Frontiers of Engineering Reports on Leading Edge Engineering from the 1999 NAE Symposium on Frontiers of Engineering (2000) / Chapter Skim
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3 Engineering Novel Structures
3 Engineering Novel Structures
Pages 29-48
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From page 31... ...
These materials have present and potential applications in optical information processing and storage, advanced coatings, and catalysis. The intellectual driving force for this process results in part from efforts to mimic hard natural materials, such as bone and shell, and soft high-strength materials like spider silk; but, current efforts fall far short of producing the structural complexity of nature, and utterly fail to mimic its full function.
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From page 32... ...
The variety of polymer morphologies potentially accessible by this approach include spherical latex particles in size ranges inaccessible to traditional emulsion polymerization techniques (radii as low as 7 rim have been reported) , as well as highly porous materials with connected open channels some tens of nanometers in diameter.
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From page 33... ...
The wire mesh photonic structure has been demonstrated to have an interesting combination of forbidden bands in the gigahertz region. As the photonic properties scale with array size, miniaturizing the structure should shift these properties to the infrared-visible region, which is of significant interest for optoelectronic devices.
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From page 34... ...
there is a lack of simple and controllable methods for extraction of colloidal crystals from their aqueous environment and mounting or shaping them into usable solid objects. A step towards producing and processing colloidal crystalline materials is assembly of spherical or globular crystalline structures (microballs)
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From page 35... ...
Colloidal-Scale Engineering 35 FIGURE 3 Schematics of the main stages of the assembly and operation of the sensor. The procedure is illustrated by an immunoglobulin test.
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From page 36... ...
The glass substrates for our sensors carry photolithographically fabricated gold patterns that form addressable electrodes of micron size with small gaps between them. To generate the active area of the sensors, the particles are collected in the gaps by dielectrophoresis and then stabilized.
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From page 37... ...
It is clear that to engineer macromolecules to function in specific ways a synergistic effort combining synthesis, physical experimentation, and theory is required. In this presentation, we will focus on how sophisticated theoretical and 37
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From page 38... ...
. Unlike proteins, which carry a specific pattern encoded in their sequence distribution, DHP sequence distributions correspond to statistical patterns.
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From page 39... ...
Our results show how a mixture of DHPs bearing different statistical patterns can be separated on a surface by discriminatory adsorption onto regions that bear complementary statistical patterns. The results also show dramatic differences in chain dynamics in the "wrong" and pattern-matched regions of the surface; these differences shed light on the kinetic behavior of frustrated systems, or systems that include biological macromolecules.
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From page 40... ...
; the other quarters are statistically random. The black and white trajectories are 2-D projections of the center of mass positions of statistically alternating and blocky DHPs, respectively.
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From page 41... ...
versus center of mass position for a statistically alternating DHP interacting with the surface in Figure 1. Blue corresponds to deep free-energy minima, red patches are shallower free-energy minima, and yellow regions are free-energy barriers.
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From page 42... ...
MOLECULAR ARCHITECTURE CAN CONTROL SURFACTANT PROPERTIES OF MACROMOLECULES The ability of amphiphilic molecules to form organized assemblies in solution has important commercial and biological consequences (Discher et al., 1999; Gompper and Schick, 1994; Larson, 1999; Lasic, 1993; Safran and Clark, 1987; Won et al., 1999; Zana, 1986; Zhao et al., 1998~. A variety of products, such as detergents, emulsifiers, catalysts, and vehicles for drug delivery, rely on this ability.
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From page 43... ...
center of mass has entered the statistically pattern matched region; c) shape selective adsorption has occurred.
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From page 44... ...
. In addition, an intermediate branching density optimizes surfactant properties due to the interplay between molecular architecture and conformational entropy (i.e., a particular architecture in an architectural class works best)
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From page 45... ...
linear polymeric amphiphiles: diblock and triblock copolymers; (c) branched amphiphiles with a well-solvated backbone and poorly solvated branches.
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From page 46... ...
1996. Polyacrylamides bearing pendant-sialoside groups strongly inhibit agglutination of erythrocytes by influenza virus: The strong inhibition reflects enhanced binding through cooperative polyvalent interactions.
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From page 47... ...
1998. Triblock copolymer syntheses of mesoporous silica with periodic 50 to 300 angstrom pores.
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