Preface

Nanotechnology, first coined as a discipline in 2000, has applications in myriad sectors, including healthcare, energy, and transportation. In this book, engineered nanomaterials are considered to be materials that have been purposely synthesized or manufactured to have at least one external dimension of approximately 1-100 nm and that exhibit unique properties determined by this size. Engineered nanomaterials, also referred to as nanomaterials throughout this book, are increasingly incorporated into consumer products and military goods, referred to as nanotechnology-enabled products or simply products. The development and manufacturing of engineered nanomaterials and products are contingent on trustworthy, validated measurements of nanomaterial properties, and product performance. Such measurements are challenging due to a number of factors, including the small dimensions and surface-dominated behavior of nanomaterials and the need to perform measurements in realistic, complex environments. These and other challenges are present at all life cycle stages, from the production of nanomaterials and manufacture of products to use and disposal or recycling of both nanomaterials and products.

Metrology - the science of measurement - is essential to the development of new instruments and methods to image, characterize, and manipulate nanomaterials, the adaptation of existing methods for large-scale materials and chemicals to nanomaterials, and the interpretation and understanding of all measurements. Standards, including consensus-based documentary standards and reference materials, are required to ensure accurate and reproducible measurements of nanomaterials and products. This book is an informational resource for researchers, developers, manufacturers, and regulators on the state and importance of metrology and standards for nanotechnology and on current and emerging applications of nanotechnology in various sectors.

Contents of this Book

The chapters in this book are organized in six major parts:

• Introduction: Chapter 1 provides an overview of standards, beginning with a general discussion of the importance of standardization to trade, technology, and innovation. The remainder of the chapter addresses nanotechnology standards, specifically three types of standards-related products: consensus-based documentary standards published by standards development organizations; reference materials and certified reference materials developed by National Metrology Institutes; and prestandards protocols and guidance documents issued by various organizations. Challenges to and opportunities for standards development are also discussed in this part.
• Nanotechnology Basics: Chapters 2-6 cover topics that are fundamental to nanotechnology and to the remaining chapters in this book. A comprehensive treatise on the challenges and successes in developing a set of nanotechnology-related terms and their definitions that are acceptable to diverse stakeholders is presented in Chapter 2. Major categories of nanoscale materials, including engineered nanomaterials, such as metallic nanoparticles, and nanostructured bulk materials, such as nanoporous catalysts, are discussed in Chapter 3. Categorization based on dimensionality, composition, and properties are presented, along with examples of applications for each category. Chapter 4 covers the synthesis of nanoscale materials by physical, chemical, mechanical, and biological methods. The identification and descriptions of key physicochemical properties of engineered nanomaterials that are important to determine prior to the use and application of a nanomaterial are provided in Chapter 5. Biological properties of engineered nanomaterials are dependent on physicochemical properties, and Chapter 6 elucidates the biological properties of engineered nanomaterials in the context of the physiological and pathological pathways encountered by a nanomaterial when it enters the body of a human or animal.
• Metrology for Engineered Nanomaterials: This part of the book consists of seven chapters, ordered from broad coverage of instrumentation and methods for the characterization of engineered nanomaterials to specific methods and properties. Collectively, these chapters demonstrate the state of the art in metrology for engineered nanomaterials. In Chapter 7, the author provides a perspective on the challenges and issues to consider in characterizing four key physicochemical aspects of engineered nanomaterials - size, shape, surface, and solubility. A comprehensive discourse on the vast array of instruments and methods for characterizing 10 physicochemical properties of engineered nanomaterials typically considered to be of prime importance, consistent with the four physicochemical aspects highlighted in Chapter 7, is presented in Chapter 8. The importance of performing measurements in realistic media cannot be overemphasized, and Chapter 9 is devoted to methods applicable to complex environments such as soil, sediment, and biological matrices. Chapter 10 focuses on dimensional metrology, covering traceability of dimensional measurements at the nanoscale, applicable methods, instrument calibration, and uncertainty estimation. Microscopes are arguably the most commonly used tools to characterize engineered nanomaterials; Chapter 11 provides an in-depth tutorial on the principles of five established microscopy-based techniques for nanoscale measurements, as well as four emerging techniques. In Chapter 10, the author describes tribological measurements, for example, friction and wear, from the microscale to the nanoscale, including three typical testing instruments and international standardization efforts for such measurements. The final chapter in this part of the book, Chapter 13, illustrates stochastic, that is, random element, factors to consider in determining the size of nanoparticles by electron microscopy methods.
• Nanotechnology Standards: In this part of the book, "standards" is taken to include reference materials, consensus-based documentary standards, and prestandardization activities. The eight chapters in this part address ongoing international standardization efforts in nanotechnology. Reference nanomaterials are essential tools to assure accurate and reproducible measurement results from research and development to production. Chapter 14 highlights the intended uses of reference nanomaterials with illustrated examples. The next three chapters, Chapters 15-17, describe the consensus-based standards activities in the three international standards development organizations with dedicated nanotechnology committees: ISO, ASTM International, and IEC. The actions taken to establish a committee and a business plan for European documentary standards in nanotechnology are described in Chapter 18. A new effort to develop standard nomenclature for nanomaterials by the International Union of Pure and Applied Chemistry is described in Chapter 19. The final chapter in this part of the book concerns prestandardization efforts on nanomaterials in VAMAS, a group of national metrology institutes concerned with developing best practices and standards.
• Risk-Related Aspects of Engineered Nanomaterials: There are many existing and future applications of nanomaterials; however, widespread commercialization of products is constrained by concerns about potential risks of nanomaterials to humans and the environment at all life cycle stages. Chapter 21 describes various categorization approaches for nanomaterials and their applicability to risk decision-making by regulatory agencies. Risk is most simply defined as the product of exposure times hazard. Exposure scenarios at each nanomaterial product lifecycle stage, with an emphasis on environmental exposure, are presented in Chapter 22, along with examples of environmental releases of nanomaterials from four common types of products. Chapter 23 on nanotoxicology presents an overview of characterization approaches and regulations and describes a new approach combining in vitro, in vivo, and in silico methods to assess nanotoxicology. This part of the book is culminated by Chapter 24, a comprehensive discourse on minimizing risk of nanomaterials that provides strategies to support and frameworks for risk assessment and nanomaterial risk management practices to protect workers, consumers, the public, and the environment.
• Nanotechnology-Based Products, Applications, and Industry: The final part of this book concerns the commercialization of nanotechnology. Chapter 25 provides extensive descriptions of the categories of consumer and industrial nanoenabled products used today, and the manufacturing methods for six major types of such products. This chapter also provides detailed case studies on applications for several of these major types of products. Chapter 26 describes applications of the most commonly used nanomaterials and issues concerning the commercialization of nanotechnology, including sources of innovation and barriers resulting from uncertainties in nanomaterial properties, regulation, and consumer perspectives. Ethical issues concerning the industrial production of nanomaterials are discussed in Chapter 27 wherein the authors provide a strategy for addressing these issues. The remaining four chapters in this part of the book cover different application areas: energy (Chapter 28), food and food-related industries (Chapter 29), magnetics (Chapter 30),...