Smart physical conditions

Modern trends in the design of composite materials presuppose the development of intelligent or smart composites [7]. These materials adapt to service conditions either through varying their charge state or physical-chemical structure, or regulation of this adaptation degree by a feedback system [8]. The principle of operation of such smart materials is illustrated in Fig. 1.6. 

Whether a stable two-phase flow can be obtained in a fluidic system depends on both fluid dynamic conditions and surface chemistries. The aim is to open the way to control the flow and to achieve versatility and reproducibility in on-chip flow management. The design will require smart network topologies and interplay of multiple physical and chemical effects. 

We have discussed in the previous sections about the physical properties and surfactant-assisted self-assembly formations of metal nanoparticles. These assembling methods are quite beautiful and intelligent, because they are induced by the spontaneous driving force for assembling by smart choice of the conditions. In the cases of practical use, however, the methods described below are rather tend to be required (1) the method to make a desirable size, length, shape, architecture and position, etc., (2) a simple and easy method, and (3) highly stable assemblies. From these viewpoints, as a final section for a preparation of nanoparticle assembly, we introduce here the template assisted self-assemblies of nanoparticles. This section is classified to three stories corresponding to the dimension (such as ID, 2D and 3D) of the template and assembly. 

Stimuli-responsive polymers consist of a class of smart materials that exhibit a physical response to changes in external conditions. Such stimuli include changes in pH, ionic strength, solvent polarity, and temperature, as well as mechanical force or electric fields. On the basis of their ability to switch conformations, stimuli-responsive polymers are being applied as sensors, actuators, and transducers (e.g., mechano-electrical or mechano-optical). Nanoporous membranes can be functionalized with stimuli-responsive polymers to modify their permeability, that is, to reversibly open and close the pores upon a given stimulus. ... 

The reversibility of the conventional Diels-Alder reaction makes it a prime candidate for the synthesis of smart materials that exhibit a temperature-dependent transition between two physical properties (such as viscosity or color). However, many applications (such as biological labeling) require irreversible conjugation chemistry that also is very fast under mild and dilute reaction conditions. Eor such purposes, the inverse electron-demand Diels-Alder (IVED-DA) reaction between electron-deficient tetrazine derivatives and various alkenes is incredibly efficient. 

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