Important Technological Questions

The unique topology and architectural components of dendrimers suggest many important applications that may be possible. We have identified at least five important factors that pose questions concerning these technological applications. Table 11.1 lists these factors along with the applicability of SANS, SAXS and TEM to address the questions. 

Another important issue is the difference between various branching types such as random hyperbranched [31], dendrigrafts and dendrimers. The complexity of synthesis requirements manifested by the statistical dendritic polymers versus the more structurally controlled dendrimers could make the former orders of magnitude more expensive than hyperbranched. Are the structures as significantly unique and of sufficient value effectiveness to justify the higher costs  

The terminal groups of a dendrimer are large in number and can have functionalities capable of chemical reactions. If the terminal reactive terminal groups were near the periphery, they would be readily accessible for attachment to surfaces or to reagents. Block copolymers or networks with dendrimers as crosslink points would benefit from having them on the outside. 

When dendrimers are exposed to forced intermolecular contact by increasing their concentration in solution, or by placing them on a surface, do they freely pass through one another or do they avoid interpenetration and align themselves Dendrimers have sizes in the range 1-20 nm and would be excellent candidates for nanoscopic structures if such ordering does occur. 

Finally, do dendrimers change greatly in size when placed in different solvents For applications as size standards or molecular probes dendrimers possessing a relatively fixed size would be preferable. For applications using the release of stored guest molecules, however, it would be preferable to open and close dendrimers by designing appropriate container release strategies . 

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Finding the path of the particle lends much information to the flow behavior of gas-solid systems. Very few measurement techniques can deal with the individual particle trajectory and its velocity. Some very important technological questions about particle flow may be made with such measurements. Laser Doppler velocimeters (LDV) are available to provide such experimental data. Numerical simulation offers another path for such analysis. The different aspect about finding the path of the particle is that the basic equation defining such behavior is nonlinear, requiring a numerical solution of the equations. This procedure should not be considered as too much of an obstacle, and one should be able to apply knowledge of numerical analysis and experience to such a problem. The basic equation or definition relates the particle position to its velocity and time as... 

Whether there is currently a nanotechnology is a question of definition. If one asks whether there are (or are soon likely to be) commercial electronic fluidic, photonic, or mechanical devices with critical lateral dimensions less than 20 nm, the answer is no, although there may be in 10 to 20 years. There is, however, a range of important technologies—especially involving colloids, emulsions, polymers, ceramic and semiconductor particles, and metallic alloys—that currently exist. But there is no question that the field of nanoscience already exists. 

The technology question can be answered quite readily, but the question about Away while not at first apparent is often the most important point of the discussion. On almost every process flow sheet or process development schematic, there is a little truck down at the lower right hand comer for waste disposal. This is the Away . Years ago, we assumed that the wastes would be taken care of and disposed properly. But because they... 

Smart materials such as these illustrate an important technological direction for materials science the design of materials with sophisticated properties that behave more like biological systems. Let s briefly recap our history. In Chapter 4 we noted a significant period of discovery when people modified natural polymers to improve their properties. We can call this period, roughly before 1900, Stage 1, and it asked the question, How can I improve upon nature This was followed by a century of synthetic polymer science in which... 

Article is denoted to the investigation and the creation of the new ultrasonic and information technologies (IT) and the technical methods of non-destructive evaluation (NDE) of material state in the product, which are based on principles of ultrasonic computing tomography (USCT). These results concern two important questions ... 

Bioremediation has many advantages over other technologies, both in cost and in effectively destroying or extracting the pollutant. An important issue is thus when to consider it, and a series of questions may lead to the appropriate answer (see Table 4). 

In using such assessments, the technology manager needs to answer two important questions (/) How do I improve our work processes (2) What processes or practices should have the highest priority for improvement ... 

A third motivation for studying gas solubilities in ILs is the potential to use compressed gases or supercritical fluids to separate species from an IL mixture. As an example, we have shown that it is possible to recover a wide variety of solutes from ILs by supercritical CO2 extraction [9]. An advantage of this technology is that the solutes can be removed quantitatively without any cross-contamination of the CO2 with the IL. Such separations should be possible with a wide variety of other compressed gases, such as C2LL6, C2LL4, and SF. Clearly, the phase behavior of the gas in question with the IL is important for this application. 

Crystal growth has, apart from its basic surface science interest, important applications in technology for instance in microelectronics, optoelectronics, recording... However, even the simplest case of homoepitaxy is not perfectly understood. In particular, growth on FCC (111) transition metal surfaces raises some interesting questions. 

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