Multifunctional structure

Segrest MP et al The amphipathic alpha-helix A multifunctional structural motif in plasma lipoproteins. Adv Protein Chem... 

Pharmaceuticals or agrochemicals usually have complex, multifunctional structures and are produced via multistep syntheses. Compared to basic chemicals, they are relatively small-scale but high-value products with short product lives,... 

Even the most experienced chemist will not be able to foresee all potential pitfalls of a synthesis, specially so if multifunctional, structurally complex intermediates must be prepared. The dose proximity or conformational fixation of functional groups in a large molecule can alter their reactivity to such an extent that even simple chemical transformations can no longer be performed [11]. Small structural variations of polyfunctional substrates might, therefore, bring about an unforeseeable change in reactivity. 

This ambivalent interaction behaviour can be explained by the multifunctional structure of this PEI derivative. On the one hand, the divalent metal ions can interact with the nitrogen atoms of the amino groups of the basis polymer, and one the other hand, the methylated moieties lead to an anion exchange character of the polymer. Thus, simultaneous complexation and retention of various elements are feasable with this polymer. 

Reaction of a-aminomethylene ketones with biselectrophiles is usually expected to occur at the -position and at the nitrogen of the enaminone under ring closure. However, enaminone chemistry, due to the multifunctional structure, is often characterized by surprising reactions such as rearrangements. 

Summarizing, it can be stated that hydrogen fluoride/pyridine and hydrogen fluoride/amine mixtures are useful for the synthesis of simple secondary and tertiary alkyl fluorides, but probably arc not suitable for fluorination reactions in complex multifunctional structures due to the highly acidic properties of these reagents. 

THE AMPHIPATHIC a HELIX A MULTIFUNCTIONAL STRUCTURAL MOTIF IN PLASMA APOLIPOPROTEINS... 

Block co-polymers Self-assembled mask Parallel, fast, small size, no resist, solvents, etc. Material constraints, no long-range order, cleanliness New amphiphilic, diblock copolymers, multifunctional structures... 

Pellegrino, T., Kudera, S., Liedl, T., Javier, A.M., Manna, L., Parak, W.J., 2005. On the development of colloidal nanoparticles towards multifunctional structures and their possible use for biological applications. Small 1 (1), 48. 

Thomas JP, Keennon MT, DuPasquier A, Qidwai MA, Matic P (2003) Multifunctional structure-battery materials for enhanced performance in small unmanned air vehicles. In Proceedings of the 2003 ASME international mechanical engineering congress and R D exposition, Washington, DC, IMECE2003-41512... 

Koratkar, N. A., Wei, B. Ajayan, P. M. Multifunctional structural reinforcement featuring carbon nanotube films. Compos. Sci. Tech-nol. 63, 1525-1531 (2003). 

Multifunctional materials are capable of providing two or more primary functions either in a simultaneous manner or sequentially. For instance, multifunctional structural materials exhibit additional functions beyond their basic mechanical strength or stiffness (which are typical attributes of structural materials). Thus, they can be designed to possess incorporated electrical, magnetic, optical, sensing, power generative, or other functionalities, which work in a synergistic manner [1]. 

Chiral molecules such as pharmaceuticals or agrochemicals usually have complex, multifunctional structures and are produced via multistep syntheses. Compared to basic chemicals, they are relatively small scale but high value products with relatively short product lives, traditionally produced in multipurpose batch equipment. The time for development of the production process is often very short since time to market affects the profitability of the product (see below). 

Qidwai, M.A., J.P. Thomas, and P. Matic. 2002. Design and Performance of Composite Multifunctional Structure-Battery Materials. Pp. 1-8 in Proceedings of the American Society for Composites Seventeenth Technical Conference, edited by C.T. Sun and H. Kim. Boca Raton, Fla CRC Press. 

Fig. 6. Schematic diagram of the formation of domains and gelation by the aggregation of the domains (the domain that is characterized by the correlation length i forms networks that act as a new unit of a multifunctional structural unit).

Modelling of the biologic materials, well-organized multifunctional structures and systems found in nature has attracted the interest of scientists working in many scientific disciplines. The constant-composition method has been used to study the... 

Brent Stucker is a professor in the Department of Industrial Engineering at the University of Louisville. His area of research is additive manufacturing technologies and their applications, including advanced materials development and multifunctional structures. 

Koratkar, N., Wei, B., Ajayan, P. - Multifunctional structural reinforcement featuring carbon nanotube film . Composites Sci. Technol. 63 (2003) 1525-1531 Binnott, S., Shenderova, O., White, C., Brenner, D. - Mechanical properties of nanotubule fibres and composites determined from theoretical calculations and simulations , PH 80008-6223(97)00144-9... 

Successful applications of ceramic materials in many structures and components need some types of ceramic-metal joining. Two main factors derive the need for the development of joining techniques (1) the difficulty to fabricate large ceramic structures with complex shapes (2) the requirement of ceramic only in one part of a structure. For the practical applications, it will be necessary to join the ceramic to either another ceramic, or to a metal. The development of feasible joining techniques will facilitate the adaptation of advanced ceramics into complex and multifunctional structures. 

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