Fundamentals of Inorganic Glasses

Arun K. Varshneya, John C. Mauro

• Editore: Elsevier
• Anno: 2019
• ISBN:
  9780128162262
• Edizione: 3
• Argomento: Naturwissenschaften
• Categoria: Anorganische Chemie

Fundamentals of Inorganic Glasses, Third Edition, is a comprehensive reference on the field of glass science and engineering that covers numerous, significant advances. This new edition includes the most recent advances in glass physics and chemistry, also discussing groundbreaking applications of glassy materials. It is suitable for upper level glass science courses and professional glass scientists and engineers at industrial and government labs. Fundamental concepts, chapter-ending problem sets, an emphasis on key ideas, and timely notes on suggested readings are all included. The book provides the breadth required of a comprehensive reference, offering coverage of the composition, structure and properties of inorganic glasses.

• Clearly develops fundamental concepts and the basics of glass science and glass chemistry
• Provides a comprehensive discussion of the composition, structure and properties of inorganic glasses
• Features a discussion of the emerging applications of glass, including applications in energy, environment, pharmaceuticals, and more
• Concludes chapters with problem sets and suggested readings to facilitate self-study

Chapter 1

Introduction

Abstract

The word glass is derived from a late-Latin term glæsum to mean a lustrous and transparent material. Glassy substances are also called vitreous, originating from Latin word vitrum (clear). The history of glass as glazed stone beads goes back perhaps as much as 12,000 years. As independent objects, glassware was available ~ 5000 years ago. The most important technological developments in glass, perhaps as the glass window, were sponsored by the Christian Church during the Middle Ages on the European continent. Although transparency, luster, and durability against elements of nature are neither sufficient nor necessary to describe glass, they remain some of the key characteristics of glass that are important to large-scale commercialization. More than 95% of the commercial tonnage is oxide glasses, of which the vast majority is silica based. Vitreous silica, soda lime silicate, borosilicate, lead silicate, aluminosilicate, and optical glasses are the primary glass families. Of the nonoxide glasses, those of significant commercial interest are the heavy metal fluoride glasses (HMFG), the amorphous semiconductor and chalcogenide group, and glassy metals. Of these, the amorphous semiconductors and the chalcogenides form the basis of miniaturization of the computer as switching and memory devices, solar cell (photovoltaics), and the xerographic process (photoconductivity). Glass is also found in nature. The more important and interesting examples are volcanic glass (obsidians), lunar glass, and tektites (generally thought to be fused ejecta from a meteorite impact).

Keywords

Glass; Silica; Natural glass

1.1 Brief history

The word glass is derived from a late-Latin term glæsum used to refer to a lustrous and transparent material. Other words often used to refer to glassy substances are vitreous, originating from the Latin word vitrum (= transparent or clear), and amorphous, originating from Greek amorphe (= without form or shape). Near-transparency, luster, or shine, and in particular, its durability when exposed to the elements of nature, were probably the most significant properties of glass recognized by early civilizations. Glazed stone beads from Egypt date back to 12,000 BC. Several of the artifacts unearthed from the tombs of the pharaohs exhibit excellent glass inlay work in a variety of colors. As independent objects, glassware perhaps existed for roughly 5000–6000 years. The technology of glass windows, exploiting the property of optical transparency, had developed around the birth of Christ, and was developed to new heights of artistry by the Christian Church during the Middle Ages. Many of these beautifully stained windows, which can still be viewed in a number of churches over the European continent, show the deep commitment of the church to preserve the history of mankind and religious teachings through the medium of glass.

Many of the uses of glass in the modern-day world continue to exploit the transparency, luster, and durability of glass. Containers, windows, lighting, insulation, fiber, stemware, and other handcrafted art objects are typical of these traditional uses. At this point, it is worth noting that for a material to be used in a product it must have certain desirable properties that determine its use. In our later discussions, it will become clear that the properties of transparency, luster, and durability are neither sufficient nor necessary to describe “glass.” Similarly, being “amorphous” does not have the same meaning as being a glass. Through the application of basic sciences to the study of glass, newer properties of glasses have been developed, and hence, newer products have been conceived.

As may be expected, much of glass science developed based on major commercial uses of glass. More than 95% of the commercial tonnage of glass consists of oxide compositions. By far the largest percentage of these is silica-based. This includes both commodity glass products and highly specialized applications of glass, such as in microelectronic packaging, where the annual volume of sale may be low but glass is a key “value-adding” component, that is, the application of glass is either a critical component or enhances the value of the assembly after the incorporating process. It is not surprising that when the term “glass” is used in scientific conversation, oxide glasses are usually implied. Over the past few decades, however, a great many studies of nonoxide glasses have been triggered by the possibility of some exotic uses of glass in the fields of healthcare and information technology. It is well, therefore, to review our thoughts on the various families of glasses, their compositions, and their uses before we ...