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Soft materials defined

In the Rockwed test a spheroconical diamond (Brale) indenter or a hardened steel bad is used with various load ranges to achieve a series of scales identified by a suffix letter (Table 3). The suffix letter defines both load and indenter. The most popular scales used are "C" for hard materials and "B" for soft materials. A Rockwed hardness number is meaningless without the letter suffix, eg, HRC 54 or HRB 95. [Pg.464]

On patterned copper wafers, after CMP, the surfaces are covered mainly by dielectric and copper features. The large scratches on the dielectric such as TEOS oxide will have similar shatter mark characteristics as described in Section 17.2. The scratches on the copper lines or features, however, have a very different signature. As the copper is a soft material with large plastic deformation area, it is very easy to scratch copper (Fig. 17.41). The scratches on copper usually show well-defined continuous lines. A copper scratch can be very shallow and very narrow (Fig. 17.42). It is worthwhile to point out that the extent of damage by scratch is also a function of the underlying dielectric. As a low-fe dielectric is usually much more fragile than silicon dioxide, the damage on copper lines with low-fc dielectric may be more severe (Fig. 17.43). [Pg.544]

Class II includes flexible macromolecules. They stay only in the states of liquid and solid, in order to reserve the integrity of chemical bonds. Evaporation of such macromolecules requires so high level of thermal energy that the chemical bonds are actually broken before reaching that level. The molecular flexibility in the liquid mainly comes from the internal rotation of the main-chain C-C bonds. This class includes structural materials of synthetic polymers such as Nylon, PVC, PET, and PC, adhesives such as PVA, epoxy resins and Glue 502, elastomers such as natural rubber, polyurethane, SBS and EPDM (mbber could be regarded as the cross-linked liquid polymers.), biomaterials such as celluloses, starch, silks and wools, and even bio-macromolecules such as DNA, RNA and proteins. The class of flexible macromolecules corresponds to the soft matter defined above. [Pg.7]

Cutting forces produce exact and defined sizes and may, even, produce exact shapes. The cutting forces are used for soft materials in operations such... [Pg.180]

Dutkiewicz et al. described a method of measuring the softness of absorbent sheets by placing a strip of material between two plates and applying force from both sides. A semicircular clamp served to hold the sheet, whose shape then mimicked the anatomy of the human body. The softness was defined to be an inverse of the energy needed to compress the web to half of the sample s width, the latter being constant for all measurements. This energy, Edmax, (expressed in J) consumed at the maximum deflection, was calculated to indicate the fabric softness. [Pg.171]

Classical physics defines three states of matter solid, liquid, and gas. It provides adequate models of gaseous and solid states. The liquid state is somewhat more difficult to characterize, due to several critical obstacles. In addition, little attention has previously been paid to boundary states (coexistence of any two or even all three states at certain thermodynamic conditions). Different sciencific disciplines created separate terminologies such as metamaterials, which properties derive from artificially created periodic microstructure. Concepts such as multiphase heterogeneous or particularly ordered media or complex materials have appeared. Finally the Nobel winner in physics J.-P. de Germes (de Gennes, 1992) united all terminologies under a common term soft materials ... [Pg.43]

In this chapter, intermolecular forces that are the basis of self-assembly are considered in Section 1.2. Section 1.3 outlines common features of structural ordering in soft materials. Section 1.4 deals similarly with general considerations concerning the dynamics of macromolecules and colloids. Section 1.5 focuses on phase transitions along with theories that describe them, and the associated definition of a suitable order parameter is introduced in Section 1.6. Scaling laws are defined in Section 1.7. Polydispersity in particle size is an important characteristic of soft materials and is described in Section 1.8. Section 1.9 details the primary experimental tools for studying soft matter and Section 1.10 summarizes the essential features of appropriate computer simulation methods. [Pg.4]

Learn to identify the defining characteristics of soft materials. [Pg.1]

Temperature is perhaps the most important experimental parameter in soft matter science because the structures of soft materials are so sensitive to energy changes on the order of kgT. (4.14 x 10 J or 0.026 eV at 300 K). Because soft materials can be so sensitive to small temperature changes, random thermal molecular motions help to define their behavior. Since the concepts of thermal equilibrium, phase behavior, and statistical physics are so central to both a basic and a more advanced understanding of this field, we must begin there. [Pg.3]

We are most familiar with the three standard phases of matter the solid, liquid, and gaseous states (Figure 1.2) however, the idea of a phase can be much broader. In fact, there are many different states of matter that have been defined in-between the solid and gas phases, and we will learn about a number of them in this book. Soft materials often exhibit complex phase behavior with many different phases possible under different conditions (i.e., temperature, composition, pressure, etc.). Understanding the structure and properties of these phases and how we can move between them is at the heart of soft matter science. [Pg.4]

I have divided the book into several broadly defined classifications of materials these classifications are by no means distinct, however, and there are many soft materials around that can quite happily span pairs of chapters in this book. There are also many crossovers between fields in terms of theoretical descriptions and experimental techniques. In fact, one of the most fascinating aspects of soft matter science lies in the many conceptual connections between different materials. For example, much of the chapter on surfactants could potentially be classified as part of the liquid crystals chapter, and certain topics in the biomaterials chapter could equally find a home as part of the surfactant or polymer chapters. One important concept to take away from this book is the universality of the physics we use to describe soft materials, and although scientists and students may identify with one or more of the main topics presented here, there is much overlap and flexibility in the subject. [Pg.231]


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Material defined

Soft materials

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