, at, and above the surface—can require an interdependent understanding to be judiciously controlled by the FIB.
Smart Nanotextiles: A Review of Materials and Applications
Authors: Coyle Shirley , Wu Yanzhe , Lau King-Tong , De Rossi Danilo , Wallace Gordon , Diamond Dermot 
Published: February 2011

AbstractThe development of smart nanotextiles has the potential to revolutionize the functionality of our clothing and the fabrics in our surroundings. Nanoscale manipulation results in new functionalities for intelligent textiles, including self-cleaning, sensing, actuating, and communicating. This is made possible by such developments as new materials, fibers, and finishings; inherently conducting polymers; carbon nanotubes; and antimicrobial nanocoatings. These additional functionalities have numerous applications, encompassing healthcare, sports, military applications, and fashion. The wearer and the surrounding environment may be monitored in an innocuous manner, giving continuous updates of individual health status or environmental hazards. More generally, smart textiles become a critical part of the emerging area of body sensor networks incorporating sensing, actuation, control, and wireless data transmission. This article reviews current research in nanotechnology application to textiles, from fiber manipulation and development to end uses of smart nanotextiles.
Laser Direct-Write Processing
Authors: Arnold Craig B. , Piqué Alberto 
Published: February 2011

AbstractDirect-write techniques enable computer-controlled two- and three-dimensional pattern formation in a serial fashion. Among these techniques, the versatility offered by laser-based direct-write methods is unique, given their ability to add, remove, and modify different types of materials without physical contact between a tool or nozzle and the material of interest. Laser pulses used to generate the patterns can be manipulated to control the composition, structure, and even properties of individual three-dimensional volumes of materials across length scales spanning six orders of magnitude, from nanometers to millimeters. Such resolution, combined with the ability to process complex or delicate material systems, enables laser direct-write tools to fabricate structures that are not possible to generate using other serial or parallel fabrication techniques. The goal of the articles in this issue ofMRS Bulletinis to illustrate the range of materials processing capabilities, fundamental research opportunities, and commercially viable applications that can be achieved using recently developed laser direct-write techniques. We hope that the articles provide the reader with a fresh perspective on the challenges and opportunities that these powerful techniques offer for the fabrication of novel devices and structures.
Molecular Biomimetics: Genetic Synthesis, Assembly, and Formation of Materials Using Peptides
Authors: Tamerler Candan , Sarikaya Mehmet 
Published: February 2011

AbstractIn nature, the molecular-recognition ability of peptides and, consequently, their functions are evolved through successive cycles of mutation and selection. Using biology as a guide, it is now possible to select, tailor, and control peptide–solid interactions and exploit them in novel ways. Combinatorial mutagenesis provides a protocol to genetically select short peptides with specific affinity to the surfaces of a variety of materials including metals, ceramics, and semiconductors. In the articles of this issue, we describe molecular characterization of inorganic-binding peptides; explain their further tailoring using post-selection genetic engineering and bioinformatics; and finally demonstrate their utility as molecular synthesizers, erectors, and assemblers. The peptides become fundamental building blocks of functional materials, each uniquely designed for an application in areas ranging from practical engineering to medicine.
Biofunctionalized Nanoparticles and Their Uses
Authors: Tomczak Melanie M. , Slocik Joseph M. , Stone Morley O. , Naik Rajesh R. 
Published: February 2011

AbstractNanotechnology is revolutionizing the way that sensing, electronic, optical, and medical devices are designed because the properties of nanostructures are distinct from their bulk-material counterparts. The incorporation of nanomaterials into devices and sensors to exploit their unique properties has been a challenge because they must be functionalized in a manner that does not destroy their properties. Biological macromolecules can non-covalently or covalently bind to nanomaterials, resulting in the formation of biofunctionalized nanoparticles. These biofunctionalized nanoparticles are exemplified by the peptide-mediated suspension of carbon nanotubes in solution and the templating of bimetallic nanoparticles using multifunctional peptides.
In AquaManufacturing of a Three-Dimensional Nanostructure Using a Peptide Aptamer
Authors: Sano Ken-Ichi , Shiba Kiyotaka 
Published: February 2011

AbstractTBP-1 is a 12-amino-acid peptide aptamer that has been isolated as a Ti binder using a peptide-phage system. Subsequent analyses have shown that TBP1 also binds Si and Ag, and has the ability to enhance the formation of titania and silica as well as nanoparticles of Ag. TBP-1 is thus a bifunctional peptide: a binder that also acts as a mediator of mineralization. These two functions can be grafted onto heterologous molecules. For instance, mutational analysis of the TBP-1 revealed that itsN-terminal hexapeptide, RKLPDA (minTBP-1), is sufficient for Ti binding. When the surface of ferritin, a nano-sized spherical cargo protein, was ornamented with minTBP-1 either genetically or chemically, the resultant modified ferritin acquired the ability to bind Ti and mediate mineralization. By alternately applying the binding and mineralization activities of the minTBP-1-modified nanocage, we were able to construct, in stepwise fashion, multilayer structures composed of titania (or silica) and nanocages. We named this process the biomimetic layer-by-layer (BioLBL) method. By coupling BioLBL with a conventional top-down lithographic method,in aquastructuralization of a three-dimensional (3D) configuration of nanomolecules was realized. As shown in this article, binding and mineralization activities of peptide aptamers, when they are combined with nanostructured materials, play active roles in manufacturing nanostrucutrein aqua.